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Background: Severe malaria is associated with impaired nitric oxide (NO) synthase (NOS)-dependent vasodilation, and reversal of this deficit improves survival in murine models. Malaria might have selected for genetic polymorphisms that increase endothelial NO signaling and now contribute to heterogeneity in vascular function among humans. One protein potentially selected for is alpha globin, which, in mouse models, interacts with endothelial NOS (eNOS) to negatively regulate NO signaling. We sought to evaluate the impact of alpha globin gene deletions on NO signaling and unexpectedly found human arteries use not only alpha but also beta globin to regulate eNOS., Methods: The eNOS-hemoglobin complex was characterized by multiphoton imaging, gene expression analysis, and coimmunoprecipitation studies of human resistance arteries. Novel contacts between eNOS and hemoglobin were mapped using molecular modeling and simulation. Pharmacological or genetic disruption of the eNOS-hemoglobin complex was evaluated using pressure myography. The association between alpha globin gene deletion and blood pressure was assessed in a population study., Results: Alpha and beta globin transcripts were detected in the endothelial layer of the artery wall. Imaging colocalized alpha and beta globin proteins with eNOS at myoendothelial junctions. Immunoprecipitation demonstrated that alpha globin and beta globin form a complex with eNOS and cytochrome b5 reductase. Modeling predicted negatively charged glutamic acids at positions 6 and 7 of beta globin to interact with positively charged arginines at positions 97 and 98 of eNOS. Arteries from donors with a glutamic acid-to-valine substitution at beta globin position 6 (sickle trait) exhibited increased NOS-dependent vasodilation. Alpha globin gene deletions were associated with decreased arterial alpha globin expression, increased NOS-dependent vasodilation, and lower blood pressure. Mimetic peptides that targeted the interactions between hemoglobin and eNOS recapitulated the effects of these genetic variants on human arterial vasoreactivity., Conclusions: Alpha and beta globin subunits of hemoglobin interact with eNOS to restrict NO signaling in human resistance arteries. Malaria-protective genetic variants that alter the expression of alpha globin or the structure of beta globin are associated with increased NOS-dependent vasodilation. Targeting the hemoglobin-eNOS interface could potentially improve NO signaling in diseases of endothelial dysfunction such as severe malaria or chronic cardiovascular conditions., Competing Interests: H.C.A., S.B., and P.C. are co-inventors on a patent held by the National Institute of Allergy and Infectious Diseases for structures and uses of beta globin mimetic peptides (PCT/US2023/065432). The other authors report no conflicts.

Abstract: Sickle cell trait (SCT) is a risk factor for venous thromboembolism (VTE). Prior studies investigating the association between SCT and VTE have been performed nearly exclusively in Black populations. However, race-based research can contribute to systemic racism in medicine. We leveraged data from the 23andMe research cohort (4 184 082 participants) to calculate the ancestry-independent risk of VTE associated with SCT as well as comparative risk estimates for heterozygous factor V Leiden (FVL). Odds ratios (ORs) were calculated using a meta-analysis of 3 genetic ancestry groups (European [n = 3 183 142], Latine [n = 597 539], and African [n = 202 281]) and a secondary full-cohort analysis including 2 additional groups (East Asian [n = 159 863] and South Asian [n = 41 257]). Among the full cohort, 94 323 participants (2.25%) reported a history of VTE. On meta-analysis, individuals with SCT had a 1.45-fold (confidence interval [CI], 1.32-1.60) increased risk of VTE compared with SCT noncarriers, which was similar to the full-cohort estimate. The risk of pulmonary embolism (PE) in SCT (OR, 1.95; CI, 1.72-2.20) was higher than that of isolated deep venous thrombosis (DVT; OR, 1.04; CI, 0.90-1.21). FVL carriers had 3.30-fold (CI, 3.24-3.37) increased risk of VTE compared with FVL noncarriers, with a higher risk of isolated DVT (OR, 3.59; CI, 3.51-3.68) than PE (OR, 2.72; CI, 2.64-2.81). In this large, diverse cohort, the risk of VTE was increased among individuals with SCT compared with those without, independent of race or genetic ancestry. The risk of VTE with SCT was lower than that observed in FVL; however, the pattern of VTE in SCT was PE predominant, which is the opposite to that observed in FVL., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Children with hemoglobin AC or AS have decreased susceptibility to clinical malaria. Parasite variant surface antigen (VSA) presentation on the surface of infected erythrocytes is altered in erythrocytes with hemoglobin C (Hb AC) or sickle trait (Hb AS) mutations in vitro. The protective role of incomplete or altered VSA presentation against clinical malaria in individuals with Hb AC or AS is unclear. Using a high-throughput protein microarray, we sought to use serological responses to VSAs as a measure of host exposure to VSAs among Malian children with Hb AC, Hb AS, or wildtype hemoglobin (Hb AA). In uncomplicated malaria, when compared to Hb AA children, Hb AC children had significantly lower serological responses to extracellular Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP1) domains but did not differ in responses to intracellular PfEMP1 domains and other VSAs, including members of the repetitive interspersed family (RIFIN) and subtelomeric variable open reading frame (STEVOR) family. Healthy children with Hb AC and Hb AS genotypes recognized fewer extracellular PfEMP1s compared to children with Hb AA, especially CD36-binding PfEMP1s. These reduced serologic responses may reflect reduced VSA presentation or lower parasite exposure in children with Hb AC or AS and provide insights into mechanisms of protection., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The study of Ellsworth et al. (Br J Haematol, 2024) demonstrated the usefulness of oxygen gradient ektacytometry technique to better identify the physiological parameters that could increase the risk of sickling of red blood cells (RBCs) from sickle cell trait (SCT) carriers. Oxygen gradient ektacytometry combined with pH and osmolality modulations could help in identifying SCT carriers at risk for kidney disorders or exercise-related complications. Other factors than the percentages of haemoglobin S are probably involved in the propensity of RBCs from SCT carriers to sickle during deoxygenation. Commentary on: Ellsworth et al. Hypertonicity and/or acidosis induce marked rheological changes under hypoxic conditions in sickle trait red blood cells. Br J Haematol 2024; 205:1565-1569., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Sickle cell disease (SCD) is a single gene blood disorder characterised by frequent episodes of pain, chronic anaemic, acute chest syndrome, severe disease complications and lifelong debilitating multi-system organ damage. Genetic testing and screening programs for SCD and the sickle cell trait (SCT) are valuable for early diagnosis and management of children living with SCD, and in the identification of carriers of SCT. People with SCT are for the most part asymptomatic and mainly identified as through genetic testing or when they have a child with SCD. This qualitative study explored perceptions towards genetic testing for SCD and SCT in Cameroon, Ghana, and Tanzania. The results show a general preference for newborn screening for SCD over prenatal and premarital/preconception testing, primarily due to its simpler decision-making process and lower risk for stigmatization. Premarital testing for SCT was perceived to be of low public health value, as couples are unlikely to alter their marriage plans despite being aware of their risk of having a child with SCD. Adolescents were identified as a more suitable population for SCT testing. In the case of prenatal testing, major concerns were centred on cultural, religious, and personal values on pregnancy termination. The study revealed a gender dimension to SCD/SCT testing. Participants mentionned that women bear a heightened burden of decision making in SCD/SCT testing, face a higher risk of rejection by potential in-laws/partners if the carriers of SCT, as well as the possibility of  divorce if they have a child with SCD. The study highlights the complex cultural, ethical, religious and social dynamics surrounding genetic testing for SCD and emphasises the need for public education on SCD and the necessity of incorporating genetic and psychosocial counselling into SCD/SCT testing programs., (© 2024. The Author(s).)

Abstract: Sickle cell trait is typically thought to be an asymptomatic carrier state, but it is rarely associated with exertional rhabdomyolysis in cases termed Exercise Collapse Associated with Sickle Cell Trait (ECAST). In a subset of these cases, underlying disease contributes to the development and/or severity of the ensuing medical complications. We describe the first ever case of ECAST reported in a previously asymptomatic, multiply deployed, highly physically active service member with an underlying heterozygous LAMA2 mutation. Moreover, the mutation identified via whole exome sequencing is a novel, likely pathogenic variant that has yet to be described in the literature., Competing Interests: Conflicts of interest and sources of funding: The authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The aim of this study was to present the results obtained in the Newborn Screening Program (NSP) for sickle cell disease (SCD) in western Andalusia and the autonomous city of Ceuta in the first 3 years of implementation, and to describe the discrepancies found in the diagnosis of hemoglobinopathies between the screening method and the confirmatory tests., Study Design: A descriptive and retrospective study was carried out, and the findings obtained in the newborns included in the NSP between November 2018 and December 2021 were analyzed., Results: A total of 111,205 samples were screened by high-performance liquid chromatography (HPLC). The birth prevalence of SCD, sickle cell trait, hemoglobin C carriers, and the compound heterozygosity Hb C/β-thalassemia was 1/12,356, 1/467, 1/1,278, and 1/55,602 newborns, respectively. Although there was a correlation between the first-line HPLC screening technique (VARIANTnbs HPLC analyzer, Bio-Rad) and the confirmatory tests in most cases, major discrepancies were found in detecting carriers of G-Philadelphia, D, E, and O-Arab hemoglobin variants, with the former having an incidence of 1/10,110 and the others 1/22,241. The carrier status of Hb G-Philadelphia produced an FAD pattern on the screening method that could be mistaken as Hb D, while Hb O-Arab was identified as an FA5 pattern. Hb D was initially recognized as Hb D in two cases., Conclusion: An NSP requires at least two different combined methods in order to identify the hemoglobin variant with sufficient certainty. Furthermore, even though software solutions for HPLC suggest a pattern, it must be confirmed with another technique to obtain a correct interpretation of the chromatograms., Key Points: · The NSPs are an essential activity in preventive medicine.. · At least two different combined methods are required to correctly identify hemoglobin variants.. · Different variants can produce a similar or identical pattern by a single method.., Competing Interests: None declared., (Thieme. All rights reserved.)

Sickle cell trait (SCT), although generally a benign carrier state of hemoglobin S (HbAS), is a risk factor for exertional rhabdomyolysis (ERM), a rare but potentially fatal consequence of highly intense physical exercise, particularly among active-duty military personnel and high-performance athletes. The association between SCT and ERM is poorly understood. The objective of this study was to elucidate the genetic basis of ERM in an SCT-positive African American cohort. SCT-positive African Americans with a personal history of ERM (cases, n = 30) and without history of ERM (controls, n = 53) were enrolled in this study. Whole-genome sequencing was performed on DNA samples isolated from peripheral white blood cells. Participants' demographic, behavioral, and medical history information was obtained. An additional 131 controls were extracted from SCT-positive subjects of African descent from the 1000 Genomes Project. SCT carriers with ERM were characterized by myotoxicity features, significant muscle involvement dominated by muscle weakness, and severe pain and substantial increase in serum creatine kinase, with a mean value of 50,480 U/L. A distinctive feature of the SCT individuals with ERM was exertional collapse, which was reported in 53.3% of the cases in the study cohort. An important factor for the development of ERM was the duration and frequency of strenuous physical activity in the cases compared to the controls. Whole-genome sequencing identified 79,696 protein-coding variants. Genome-wide association analysis revealed that the p.C477R, rs115958260 variant in the SLC44A3 gene was significantly associated with ERM event in SCT-positive African Americans. The study results suggest that a combination of vigorous exercise and a genetic predisposing factor is involved in ERM.

Background: Sickle Cell Disorder is Africa's most prevalent genetic disease. Yet, it remains a neglected condition, with high mortality under-five, and a lack of population-based studies in the region. This is the first of its kind in São Tomé e Príncipe, aiming to estimate the prevalence of sickle cell trait and other haemoglobin variants in women of reproductive age and its associated factors., Methods: We conducted a cluster survey in 35 neighbourhoods. Haemoglobin was assessed through point-of-care capillary electrophoresis or high-performance liquid chromatography, and sociodemographic data through questionnaires. The weighted prevalence of sickle cell trait (HbAS) and HbC carriers was estimated with a 95% confidence interval (95% CI). We calculated weighted prevalence ratios (95% CI) through robust Poisson regression for its association with age and individual and collective genetic heritage., Findings: The prevalence of sickle cell trait in women of reproductive age in São Tomé e Príncipe (n = 376) was 13.45% (95% CI: 9.05-19.00). The prevalence of HbC carriers was 8.00% (95% CI: 4.71-12.00). Older age and speaking Forro or Angolar were positively associated with having sickle cell trait., Interpretation: The prevalence of sickle cell trait in São Tomé e Príncipe ranks high in the West African region. The country should follow international guidelines, implementing newborn screening and comprehensive healthcare management., (© 2024. The Author(s).)

Background: Sickle cell disease (SCD) is one of the most frequent and traumatizing genetic disease in Uganda, with the prevalence of the sickle cell trait (SCT) estimated at 13.3% leading to serious psycho-social and economic impact on the patients and their families., Aim: This study aimed to determine the burden of SCT and factors influencing the uptake of screening services among secondary school students in Uganda., Methods: We used an analytical cross-sectional design with a multi-stage sampling approach. A total of 399 students from four secondary schools in Kampala City were enrolled in this study. Data were gathered using semi-structured questionnaires and blood screening. We used the sickling test to determine the presence of sickle cell alleles among the participants and hemoglobin electrophoresis as a confirmatory test. Data gathered using the questionnaire were analyzed using descriptive and inferential statistics., Results: In total, 5.8% of participants who were tested during this study had SCT. Most (80.2%) participants were not in an intimate relationship at the time of data collection. The majority (60.4%) had moderate knowledge about SCT screening and obtained information about screening from the school. Only 29 (7.3%) participants knew of a family member with sickle cell. Overall, participants had a negative attitude toward SCT screening (67%), although 41.6% believed that most people who were sickle cell carriers did not live long and were often sick. Statistically significant associations were found between testing for SCT and knowing a partner's sickle cell status (odds ratio [OR] 2.112, p = 0.043) and Anglican religion (OR 2.075, p = 0.047)., Conclusion: Despite the moderate level of knowledge and negative attitudes, a relatively large number of participants had SCT. This highlights the need for a comprehensive health education package targeting adolescents to promote SCD/SCT screening., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Namukasa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Sickle cell disease (SCD) is an autosomal recessive disorder. Although the molecular mechanisms at the origin of SCD have been well characterized, its clinical expression is highly variable. SCD is characterized by blood rheological abnormalities, increased inflammation and oxidative stress, and vascular dysfunction. Individuals with only one copy of the mutated β-globin gene have sickle cell trait (SCT) and are usually asymptomatic. The first part of this review focuses on the biological responses of SCT carriers during exercise and on the effects of combined SCT and diabetes on vascular function, several biomarkers and clinical complications. The second part of the review focuses on SCD and shows that the magnitude of red blood cell (RBC) rheological alterations is highly variable from one patient to another, and this variability reflects the clinical and hematological variability: patients with the less deformable RBCs have high hemolytic rate and severe anemia, and are prone to develop leg ulcers, priapism, cerebral vasculopathy, glomerulopathy or pulmonary hypertension. In contrast, SCD patients characterized by the presence of more deformable RBCs (but still rigid) are less anemic and may exhibit increased blood viscosity, which increases the risk for vaso-occlusive events. Several genetic and cellular factors may modulate RBC deformability in SCD: co-existence of α-thalassemia, fetal hemoglobin level, oxidative stress, the presence of residual mitochondria into mature RBCs, the activity of various non-selective cationic ion channels, etc. The last part of this review presents the effects of hydroxyurea and exercise training on RBC rheology and other biomarkers in SCD.

Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that significantly contributes to childhood cancer burden in sub-Saharan Africa. Plasmodium falciparum, which causes malaria, is geographically associated with BL, but the evidence remains insufficient for causal inference. Inference could be strengthened by demonstrating that mendelian genes known to protect against malaria-such as the sickle cell trait variant, HBB-rs334(T)-also protect against BL. We investigated this hypothesis among 800 BL cases and 3845 controls in four East African countries using genome-scan data to detect polymorphisms in 22 genes known to affect malaria risk. We fit generalized linear mixed models to estimate odds ratios (OR) and 95% confidence intervals (95% CI), controlling for age, sex, country, and ancestry. The ORs of the loci with BL and P. falciparum infection among controls were correlated (Spearman's ρ = 0.37, p = .039). HBB-rs334(T) was associated with lower P. falciparum infection risk among controls (OR = 0.752, 95% CI 0.628-0.9; p = .00189) and BL risk (OR = 0.687, 95% CI 0.533-0.885; p = .0037). ABO-rs8176703(T) was associated with decreased risk of BL (OR = 0.591, 95% CI 0.379-0.992; p = .00271), but not of P. falciparum infection. Our results increase support for the etiological correlation between P. falciparum and BL risk., (© 2023 Wiley Periodicals LLC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Our long-term goal is to foster genetically informed reproductive health knowledge and behaviors among young adults with sickle cell disease (SCD) or sickle cell trait (SCT) with a web-based, tailored, multimedia intervention called CHOICES. CHOICES is designed to help young adults with SCD or SCT preconception to gain knowledge of genetic inheritance, specify their reproductive health intentions (their parenting plan), and engage in reproductive health behaviors concordant with their parenting plan. In a previous study, we found high acceptability of both the e-Book (usual care control) and CHOICES interventions. We also found sustained (24 months), significant effects on knowledge but not on behavior, most likely because half of the recruited group was not at risk for their children inheriting SCD. Hence, we propose an adequately powered randomized controlled trial with the CHOICES intervention and an e-Book control to compare their effects on genetic inheritance knowledge and at-risk reproductive health behaviors (immediate posttest and at 6, 12, 18, and 24 months). We will conduct subgroup analyses to provide insight into the baseline knowledge and behavior as well as the intervention effects in different demographic or acceptability groups. Given the scalability and low cost of CHOICES, if proved to be effective, it can reach the affected population at low cost., Competing Interests: D.J.W. is chairman and founder of eNursing llc, a company with no interests in the work presented in this manuscript. All other authors declare no conflicts of interests., (Copyright: © 2023 Wilkie et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Disease-specific knowledge allows individuals with sickle cell disease, sickle cell trait, and unaffected family members alike to make informed decisions and support those affected by the condition. The current study assesses how sickle cell knowledge varies by disease status within families affected by sickle cell disease. One hundred seventy-nine participants from 84 families completed an online survey and telephone interview. Generalized linear models, with generalized estimating equations, were fitted to evaluate differences in both item-level responses and total scores on the Sickle Cell Knowledge Scale by sickle cell status. Those with negative or unknown sickle cell status scored significantly lower than those with sickle cell disease or trait, despite being related to someone with sickle cell disease (χ 2 (2) = 9.72, p = 0.008). Overall, participants performed poorly on items related to sickle cell trait, with limited understanding of autosomal recessive inheritance patterns. The study's findings suggest a need to move beyond patient-centered approaches to family-centered education efforts that reach those with sickle cell traits and negative or unknown status. Findings point to knowledge gaps related to sickle cell trait and patterns of inheritance, representing key enhancement areas for future sickle cell education efforts., (Published 2023. This article is a U.S. Government work and is in the public domain in the USA.)

Introduction: Sickle cell trait (SCT) is common in African descendants. Its association with several adverse pregnancy outcomes (APOs) has been reported but remains inconsistent. The objectives of this study are to test associations of SCT with APOs in non-Hispanic Black women, including (1) validate the associations of SCT with previously reported APOs, (2) test novel associations of SCT with broad spectrum of APOs, and (3) estimate the attributable risk of SCT for implicated APOs., Material and Methods: This is a retrospective analysis of a prospectively designed population-based cohort. Women/participants were self-reported non-Hispanic Black women from the UK Biobank (UKB). SCT status was determined based on heterozygous Glu6Val in the HBB gene. Several APOs were studied, including four previously reported SCT-associated APOs (preeclampsia, bacteriuria, pregnancy loss, and preterm delivery), and broad conditions related to pregnancy, childbirth, and the puerperium. APOs were curated by experts' peer review and consensus processes. Associations of SCT with APOs were tested by estimating its relative risk and 95% confidence interval (95% CI), adjusting for number of live births and age at first birth. Attributable risk proportion (ARP) and population attributable risk proportion (PARP) of SCT to APOs were estimated., Results: Among the 4057 self-reported non-Hispanic Black women with pregnancy records in the UKB, 581 (14.32%) were SCT carriers. For four previously reported SCT-associated APOs, two were confirmed at a nominal P < 0.05; relative risk (RR) was 2.39 (95% CI 1.09-5.23) for preeclampsia, and 4.85 (95% CI 1.77-13.27) for bacteriuria. SCT contributed substantially to these two APOs among SCT carriers, with attributable risk proportion estimated at 61.00% and 68.96% for preeclampsia and bacteriuria, respectively. SCT also contributed substantially to these two APOs in the population (self-reported Black UK women), with population attributable risk proportion estimated at 18.30% and 24.14% for preeclampsia and bacteriuria, respectively. In addition, novel associations were found for seven other APOs (nominal P < 0.05)., Conclusions: SCT is significantly associated with APOs in this study and contributes substantially to APOs among self-reported Black women in the UK. Confirmation of these findings in independent study populations is required., (© 2023 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Sickle cell disease (SCD) is caused by the homozygous beta-globin gene mutation that can lead to ischemic multi-organ damage and consequently reduce life expectancy. On the other hand, sickle cell trait (SCT), the heterozygous beta-globin gene mutation, is still considered a benign condition. Although the mechanisms are not well understood, clinical evidence has recently shown that specific pathological symptoms can also be recognized in SCT carriers. So far, there are still scant data regarding the morphological modifications referable to possible multi-organ damage in the SCT condition. Therefore, after genotypic and hematological characterization, by conventional light microscopy and transmission electron microscopy (TEM), we investigated the presence of tissue alterations in 13 heterozygous Townes mice, one of the best-known animal models that, up to now, was used only for the study of the homozygous condition. We found that endothelial alterations, as among which the thickening of vessel basal lamina, are ubiquitous in the lung, liver, kidney, and spleen of SCT carrier mice. The lung shows the most significant alterations, with a distortion of the general tissue architecture, while the heart is the least affected. Collectively, our findings contribute novel data to the histopathological modifications at microscopic and ultrastructural levels, underlying the heterozygous beta-globin gene mutation, and indicate the translational suitability of the Townes model to characterize the features of multiple organ involvement in the SCT carriers.

Renal medullary carcinoma (RMC) is an aggressive kidney cancer that almost exclusively develops in individuals with sickle cell trait (SCT) and is always characterized by loss of the tumor suppressor SMARCB1 . Because renal ischemia induced by red blood cell sickling exacerbates chronic renal medullary hypoxia in vivo, we investigated whether the loss of SMARCB1 confers a survival advantage under the setting of SCT. Hypoxic stress, which naturally occurs within the renal medulla, is elevated under the setting of SCT. Our findings showed that hypoxia-induced SMARCB1 degradation protected renal cells from hypoxic stress. SMARCB1 wild-type renal tumors exhibited lower levels of SMARCB1 and more aggressive growth in mice harboring the SCT mutation in human hemoglobin A (HbA) than in control mice harboring wild-type human HbA. Consistent with established clinical observations, SMARCB1-null renal tumors were refractory to hypoxia-inducing therapeutic inhibition of angiogenesis. Further, reconstitution of SMARCB1 restored renal tumor sensitivity to hypoxic stress in vitro and in vivo. Together, our results demonstrate a physiological role for SMARCB1 degradation in response to hypoxic stress, connect the renal medullary hypoxia induced by SCT with an increased risk of SMARCB1-negative RMC, and shed light into the mechanisms mediating the resistance of SMARCB1-null renal tumors against angiogenesis inhibition therapies.

Background: Sickle cell trait (SCT) refers to the carriage of one abnormal copy of the β-globin gene, the HbS allele. SCT offers protection against malaria, controlling parasite density and preventing progression to symptomatic malaria. However, it remains unclear whether SCT also affects transmission stages and mosquito infection parameters. Deciphering the impact of the SCT on human to mosquito malaria transmission is key to understanding mechanisms that maintain the trait in malaria endemic areas., Methods: The study was conducted from June to July 2017 among asymptomatic children living in the locality of Mfou, Cameroon. Blood samples were collected from asymptomatic children to perform malaria diagnosis by microscopy, Plasmodium species by PCR and hemoglobin typing by RFLP. Infectiousness of gametocytes to mosquitoes was assessed by membrane feeding assays using blood from gametocyte carriers of HbAA and HbAS genotypes. A zero-inflated model was fitted to predict distribution of oocysts in mosquitoes according to hemoglobin genotype of the gametocyte source., Results: Among the 1557 children enrolled in the study, 314 (20.16%) were of the HbAS genotype. The prevalence of children with P. falciparum gametocytes was 18.47% in HbAS individuals and 13.57% in HbAA, and the difference is significant (χ 2  = 4.61, P = 0.032). Multiplicity of infection was lower in HbAS gametocyte carriers (median = 2 genotypes/carrier in HbAS versus 3.5 genotypes/carrier in HbAA, Wilcoxon sum rank test = 188, P = 0.032). Gametocyte densities in the blood donor significantly influenced mosquito infection prevalence in both HbAS and HbAA individuals. The HbAS genotype had no significant effect on mosquito infection outcomes when using immune or naïve serum in feeding assays. In AB replacement feeding experiments, the odds ratio of mosquito infection for HbAA blood as compared to HbAS was 0.56 (95% CI 0.29-1.10), indicating a twice higher risk of infection in mosquitoes fed on gametocyte-containing blood of HbAS genotype., Conclusion: Plasmodium transmission stages were more prevalent in SCT individuals. This may reflect the parasite's enhanced investment in the sexual stage to increase their survival rate when asexual replication is impeded. The public health impact of our results points the need for intensive malaria control interventions in areas with high prevalence of HbAS. The similar infection parameters in feeding experiments where mosquitoes received the original serum from the blood donor indicated that immune responses to gametocyte surface proteins occur in both HbAS and HbAA individuals. The higher risk of infection in mosquitoes fed on HbAS blood depleted of immune factors suggests that changes in the membrane properties in HbAS erythrocytes may impact on the maturation process of gametocytes within circulating red blood cells., (© 2023. The Author(s).)

The sickle cell mutation increases morbidity in those with sickle cell disease (SCD) and potentially sickle cell trait, impacting pulmonary, coagulation, renal, and other systems that are implicated in COVID-19 severity. There are no population-based registries for hemoglobinopathies, and they are not tracked in COVID-19 testing. We used COVID-19 test data from 2 states linked to newborn screening data to estimate COVID outcomes in people with SCD or trait compared with normal hemoglobin. We linked historical newborn screening data to COVID-19 tests, hospitalization, and mortality data and modeled the odds of hospitalization and mortality. Georgia's cohort aged 0 to 12 years; Michigan's, 0 to 33 years. Over 8% of those in Michigan were linked to positive COVID-19 results, and 4% in Georgia. Those with SCD showed significantly higher rates of COVID-19 hospitalization than the normal hemoglobin Black cohort, and Michigan had higher rates of mortality as well. Outcomes among those with the trait did not differ significantly from the normal hemoglobin Black group. People with SCD are at increased risk of COVID-19-related hospitalization and mortality and are encouraged to be vaccinated and avoid infection. Persons with the trait were not at higher risk of COVID-related severe outcomes., Competing Interests: The authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Sickle cell anaemia (SCA) is a genetic disorder associated with chronic inflammation and a hypercoagulable state. This study evaluated the serum homocysteine level and its correlation with disease severity and body mass index (BMI) among individuals with SCA in a steady state., Methods: A cross-sectional study was carried out and the serum level of homocysteine was analysed using the ELISA method. Disease severity and BMI were also calculated. Data generated were analyzed using SPSS software, version 21., Results: Ninety subjects participated in this study and were made up of 30 homozygous sickle cell (HbSS, SCA) subjects, 30 individuals with sickle cell trait (HbAS), and 30 individuals with normal adult haemoglobin (HbAA) with a mean age of 27.3 ± 6.4years, 26.0 ± 6.0years, and 27.2 ± 6.6years respectively. The mean serum level of homocysteine among HbSS was 26.2 ± 11.8umol/l which was significantly higher than 17.9 ± 8.0umol/l and 18.9 ± 7.9umol/l among HbAA or HbAS respectively (p< 0.05). Mean BMI of 21.9 ± 2.8kg/m2 among HbSS was significantly lower than those of HbAS (23.7 ± 2.5kg/m2) and HbAA (24.7 ± 2.4kg/m2) (p<0.05). There was a positive correlation between homocysteine level and disease severity in patients with HbSS, though not significant (r = 0.168; p>0.05). There was a significant negative correlation between homocysteine level and BMI(r = -0.0258; p = 0.021); and between disease severity and BMI (r = -0.400; p = 0.028)., Conclusion: Individuals with HbSS have significantly higher mean serum homocysteine level and lower BMI compared to HbAS and HbAA. There was a positive correlation between homocysteine level and disease severity, though not significant but a strong negative correlation between homocysteine levels and BMI, and between disease severity and BMI among HbSS participants. A similar study should be carried out on a wide scale to determine the actual relationship between homocysteine level and disease severity in SCA and whether patients will benefit from routine administration of vitamin B12, vitamin B6, and folic acid., Competing Interests: The Authors declare that no competing interest exists., (Copyright © 2023 by West African Journal of Medicine.)

Malaria affects a significant portion of the global population, with 247 million cases in 2021, primarily in Africa. However, certain hemoglobinopathies, such as sickle cell trait (SCT), have been linked to lower mortality rates in malaria patients. Hemoglobin (Hb) mutations, including HbS and HbC, can cause sickle cell disease (SCD) when both alleles are inherited (HbSS and HbSC). In SCT, one allele is inherited and paired with a normal allele (HbAS, HbAC). The high prevalence of these alleles in Africa may be attributed to their protective effect against malaria. Biomarkers are crucial for SCD and malaria diagnosis and prognosis. Studies indicate that miRNAs, specifically miR-451a and let-7i-5p, are differentially expressed in HbSS and HbAS compared to controls. Our research examined the levels of exosomal miR-451a and let-7i-5p in red blood cells (RBCs) and infected red blood cells (iRBCs) from multiple sickle Hb genotypes and their impact on parasite growth. We assessed exosomal miR-451a and let-7i-5p levels in vitro in RBC and iRBC supernatants. Exosomal miRNAs exhibited distinct expression patterns in iRBCs from individuals with different sickle Hb genotypes. Additionally, we discovered a correlation between let-7i-5p levels and trophozoite count. Exosomal miR-451a and let-7i-5p could modulate SCD and malaria severity and serve as potential biomarkers for malaria vaccines and therapies.

There is a paucity of literature on the association of α + -thalassemia, sickle-cell hemoglobin disorders, and malaria in India. This study aimed to understand the effect of α + -thalassemia on the severity of Plasmodium falciparum malaria in adults with respect to sickle-cell genotypes. The study subjects were categorized into 'severe-malaria' and 'uncomplicated-malaria' and age-gender matched 'control' groups. Sickle-cell and α + -thalassemia were investigated in all the recruited subjects. The effect of α + -thalassemia on the severity of malaria was analyzed in HbAA and sickle-cell genotypes (HbAS and HbSS) separately. The prevalence of α + -thalassemia in various groups ranged from 41.5% to 81.8%. The prevalence of α + -thalassemia was lower (OR = 1.64; p =  0.0013) in severe malaria (41.5%) as compared to healthy controls (53.8%) with HbAA genotype. In contrast, in HbAS genotype, the prevalence of α + -thalassemia was higher (OR = 4.11; p =  0.0002) in severe malaria (81.8%) compared to controls (52.2%). In severe malaria with HbAA genotype, there was a significantly higher hemoglobin level and low MCV and MCH level in patients with α + -thalassemia compared to the normal α-globin genotype. Further, the incidence of cerebral malaria, hepatopathy, and mortality was lower in patients (HbAA) with α + -thalassemia as compared to normal α-globin genotype (HbAA). In severe malaria with either HbAS or HbSS genotype, only a few parameters showed statistical differences with respect to α + -thalassemia. Low prevalence of α + -thalassemia in severe malaria with HbAA genotype compared to healthy controls with HbAA genotype indicates the protective effect of α + -thalassemia against severe malaria. However, the high prevalence of α + -thalassemia in patients with HbAS genotype depicts its interference in the protective effect of sickle-cell against severe malaria.

The redox state of the host-parasite unit has been hypothesized to play a central role for the fitness of the intraerythrocytic blood stages of the human malaria parasite Plasmodium falciparum. In particular, hemoglobinopathies have been suggested to cause a more oxidizing environment, thereby protecting from severe malaria. Here we determined the redox potential of infected wild-type (hemoglobin AA) or sickle trait (hemoglobin AS) erythrocytes using parasite-encoded variants of the redox-sensitive green-fluorescent protein 2 (roGFP2). Our non-invasive roGFP2 single-cell measurements revealed a reducing steady-state redox potential of -304 ± 11 mV for the erythrocyte cytosol during ring-stage development and a rather sudden oxidation to -278 ± 12 mV during trophozoite-stage development around 28 h post invasion. There was no significant difference between wild-type or sickle trait erythrocytes regarding the stage dependence and the detected increase of the redox potential during the intraerythrocytic life cycle. The steady-state redox potential of the parasite cytosol, between -304 and -313 mV, was highly reducing throughout the life cycle. The redox potential in the parasitophorous vacuole at the interface between the secretory pathway and the erythrocyte was -284 ± 10 mV and remained stable during trophozoite-stage development with implications for the export of disulfide-containing proteins. In summary, P. falciparum blood stage development from the late ring to the early trophozoite stage causes a physiological jump in erythrocyte redox potential irrespective of the presence or absence of hemoglobin S., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Our study purpose was to evaluate the variation and accuracy of tailored parenting plans individually generated as a supplement to reproductive health education on the genetic inheritance of sickle cell disease or sickle cell trait. We present a secondary data analysis of experimental group data from a randomized controlled trial. Participants completed the valid and reliable Internet-based Sickle Cell Reproductive Health Knowledge Parenting Intent Questionnaire. We created a computerized algorithm that used participants' responses to generate tailored parenting plans based on their parenting preferences and partner's sickle cell status. Thirty-one different parenting plans were generated to meet the variety in the participants' preferences. The most frequently generated plan was for participants with sickle cell disease who had a partner with hemoglobin AA, who wanted to be a parent, was not likely to be pregnant, and wanted their child to be sickle cell disease free. More than half of the participants required alteration in their reproductive behavior to achieve their parenting goals. Findings provide insight into the variety and accuracy of computer algorithm-generated parenting plans, which could further guide refinement of the algorithm to produce patient-centered, tailored parenting plans supplemental to Internet-based genetic inheritance education., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Sickle cell trait is typically considered benign. Although evidence remains inconsistent, recent studies suggest that it is associated with several common diseases. We systematically assessed associations of sickle cell trait with reported diseases in a large population-based cohort., Methods: Study subjects were self-reported Blacks from the UK Biobank (UKB), a United Kingdom population-based cohort of subjects aged 40-69 years at recruitment in the United Kingdom. Sickle cell status was based on the International Classification of Diseases, Tenth Revision (ICD-10) or mutations in the HBB gene. Diagnoses of diseases were obtained from ICD-10 and self-reports. Associations of sickle cell trait and diseases were tested using logistic regression, adjusting for age at recruitment, sex, and genetic background (top 10 principal components)., Results: Among the 8019 Blacks in the UKB, 699 (8.72%) were sickle cell trait carriers; the rate was significantly higher in females (9.74%) than males (7.48%), P = .0005. Sickle cell trait was under-diagnosed; most heterozygous hemoglobin subunit beta (HBB) gene Glu6Val carriers did not have a sickle cell trait ICD-10 record. Compared with non-sickle cell trait, sickle cell trait carriers had significantly increased risk for type 2 diabetes; odds ratio 1.38; 95% confidence interval, 1.12-1.68; P = .002. Sickle cell trait was also significantly associated with increased risk for renal diseases (rhabdomyolysis, end-stage renal disease, chronic kidney disease, renal papillary necrosis) and vascular diseases (hypertension, retinopathy, non-ischemic stroke), P < .05. While most of these diseases are complications/comorbidities of diabetes, their associations with sickle cell trait remained significant after adjusting for diabetes. Association with end-stage renal disease was stronger in subjects without diabetes, odds ratio 6.45; 95% confidence interval, 1.93-19.61; P = .001., Conclusions: Sickle cell trait is significantly associated with increased risk for diabetes and diabetes-related complications/comorbidities., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Importance: Sickle cell trait (SCT), defined as the presence of 1 hemoglobin beta sickle allele (rs334-T) and 1 normal beta allele, is prevalent in millions of people in the US, particularly in individuals of African and Hispanic ancestry. However, the association of SCT with COVID-19 is unclear., Objective: To assess the association of SCT with the prepandemic health conditions in participants of the Million Veteran Program (MVP) and to assess the severity and sequelae of COVID-19., Design, Setting, and Participants: COVID-19 clinical data include 2729 persons with SCT, of whom 353 had COVID-19, and 129 848 SCT-negative individuals, of whom 13 488 had COVID-19. Associations between SCT and COVID-19 outcomes were examined using firth regression. Analyses were performed by ancestry and adjusted for sex, age, age squared, and ancestral principal components to account for population stratification. Data for the study were collected between March 2020 and February 2021., Exposures: The hemoglobin beta S (HbS) allele (rs334-T)., Main Outcomes and Measures: This study evaluated 4 COVID-19 outcomes derived from the World Health Organization severity scale and phenotypes derived from International Classification of Diseases codes in the electronic health records., Results: Of the 132 577 MVP participants with COVID-19 data, mean (SD) age at the index date was 64.8 (13.1) years. Sickle cell trait was present in 7.8% of individuals of African ancestry and associated with a history of chronic kidney disease, diabetic kidney disease, hypertensive kidney disease, pulmonary embolism, and cerebrovascular disease. Among the 4 clinical outcomes of COVID-19, SCT was associated with an increased COVID-19 mortality in individuals of African ancestry (n = 3749; odds ratio, 1.77; 95% CI, 1.13 to 2.77; P = .01). In the 60 days following COVID-19, SCT was associated with an increased incidence of acute kidney failure. A counterfactual mediation framework estimated that on average, 20.7% (95% CI, -3.8% to 56.0%) of the total effect of SCT on COVID-19 fatalities was due to acute kidney failure., Conclusions and Relevance: In this genetic association study, SCT was associated with preexisting kidney comorbidities, increased COVID-19 mortality, and kidney morbidity.

Individuals with sickle cell disease (SCD) and individuals with sickle cell trait (SCT) have different health trajectories, but it is unknown whether sociodemographic and clinical characteristics are associated with their likelihood to be a parent. The purpose of this study was to examine the sociodemographic and clinical characteristics associated with perceived likelihood-to-parent among a cohort of young adults with SCD or SCT in the USA. The participants were 234 young adults (82 males, 152 females) who had either SCD (n = 138) or SCT (n = 96). The average age was 25.9 years (SD = 4.9), and most participants (87%) were single. Study participants completed the likelihood-to-parent item (0-4 scale) included in the valid and reliable Sickle Cell Reproductive Health Knowledge Parenting Intent and Behavior Questionnaire (SCKnowIQ). The mean likelihood-to-parent score was M = 2.3 (SD = 1.1) and 41% indicated that they were 'very' or 'extremely' likely to be a parent. Bivariate analysis showed that likelihood-to-parent was associated with the participant's sickle cell genotype (p = .03), age (p = .003), educational level (p = .04), income (p = .01), employment (p = .04), number of children (p < .001), health insurance (p = .02), and influenced by others (p < .001). In multiple regression analysis, participants reported higher likelihood-to-parent scores if they had at most 2 children (p = .03), higher income (p = .03), had no insurance (p = .01), and reported higher levels of being influenced by others (p = .001). Additional research is needed to confirm these findings in larger representative samples with more young adult males and to understand the likelihood to become parents over time by implementing longitudinal studies in the SCD and SCT populations. Such research is needed to guide appropriate education and genetic counseling for reproductive decision-making among young adults with SCD or SCT., (© 2021 National Society of Genetic Counselors.)

Objective: To evaluate the incidence of variant hemoglobins of newborn samples from the Neonatal Screening Center in the state of Mato Grosso do Sul, Brazil, and to analyze the distribution and spatial autocorrelation of newborns with sickle cell trait., Methods: Samples from 35,858 newborns screened by the Neonatal Screening Center. The samples with inconclusive diagnosis were submitted to electrophoretic, chromatographic, cytological and molecular analyses. The spatial distribution analysis of newborns with sickle cell trait was performed by spatial autocorrelation., Results: A total of 919 newborns showed an abnormal hemoglobin profile; in that, ten genotypes had significant clinical impacts identified. Among the asymptomatic newborns, the sickle cell trait was the most frequent (incidence of 1.885 cases/100 newborns). The highest incidence rates were registered in the municipalities of Terenos, Figueirão, Corguinho and Selvíria. There was positive spatial autocorrelation between the proportion of declared individuals of black race/color and the incidence of newborns with sickle cell trait., Conclusion: The early diagnosis by neonatal screening and laboratory tests was very important to identify abnormal hemoglobin profiles and guide the spatial autocorrelation analysis of sickle cell trait newborns in Mato Grosso do Sul, serving as a support to anticipate health measures aimed to discuss efficient therapeutic behaviors and effective planning of municipalities with the greatest need for care, monitoring and orientations for affected families.

Introduction: Sickle cell disease (SCD), an inherited hemoglobinopathy, affects primarily African Americans in the U.S.A. In addition, about 15% African Americans carry sickle cell trait (SCT). Despite the risk associated with blood transfusions, SCD patients have lower risk of acquiring HIV-1 infection. SCT individuals might also have some protection from HIV-1 infection., Areas Covered: Here, we will review recent and previous studies with the focus on molecular mechanisms that might underlie and contribute to the protection of individuals with SCD and SCT from HIV-1 infection. As both of these conditions predispose to hemolysis, we will focus our discussion on the effects of systemic and intracellular iron on HIV-1 infection and progression. We will also review changes in iron metabolism and activation of innate antiviral responses in SCD and SCT and their effects on HIV-1 infection., Expert Opinion: Previous studies, including ours, showed that SCD might protect from HIV-1 infection. This protection is likely due to the upregulation of complex protein network in response to hemolysis, hypoxia and interferon signaling. These findings are important not only for HIV-1 field but also for SCD cure efforts as antiviral state of SCD patients may adversely affect lentivirus-based gene therapy efforts.

It remains unclear whether sickle cell trait (SCT) should be considered a risk factor during intense physical activity. By triggering the polymerization-sickling-vaso-occlusion cascade, lactate accumulation-associated acidosis in response to high-intensity exercise is believed to be one of the causes of complications. However, our understanding of lactate metabolism in response to high-intensity exercise in SCT carriers is incomplete. Thirty male SCT carriers ( n = 15) and healthy subjects ( n = 15) with and without α-thalassemia performed a 2-min high-intensity exercise. Blood and muscle lactate concentrations were measured at exercise completion. Time courses of blood lactate and glucose concentrations were followed during the subsequent recovery. Additional biochemical analyses were performed on biopsies of the vastus lateralis muscle. SCT was associated with lower blood and muscle lactate concentrations in response to the short high-intensity exercise. Compared to controls, the muscle content among SCT carriers of lactate transporter MCT4 and β 2 -adrenergic receptor were higher and lower, respectively. During recovery, the lactate removal ability was higher in SCT carriers. In the present study, no effect of α-thalassemia was observed. The lower blood and muscle lactate accumulations in SCT carriers may, to some extent, act as protective mechanisms: (i) against exercise-related acidosis and subsequent sickling, that may explain the relatively rare complications observed in exercising SCT carriers; and (ii) against the deleterious effects of intracellular lactate and associated acidosis on muscle function, that might explain the elevated presence of SCT carriers among the best sprinters.

Background: Approximately 8% of African Americans born annually have sickle cell trait (SCT), a public health concern that may contribute to health disparities if individuals with SCT do not know it and lack access to understandable information about reproductive implications. Pre-pandemic, Ohio offered in-person SCT education for parents of SCT-affected children but many did not attend. Those with limited health literacy (HL) were less likely to achieve high knowledge. We used a HL-focused evaluation of this education to develop a virtual program (SCTaware) to communicate clear, actionable information and promote knowledge retention., Methods: Seven English-speaking parents, three with limited HL, were recruited in 2019 for in-person session videotaping and SCT knowledge assessments. Clinicians, HL experts, educators, genetic counselors, and parent stakeholders (evaluators) reviewed sessions, assessments, and accompanying visuals., Results: Evaluators: observed parents asked few questions; noted undefined technical terms, closed questions, key concept omission, and limited explanation of visuals scoring low for understandability, actionability, and clarity; and developed SCTaware for individual videoconference delivery (knowledge objectives; plain language guide; HL-informed communication strategies; new visuals scoring highly for understandability, actionability, and clarity; narrated post-education version; standardized educator training)., Conclusions: Using a HL-focused evaluation, our diverse team created a promising virtual SCT education program addressing a common issue affecting populations at risk for disparities. Given virtual education will likely continue post-pandemic and limited HL is common, this approach may be essential and replicable for other public health education programs, especially those transitioning to virtual formats, to convey clear, actionable information and promote health equity.

Patients with sickle cell disease (SCD) have a lower risk for HIV-1 infection. We reported restriction of ex vivo HIV-1 infection in SCD peripheral blood mononuclear cells (PBMCs) that was due, in part, to the upregulation of antiviral, inflammatory, and hemolytic factors, including heme oxygenase-1 (HO-1). Here, we investigated whether individuals with sickle cell trait (SCT), who develop mild hemolysis, also restrict HIV-1 infection. Ex vivo infection of SCT PBMCs exhibited an approximately twofold reduction of HIV-1 replication and lower levels of HIV-1 reverse transcription products, 2-long terminal repeat circle, HIV-1 integration, and gag RNA expression. SCT PBMCs had higher HO-1 messenger RNA (mRNA) and protein levels and reduced ribonucleotide reductase 2 (RNR2) protein levels. HO-1 inhibition by tin porphyrin eliminated ex vivo HIV-1 restriction. Among Howard University clinic recruits, higher levels of HO-1 and RNR2 mRNA and lower HIV-1 env mRNA levels were found in SCT individuals living with HIV-1. To determine the population-level effect of SCT on HIV-1 prevalence, we assessed SCT among women living with HIV (WLH) in the WIHS (Women Interagency HIV-1 Study). Among WIHS African-American participants, the prevalence of SCT was lower among women with HIV compared with uninfected women (8.7% vs 14.2%; odds ratio, 0.57; 95% confidence interval, 0.36-0.92; P = .020). WIHS WLH with SCT had higher levels of CD4+/CD8+ ratios over 20 years of follow-up (P = .003) than matched WLH without SCT. Together, our findings suggest that HIV-1 restriction factors, including HO-1 and RNR2, might restrict HIV-1 infection among individuals with SCT and limit the pathogenicity of HIV., (© 2021 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Sickle-trait hemoglobin (HbAS) confers nearly complete protection from severe, life-threatening falciparum malaria in African children. Despite this clear protection, the molecular mechanisms by which HbAS confers these protective phenotypes remain incompletely understood. As a forward genetic screen for aberrant parasite transcriptional responses associated with parasite neutralization in HbAS red blood cells (RBCs), we performed comparative transcriptomic analyses of Plasmodium falciparum in normal (HbAA) and HbAS erythrocytes during both in vitro cultivation of reference parasite strains and naturally occurring P. falciparum infections in Malian children with HbAA or HbAS. During in vitro cultivation, parasites matured normally in HbAS RBCs, and the temporal expression was largely unperturbed of the highly ordered transcriptional program that underlies the parasite's maturation throughout the intraerythrocytic development cycle (IDC). However, differential expression analysis identified hundreds of transcripts aberrantly expressed in HbAS, largely occurring late in the IDC. Surprisingly, transcripts encoding members of the Maurer's clefts were overexpressed in HbAS despite impaired parasite protein export in these RBCs, while parasites in HbAS RBCs underexpressed transcripts associated with the endoplasmic reticulum and those encoding serine repeat antigen proteases that promote parasite egress. Analyses of P. falciparum transcriptomes from 32 children with uncomplicated malaria identified stage-specific differential expression: among infections composed of ring-stage parasites, only cyclophilin 19B was underexpressed in children with HbAS, while trophozoite-stage infections identified a range of differentially expressed transcripts, including downregulation in HbAS of several transcripts associated with severe malaria in collateral studies. Collectively, our comparative transcriptomic screen in vitro and in vivo indicates that P. falciparum adapts to HbAS by altering its protein chaperone and folding machinery, oxidative stress response, and protein export machinery. Because HbAS consistently protects from severe P. falciparum, modulation of these responses may offer avenues by which to neutralize P. falciparum parasites. IMPORTANCE Sickle-trait hemoglobin (HbAS) confers nearly complete protection from severe, life-threatening malaria, yet the molecular mechanisms that underlie HbAS protection from severe malaria remain incompletely understood. Here, we used transcriptome sequencing (RNA-seq) to measure the impact of HbAS on the blood-stage transcriptome of Plasmodium falciparum in in vitro time series experiments and in vivo samples from natural infections. Our in vitro time series data reveal that, during its blood stage, P. falciparum 's gene expression in HbAS is impacted primarily through alterations in the abundance of gene products as opposed to variations in the timing of gene expression. Collectively, our in vitro and in vivo data indicate that P. falciparum adapts to HbAS by altering its protein chaperone and folding machinery, oxidative stress response, and protein export machinery. Due to the persistent association of HbAS and protection from severe disease, these processes that are modified in HbAS may offer strategies to neutralize P. falciparum.

Introduction: Prospective blood donors are routinely screened for blood borne infections but medical illnesses and haemoglobin genotype are overlooked despite a high prevalence of haemoglobin AS among Nigerian donors., Objective: To determine the prevalence of haemoglobin AS and its association to renal function, if any., Method: Apparently healthy donors were studied between February and December 2018. Their haemoglobin genotype and, estimated glomerular filtration rates were determined., Results: There were 96 males (94.1%) and 6 (5.9%) females with mean age of 26.7±4.5 years (range 19-44 years) and mean eGFR of 103.97±19.00ml/min/1.73m2. Eighty one (79.4%) and 21 (20.6%) subjects had haemoglobin AA and AS genotypes respectively. The mean eGFR for subjects with haemoglobin AA and AS were 105.2±18.6ml/min/1.73m 2 and 99.9 ± 21.2ml/min/1.73m 2 respectively (p value = 0.270). Eighty one (79.4%), 20 (19.6%) and 1 (1.0%) subjects had renal function at >90ml/min/1.73m 2 , 60-89ml/min/1.73m 2 and 30-59ml/min/m 2 respectively. There was no significant difference in the mean eGFR between subjects with haemoglobin AA and AS (mean difference 5.3, p = 0.265, 95%CI = -4.07 to 14.60)., Conclusion: The prevalence of sickle cell trait among Nigerian blood donors is high. There is no significant difference in the renal function status of blood donors with SCT and normal haemoglobin genotype., (© 2021 Akinbodewa AA et al.)

Background: Haemoglobin genotype screening at prenatal care offers women an opportunity to be aware of their genotype, receive education on sickle cell disease (SCD) and may increase maternal demand for SCD newborn screening. In developed countries, most pregnant women who access prenatal care and deliver at the hospital receive haemoglobin genotype screening. In settings with low prenatal care attendance and low hospital deliveries, community-based screening may provide similar opportunity for pregnant women. We assessed the feasibility and acceptability of integrating haemoglobin genotype screening into an existing community-based HIV program., Methods: Onsite community-based integrated testing for HIV, hepatitis B virus and haemoglobin electrophoresis, were conducted for pregnant women and their male partners. Community Health Advisors implementing the NIH and PEPFAR-supported Healthy Beginning Initiative (HBI) program provided education on SCD, collected blood sample for haemoglobin electrophoresis and provided test results to participants enrolled into the HBI program. We concurrently conducted a cross-sectional study using a pretested, semi-structured, interviewer administered questionnaire to collect demographic data and assess awareness of individual haemoglobin "genotype" among HBI pregnant women participants., Results: In this study, 99.9% (10,167/10,168) of pregnant women who received education on SCD accepted and completed the survey, had blood drawn for haemoglobin electrophoresis and received their results. A majority of participating pregnant women (97.0%) were not aware of their haemoglobin "genotype". Among the participants who were incorrect about their haemoglobin "genotype", 41.1% (23/56) of women who reported their haemoglobin "genotype" as AA were actually AS. The odds of haemoglobin "genotype" awareness was higher among participants who were in younger age group, completed tertiary education, had less number of pregnancies, and attended antenatal care. Overall prevalence of sickle cell trait (AS) was 18.7%., Conclusions: It is feasible to integrate haemoglobin "genotype" testing into an existing community-based maternal-child program. Most pregnant women who were unaware of their haemoglobin "genotype" accepted and had haemoglobin genotype testing, and received their test results. Increasing parental awareness of their own haemoglobin "genotype" could increase their likelihood of accepting newborn screening for SCD.

Background: Minority RBC donors are important to support the transfusion needs of patients with sickle cell disease. Testing of donors for sickle cell trait (SCT) is performed to avoid transfusion of hemoglobin S+ (HbS+) RBCs to specific patient groups and to investigate leukoreduction failures. A screening assay based on hemoglobin solubility is commonly used. The purpose of this study was to validate a DNA approach for HbS screening., Methods: Hemoglobin solubility screening (Pacific Hemostasis or SICKLEDEX) and PreciseType human erythrocyte antigen (HEA)-HbS (Immucor) targeting c.20A>T in the β-globin gene were performed according to manufacturer's directions. Resolution of differences in results included gene sequencing and high-performance liquid chromatography (HPLC)., Results: Initial validation of HEA-HbS performed by testing 60 known samples, 20 HbS/A, A/A, and S/S, gave expected results. However, in the subsequent parallel testing phase, 4/58 samples HbS+ by solubility assay tested negative by HEA-HbS; the negative results were confirmed by β-globin gene sequencing. Samples from donors self-identifying as White testing HbS+ by solubility assay (n = 60) were retested by HEA-HbS and HPLC. The HEA-HbS assay was concordant with HPLC which is recognized as the gold standard for hemoglobin variation., Conclusion: A DNA-based approach is an alternative to screen donors for SCT, found in approximately 7% of Black and 1.7% of our random donors. HEA-HbS correlated with HPLC results in all samples tested, supporting the use of HEA-HbS as the test of record. The method allows higher throughput screening and testing at the donor center allows association of the screening result with the donor record to avoid repeat testing., (© 2021 AABB.)

Sickle-trait hemoglobin protects against severe Plasmodium falciparum malaria. Severe malaria is governed in part by the expression of the Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) that are encoded by var genes, specifically those variants that bind Endothelial Protein C Receptor (EPCR). In this study, we investigate the effect of sickle-trait on parasite var gene expression and function in vitro and in field-collected parasites. We mapped var gene reads generated from RNA sequencing in parasite cultures in normal and sickle-cell trait blood throughout the asexual lifecycle. We investigated sickle-trait effect on PfEMP1 interactions with host receptors CD36 and EPCR using static adhesion assays and flow cytometry. Var expression in vivo was compared by assembling var domains sequenced from total RNA in parasites infecting Malian children with HbAA and HbAS. Sickle-trait did not alter the abundance or type of var gene transcripts in vitro, nor the abundance of overall transcripts or of var functional domains in vivo. In adhesion assays using recombinant host receptors, sickle-trait reduced adhesion by 73-86% to CD36 and 83% to EPCR. Similarly, sickle-trait reduced the surface expression of EPCR-binding PfEMP1. In conclusion, Sickle-cell trait does not directly affect var gene transcription but does reduce the surface expression and function of PfEMP1. This provides a direct mechanism for protection against severe malaria conferred by sickle-trait hemoglobin. Trial Registration: ClinicalTrials.gov Identifier: NCT02645604., Competing Interests: The authors have declared that no competing interests exist.

Objective: To determine the regional- and district-level newborn prevalence of sickle cell trait and disease, and the prevalence of haemoglobin variants and genetic modifiers of sickle cell disease, in the nine regions of north-western United Republic of Tanzania., Methods: We repurposed dried blood spot samples from children (aged 0-24 months) born to mothers living with human immunodeficiency virus (HIV), collected as part of the HIV Early Infant Diagnosis programme, for sickle cell diagnosis. We performed isoelectric focusing to determine whether samples had normal haemoglobin, sickle cell trait, sickle cell disease or a rare haemoglobin variant. We shipped samples diagnosed as disease or variant to Cincinnati Children's Hospital in the United States of America for deoxyribonucleic-acid-based analyses to determine the prevalence of α-thalassaemia, glucose-6-phosphate dehydrogenase (G6PD) deficiency or fetal haemoglobin genetic modifiers., Findings: We analysed a total of 17 200 specimens during February 2017-May 2018. We observed a prevalence of sickle cell trait and disease of 20.3% (3492/17 200) and 1.2% (210/17 200), respectively. District-level trait varied from 8.6% (5/58) to 28.1% (77/274). Among confirmed sickle cell disease specimens, we noted 42.7% (61/143) had 1-gene deletion and 14.7% (21/143) had 2-gene deletion α-thalassaemia trait. We documented G6PD A - deficiency in 19.2% (14/73) of males., Conclusion: Our calculated prevalence is twice as high as previously reported and reinforces the need for enhanced sickle cell diagnostic services. Our district-level data will inform public health policy, allowing screening and disease-modifying hydroxyurea therapy to be focused on high-prevalence areas, until universal newborn screening is available., ((c) 2020 The authors; licensee World Health Organization.)

Introduction: Sickle cell trait (SCT) is a rare and underdiagnosed disorder in the Argentinian population. In this condition, individuals carry the mutation of the HbS gene in one of the two beta-globin genes. In general, SCT does not present with the typical manifestations of sickle cell anemia. However, under certain circumstances, some clinical characteristics of the disease may develop., Methods: We discussed the case of a 39-Year old man who presented with persistent abdominal pain of unknown origin after traveling to a high-altitude place. He underwent laparotomy without a definite diagnosis. After that, the patient developed signs of splenic infarction and pulmonary thromboembolism that were confirmed by computed tomography., Results: A sickling test was positive, and a hemoglobin electrophoresis revealed an abnormal fraction at the HbS level. In this context a diagnosis of SCT was made. Additional, tests revealed a strongly positive lupus anticoagulant., Conclusion: SCT presentation as abdominal pain and thromboembolic disease in adult patients after exposure to high altitudes is a rarely suspected diagnosis., (Universidad Nacional de Córdoba.)

Coronavirus Disease 2019 (COVID-19) pandemic is a rapidly evolving public health problem. The severity of COVID-19 cases reported hitherto has varied greatly from asymptomatic to severe pneumonia and thromboembolism with subsequent mortality. An improved understanding of risk factors for adverse clinical outcomes may shed some light on novel personalized approaches to optimize clinical care in vulnerable populations. Emerging trends in the United States suggest possibly higher mortality rates of COVID-19 among African Americans, although detailed epidemiological study data is pending. Sickle cell disease (SCD) disproportionately affects Black/African Americans in the United States as well as forebearers from sub-Saharan Africa, the Western Hemisphere (South America, the Caribbean, and Central America), and some Mediterranean countries. The carrier frequency for SCD is high among African Americans. This article underscores the putative risks that may be associated with COVID-19 pneumonia in sickle cell trait as well as potential opportunities for individualized medical care in the burgeoning era of personalized medicine., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

In the United States, causes of racial differences in stroke and its risk factors remain only partly understood, and there is a long-standing disparity in stroke incidence and mortality impacting Black Americans. Only half of the excess risk of stroke in the United States Black population is explained by traditional risk factors, suggesting potential effects of other factors including genetic and biological characteristics. Here, we nonsystematically reviewed candidate laboratory biomarkers for stroke and their relationships to racial disparities in stroke. Current evidence indicates that IL-6 (interleukin-6), a proinflammatory cytokine, mediates racial disparities in stroke through its association with traditional risk factors. Only one reviewed biomarker, Lp(a) (lipoprotein[a]), is a race-specific risk factor for stroke. Lp(a) is highly genetically determined and levels are substantially higher in Black than White people; clinical and pharmaceutical ramifications for stroke prevention remain uncertain. Other studied stroke risk biomarkers did not explain racial differences in stroke. More research on Lp(a) and other biological and genetic risk factors is needed to understand and mitigate racial disparities in stroke.

Introduction: sickle cell disease (SCD) is one of the commonest genetic causes of morbidity and mortality in the world. In resource-limited settings, SCD prevention through public education and screening could be a significant strategy to curb its prevalence. The study aimed at determining the distribution of haemoglobin genotypes among unmarried youths in Buea, Cameroon as well as their knowledge, attitude and practices towards SCD., Methods: a community-based, analytic, cross-sectional study was conducted within the city of Buea. Data was collected from 410 youths using self-administered questionnaires. Of the 410 youths, 100 were selected by purposive random sampling and their haemoglobin genotyping was done using haemoglobin electrophoresis. The data was analysed using the statistical software Epi Info Version 7., Results: the majority (51.5%) of the 410 respondents were females. The modal age range was 18- 21 years (46.8%) and 60.4% had tertiary education. Less than one quarter (20.5%) had good knowledge of SCD. Only 13.2% knew their genotype and 59.3% were willing to avoid carrier marriages. Out of the 100 participants for genotyping, 84.0% had normal haemoglobin (HbAA) and 16.0% had the sickle cell trait (HbAS)., Conclusion: most of the respondents had moderate knowledge of SCD. Only a few knew their haemoglobin genotype and more than half were willing to avoid carrier marriages. The prevalence of sickle cell trait is high in Buea. The promotion of preventive methods like public education and genetic screening is recommended to reduce the burden of SCD in Cameroon., Competing Interests: The authors declare no competing interests., (Copyright: Nini Yesih Ngwengi et al.)

Background and Purpose: Approximately 8% of Blacks have sickle cell trait (SCT), and there are conflicting reports from recent cohort studies on the association of SCT with ischemic stroke (IS). Most prior studies focused on older populations, with few data available in young adults., Methods: A population-based case-control study of early-onset IS was conducted in the Baltimore-Washington region between 1992 and 2007. From this study, 342 Black IS cases, ages 15 to 49, and 333 controls without IS were used to examine the association between SCT and IS. Each participant's SCT status was established by genotyping and imputation. For analysis, χ 2 tests and logistic regression models were performed with adjustment for potential confounding variables., Results: Participants with SCT (n=55) did not differ from those without SCT (n=620) in prevalence of hypertension, previous myocardial infarction, diabetes mellitus, and current smoking status. Stroke cases had increased prevalence in these risk factors compared with controls. We did not find an association between SCT and early-onset IS in our overall population (odds ratio=0.9 [95% CI, 0.5-1.7]) or stratified by sex in males (odds ratio=1.26 [95% CI, 0.56-2.80]) and females (odds ratio=0.67 [95% CI, 0.28-1.69])., Conclusions: Our data did not find evidence of increased risk of early-onset stroke with SCT.

Background: Genetic diversity of ABO blood, glucose-6-phosphate dehydrogenase (G6PD) deficiency and haemoglobin type and their ability to protect against malaria vary geographically, ethnically and racially. No study has been carried out in populations resident in malaria regions in western Kenya., Method: A total of 574 malaria cases (severe malaria anaemia, SMA = 137 and non-SMA = 437) seeking treatment at Vihiga County and Referral Hospital in western Kenya, were enrolled and screened for ABO blood group, G6PD deficiency and haemoglobin genotyped in a hospital-based cross-sectional study., Result: When compared to blood group O, blood groups A, AB and B were not associated with SMA (P = 0.380, P = 0.183 and P = 0.464, respectively). Further regression analysis revealed that the carriage of the intermediate status of G6PD was associated with risk to SMA (OR = 1.52, 95%CI = 1.029-2.266, P = 0.035). There was, however, no association between AS and SS with severe malaria anaemia. Co-occurrence of both haemoglobin type and G6PD i.e. the AA/intermediate was associated with risk to SMA (OR = 1.536, 95%CI = 1.007-2.343, P = 0.046) while the carriage of the AS/normal G6PD was associated with protection against SMA (OR = 0.337, 95%CI = 0.156-0.915, P = 0.031)., Conclusion: Results demonstrate that blood group genotypes do not have influence on malaria disease outcome in this region. Children in Vihiga with blood group O have some protection against malaria. However, the intermediate status of G6PD is associated with risk of SMA. Further, co-inheritance of sickle cell and G6PD status are important predictors of malaria disease outcome. This implies combinatorial gene function in influencing disease outcome.

Malaria caused by the apicomplexan parasite Plasmodium falciparum has served as a strong evolutionary force throughout human history, selecting for red blood cell polymorphisms that confer innate protection against severe disease. Recently, gain-of-function mutations in the mechanosensitive ion channel PIEZO1 were shown to ameliorate Plasmodium parasite growth, blood-brain barrier dysfunction, and mortality in a mouse model of malaria. In humans, the gain-of-function allele PIEZO1 E756del is highly prevalent and enriched in Africans, raising the possibility that it is under positive selection due to malaria. Here we used a case-control study design to test for an association between PIEZO1 E756del and malaria severity among children in Gabon. We found that the E756del variant is strongly associated with protection against severe malaria in heterozygotes. In subjects with sickle cell trait, heterozygosity for PIEZO1 E756del did not confer additive protection and homozygosity was associated with an elevated risk of severe disease, suggesting an epistatic relationship between hemoglobin S and PIEZO1 E756del. Using donor blood samples, we show that red cells heterozygous for PIEZO1 E756del are not dehydrated and can support the intracellular growth of P. falciparum similar to wild-type cells. However, surface expression of the P. falciparum virulence protein PfEMP-1 was significantly reduced in infected cells heterozygous for PIEZO1 756del, a phenomenon that has been observed with other protective polymorphisms, such as hemoglobin C. Our findings demonstrate that PIEZO1 is an important innate determinant of malaria susceptibility in humans and suggest that the mechanism of protection may be related to impaired export of P. falciparum virulence proteins., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)