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Undernutrition is a risk factor for under-5 mortality and is also postulated to be a risk factor for mortality in older children and adults with sickle cell anemia (SCA). We tested the hypothesis that underweight is associated with mortality in children aged 5 to 12 years with SCA. We performed a secondary analysis of participants in the Primary Prevention of Stroke in Children with Sickle Cell Disease in Nigeria trial, a double-blind, parallel-group randomized controlled trial for low-dose or moderate-dose hydroxyurea in children with abnormal transcranial Doppler velocities and a comparison group of participants with nonelevated transcranial Doppler velocities in northern Nigeria. Nutritional status was classified as underweight (weight-for-age z score), stunting (height-for-age z score), and wasting (body mass index z score) using the World Health Organization growth reference. The mean weight-for-age z score was lower in children who died during the study than in those who survived. Otherwise, the baseline characteristics of children who died during the study were not significantly different from those of the children who survived. A pooled analysis of participants demonstrated that a lower weight-for-age z score was associated with an increased hazard of death. Underweight participants (weight-for-age z score

We tested the hypothesis that fixed oral moderate-dose hydroxyurea (20 mg/kg per day) for initial treatment of secondary stroke prevention results in an 80% relative risk reduction of stroke or death when compared with fixed oral low-dose hydroxyurea (10 mg/kg per day) in a phase 3 double-blind, parallel-group, randomized controlled trial in children with sickle cell anemia (SCA) living in Nigeria. A total of 101 participants were randomly allocated to low-dose (n = 49) and moderate-dose (n = 52) hydroxyurea treatment groups. The median participant follow-up was 1.6 years (interquartile range, 1.0-2.3), with a planned minimum follow-up of 3.0 years. A total of 6 recurrent strokes and 2 deaths vs 5 recurrent strokes and 3 deaths occurred in the low- and moderate-dose groups, respectively. The incidence rate ratio (IRR) of the primary outcome measure of stroke or death in the low- and moderate-dose hydroxyurea treatment groups was 0.98 (95% confidence interval [CI], 0.32-3.00; P = .97). The trial was stopped early owing to no clinical difference in the incidence rates of the primary outcome measure. The incidence rates of recurrent strokes were 7.1 and 6.0 per 100 person-years in the low- and moderate-dose groups, respectively, (IRR, 1.18; 95% CI, 0.30-4.88; P = .74). As a measure of adherence to the oral hydroxyurea therapy, the median percent of returned pills was 3.0% and 2.6% in the low- and moderate-dose groups, respectively. No participant had hydroxyurea therapy stopped for myelosuppression. For children with SCA in low-income settings without access to regular blood transfusion therapy, initial low-dose hydroxyurea is a minimum known efficacious dose for secondary stroke prevention.

We conducted one of the first prospective studies to test the hypothesis that the clinical history of priapism underestimates priapism incidence compared with a priapism pain diary. Eligibility criteria were men with sickle cell anemia (SCA) between 18 and 40 years of age who have had at least 3 episodes of priapism in the past 12 months. Seventy-one men with SCA completed the diary for at least 3 months. The first 3 months of the priapism diary were included in the analysis. A total of 298 priapism episodes were recorded, and 80% (57 of 71) of the participants had at least 1 priapism event. Priapism severity was reported in the range of moderate to the worst imaginable pain in 81.5% (263 of 298), and a total 57 participants (80%) had a median pain rating of 6 (interquartile range: 5-8) on a scale from 1 to 10. The monthly incidence rate of priapism per participant based on history versus self-report pain diary was 2.0 (95% confidence interval, 1.9-2.1) and 1.4 (95% confidence interval, 1.2-1.6), respectively (P < .001). For participants that had a prior priapism episode, 80% had another episode during the 3-month interval follow-up. The median time to that second episode was 27.5 days. Major priapism occurred in 9.9% of episodes and was associated with the sum of all prospective priapism events. Men with SCA and at least 3 priapism episodes in the past 12 months are at significant risk for recurrent priapism in the following 3 months.

In high-income countries, standard care for primary stroke prevention in children with sickle cell anaemia and abnormal transcranial Doppler velocities results in a 92% relative risk reduction of strokes but mandates initial monthly blood transfusion. In Africa, where regular blood transfusion is not feasible for most children, we tested the hypothesis that initial moderate-dose compared with low-dose hydroxyurea decreases the incidence of strokes for children with abnormal transcranial Doppler velocities.SPRING is a double-blind, parallel-group, randomised, controlled, phase 3 trial of children aged 5-12 years with sickle cell anaemia with abnormal transcranial Doppler velocities conducted at three teaching hospitals in Nigeria. For randomisation, we used a permuted block allocation scheme with block sizes of four, stratified by sex and site. Allocation was concealed from all but the pharmacists and statisticians. Participants were assigned in a 1:1 ratio to low-dose (10 mg/kg per day) or moderate-dose (20 mg/kg per day) oral hydroxyurea taken once daily with monthly clinical evaluation and laboratory monitoring. The primary outcome was initial stroke or transient ischaemic attack, centrally adjudicated. The secondary outcome was all-cause hospitalisation. We used the intention-to-treat population for data analysis. The trial was stopped early for futility after a planned minimum follow-up of 3·0 years to follow-up for participants. This trial was registered with ClinicalTrials.gov, number NCT02560935.Between Aug 2, 2016, and June 14, 2018, 220 participants (median age 7·2 years [IQR 5·5-8·9]; 114 [52%] female) were randomly allocated and followed for a median of 2·4 years (IQR 2·0-2·8). All participants were Nigerian and were from the following ethnic groups: 179 (82%) people were Hausa, 25 (11%) were Fulani, and 16 (7%) identified as another ethnicity. In the low-dose hydroxyurea group, three (3%) of 109 participants had strokes, with an incidence rate of 1·19 per 100 person-years and in the moderate-dose hydroxyurea group five (5%) of 111 had strokes with an incidence rate of 1·92 per 100 person-years (incidence rate ratio 0·62 [95% CI 0·10-3·20], p=0·77). The incidence rate ratio of hospitalisation for any reason was 1·71 (95% CI 1·15-2·57, p=0·0071), with higher incidence rates per 100 person-years in the low-dose group versus the moderate-dose group (27·43 vs 16·08). No participant had hydroxyurea treatment stopped for myelosuppression.Compared with low-dose hydroxyurea therapy, participants treated with moderate-dose hydroxyurea had no difference in the stroke incidence rate. However, secondary analyses suggest that the moderate-dose group could lower incidence rates for all-cause hospitalisations. These findings provide an evidence-based guideline for the use of low-dose hydroxyurea therapy for children with sickle cell anaemia at risk of stroke.National Institute of Neurological Disorders and Stroke.

HbSC disease is the second most frequent sickle cell disease (SCD) genotype after HbSS. Globally, approximately 55,000 newborns are delivered annually with HbSC disease, with the highest HbC gene frequency in West Africa. In Ghana, 40% of adults attending the Ghana Institute of Clinical Genetics SCD clinic have HbSC. Unlike HbSS, hydroxyurea is not routinely recommended for use in individuals with HbSC disease because of the perceived high risk benefit ratio. To test the hypothesis that at least 5% of adults with HbSC will meet the American Society of Hematology (ASH) criteria for severe disease, we conducted a retrospective descriptive cohort study of all individuals with HbSC (≥18 years) who attended the clinic in 2019 (N=1,018). HbSC adults ages 18-45 years were then selected (n=639). We identified a comparison group of 639 individuals with HbSS, frequency matched by age and gender to the individuals with HbSC. Severe disease was defined as a history of ≥ 3 SCD-associated moderate to severe pain episodes/year, a history of acute chest syndrome, and severe symptomatic chronic anemia that interferes with daily activities or quality of life. Study endpoints were the proportion of individuals with SCD who met the definition of severe disease and were eligible for hydroxyurea. In total, 10.0% (64/639) of individuals with HbSC met the eligibility criteria for hydroxyurea therapy, compared to 24.1% (154/639) of individuals with HbSS, p

Pregnancy in women with sickle cell disease (SCD) is a life-threatening condition. In both high- and low-income countries, there is an 11-fold increased risk of maternal death and a 4-fold increased risk of perinatal death. We highlight the epidemiology of SCD-specific and obstetric complications commonly seen during pregnancy in SCD and propose definitions for acute pain and acute chest syndrome (ACS) episodes during pregnancy. We conducted a systematic review of the recent obstetric and hematology literature using full research articles published within the last 5 years that reported outcomes in pregnant women with SCD. The prevalence of acute pain episodes during pregnancy ranged between 4% and 75%. The prevalence of ACS episodes during pregnancy ranged between 4% and 13%. The estimated prevalence of pulmonary thromboembolism in women with SCD during pregnancy is approximately 0.5 to 1%. ACS is the most common cause of death and is often preceded by acute pain episodes. The most crucial time to develop these complications in pregnancy is during the third trimester and postpartum period. In a pooled analysis from studies in low- and middle-income settings, maternal death in women with SCD is approximately 2393 and 4300 deaths per 100 000 live births with and without multidisciplinary care, respectively. In comparison, in the US and northern Europe, the general maternal mortality rate is approximately 23.8 and 8 deaths per 100 000 live births, respectively. A multidisciplinary SCD obstetrics care approach reduces maternal and perinatal morbidity and mortality in low- and middle-income countries.

Ischemic priapism is a common but underrecognized morbidity affecting about 33% of adult men with sickle cell disease (SCD). The onset of priapism occurs in the prepubertal period and tends to be recurrent with increasing age. Significantly, priapism is associated with an unrecognized high burden of mental duress and sexual dysfunctions. The diagnosis of priapism is clinical. Many episodes of priapism will resolve spontaneously, but when an episode lasts longer than 4 hours, the episode is considered a urologic emergency requiring quick intervention with either corporal aspiration or shunt surgery. Only 3 randomized clinical trials (stilbesterol, ephedrine or etilefrine, and sildenafil) have been conducted for secondary priapism prevention in SCD. All 3 trials were limited with small sample sizes, selection biases, and inconclusive results after completion. The current molecular understanding of the pathobiology of priapism suggests a relative nitric oxide (NO) deficiency secondary to chronic hemolysis in SCD and associated phosphodiesterase type 5 dysregulation. We posit an increase in NO levels will restore the normal homeostatic relationship between voluntary erection and detumescence. Currently, 2 randomized phase 2 trials (1 double-blind, placebo-controlled trial and 1 open-label, single-arm intervention) are being conducted for secondary priapism prevention in men at high risk for recurrent priapism (NCT03938454 and NCT05142254). We review the epidemiology and pathobiology of priapism, along with mechanistic therapeutic approaches for secondary prevention of priapism in SCD.

For participants receiving experimental gene therapy or gene editing clinical trials, the FDA requires contemporaneous controls to compare clinical outcomes. However, developing a contemporaneous cohort of rare diseases is costly and requires multiple person-hours. In a single referral center for sickle cell disease, we tested the hypothesis that we could create an automated contemporaneous cohort of children and adults with sickle cell anemia (SCA) to predict mortality. Data were obtained between 1/1/2004 and 4/30/2021. We identified 419 individuals with SCA with consistent medical care (i.e., followed continuously for >0.5 years with no visit gaps ≥3.0 years). The median age was 10.2 years (IQR 1.0 - 24.0 years), with a median follow-up of 7.4 years (IQR 3.6-13.5 years) and 47 deaths. A total of 98% (274 of 277) of the children remained alive at 18 years of age, and 34.3% (94 of 274) of those children were followed into adulthood. For adults, the median age of survival was 49.3 years of age. Treatment groups were mutually exclusive and in a hierarchical order: hematopoietic stem cell transplant (n=22)>regular blood transfusion for at least two years (n=56)>hydroxyurea for at least one year (n=243)>no disease-modifying therapy (n=98). Compared to those receiving no disease-modifying treatment, those treated with hydroxyurea therapy had significantly lower hazard of mortality (hazard ratio=0.38, p=0.016), but no statistical difference for those receiving regular blood transfusions compared to no disease-modifying therapy (hazard ratio=0.71, p=0.440). An automated contemporaneous SCA cohort can be generated to estimate mortality in children and adults with SCA.

The harsh realities of racial inequities related to COVID-19 and civil unrest following police killings of unarmed Black men and women in the United States in 2020 heightened awareness of racial injustices around the world. Racism is deeply embedded in academic medicine, yet the nobility of medicine and nursing has helped health care professionals distance themselves from racism. Vanderbilt University Medical Center (VUMC), like many U.S. academic medical centers, affirmed its commitment to racial equity in summer 2020. A Racial Equity Task Force was charged with identifying barriers to achieving racial equity at the medical center and medical school and recommending key actions to rectify long-standing racial inequities. The task force, composed of students, staff, and faculty, produced more than 60 recommendations, and its work brought to light critical areas that need to be addressed in academic medicine broadly. To dismantle structural racism, academic medicine must: (1) confront medicine’s racist past, which has embedded racial inequities in the U.S. health care system; (2) develop and require health care professionals to possess core competencies in the health impacts of structural racism; (3) recognize race as a sociocultural and political construct, and commit to debiologizing its use; (4) invest in benefits and resources for health care workers in lower-paid roles, in which racial and ethnic minorities are often overrepresented; and (5) commit to antiracism at all levels, including changing institutional policies, starting at the executive leadership level with a vision, metrics, and accountability.

We used the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework to evaluate a Stroke Prevention Team’s readiness to prevent strokes in children with sickle cell anemia living in northern Nigeria. The NIH sponsored Stroke Prevention Trial in Nigeria included a goal of a sustainable stroke prevention program. The program’s 1-year reach for transcranial Doppler screening was 14.7% (4710/32,000) of which 6.0% (281/4710) had abnormal velocities (≥200 cm/s). All participants with abnormal transcranial Doppler velocities were started on hydroxyurea (effectiveness). The leaders of all 5 hospitals agreed to adopt the program. After 1 year, program-implementation and maintenance rates were 100%, demonstrating the program’s feasibility and short-term sustainability.

OBJECTIVE: The primary objective of this study was to test perceived controllability of stressors as a moderator of the association between coping and depressive symptoms in children and adolescents with sickle cell anemia (SCA). METHOD: Twenty-eight children and adolescents (M(age) = 11.71, SD = 4.31; 60.7% female) with SCA were enrolled. Caregivers provided reports of child and adolescent coping using the Response to Stress Questionnaire (RSQ), perceived control of stressors on the RSQ, and depressive symptoms using the Child Behavior Checklist. Children and adolescents also completed Wechsler assessments of working memory and verbal comprehension. RESULTS: Secondary control coping (i.e., cognitive reappraisal, acceptance, distraction) was a significant predictor of depressive symptoms such that greater use of secondary control coping was related to fewer reported depressive symptoms when accounting for use of primary control (problem-solving, emotion expression and regulation) and disengagement coping and neurocognitive variables. Further, perceived control of peer-related stress was a significant moderator of the association between secondary control coping and depressive symptoms, such that there was a significant negative association of secondary control coping with depressive symptoms only for low perceived control. CONCLUSION: Secondary control coping may be particularly helpful for reducing depressive symptoms when adolescents’ peer-related stressors are perceived as uncontrollable. Interventions to reduce internalizing problems in this population should consider teaching children and adolescents secondary control coping skills in addition to skills in identifying uncontrollable sources of stress.

Despite priapism being one of the most frequent complications of sickle cell anemia (SCA) in male individuals, little has been reported about the impact of priapism in this population. The authors used a sequential independent mixed-methods design, which used both international multicenter focus group discussions (n=35) and a quantitative patient-reported outcome measure (n=131) to determine the impact of priapism on men with SCA in Nigeria and the United States. The authors analyzed data from focus groups using an iterative inductive-deductive approach. Comparison of the Priapism Impact Profile data was done using the Kruskal-Wallis H test. Our result showed that priapism, across cultures, is associated with shame and embarrassment. These emotions interfere with timely clinical and family communication about priapism symptoms and complications. Participants were dissatisfied with the quality of care at emergency facilities. The quality of life and physical wellness of men with SCA-related priapism were significantly different for the 3 groups: (1) priapism condition getting better, (2) priapism condition getting worse, and (3) priapism condition remain the same (P=0.002 and P=0.019, respectively). Psychological, sexual, and physical wellbeing are all adversely affected by priapism. Evidence-based methods are necessary for adequate medical, educational, and psychological treatment for recurrent priapism.

Prevalence and contribution of intracranial and extracranial arterial stenosis to stroke risk were assessed prospectively in children and young adults with sickle cell disease.In this cross-sectional study, children and young adults (mean = 19.4 years) with sickle cell disease underwent neurological examination, brain MRI, and magnetic resonance angiography of the head and neck. Two neuroradiologists independently recorded infarcts and arterial stenosis. Clinical features and stroke outcomes were compared between participants with and without stenosis and between children and young adults. Logistic regression analysis assessed the association of variables of interest with overt stroke and silent cerebral infarct.Of 167 participants (79 children and 88 young adults), 20 (12.0%) had intracranial stenosis, all in the anterior circulation, and nine had concurrent extracranial stenosis. No participants had isolated extracranial stenosis. Participants with intracranial stenosis were more likely than those without stenosis to have an overt stroke (70% vs 5%, P 0.001) or silent cerebral infarct (95% vs 35%, P 0.001). Logistic regression analysis indicated that intracranial stenosis was strongly associated with overt stroke when compared with participants with silent cerebral infarct alone and strongly associated with silent cerebral infarct when compared with participants with normal brain MRI; male sex and age were also significant predictors of silent cerebral infarct.Intracranial stenosis was strongly associated with both overt stroke and silent cerebral infarct; prevalence of intracranial stenosis was similar to prior estimates in sickle cell disease. Extracranial stenosis without concurrent intracranial stenosis did not occur and thus could not be evaluated as an independent risk factor for stroke.

The goal of curing children and adults with sickle cell disease (SCD) is to maximize benefits and minimize intermediate and long-term adverse outcomes so that individuals can live an average life span with a high quality of life. While greater than 2000 individuals with SCD have been treated with curative therapy, systematic studies have not been performed to evaluate the long-term health effects of hematopoietic stem cell transplant (HSCT) in this population. Individuals with SCD suffer progressive heart, lung, and kidney disease prior to curative therapy. In adults, these sequalae are associated with earlier death. In comparison, individuals who undergo HSCT for cancer are heavily pretreated with chemotherapy, resulting in potential acute and chronic heart, lung, and kidney disease. The long-term health effects on the heart, lung, and kidney for children and adults undergoing HSCT for cancer have been extensively investigated. These studies provide the best available data to extrapolate the possible late health effects after curative therapy for SCD. Future research is needed to evaluate whether HSCT abates, stabilizes, or exacerbates heart, lung, kidney, and other diseases in children and adults with SCD receiving myeloablative and non-myeloablative conditioning regimens for curative therapy.

Background In Nigeria, approximately 150,000 children with sickle cell anemia (SCA) are born annually, accounting for more than half of all SCA births worldwide. Without intervention, about 11% of children with SCA will develop a stroke before their 20th birthday. Evidence-based practices for primary stroke prevention include screening for abnormal transcranial Doppler (TCD) measurements coupled with regular blood transfusion therapy for at least one year, followed by hydroxyurea (HU) therapy indefinitely. In high-resource countries, this strategy contributes to a 92% decrease in stroke incidence rates. In 2016, as part of a capacity building objective of the Stroke Prevention Trial in Nigeria (1R01NS094041: SPRING), TCD screening was adopted as standard care at Barau Dikko Teaching Hospital in Kaduna. However, with just 70 radiologists and only 3 certified in TCD screening in the state, just 5.49% (1101/20,040) of eligible children with SCA were screened. Thus, there is a need to explore alternate implementation strategies to ensure children with SCA receive standard care TCD screening to decrease stroke incidence. Objective This protocol describes a study to create a stroke prevention program in a community hospital in Kaduna through task shifting TCD screening to nurses and training medical officers to initiate and monitor HU utilization for stroke prevention. Methods This study will be conducted at 2 sites (teaching hospital and community hospital) over a period of 3 years (November 2020 to November 2023), in 3 phases using both quasi-experimental and effectiveness-implementation study designs. In the needs assessment phase, focus groups and structured interviews will be conducted with health care providers and hospital administrators to identify barriers and facilitators to evidence-based stroke prevention practices. Results from the needs assessment will inform intervention strategies and a process plan to fit the needs of the community hospital. In the capacity building phase, nurses and medical officers at the community hospital will be trained on TCD screening and HU initiation and monitoring. In the implementation phase, children with SCA aged 2-16 years will be recruited into a nonrandomized single-arm prospective trial to determine the feasibility of initiating a task-shifted stroke prevention program by recording recruitment, retention, and adherence rates. The Reach and Effectiveness components of the RE-AIM (Reach, Effectiveness, Adoption, Implementation and Maintenance) framework will be used to evaluate implementation outcomes between the community and teaching hospitals. Results The needs assessment phase of the study was completed in February 2021. Manuscript on findings is currently in preparation. Capacity building is ongoing with TCD training and sickle cell disease and stroke education sessions for nurses and doctors in the community hospital. Recruitment for the implementation trial is expected to commence in July 2022. Conclusions This study proposes a structured, theory-driven approach to create a stroke prevention program in a community hospital in Kaduna, Nigeria, to decrease stroke incidence among children with SCA. Results will provide preliminary data for a definitive randomized clinical trial in implementation science. International Registered Report Identifier (IRRID) PRR1-10.2196/37927

BACKGROUND In Nigeria, approximately 150,000 children with sickle cell anemia (SCA) are born annually, accounting for more than half of all SCA births worldwide. Without intervention, about 11% of children with SCA will develop a stroke before their 20th birthday. Evidence-based practices for primary stroke prevention include screening for abnormal transcranial Doppler (TCD) measurements coupled with regular blood transfusion therapy for at least one year, followed by hydroxyurea (HU) therapy indefinitely. In high-resource countries, this strategy contributes to a 92% decrease in stroke incidence rates. In 2016, as part of a capacity building objective of the Stroke Prevention Trial in Nigeria (1R01NS094041: SPRING), TCD screening was adopted as standard care at Barau Dikko Teaching Hospital in Kaduna. However, with just 70 radiologists and only 3 certified in TCD screening in the state, just 5.49% (1101/20,040) of eligible children with SCA were screened. Thus, there is a need to explore alternate implementation strategies to ensure children with SCA receive standard care TCD screening to decrease stroke incidence. OBJECTIVE This protocol describes a study to create a stroke prevention program in a community hospital in Kaduna through task shifting TCD screening to nurses and training medical officers to initiate and monitor HU utilization for stroke prevention. METHODS This study will be conducted at 2 sites (teaching hospital and community hospital) over a period of 3 years (November 2020 to November 2023), in 3 phases using both quasi-experimental and effectiveness-implementation study designs. In the needs assessment phase, focus groups and structured interviews will be conducted with health care providers and hospital administrators to identify barriers and facilitators to evidence-based stroke prevention practices. Results from the needs assessment will inform intervention strategies and a process plan to fit the needs of the community hospital. In the capacity building phase, nurses and medical officers at the community hospital will be trained on TCD screening and HU initiation and monitoring. In the implementation phase, children with SCA aged 2-16 years will be recruited into a nonrandomized single-arm prospective trial to determine the feasibility of initiating a task-shifted stroke prevention program by recording recruitment, retention, and adherence rates. The Reach and Effectiveness components of the RE-AIM (Reach, Effectiveness, Adoption, Implementation and Maintenance) framework will be used to evaluate implementation outcomes between the community and teaching hospitals. RESULTS The needs assessment phase of the study was completed in February 2021. Manuscript on findings is currently in preparation. Capacity building is ongoing with TCD training and sickle cell disease and stroke education sessions for nurses and doctors in the community hospital. Recruitment for the implementation trial is expected to commence in July 2022. CONCLUSIONS This study proposes a structured, theory-driven approach to create a stroke prevention program in a community hospital in Kaduna, Nigeria, to decrease stroke incidence among children with SCA. Results will provide preliminary data for a definitive randomized clinical trial in implementation science. INTERNATIONAL REGISTERED REPORT PRR1-10.2196/37927

The basic model of SCD physiology states that vaso-occlusion occurs when hemoglobin S-containing red blood cells (RBC) undergo sickling before they escape the capillary into a larger vessel. We have shown that mental stress, pain and cold, and events reported by patients to trigger SCD vaso-occlusive crisis (VOC), cause rapid and significant decrease in blood flow, reducing the likelihood that RBC could transit the microvasculature before sickling occurs. However, the critical link between decrease in microvascular blood flow and the incidence of future sickle VOC has never been established experimentally in humans. Using data from centrally adjudicated, overnight polysomnograms (PSG), previously collected in a prospective multi-center cohort sleep study, we analyzed the beat-to-beat amplitudes of vasoconstriction reported by the fingertip photoplethysmogram in 212 children and adolescents with SCD and developed an algorithm that detects vasoconstriction events and quantifies the magnitude (Mvasoc ), duration, and frequency of vasoconstriction that reflect the individual's inherent peripheral vasoreactivity. The propensity to vasoconstrict, quantified by median Mvasoc , predicted the incidence rate of post-PSG severe acute vaso-occlusive pain events (P = .006) after accounting for age and hemoglobin. Indices of sleep-disordered breathing contributed to median Mvasoc but did not predict future pain rate. Median Mvasoc was not associated with vaso-occlusive pain events that occurred prior to each PSG. These results show that SCD individuals with high inherent propensity to vasoconstrict have more frequent severe acute pain events. Our empirical findings are consistent with the fundamental SCD hypothesis that decreased microvascular flow promotes microvascular occlusion.

Recurrent ischemic priapism is a common complication of sickle cell disease (SCD). We assessed the burden, characteristics, and types of priapism, including sexual dysfunction, in a cohort of men with and those without SCD, to test the hypothesis that sexual dysfunction is more prevalent in men with SCD. In Kano, Nigeria, we conducted a comparative cross-sectional survey that included 500 and 250 men 18 to 40 years of age, with and without SCD, respectively. The survey used the Priapism Questionnaire and the International Index of Erectile Function for sexual function assessment. All eligible participants approached for the study gave informed consent and were enrolled. Stuttering and major priapism were defined based on the average duration of priapism experiences that lasted ≤4 and >4 hours, respectively. The prevalence of priapism was significantly higher in men with SCD than in those without it (32.6% vs 2%; P < .001). Stuttering priapism accounted for 73.6% of the priapism episodes in men with SCD. Nearly 50% of the participants with SCD-related priapism had never sought medical attention for this complication. The majority of the men with SCD-related priapism used exercise as a coping mechanism. Priapism affected the self-image of the men with SCD, causing sadness, embarrassment, and fear. The percentage of the men with SCD who had erectile dysfunction was more than twofold higher than that of those without SCD who had erectile dysfunction (P = .01). The men with SCD had a higher prevalence of priapism and sexual dysfunction than the men without SCD.