Search

Recombinant human erythropoietin (rhEPO) is prohibited by the World Anti-Doping Agency. rhEPO abuse can be indirectly detected via the athlete biological passport (ABP). However, altitude exposure challenges interpretation of the ABP. This study investigated whether 5'-aminolevulinate synthase 2 (ALAS2) and carbonic anhydrase 1 (CA1) in capillary dried blood spots (DBSs) are sensitive and specific markers of rhEPO treatment at altitude. ALAS2 and CA1 expression was monitored in DBS collected weekly before, during, and after a 3-week period at sea level or altitude. Participants were randomly assigned to receive 20 IU kg bw -1 epoetin alpha (rhEPO) or placebo injections every second day for 3 weeks while staying at sea level (rhEPO, n = 25; placebo, n = 9) or altitude (rhEPO, n = 12; placebo, n = 27). ALAS2 and CA1 expression increased up to 300% and 200%, respectively, upon rhEPO treatment at sea-level and altitude (P-values <0.05). When a blinded investigator interpreted the results, ALAS2 and CA1 expression had a sensitivity of 92%. Altitude did not confound the interpretation. Altitude affected ALAS2 and CA1 expression less than actual ABP markers when compared between sea level and altitude results. An individual athlete passport-like approach simulation confirmed the biomarker potential of ALAS2 and CA1. ALAS2 and CA1 were sensitive and specific biomarkers of micro-dose rhEPO treatment at sea level and altitude. Altitude seemed less a confounding factor for these biomarkers, especially when they are combined. Thus, micro-dose rhEPO injections can be detected in a longitudinal blinded setting using mRNA biomarkers in DBS., (© 2024 John Wiley & Sons Ltd.)

Recombinant human erythropoietin (rhEPO) has been abused as a performance enhancer in sports for several years, but with advancements in detection methods, even micro-doses can be detected in dried blood spot (DBS) samples. Here, we present the results from an Eporatio® (epoetin theta) micro-dose administration study to detect rhEPO in DBS samples. Five healthy male volunteers received a 15 IU/kg subcutaneous dose of Eporatio®. Urine and DBS samples (Mitra® VAMS and Capitainer® B50) were collected 1, 10, 24, 36, 48 and 72 h after drug administration. After 1 h, all urine samples were negative for rhEPO, whereas 40% of DBS samples were considered suspicious. All samples between 10 and 48 h were suspicious for the presence of Eporatio®, except one urine sample that was negative at 48 h. After 72 h, 40% of urine samples and 60% of DBS samples were suspicious and would have proceeded to a confirmation analysis. DBS is an efficient complementary matrix to urine for detection of rhEPO micro-doses., (© 2024 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.)

Lowlanders sojourning for more than 1 day at high altitude (HA) experience a reduction in plasma volume (PV) that increases haemoglobin concentration and thus restores arterial oxygen content. If the sojourn extends over weeks, an expansion of total red cell volume (RCV) occurs and contributes to the haemoconcentration. While the reduction in PV was classically attributed to an increased diuretic fluid loss, recent studies support fluid redistribution, rather than loss, as the underlying mechanism. The fluid redistribution is presumably driven by a disappearance of proteins from the circulation and the resulting reduction in oncotic pressure exerted by the plasma, although the fate of the disappearing proteins remains unclear. The RCV expansion is the result of an accelerated erythropoietic activity secondary to enhanced renal erythropoietin release, but a contribution of other mechanisms cannot be excluded. After return from HA, intravascular volumes return to normal values and the normalisation of RCV might involve selective destruction of newly formed erythrocytes, although this explanation has been strongly challenged by recent studies. In contrast to acclimatised lowlanders, native highlanders originating from the Tibetan and the Ethiopian plateaus present with a normal or only mildly elevated haemoglobin concentration. Genetic adaptations blunting the erythropoietic response to HA exposure have been proposed as an explanation for the absence of more pronounced haemoconcentration in these populations, but new evidence also supports a contribution of a larger than expected PV. The functional significance of the relatively low haemoglobin concentration in Tibetan and Ethiopian highlanders is incompletely understood and warrants further investigation., (© 2023 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

Purpose: Nutritional ketosis synergistically with body-weight loss induced by a very-low-calorie ketogenic diet (VLCKD) has proven to be effective in improving obesity-related pathophysiology. Recently, growing attention has been focused on the relation between erythropoietin (EPO) and obesity. Thus, this study aims to investigate whether nutritional ketosis and weight loss induced by a VLCKD modify the circulating levels of EPO in patients with obesity in comparison with the effect of low-calorie diet (LCD) or bariatric surgery (BS)., Methods: EPO levels, iron status and body composition parameters were evaluated in 72 patients with overweight or obesity and 27 normal-weight subjects at baseline and after the three different weight-reduction therapies (VLCKD, LCD and BS) in 69 patients with excess body weight. β-hydroxybutyrate levels were also measured in the VLCKD group. The follow-up was established at 2-3 months and 4-6 months., Results: It was found that EPO levels were higher in morbid obesity and correlated with higher basal weight, fat mass (FM) and fat-free mass (FFM) in the overall sample. High baseline EPO levels were also correlated with higher impact on the course of weight loss and changes in FM and FFM induced by the three weight-loss interventions. Furthermore, the VLCKD induced a decrease in EPO levels coinciding with maximum ketosis, which was maintained over time, while statistically significant changes were not observed after LCD and BS., Conclusion: The obesity-related increased EPO levels are restored after VLCKD intervention at the time of maximum ketosis, suggesting a potential role of the nutritional ketosis induced by the VLCKD. Baseline EPO levels could be a biomarker of response to a weight-loss therapy., (© 2024. The Author(s).)

The EPO gene variant, c.577del (VAR-EPO), was discovered in the Chinese population in 2021. The mutated protein is naturally present in urine from individuals heterozygous for the variant. Electrophoresis methods currently applied in anti-doping laboratories produce a pattern in samples from individuals carrying VAR-EPO that cannot be unambiguously distinguished from individuals who received recombinant EPO doses. Consequently, the analysis of blood samples is obligatory to facilitate interpretation of suspicious findings from urine samples. However, this complicates the process and delays the reporting. Objective of this study was to develop EPO c.577del detection in urine and dried blood samples (DBS) in order to facilitate and accelerate EPO results management. Moreover, estimation of the success rate of sequencing regarding concentration of DNA in urine and DBS was evaluated. Conclusive results regarding Sanger sequencing were obtained for all samples with DNA concentrations above 0.024 ng/μL DNA in 80% of urines samples from volunteers. The potential success of DNA sequencing rate in athletes' urines was investigated. A total of 191 urine samples were considered. DNA concentration exceeding 0.024 ng/μL was detected in 85% of the samples. Interestingly, in-competition samples had a significantly higher DNA concentration than out-of-competition male urine samples (0.330 vs. 0.084 ng/μL). Moreover, conclusive EPO sequences were obtained for 100% of DBS (cellulose and polymer matrices). In conclusion, method for detection of EPO gene variant was developed in urine and DBS. Characterization of DNA concentration was performed in order to evaluate the probability of success of sequencing EPO gene in anti-doping field., (© 2024 John Wiley & Sons Ltd.)

The use of acute carbon monoxide inhalation (COi) and hot water immersion (HWI) are of growing interest as interventions to stimulate erythropoietin (EPO) production. However, whether EPO production is further augmented when combining these stressors and whether there are sex differences in this response are poorly understood. Therefore, we measured circulating EPO concentration in response to acute COi and HWI independently and in combination and determined whether the responses were altered by sex. Participants completed three study visits-COi, HWI, and combined COi and HWI-separated by 1 week in a randomized, balanced, crossover design. Renal blood velocity was measured during all interventions, and carboxyhaemoglobin was measured during and after COi. Serum samples were analysed every hour for 6 h post-intervention for EPO concentration. HWI decreased renal blood velocity (46.2 cm/s to 36.2 cm/s) (P < 0.0001), and COi increased carboxyhaemoglobin (1.5%-12.8%) (P < 0.0001) without changing renal blood velocity (46.4-45.2 cm/s) (P = 0.4456). All three interventions increased peak EPO concentration from baseline (COi: 6.02-9.74 mIU/mL; HWI: 6.80-11.10 mIU/mL; COi + HWI: 6.71-10.91 mIU/mL) (P = 0.0048) and to the same extent (P = 0.3505). On average, females increased EPO while males did not in response to COi (females: 6.17 mIU/mL; males: 1.27 mIU/mL) (P = 0.0010), HWI (females: 6.47 mIU/mL; males: 2.14 mIU/mL) (P = 0.0104), and COi and HWI (females: 6.65 mIU/mL; males: 1.76 mIU/mL) (P = 0.0256). These data emphasize that combining these interventions does not augment EPO secretion and that these interventions may work better in females., (© 2024 The Author(s). Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

Objective: Our study aimed to investigate the relationship between vascular endothelial growth factor (VEGF), NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammatory complex, erythropoietin (EPO) levels, and ocular hemodynamics in patients diagnosed with primary open-angle glaucoma (POAG)., Methods: This is a prospective observational study. Patients diagnosed with POAG at The Sixth Hospital of Wuhan hospital between November 2022 and February 2023were enrolled.The patients were categorized into three groups based on the average visual field defect (mean deviation, MD) value: severe injury group (MD > 12 dB, 93 cases), moderate injury group (7 ≤ MD ≤ 12 dB, 89 cases), and mild injury group (MD < 7 dB, 85 cases). The levels of VEGF, NLRP3 inflammatory complex, EPO, and ocular hemodynamics were compared among the groups. Furthermore, the relationship between VEGF, NLRP3, EPO levels, and ocular hemodynamics in patients with POAG was analyzed using Pearson correlation analysis. After adjusting for confounding factors such as age and gender, multivariate Logistic regression analysis was performed with the ocular hemodynamics indexes being used as dependent variables, and VEGF, NLRP3, ASC, Caspase-1, and EPO being used as independent variables., Results: A total of267 patients with POAG were enrolled. There were no significant differences in sex, age, body mass index, systolic blood pressure, diastolic blood pressure, smoking, alcohol consumption, and blood glucose between the two groups (P > 0.05). The levels of NLRP3, ASC, Caspase-1, and EPO in the severe and moderate injury groups were higher than those in the mild injury group, whereas the VEGF levels were lower in the severe and moderate groups compared to the mild group, showing significant differences (P < 0.05). The severe group exhibited higher levels of NLRP3, ASC, Caspase-1, and EPO than the moderate group, while the VEGF levels were lower in the severe group compared to the moderate group, showing significant differences (P < 0.05). The peak systolic velocity(PSV) and resistance index (RI) were higher in the severe and moderate groups than in the mild group, whereas the EDV was significantly lower in the severe and moderate groups compared to the mild group (P < 0.05). The severe group exhibited higher PSV and RI values compared to the moderate group, while the EDV was lower in the severe group compared to the moderate group, showing significant differences (P < 0.05). Pearson correlation analysis was performed to examine the relationship between VEGF, NLRP3, EPO levels, and ocular hemodynamics in patients with POAG. VEGF, NLRP3, ASC, Caspase-1, and EPO showed positive correlations with PSV and RI, and negative correlations with EDV in patients with POAG. Regression analysis showed that VEGF, NLRP3, ASC, Caspase-1 and EPO were significantly correlated with ocular hemodynamics in POAG (all P < 0.001)., Conclusion: We demonstrated that the levels of VEGF, NLRP3 inflammatory complex, and EPO were highly associated with ocular hemodynamics in patients diagnosed with POAG., (© 2024. The Author(s).)

Immunopurification of doping control samples is a mandatory necessity in erythropoietin (EPO) analysis during a confirmation procedure; moreover, it has become common practice to also immunopurify samples for the initial testing procedure. Typically used materials (e.g., Stemcell purification plate and MAIIA purification kit) rely on anti-EPO antibodies for purification. Also, the detection of EPO after electrophoretic separation and western blotting is based on a monoclonal anti-EPO antibody, clone AE7A5, directed against a 26 amino acid sequence of the N-terminal region of human EPO. While the electrophoretic separation and blot transfer efficiency can be monitored with reference standards and quality control samples, it is presently not possible to monitor the functionality of the entire sample preparation procedure. The reliance on antibodies for both purification and detection has complicated the implementation of an internal standard (ISTD). In this study, customized EPO-polyethylene glycol (PEG) conjugates were synthesized as potential ISTDs and assessed as to their compatibility with existing sample preparation procedures for urine and blood sample analysis using the most common immunopurification techniques. Moreover, probing for the impact of the ISTD on sodium N-lauroylsarcosinate ("sarcosyl") polyacrylamide gel electrophoresis (SAR-PAGE)-based EPO analysis concerning potential interference with target analytes was conducted. The presented data demonstrate that a 12-kDa PEG residue attached to human EPO represents a particularly useful construct to serve as ISTD for erythropoietin-receptor agonist (ERA) analysis. The conjugate is applicable to both urine and blood testing using the commonly employed purification techniques, supporting and improving result interpretations especially concerning specimens where the natural abundance of human EPO is low., (© 2021 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.)

The objective of this study was to examine the effect of consuming ketone monoester plus a high dose of carbohydrate from glucose (KE + CHO) on the change in erythropoietin (EPO) concentrations during load carriage exercise compared with carbohydrate (CHO) alone. Using a randomized, crossover design, 12 males consumed KE + CHO (573 mg KE/kg body mass, 110 g glucose) or CHO (110 g glucose) 30 min before 4 miles of self-paced treadmill exercise (KE + CHO:51 ± 13%, CHO: 52 ± 12% V̇O 2peak ) wearing a weighted vest (30% body mass; 25 ± 3 kg). Blood samples for analysis were obtained under resting fasted conditions before (Baseline) consuming the KE + CHO or CHO supplement and immediately after exercise (Post). βHB increased (p < 0.05) from Baseline to Post in KE + CHO, with no change in CHO. Glucose and glycerol increased (p < 0.05) from Baseline to Post in CHO, with no effect of time in KE + CHO. Insulin and lactate increased (p < 0.05) from Baseline to Post independent of treatment. EPO increased (p < 0.05) from Baseline to Post in KE + CHO and CHO with no difference between treatments. Although KE + CHO altered βHB, glucose, and glycerol concentrations, results from this study suggest that KE + CHO supplementation before load carriage exercise does not enhance immediate post-exercise increases in EPO compared with CHO alone., (Published 2024. This article is a U.S. Government work and is in the public domain in the USA. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Exercise-induced inflammation can influence iron metabolism. Conversely, the effects of vitamin D 3 , which possesses anti-inflammatory properties, on ultramarathon-induced heart damage and changes in iron metabolism have not been investigated. Thirty-five healthy long-distance semi-amateur runners were divided into two groups: one group received 150,000 IU of vitamin D 3 24 h prior to a race ( n = 16), while the other group received a placebo ( n = 19). Serum iron, hepcidin (HPC), ferritin (FER), erythroferrone (ERFE), erythropoietin (EPO), neopterin (NPT), and cardiac troponin T (cTnT) levels were assessed. A considerable effect of ultramarathon running on all examined biochemical markers was observed, with a significant rise in serum levels of ERFE, EPO, HPC, NPT, and cTnT detected immediately post-race, irrespective of the group factor. Vitamin D 3 supplementation showed a notable interaction with the UM, specifically in EPO and cTnT, with no other additional changes in the other analysed markers. In addition to the correlation between baseline FER and post-run ERFE, HPC was modified by vitamin D. The ultramarathon significantly influenced the EPO/ERFE/HPC axis; however, a single substantial dose of vitamin D 3 had an effect only on EPO, which was associated with the lower heart damage marker cTnT after the run.

The most popular treatment for end-stage renal illness is hemodialysis (HD). The study aimed to assess serum ferritin levels and their connection to Epoetin alfa resistance, along with exploring the link between hepatitis C virus, iron overload, and the prevalence of hepatitis C and B infections in chronic HD patients. This was a descriptive-analytical study conducted on 50 Patients with chronic kidney disease (CKD) who were on regular HD in the dialysis unit of Ibin Sina Teaching Hospital in Mosul City, Iraq. Out of 50 patients, 26 (52%) tested positive for Hepatitis C Virus (HCV) Antibody, 10 (20%) for Hepatitis B surface Antigen (HBsAg), and 14 (28%) tested negative for both. Higher serum iron and ferritin levels were found in HCV antibody-positive patients (p < 0.05). Despite Epoetin alfa treatment, patients with elevated ferritin levels exhibited lower Hemoglobin (HB) and Packed Cell Volume (p < 0.05). Non-diabetics exhibited significantly higher serum ferritin, Hemoglobin, Blood urea, and serum creatinine than diabetics (p < 0.05). A noteworthy association was seen between the quantity of blood transfusions and elevated levels of serum ferritin and total serum iron (p < 0.05). Most HD patients were anemic, with Hepatitis B and C prevalent. The main CKD causes were diabetes and hypertension. HCV-positive patients often showed mild to moderate iron overload, and high serum ferritin was linked to poor Epoetin alfa response. Dialysis can elevate blood urea, ferritin, and creatinine, worsening anemia. High ferritin levels may hinder response to Epoetin alfa and iron replacement. Excessive blood transfusions can lead to iron overload and inhibit erythropoiesis. Maintaining HB at 110-120 g/l improves quality of life and reduces anemia-related risks.

Erythropoietin (EPO) has neuroprotective effects by increasing oxidative stress resistance and stabilizing redox balance. Ischemic-modified albumin (IMA) is a product of protein oxidation, and recent evidence suggests that IMA can be used as an indicator of oxidative damage. This study aimed to investigate serum EPO and IMA levels in obsessive-compulsive disorder (OCD) patients and to investigate the relationship between EPO and IMA levels and clinical variables such as disease duration and disease severity. A total of 68 adolescents (11-18 years old), including 35 OCD patients (18 males/17 females) and 33 healthy controls (14 males/19 females) without comorbid disorders matched for age, gender, and BMI, were included in the study. The enzyme-amplified chemiluminescence technique determined serum EPO levels, and serum IMA levels were determined by the spectrophotometric method. Serum EPO levels were lower in OCD patients compared to healthy controls (p = 0.002; Z =  - 3.123), and serum IMA levels (ABSU) were significantly higher in the OCD group (p = 0.005). A significant positive correlation was found between IMA levels and the duration of OCD symptoms (p = 0.015, r = 0.409). The study's findings contribute to the growing body of evidence implicating inflammatory and oxidative processes in the pathogenesis of OCD. The potential of EPO and IMA levels as diagnostic biomarkers for OCD aligns with the ongoing efforts to identify reliable biological markers for the disorder. The positive correlation of IMA levels with the duration of OCD shows the importance of early detection of oxidative damage., (© 2024. The Author(s).)

Background: Autosomal dominant polycystic kidney disease (ADPKD)-related end-stage kidney disease (ESKD) often necessitates transplantation. However, the impact of ADPKD on post-transplant outcomes, specifically hemoglobin levels, remains unknown., Methods: We retrospectively analyzed 513 Kidney Transplant Recipients (KTRs), of whom 81 had ESKD due to ADPKD (20 with pre-transplant native nephrectomy and 61 without). Hemoglobin levels were evaluated at multiple time intervals post-transplant., Results: Kidney transplant recipients with ADPKD vs. KTRs with ESKD due to other causes exhibited significantly higher hemoglobin levels in repeated measurement analysis. Multivariable analyses confirmed ADPKD as an independent predictor for elevated hemoglobin levels. In a multivariable logistic regression analysis, the odds for maximum hemoglobin > 15 mg/dL at 3-12 months post-transplant were more than twice as high in ADPKD patients vs. all the other KTRs (Odds Ratio [OR] 2.31, 95% Confidence Interval [CI] 1.3-4.13, p < 0.001). Pre-transplant native nephrectomy revealed a trend toward lower hemoglobin levels. Elevated hemoglobin levels were linked to improved estimated glomerular filtration rate (eGFR) at one year post-transplant. Patient survival was enhanced among KTRs with ADPKD compared to other ESKD causes., Conclusions: Kidney transplant recipients with ADPKD exhibited elevated hemoglobin levels post-transplant, possibly due to prolonged native kidney erythropoietin production. These elevated hemoglobin levels were linked to improved outcomes, including allograft function and patient survival. Future research should further investigate the underlying mechanisms driving favorable ADPKD KTR outcomes., (© 2024. The Author(s).)

Aims: Patients with type 2 diabetes have a 20% lower total blood volume than age- and weight-matched healthy adults, suggesting a reduced capacity to transport oxygen in this population. Intermittent hypoxia, consisting of alternating short bouts of breathing hypoxic and normoxic air, increases erythropoietin levels, the hormone regulating red blood cell production, in young and older adults. The objective of this study was to determine the effect of a single session of intermittent hypoxia on erythropoietin levels and hemoglobin mass, the absolute mass of hemoglobin contained in red blood cells, in patients with type 2 diabetes., Methods: Ten patients with type 2 diabetes were exposed to an intermittent hypoxia protocol consisting of eight 4-min cycles at a targeted oxygen saturation of 80% interspersed with normoxic cycles to resaturation. Erythropoietin and hemoglobin mass responses to intermittent hypoxia in patients with type 2 diabetes were compared to previously published data from an identical intermittent hypoxia protocol performed in age-matched older adults., Results: Intermittent hypoxia increased erythropoietin levels in older adults but did not induce any change in erythropoietin levels in patients with type 2 diabetes (3.2 ± 2.2 vs. 0.2 ± 2.7 mU/ml, p = 0.01). Hemoglobin mass indexed to body weight was 21% lower in patients with type 2 diabetes than in older adults (8.1 ± 1.7 vs. 10.2 ± 2.1 g/kg, p < 0.01)., Conclusions: These findings suggest an impaired erythropoietin response to decreased oxygen levels in patients with type 2 diabetes, which may contribute to the reduced oxygen transport capacity observed in this population., (© 2024. Springer-Verlag Italia S.r.l., part of Springer Nature.)

Background: The interaction between iron status and malaria is incompletely understood. We evaluated longitudinal changes in iron homeostasis in volunteers enrolled in malaria volunteer infection studies (VIS) and in Malaysian patients with falciparum and vivax malaria., Methods: We retrieved data and samples from 55 participants (19 female) enrolled in malaria VIS, and 171 patients (45 female) with malaria and 30 healthy controls (13 female) enrolled in clinical studies in Malaysia. Ferritin, hepcidin, erythropoietin, and soluble transferrin receptor (sTfR) were measured by ELISA., Findings: In the VIS, participants' parasitaemia was correlated with baseline mean corpuscular volume (MCV), but not iron status (ferritin, hepcidin or sTfR). Ferritin, hepcidin and sTfR all increased during the VIS. Ferritin and hepcidin normalised by day 28, while sTfR remained elevated. In VIS participants, baseline ferritin was associated with post-treatment increases in liver transaminase levels. In Malaysian patients with malaria, hepcidin and ferritin were elevated on admission compared to healthy controls, while sTfR increased following admission. By day 28, hepcidin had normalised; however, ferritin and sTfR both remained elevated., Interpretation: Our findings demonstrate that parasitaemia is associated with an individual's MCV rather than iron status. The persistent elevation in sTfR 4 weeks post-infection in both malaria VIS and clinical malaria may reflect a causal link between malaria and iron deficiency., Funding: National Health and Medical Research Council (Program Grant 1037304, Project Grants 1045156 and 1156809; Investigator Grants 2016792 to BEB, 2016396 to JCM, 2017436 to MJG); US National Institute of Health (R01-AI116472-03); Malaysian Ministry of Health (BP00500420)., Competing Interests: Declaration of interests None of the authors have conflicts of interests to declare., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

The fundamental models underlying hormonal physiological regulation and homeostasis remain poorly understood. We aimed to derive quantitative evidence regarding these models from the study of population data of balance points of different parameters and their respective controlling hormones. We studied the slopes of correlations between concentrations of circulating free thyroxine and thyrotropin, calcium and parathyroid hormone, hemoglobin and erythropoietin, and glucose and insulin in such population data, as well as the slopes of the limbs of various feedback loops estimated empirically and by reverse engineering of the population data. We used computer simulations to model the factors that influence the slopes derived from the population data, and then matched these simulations with the empirically derived slopes. Our simulations showed that changes to the population distribution of feedback loop limbs may alter the slopes of correlations within population data in specific ways. Non-random (interdependent) associations of the limbs of feedback loops may also have this effect, as well as producing discrepancies between the slopes of feedback limb loops determined experimentally and the same slopes determined by derivation from population data. Our corresponding empirical findings were consistent with the presence of such interdependence in the free thyroxine/thyrotropin, hemoglobin/erythropoietin, and glucose/insulin systems. The glucose/insulin data provided evidence consistent with increasing interdependence with age in childhood. Our findings therefore provide strong evidence that the interdependence of the limbs of feedback loops is a general feature of endocrine homeostatic regulation. This interdependence potentially bestows evolutionary homeostatic and regulatory advantages.

The abuse of recombinant erythropoietin (rEPO) and other erythropoietin (EPO) receptor agonists (ERAs) in sports prompted the need for sensitive detection methods of these substances. Dried blood spot (DBS) samples offer an easy solution for simultaneous collection of blood and urine during a doping control, but sensitivity issues are often presented as a challenge for routine EPO analysis from DBS. Its potential use for detecting rEPO micro-doses and the EPO gene c.577del variant thus needed further demonstration. Here, capillary blood collected from the arm skin of 111 athletes with Tasso-M20 (17.5 μL/spot), collected during professional triathlon competitions, were analysed. Also, venous blood samples from healthy volunteers were used to prepare several spots of 20 μL on Mitra VAMS (from an rEPO micro-dose study) and Whatman filter paper (from an EPO gene variant study). Immunopurification of 2 spots with MAIIA EPO Purification Gel Kit and analysis with sodium N-lauroylsarcosinate polyacrylamide gel electrophoresis (SAR-PAGE)/Western blot resulted in sensitive detection of (1) micro-doses of rEPO from Mitra VAMS, (2) endogenous EPO from Tasso-M20 in all in-competition subjects, and (3) the EPO c.577del variant from Whatman filter paper. Additionally, in-competition endogenous EPO was detected in DBS even when matching urine samples had undetectable EPO. In conclusion, this work demonstrated that DBS can be a useful complementary matrix to urine samples for EPO detection., (© 2023 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.)

An absolute erythrocytosis is present when the red cell mass is greater than 125% of the predicted. This is suspected when the hemoglobin or hematocrit is above the normal range. An erythrocytosis can be classified as primary or secondary and congenital or acquired. The commonest primary acquired disorder is polycythemia vera. The diagnostic criteria for PV have evolved over time and this is the main diagnosis managed in hematology clinics. There are a variety of rare congenital causes both primary and secondary. In particular in young patients and/or those with a family history a congenital cause is suspected. There remains a larger cohort with acquired erythrocytosis mainly with non-hematological pathology. In order to explore for a cause of erythrocytosis, measurement of the erythropoietin level is a first step. A low erythropoietin level indicates a primary cause and a normal or elevated level indicates a secondary etiology. Further investigation is then dictated by initial findings and includes mutational testing with PCR and NGS for those in whom a congenital cause is suspected. Following this possibly bone marrow biopsy, scans, and further investigation as indicated by history and initial findings. Investigation is directed toward the identification of those with a hematological disorder which would be best managed following guidelines in hematology clinics and referral elsewhere in those for whom there are non-hematological reasons for the elevated hemoglobin., (© 2024 The Authors. International Journal of Laboratory Hematology published by John Wiley & Sons Ltd.)

Introduction: Disordered iron balance and abnormal parathyroid hormone (PTH) concentrations, both prevalent in hemodialysis patients, are risk factors of erythropoietin (EPO) resistance. Few studies have evaluated the correlation between iron indices and PTH and the potential role of iron markers on the association of PTH with EPO resistance in hemodialysis population., Methods: In this cross-sectional study of 71 maintenance hemodialysis patients, iron indices including hepcidin, ferritin, reticulocyte hemoglobin content (CHr), and transferrin saturation (TSAT) were examined. EPO responsiveness was measured as EPO resistance index (ERI). Lowess regression curves were performed to explore the correlations of iron indices, PTH, and ERI. The association between PTH and ERI was modeled using linear regressions. Potential role of iron indices on this association was examined using stratified analyses and mediation analyses., Results: The average ERI value was 10.3 ± 5.3 IU w-1 kg-1 (g/dL) -1. ERI was correlated to PTH, hepcidin, CHr, and TSAT (all p &lt; 0.05). Hepcidin and PTH were closely correlated with each other (r = 0.28, p = 0.020). Analysis by PTH categories yielded a total association effect of 2.53 (95% CI: 0.27-4.85, p = 0.027) for high PTH subgroup versus the reference low subgroup. No clinically significant interaction between iron indexes and PTH was identified. Hepcidin appeared to mediate about one-third of the total association between PTH and ERI in hemodialysis population (33.6%, p = 0.025)., Conclusion: Iron indices and PTH levels were related to ERI values. Hepcidin appeared to be closely correlated to PTH and partly mediate the association between PTH and ERI in hemodialysis population., (© 2024 S. Karger AG, Basel.)

According to the current treatment recommendations, anagrelide, an oral antiplatelet agent, is recommended as a second-line therapy for patients with high-risk essential thrombocythemia experiencing intolerance or refractoriness to first-line approach, such as hydroxyurea or pegylated interferon alpha-2a. If there is a need for introduction of cytoreductive treatment in young patients with a perspective of lifelong exposure, both the efficacy and long-term outcomes should be known. We present the analysis of 48 young patients, diagnosed with essential thrombocythemia below the age of 60, who were exposed to anagrelide treatment for over 10 years. Our observations show that the highest proportion of complete remissions without adverse events and disease progression is seen in the JAK2-mutated patients. By evaluating the changes in hemoglobin concentration and serum erythropoietin throughout the study, we were able to reveal the development of progressive anemia, resulting from diminished susceptibility to erythropoietin and unrelated to bone marrow fibrosis, in patients harboring CALR mutation. Additionally, occurrence of new bone marrow fibrosis was confirmed in seven JAK2-unmutated patients at the end of the study. In summary, in young patient population, we recommend limiting the use of anagrelide to JAK2-mutated subgroup, reducing exposure time and underline the importance of periodic monitoring for the presence of bone marrow fibrosis., Competing Interests: Competing interests The authors have no relevant financial or non-financial interests to disclose., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Inflammatory states are associated with anemia of chronic disease and acute infection. Hepcidin, a regulator of iron metabolism, is involved in iron pathophysiology during inflammation. We investigated biochemical characteristics in children with anemia from different causes. Four patient groups (n = 38; mean age: 12.44 ± 4.35 years) were studied: (1) inflammatory bowel disease (IBD, 10 patients); (2) iron deficiency anemia (IDA, 12); (3) celiac disease (CD, 8); (4) acute infection (AI, 8). Laboratory measurements were evaluated at diagnosis: blood count, serum iron, transferrin, ferritin, vitamin B 12 , folic acid, CRP, erythropoietin, hepcidin and soluble transferrin receptor (sTfR). IDA patients had the lowest Hgb (6.9 ± 1.7 g/dL), MCV (63.2 ± 7.2 fL), iron (16.8 ± 13.5 µg/dL), ferritin (4.5 ± 4.5 ng/mL) and hepcidin (3.1 ± 0.8 ng/mL) values, and the highest transferrin and sTfR values. AI patients had the highest ferritin (156.2 ± 124.5 ng/mL), CRP (144.6 ± 94 mg/L) and hepcidin (74.67 ± 12.3 ng/ml) values. Overall, hepcidin levels correlated with CRP and with ferritin (r = 0.83 and 0.85, respectively). Elucidating specific etiology-related biochemical profiles in pediatric patients with anemia from different causes using a combination of laboratory biomarkers, including hepcidin, can help physicians treat the anemia., (© 2022. The Author(s).)

We assessed the diagnostic performances of erythropoietin and JAK2 mutations in 1,090 patients with suspected polycythemia who were referred for red cell mass (RCM) measurement. In patients with a high haematocrit and/or haemoglobin level, a low erythropoietin level (<=3·3 mUI/ml) and JAK2 mutation showed comparable positive predictive value (PPV) for true polycythemia (RCM>=125%), 92·1% and 90% respectively. A very-low erythropoietin level (<=1·99 mUI/ml) had a PPV of 100% for polycythemia vera (PV) diagnosis. We confirmed the correlations between RCM, erythropoietin and JAK2 variant allelic frequency in PV patients. This study prompts the need to revisit the role of EPO in PV diagnostic criteria., (© 2021 British Society for Haematology and John Wiley & Sons Ltd.)

This study aims to establish the isolation and purification method of polysaccharides from medicinal residue of Panax notoginseng (PPN). The structure and protective effect of PPN on myelosuppression mice were investigated. One neutral polysaccharide (NPPN) and five acidic polysaccharides (APPN I, APPN II-A, APPN II-B, APPN III-A, and APPN III-B) were obtained. The results confirmed that NPPN, APPN I and APPN II-A are glycan with 1, 4 main chains. APPN III-A is a glycan. APPN II-B and APPN III-B are homogalacturonan pectin with 1, 4 main chains. This study demonstrated that NPPN played a bone marrow protective role in myelosuppression mice induced by cyclophosphamide. NPPN could relieve cell cycle arrest, reduce the apoptosis rate of marrow cells, and improve granulocyte-macrophage colony-stimulating (GM-CSF), thermoplastic polyolefin (TPO) and erythropoietin (EPO) serum level, which contributes to promoting the proliferation of hematopoietic cells., (© 2021 The Authors. Chemistry & Biodiversity published by Wiley-VHCA AG, Zurich, Switzerland.)

The molecular mechanism that regulates iron homeostasis is based on a network of signals, which reflect on the iron requirements of the body. HFE-related hemochromatosis is characterized by excessive intestinal absorption of dietary iron, in particular cases resulting in pathologically high iron storage in tissues and organs. During childhood, HFE gene homozygosity or heterozygosity manifests exclusively in the form of biochemical abnormalities. Because of their mutual link, bioavailable iron and endogenous erythropoietin (EPO) are indispensable for effective erythropoiesis. We analyzed the impact of p.(His63Asp) polymorphism of the HFE gene on erythropoiesis taking into consideration endogenous EPO production in the developmental age. In the study we performed, we observed a significant, strong and negative correlation between the concentration of EPO, hemoglobin, and red blood cell count. A negative trend was also noted on the impact of iron concentration and transferrin saturation on EPO production. In conclusion, this preliminary study demonstrates an impaired impact of endogenous EPO on erythropoiesis in the presence of increased iron content in carriers of p.(His63Asp) (heterozygotes) variant of the HFE gene in developmental age., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abnormally high serum ferritin levels have been reported during pediatric ECMO, attributed to frequent red blood cell transfusion and suggestive of iron overload. However, the utility of ferritin for diagnosing iron overload is complicated by its response as an acute-phase reactant. In this study, we aimed to assess the utility of ferritin for diagnosing ECMO-related iron overload, with secondary aims of understanding its relationship with inflammation and erythropoiesis. Ferritin was elevated in all pediatric ECMO runs (median 459 ng/ml, IQR = 327.3-694.4). While intermittent elevations in serum iron were observed, all normalized prior to decannulation. Unreported previously, erythropoietin (EPO) remained well above normative values prior to and throughout ECMO runs, despite frequent transfusion and exposure to hyperoxia. Ferritin correlated poorly with serum iron [r(80) = 0.05, p = 0.65], but correlated well with IL-6 [r(76) = 0.48, p < 0.001] and EPO [r(81) = 0.55, p < 0.001]. We suggest that serum ferritin is a poor biomarker of iron overload in ECMO patients, and that future investigation into its relationship with EPO is warranted., (Published by Elsevier Inc.)

Introduction: Erythropoiesis stimulating agents (ESAs) represents the principal treatments for anemia in patients with lower-risk myelodysplastic syndromes (MDS). Pre-treatment erythropoietin (EPO) level and previous blood transfusion requirement are the two major predictors for response to ESAs. However, most evidence was derived from Western countries whereas there have been limited data in patients with Asian background., Methods: We retrospectively collected data on patients with low-risk MDS who received ESAs. Erythroid response was evaluated according to IWG 2006 criteria. MDS subtypes, r-IPSS, baseline hemoglobin (Hb), ESAs dosage and erythropoietin level were reviewed from medical records. Gene mutations were analyzed in patients' blood or bone marrow at diagnosis by 40-gene myeloid panel targeted sequencing. Clinical and laboratory parameters were compared between erythroid responder and non-responder groups., Results: A total of 47 patients were recruited in the study. The median age at diagnosis of the patients in this cohort was 77 years (IQR, 70-83) and 44.7% were male. The median revised international prognostic scoring system (R-IPSS) score of patients was 2.5. Response rate to ESAs was 46.8% (22/47). Median EPO level in responders was significantly lower than non-responders (27.7 vs. 59.1 U/L, p=0.02). Median ESAs dosage in responder group was 30,000 units per week. Cytogenetic abnormalities were detected in 27.3% and 24% of the responder and non-responder groups, respectively. Of 22 patients with available 40 gene mutation targeted sequencing, ASXL1, IDH2 and TET2 represented the 3 most common mutations and were found in 22%, 22% and 17%, respectively. There were no differences in cytogenetic abnormalities and gene mutations between groups. Patients who responded to ESAs showed a higher 5-year overall survival (OS) compared to non-responders (5-year OS 75% vs. 60.9%; p=0.008)., Conclusion: We conclude that a low serum EPO level is a predictive factor for responsiveness to ESAs in Asian patients with low-risk MDS.

Athletes abuse recombinant human erythropoietin (rhEPO) and erythropoiesis stimulating agents to increase hemoglobin mass and improve performance. To evade detection, athletes have developed sophisticated blood doping regimens, which often include rhEPO micro-dosing. Detection of these methods requires biomarkers with increased sensitivity and a sample matrix that is more amenable to frequent testing in the field. We have developed a method to measure two immature reticulocyte proteins, CD71 and ferrochelatase (FECH), and one total erythrocyte protein, Band 3, in dried blood spots (DBS). This method was tested in response to rhEPO administration after low doses, 40 IU/kg, micro-doses, 900 IU, or saline injection in 20 healthy subjects. During administration of low-dose rhEPO, the mean CD71/Band 3 and FECH/Band 3 ratio increased by 412 ± 197% and 250 ± 44%, respectively. The mean response for the current biomarker, RET%, increased by 195 ± 35%. During administration of rhEPO micro-doses, CD71/Band 3 increased to 127 ± 25% on day 35 and 139 ± 36% on day 39, while no increase was observed in RET%. After rhEPO administration, during the washout phase, mean values decreased to a minimum of 64 ± 4% and 64 ± 11% for CD71/Band 3 and RET%, respectively. However, CD71/Band 3 remained below 75% of baseline for at least 4 weeks after rhEPO injection, while RET% returned to baseline levels. The results demonstrate that immature reticulocyte proteins have a larger response to rhEPO administration than the current biomarker, RET%, and can be monitored in the DBS matrix., (© 2021 Wiley Periodicals LLC.)

Objective: High serum erythropoietin (EPO) levels have been reported in adult patients with obstructive sleep apnea (OSA), however there is a lack of related literature in children with OSA. The main objective of this study was to explore the potential use of EPO as a pediatric OSA biomarker by exploring the relationship between serum EPO levels and the presence of pediatric OSA., Methods and Materials: A prospective study was conducted on children (4-12 years old) referred for overnight PSG. Thirty (30) consecutive children with mild. 30 consecutives with moderate, and 30 consecutives with severe OSA (OSA group), as well as 30 consecutive children with AHI≤1 (non-OSA group) were recruited. Morning blood specimens after PSG studies were obtained in order to compare EPO levels., Results: Finally, 115 children included for analysis. Non-OSA group consisted of 29 children (mean age: 6.93 ± 2.10) and OSA-group of 86 children (mean age: 6.78 ± 2.53). Mean EPO values for the non-OSA and OSA groups were 5.46 ± 2.29 mIU/ml and 8.33 ± 4.10 mIU/ml respectively. OSA-group had significant higher EPO levels than non-OSA (P: 0.01) while EPO levels were significantly correlated with AHI (p < 0.001)., Conclusion: Our study showed that serum EPO levels of children with OSA are significantly higher than those without OSA and correlate significantly with AHI. These results suggest that EPO may be considered as a biomarker candidate for pediatric OSA. Since this may be the first study on the topic further research is needed., (Copyright © 2021 Elsevier B.V. All rights reserved.)

[Figure: see text].

Previous studies suggested that erythropoietin (EPO) may protect against severe COVID-19-induced injuries, ultimately preventing mortality. This hypothesis is based on the fact that, in addition to promoting the increase in red blood cells, EPO is an anti-inflammatory, anti-apoptotic and protective factor in several non-erythropoietic tissues. Furthermore, EPO promotes nitric oxide production in the hypoxic lung and stimulates ventilation by interacting with the respiratory centers of the brainstem. Given that EPO in the blood is increased at high-altitude, we evaluated the serum levels of EPO in critical patients with COVID-19 at "Hospital Agramont" in the city of El Alto (4150 masl) in Bolivia. A total of 16 patients, 15 men, one woman, with a mean age of 55.8 ± 8.49 years, admitted to the Intensive Care Unit were studied. All patients were permanent residents of El Alto, with no travel history below 3000 masl for at least one year. Blood samples were collected upon admission to the ICU. Serum EPO concentration was assessed using an ELISA kit, and a standard technique determined hemoglobin concentration. Only half of the observed patients survived the disease. Remarkably, fatal cases showed 2.5 times lower serum EPO than survivors (2.78 ± 0.8643 mU/mL vs 7.06 ± 2.713 mU/mL; p = 0.0096), and 1.24 times lower hemoglobin levels (13.96 ± 2.56 g/dL vs 17.41 ± 1.61 g/dL; p = 0.0159). While the number of cases evaluated in this work is low, our findings strongly warrant further investigation of EPO levels in COVID-19 patients at high and low altitudes. Our results also support the hypothesis that exogenous EPO administration could help critically ill COVID-19 patients overcome the disease., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: This study was designed to investigate the mechanism of Dapagliflozin (Dapa) cardioprotection against diabetic cardiomyopathy (DCM). Structural and functional changes in the heart as well as decrease of erythropoietin (EPO) levels were reported in DCM. EPO simultaneously activates three pathways: the Janus-activated kinase-signal transducer and activator of transcription (JAK2/STAT5), phosphatidylinositol-3-kinase-Akt (PI3K/Akt), and extracellular signal-related kinase (ERK/MAPK) cascades, that result in proliferation and differentiation of cardiac cells., Methods and Results: DCM was induced by a high fat diet for 10 weeks followed by administration of streptozotocin. After confirmation of diabetes, rats were divided randomly to 5 groups: Group 1; normal control group, Group 2; untreated diabetic group and Groups (3-5); diabetic groups received Dapa daily (0.75 mg, 1.5 or 3 mg/Kg, p.o) respectively for a month. At the end of the experiment, full anaesthesia was induced in all rats using ether inhalation and ECG was recorded. Blood samples were collected then rats were sacrificed and their heart were dissected out and processed for biochemical and histopathological studies. Untreated diabetic rats showed abnormal ECG pattern, elevation of serum cardiac enzymes, decrease EPO levels, downregulation of P-Akt, P-JAK2 and pMAPK pathways, abnormal histological structure of the heart and increase immunostaining intensity of P53 and TNF α in the cardiomyocytes. Dapa in a dose dependent manner attenuated the alterations in the previously mentioned parameters., Conclusion: The cardioprotective effect of Dapa could be mediated by increasing EPO levels and activation of P-Akt, P-JAK2 and pMAPK signalling cascades which in turn decrease apoptosis., (Copyright © 2021. Published by Elsevier B.V.)

It is hypothesized that major depression disorder (MDD) is associated with impaired neuronal plasticity, and that antidepressant treatments restore neuroplasticity. Brain-derived neurotrophic factor (BDNF) and erythropoietin (Epo) show neurotrophic and neuroprotective effects. We evaluated plasma Epo and BDNF levels in 50 MDD inpatients before treatment and in 50 healthy controls. The MDD inpatients consisted of 20 MDD patients without and 30 MDD patients with a recent suicide attempt. The plasma Epo level was significantly higher in nonsuicidal and suicidal MDD patients than in healthy controls (p ≤ 0.001), while the plasma BDNF level was significantly lower in suicidal MDD than in nonsuicidal MDD patients and healthy controls (p ≤ 0.001). When classifying study participants into low-Epo and high-Epo and low-BDNF and high-BDNF subgroups based on the cutoff of Epo or BDNF calculated using receiver operating characteristics (ROC) curve analysis, logistic regression analysis revealed that high-Epo and low-BDNF status correlated with a respective significant odds ratio of 7.367 (p = 0.015) and 33.123 (p ≤ 0.001) for suicidal MDD. In conclusion, plasma BDNF level was decreased in untreated MDD patients, which was presumed to be a dysfunctional effect of the onset of MDD. However, an increase in plasma Epo was observed in MDD in connection with a recent suicide attempt, indicating that this triggers hypoxic stress to induce a compensatory increase in Epo., (Copyright © 2021 Elsevier Inc. All rights reserved.)

In the 2016 WHO classification, hemoglobin and hematocrit thresholds for diagnosing polycythemia vera (PV) have been lowered, increasing the number of consultations for polycythemia investigations. In PV, beta-2 microglobulin (B2m) levels are reportedly increased, whereas erythropoietin (EPO) levels are usually low. Most secondary polycythemia cases (SP) are caused by tobacco use. We decided to analyze the relevance of these three parameters in all patients seen for polycythemia investigations to help differentiate PV from SP cases. A cohort of 257 patients (123 PV; 134 SP) was identified. The median B2m level was higher for PV patients (3.16 vs 1.98 mg/l, p < 0.0001). Increased B2m levels were observed in 83.7% of PV patients (11.9% in SP). The median EPO level was lower in PV patients (4.4 vs 12.3 UI/l, p < 0.0001). Tobacco was used by 42.8% of SP patients (8% in PV, p < 0.0001). Increased B2m, low EPO and no tobacco exposure was predictive of PV (specificity and positive predictive value = 100%). Normal B2m, normal EPO and tobacco exposure was predictive of SP (positive predictive value = 100%). These simple and inexpensive parameters could be used to rapidly differentiate PV from SP cases, before prescribing time-consuming JAK2 V617F mutation analysis by specialists., (© 2021. Japanese Society of Hematology.)

Introduction: Studies have shown that iron metabolism is affected by coronavirus disease 19 (COVID-19), which has spread worldwide and has become a global health problem. Our study aimed to evaluate the relationship between COVID-19 and serum erythropoietin (EPO), hepcidin, and haptoglobin (Hpt) levels with disease severity, and other biochemical values., Methods: Fifty nine COVID-19 patients hospitalized in the intensive care unit (ICU) and wards in our hospital between March and June 2020 and 19 healthy volunteers were included in the study. Participants were divided into mild, severe, and critical disease severity groups. Group mean values were analyzed with SPSS according to disease severity, mortality, and intubation status., Results: Hemoglobin (Hb) levels were significantly lower in the critical patient group (P < .0001) and deceased group (P < .0001). The red blood cell distribution width-coefficient of variation (RDW-CV) and ferritin values were significantly higher in the intubated (P = .001, P = .005) and deceased (P = .014, P = .003) groups. Ferritin values were positively correlated with disease severity (P < .0001). Serum iron levels were lower in the patient group compared with the reference range. (P < .0001). It was found that the transferrin saturation (TfSat) was lower in the patient group compared with the control group (P < .0001). It was found that the mean EPO of the deceased was lower than the control group and the survived patient group (P = .035). Hepcidin levels were found to be significantly lower in the patient group (P < .0001). Hpt values were found to be significantly lower in the intubated group (P = .004) and the deceased group (P = .042)., Conclusion: In our study, while serum iron and hepcidin levels decreased in patients diagnosed with COVID-19, we found that EPO and Hpt levels were significantly lower in critical and deceased patient groups. Our study is the first study examining EPO and Hpt levels in patients diagnosed with COVID-19., (© 2021 John Wiley & Sons Ltd.)

Background: The mechanisms whereby inhibitors of sodium-glucose linked cotransporter-2 (SGLT2) exert their nephroprotective effects in patients with diabetes are incompletely understood but have been hypothesized to include improved tissue oxygen tension within the renal cortex. The impact of SGLT2 inhibition is likely complex and region specific within the kidney. We hypothesize that SGLT2 inhibitors have differential effects on renal tissue oxygen delivery and consumption in specific regions of the diabetic kidney, including the superficial cortex, containing SGLT2-rich components of proximal tubules, versus the deeper cortex and outer medulla, containing predominantly SGLT1 receptors., Methods: We measured glomerular filtration rate (GFR), microvascular kidney oxygen tension (P k O 2 ), erythropoietin (EPO) mRNA, and reticulocyte count in diabetic rats (streptozotocin) treated with the SGLT2 inhibitor, dapagliflozin. Utilizing phosphorescence quenching by oxygen and an intravascular oxygen sensitive probe (Oxyphor PdG4); we explored the effects of SGLT2 inhibition on P k O 2 in a region-specific manner, in vivo, in diabetic and non-diabetic rats. Superficial renal cortical or deeper cortical and outer medullary P k O 2 were measured utilizing excitations with blue and red light wavelengths, respectively., Results: In diabetic rats treated with dapagliflozin, measurement within the superficial cortex (blue light) demonstrated no change in P k O 2 . By contrast, measurements in the deeper cortex and outer medulla (red light) demonstrated a significant reduction in P k O 2 in dapagliflozin treated diabetic rats (p = 0.014). Consistent with these findings, GFR was decreased, hypoxia-responsive EPO mRNA levels were elevated and reticulocyte counts were increased with SGLT2 inhibition in diabetic rats (p < 0.05 for all)., Conclusions: These findings indicate that microvascular kidney oxygen tension is maintained in the superficial cortex but reduced in deeper cortical and outer medullary tissue, possibly due to the regional impact of SGLT-2 inhibition on tissue metabolism. This reduction in deeper P k O 2 had biological impact as demonstrated by increased renal EPO mRNA levels and circulating reticulocyte count., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

In a two-part process, we assessed elements of the principal hormonal pathway regulating iron homeostasis in human neonates. Part 1: Quantifying erythropoietin (Epo), erythroferrone (ERFE), hepcidin, and relevant serum and erythrocytic iron-related metrics in umbilical cord blood from term (n = 13) and preterm (n = 10) neonates, and from neonates born to mothers with diabetes and obesity (n = 13); Part 2: Quantifying serum Epo, ERFE, and hepcidin before and following darbepoetin administration. Part 1: We measured Epo, ERFE and hepcidin in all cord blood samples. Epo and ERFE levels did not differ between the three groups. Preterm neonates had the lowest hepcidin levels, while neonates born to diabetic women with a very high BMI had the lowest ferritin and RET-He levels. Part 2: Following darbepoetin dosing, ERFE levels generally increased (p < 0.05) and hepcidin levels generally fell (p < 0.05). Our observations suggest that the Epo/ERFE/hepcidin axis is intact in the newborn period., (Copyright © 2021. Published by Elsevier Inc.)

Fetal anemia is common in malaria-endemic areas and a risk factor for anemia as well as mortality during infancy. Placental malaria (PM) and red cell abnormalities have been proposed as possible etiologies, but the relationship between PM and fetal anemia has varied in earlier studies, and the role of red cell abnormalities has not been studied in malaria-endemic areas. In a Tanzanian birth cohort study designed to elucidate the pathogenesis of severe malaria in young infants, we performed a cross-sectional analysis of risk factors for fetal anemia. We determined PM status, newborn red cell abnormalities, and maternal and cord blood levels of iron regulatory proteins, erythropoietin (EPO), cytokines and cytokine receptors. We examined the relationship between these factors and fetal anemia. Fetal anemia was present in 46.2% of the neonates but was not related to PM. Maternal iron deficiency was common (81.6%), most frequent in multigravidae, and interacted with parity to modify risk of fetal anemia, but it was not directly related to risk. Among offspring of iron-deficient women, the odds of fetal anemia increased with fetal α + -thalassemia, as well as these patterns of cord blood cytokines: increased cord IL-6, decreased TNF-RI, and decreased sTfR. The EPO response to fetal anemia was low or absent and EPO levels were significantly decreased in newborns with the most severe anemia. This study from an area of high malaria transmission provides evidence that 1) fetal α + -thalassemia and cytokine balance, but not PM at delivery, are related to fetal anemia; 2) maternal iron deficiency increases the risk that other factors may cause fetal anemia; and 3) fetal anemia has a multifactorial etiology that may require a variety of interventions, although measures that reduce maternal iron deficiency may be generally beneficial., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kabyemela, Fried, Kurtis, Moses, Gorres, Muehlenbachs and Duffy.)

Introduction: Considering the evolving diagnostic criteria of polycythemia vera (PV), we analyzed the utility of serum erythropoietin (EPO) as a predictive marker for differentiating polycythemia vera (PV) from other etiologies of erythrocytosis., Patients and Methods: We conducted a retrospective study after a review of electronical medical records from January 2005 to December 2016 with diagnosis of erythrocytosis using International Classification of Disease-specific codes. To evaluate the diagnostic performance of EPO levels and JAK2-V617F mutation, we constructed a receiver-operated characteristic curve of sensitivity versus 1-specificity for serum EPO levels and JAK2-V617F mutation as predictive markers for differentiating PV from other causes of erythrocytosis., Results: We surveyed 577 patients with erythrocytosis. Median patient age was 59.2 years, 57.72% (n = 329) were male, 86.3% (n = 491) were white, and only 3.3% (n = 19) were African American. A total of 80.88% (n = 351) of those diagnosed with PV had a JAK2-V617F mutation compared to only 1.47% (n = 2) whose primary diagnosis was secondary polycythemia. When comparing JAK2-V617 mutation to the EPO level, the area under the curve of JAK2-V617 (0.8970) was statistically larger than that of EPO test (0.6765). Therefore, the PV diagnostic methodology using JAK2-V617 is better than the EPO test. An EPO level of < 2 mIU/mL was > 99% specific to predict PV but was only 12% sensitive., Conclusion: In the appropriate clinical setting, cytogenetic and molecular studies such as JAK2 mutation status prevail as the most useful tools for PV case identification. The use of isolated EPO to screen patients with erythrocytosis is not a good diagnostic approach., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Aim: To assess the level of erythropoietin (EPO) in blood sera of patients with different subtypes of myelodysplastic syndromes (MDS) from different risk subgroups and to determine its prognostic role., Materials and Methods: EPO was measured by enzyme-linked immunosorbent assay in peripheral blood of 54 patients with different MDS subtypes according to the French-American-British (FAB) classification. The comparison group consisted of 15 healthy individuals. Complete blood count (hemoglobin, leukocyte and platelet levels) was determined and bone marrow cells were characterized morphologically. The overall and leukemia-free survivals were estimated by Kaplan - Meier method., Results: The level of ЕРО in MDS was reliably higher in comparison with healthy persons (p < 0.01, Mann - Whitney test). No statistically significant difference was found in serum EPO concentration between the groups of patients with low- and high-risk MDS (603.5 pg/ml vs 721.0 pg/ml; p > 0.05). In transfusion-dependent patients, the level of EPO was significantly higher than in other patients, which may be due to increased endogenous EPO secretion resulting from chronic hypoxia. A negative correlation was revealed between EPO level and Hb level as well as between EPO level and percentage of blast cells in bone marrow in high-risk MDS patients but not in patients with less aggressive variants of MDS. Instead, patients with low-risk MDS had a negative relationship between concentrations of EPO and tumor necrosis factor alpha (p = 0.06, Kendall's tau test). No significant difference was found between EPO concentration in cases differing by bone marrow cellularity or the presence of cytogenetic abnormalities. An EPO concentration below 200 pg/ml was a predictor of shorter overall survival in patients with all MDS subtypes (p < 0.05, Mann - Whitney test). In patients with all FAB disease subtypes, there was no relationship between the leukemia-free survival and serum EPO concentration., Conclusion: This study shows that lower serum EPO level may be considered as one of the additional adverse prognostic factors in MDS patients.

Background: Myeloproliferative neoplasms (MPNs) such as polycythemia Vera (PV) and Essential Thrombocythemia (ET) can be associated with a high risk of both venous and arterial thrombosis. However, the co-existence between these two complications is very rare and has never been described before, especially in young adults with no known history of MPNs., Case Presentation: We report the case of a 39 year-old Caucasian Moroccan male patient without cardiovascular risk factors (CVRF), who presented with acute chest pain. He also suffered from a severe headache since 2 weeks. Electrocardiogram (ECG) showed ST segment elevation myocardial infarction in the posterolateral leads. Cerebral Computed Tomography (CT) scan revealed subarachnoid hemorrhage (SAH), and cerebral Magnetic Resonance Angiography (MRA) found a Superior Sagittal Sinus Thrombosis (SSST). Routine blood tests showed raised hemoglobin and hematocrit in addition to leukocytosis and thrombocythemia. His coronary angiography revealed a thrombus in the ostial left circumflex artery (LCX). Further testing revealed positive Janus kinase 2 (JAK2) V617F mutation and low erythropoietin level, confirming the diagnosis of PV according to the 2008 World Health Organization (WHO) criteria. Antithrombotic and anti-ischemic treatments, in addition to myelosuppressive therapy with hydroxyurea, were initiated with a good clinical and biological evolution., Conclusion: This case shows that MPNs are an important cause of thrombosis, especially in young patients with no other risk factors. Early diagnosis and appropriate management are fundamental before the occurrence of life-threatening complications that can sometimes present in unusual forms associating arterial and venous thrombotic events.

MYH9 disorders are characterized by giant platelets, thrombocytopenia, and Döhle body-like cytoplasmic inclusion bodies in granulocytes. However, whether these disorders cause any changes in erythroid cells has yet to be determined. This study analyzed the influence of Myh9 R702C, as one of the most commonly detected MYH9 disorders, on erythroid cells in a mouse model. Knock-in mice expressing Myh9 R702C mutation either systemically or specific to hematological cells (R702C and R702C vav1 mice, respectively) were used in this study. Both displayed lower hemoglobin and higher erythropoietin levels than wild-type (WT) mice, along with significant splenomegaly. Flow cytometric analysis revealed erythroblasts present at a higher rate than WT mice in the spleen. However, no obvious abnormalities were seen in erythroid differentiation from megakaryocyte/erythroid progenitor to erythrocyte. Cell culture assay by fetal liver and colony assay also showed normal progression of erythroid differentiation from erythroid burst-forming unit to red blood cell. In conclusion, R702C and R702C vav1 mice displayed erythroid abnormality with splenomegaly. However, erythroid differentiation showed no obvious abnormality. Further research is required to elucidate the underlying mechanisms., Competing Interests: None.

This study evaluated whether recombinant human erythropoietin (rhEpo) treatment combined with chronic hypoxia provided an additive erythropoietic response and whether the athlete biological passport (ABP) sensitivity improved with hypoxia. Two interventions were completed, each containing 4 weeks baseline, 4 weeks exposure at sea level or 2,320 m of altitude, and 4 weeks follow-up. Participants were randomly assigned to 20 IU·kg bw -1 rhEpo or placebo injections every second day for 3 weeks during the exposure period at sea level (rhEpo n = 25, placebo n = 9) or at altitude (rhEpo n = 12, placebo n = 27). Venous blood was analyzed weekly. Combining rhEpo and hypoxia induced larger changes compared with rhEpo or hypoxia alone for [Hb] (p < 0.001 and p > 0.05, respectively), reticulocyte percentage (p < 0.001), and OFF-hr score (p < 0.01 and p < 0.001, respectively). The most pronounced effect was observed for reticulocyte percentage with up to ~35% (p < 0.001) and ~45% (p < 0.001) higher levels compared with rhEpo or hypoxia only, respectively. The ABP sensitivity for the combined treatment was 54 and 35 percentage points higher for [Hb] (p < 0.05) and reticulocyte percentage (p < 0.05), respectively, but similar for OFF-hr score, compared with rhEpo at sea level. Across any time point, [Hb] and OFF-hr score combined identified 14 unique true-positive participants (56%) at sea level and 12 unique true-positive participants (100%) at altitude. However, a concurrent reduction in specificity existed at altitude. In conclusion, rhEpo treatment combined with hypoxic exposure provided an additive erythropoietic response compared with rhEpo or hypoxic exposure alone. Correspondingly, ABP was more sensitive to rhEpo at altitude than at sea level, but a compromised specificity existed with hypoxic exposure., (© 2020 John Wiley & Sons, Ltd.)

To investigate the value of erythrocyte sedimentation rate (ESR) and serum EPO levels in evaluating the condition and prognosis of chronic obstructive pulmonary disease (COPD) in the elderly. 120 elderly patients with acute exacerbation of COPD admitted to our hospital from May 2016 to April 2019 were selected. Pulmonary function tests and CT scans were performed on all patients. According to Gold's guidelines for the diagnosis and treatment of chronic obstructive pulmonary disease, patients with different degrees of illness were divided into mild group, moderate group and severe group. The levels of EPO and ESR were measured in the morning after admission and the differences of EPO and ESR between the three groups were compared. The correlation between EPO, ESR and FEV1% of lung function index was analyzed by linear correlation analysis. There was no significant difference in age, sex, BMI index and course of disease among the three groups (P>0.05); ESR and EPO increased in turn among mild, moderate and severe groups, while FEV1% decreased in turn, with significant differences between the two groups (P<0.05). Negative correlation (r values were - 0.33, - 0.49, P<0.05). ESR and serum EPO levels can reflect the severity of COPD in elderly patients to some extent, and are negatively correlated with FEV1% of lung function indicators, which can provide some clues to the condition and prognosis of COPD in elderly patients.