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Sickle cell diseases (SCD) are the most common genetic disorders with significant morbidity and mortality worldwide, including in India. The high prevalence of this disorder in many geographical regions calls for the use of a point-of-care rapid diagnostic test (RDT) for early screening and management of the diagnosed cases to reduce the allied clinical severity. In view of this, the present study was undertaken for the validation of a point-of-care RDT kit (SICKLECHECKTM) for the screening of SCD. This validation and diagnostic accuracy study was conducted among the cases advised for screening of SCD. For validation, all the recruited cases were investigated for both the SICKLECHECKTM RDT kit and HPLC (Variant-II) considering HPLC as a gold standard. A total of 400 cases were screened for both tests. For the presence and absence of sickle cell hemoglobin in the samples, SICKLECHECKTM RDT kit results showed a sensitivity and specificity of 99.39% and 98.73% respectively with references to HPLC findings. For the detection of the 'AS' pattern, the SICKLECHECKTM RDT kit has shown a sensitivity and specificity of 99.07% and 98.81% respectively. For the detection of the 'SS' pattern, the SICKLECHECKTM RDT kit has shown a sensitivity and specificity of 97.92% and 100.0% respectively. Cases with β thalassemia trait, hemoglobin E trait, hemoglobin Lepore trait and trait for hereditary-persistence-of-fetal-hemoglobin (high HbF %) diagnosed in HPLC were resulted with 'AA' pattern in SICKLECHECKTM RDT kit. The high sensitivity and specificity of the SICKLECHECKTM RDT kit insist on its use as a point-of-care screening tool for SCD especially where there is a lack of laboratory facilities as well as in hospital-based set-up requiring immediate diagnosis and management of SCD. However, for further confirmation, the samples should be analyzed with other gold standard techniques like HPLC., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Purohit et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Primum non nocere! Can iron deficiency, an abnormality that causes anemia, benefit people with sickle cell disease (SCD) who already have an anemia? The published literature we review appears to answer this question in the affirmative: basic science considerations, animal model experiments, and noncontrolled clinical observations all suggest a therapeutic potential of iron restriction in SCD. This is because SCD's clinical manifestations are ultimately attributable to the polymerization of hemoglobin S (HbS), a process strongly influenced by intracellular HbS concentration. Even small decrements in HbS concentration greatly reduce polymerization, and iron deficiency lowers erythrocyte hemoglobin concentration. Thus, iron deficiency could improve SCD by changing its clinical features to those of a more benign anemia (i.e., a condition with fewer or no vaso-occlusive events). We propose that well-designed clinical studies be implemented to definitively determine whether iron restriction is a safe and effective option in SCD. These investigations are particularly timely now that pharmacologic agents are being developed, which may directly reduce red cell hemoglobin concentrations without the need for phlebotomies to deplete total body iron., (© 2024 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

Background: Red blood cell exchange is often used prophylactically in patients with sickle cell disease, with the goal to maintain hemoglobin S (HbS) below a target threshold level. We reviewed whether the daily "rate of rise" (RoR) in HbS that occurs between procedures can be used for patient management. For some patients not achieving their HbS goals despite efficient exchanges, the post-procedure hematocrit (Hct) target is increased to potentially suppress HbS production. This case series explores the utility of this approach, other clinical uses of the daily RoR in HbS, and the factors that influence it., Study Design and Methods: A total of 660 procedures from 24 patients undergoing prophylactic RBC depletion/exchange procedures were included. Laboratory values and clinical parameters were collected and used to calculate the daily RoR in HbS. Factors such as Hct or medications that might influence the RoR in HbS were evaluated., Results: The RoR in HbS varied widely between patients but remained relatively stable within individuals. Surprisingly, this value was not significantly influenced by changes in post-procedure Hct or concurrent hydroxyurea use. A patient's average RoR in HbS effectively predicted the pre-procedure HbS at the following visit (R 2  = 0.65)., Discussion: The RoR in HbS is a relatively consistent parameter for individual patients that is unaffected by medication use or procedural Hct targets and may be useful in determining intervals between procedures., (© 2024 The Authors. Transfusion published by Wiley Periodicals LLC on behalf of AABB.)

Objectives: Newborn screening (NBS) for sickle cell disease (SCD) requires a robust, high-throughput method to detect hemoglobin S (HbS). Screening for SCD is performed by qualitative methods, such as isoelectric focusing (IEF), and both qualitative and quantitative methods such as high performance liquid chromatography (HPLC), capillary electrophoresis (CE), and tandem mass spectrometry (MS/MS). All these methods detect HbS, as well as low-level or absent HbA, and also other variants of hemoglobin. HPLC is considered as a reference method for NBS, because of its high sensitivity and specificity in detecting HbS. NeoSickle ® , a fully automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) platform, combined with automated sample processing, a laboratory information management system and NeoSickle ® software for automatic data interpretation, has increased the throughput of SCD testing. The purpose of this study was to compare the performances of NeoSickle ® and HPLC., Methods: A prospective study was conducted including 9,571 samples from the NBS program to compare MALDI-MS using NeoSickle ® with an HPLC method. Correlation between the two methods was studied. For the MALDI-MS method, sensitivity, specificity, NPV, and PPV were calculated., Results: We found over 99.4 % correlation between the HPLC and MALDI-MS results. NeoSickle ® showed 100 % of sensitivity and specificity in detecting SCD syndrome, leading to positive and negative predictive values of 100 %., Conclusions: NeoSickle ® is adapted to NBS for SCD, and can be used in first-line high-throughput screening to detect HbS, and beta-thalassemia major warning. When HbS is detected, second-line use of another specific method as HPLC is necessary., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)

Sickle cell disease (SCD) is a life-threatening disease requiring reliable early diagnosis. We assessed the acceptability and diagnostic performances of two rapid diagnostic tests (RDTs) to identify SCD (HbSS, HbSC, HbS/β-thalassaemia) or SCD carrier (HbS/HbC) in a pilot SCD newborn screening (NBS) strategy in Mali. All consenting delivering women were offered SCD NBS using cord blood sampling on two RDTs (SickleScan® and HemotypeSC®) compared to the high-performance liquid chromatography (HPLC) gold standard to detect SCD states. From April 2021 to August 2021, 4333 delivering women were eligible of whom 96.1% were offered NBS: 1.6% refused, 13.8% delivered before consenting and 84.6% consented; 3648 newborns were diagnosed by HPLC; 1.64% had SCD (0.63% HbSS, 0.85% HbSC, 0.16 HbS/β-plus-thalassaemia); 21.79% were SCD carrier. To detect accurately SCD, SickleScan® had a sensitivity of 81.67% (95% confidence interval [CI]: 71.88-91.46) and a negative predictive value (NPV) of 99.69% (95% CI: 99.51-99.87); HemotypeSC® had a sensitivity of 78.33% (95% CI: 67.91-88.76) and a NPV of 99.64% (95% CI: 99.44-99.83). To detect SCD carrier: SickleScan® sensitivity was 96.10% (95% CI: 94.75-97.45) and NPV, 98.90% (95% CI: 98.51-99.29); HemotypeSC® sensitivity was 95.22% (95% CI: 93.74-96.70) and NPV, 98.66% (95% CI: 98.24-99.03). Routine SCD NBS was acceptable. Compared with HPLC, both RDTs had reliable diagnostic performances to exclude SCD-free newborns and to identify SCD carriers to be further confirmed. This strategy could be implemented in large-scale NBS programmes., (© 2023 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Background: Sickle cell disease (SCD) is a group of hemoglobinopathies with a common point mutation causing the production of sickle cell hemoglobin (HbS). In high-throughput newborn screening (NBS) for SCD, a two-step procedure is suitable, in which qPCR first pre-selects relevant samples that are differentiated by a second method., Methods: Three NBS centers using qPCR-based primary screening for SCD performed a laboratory comparison. Methods using tandem MS or HPLC were used for differentiation., Results: In a benchmarking test, 450 dried blood samples were analyzed. Samples containing HbS were detected as reliably by qPCR as by methods established for hemoglobinopathy testing. In a two-step screening approach, the 2 nd -tier-analyses have to distinguish the carrier status from pathological variants. In nine months of regular screening, a total of 353,219 samples were analyzed using two-stage NBS procedures. The 1 st -tier screening by qPCR reduced the number of samples for subsequent differentiation by>99.5%. Cases with carrier status or other variants were identified as inconspicuous while 78 cases with SCD were revealed. The derived incidence of 1:4,773, is in good agreement with previously published incidences., Conclusion: In high-throughput NBS for SCD, qPCR is suitable to focus 2 nd -tier analyses on samples containing HbS, while being unaffected by factors such as prematurity or transfusions. The substantial reduction of samples numbers positively impacts resource conservation, sustainability, and cost-effectiveness. No false negative cases came to attention., Competing Interests: The authors declare that they have no conflict of interest., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

A deeper pathophysiologic understanding of available mouse models of sickle cell disease (SCD), such as the Townes model, will help improve preclinical studies. We evaluated groups of Townes mice expressing either normal adult human hemoglobin (HbA), sickle cell trait (HbAS), or SCD (HbS), comparing younger versus older adults, and females versus males. We obtained hematologic parameters in steady-state and hypoxic conditions and evaluated metabolic markers and cytokines from serum. Kidney function was evaluated by measuring the urine protein/creatinine ratio and urine osmolality. In vivo studies included von Frey assay, non-invasive plethysmography, and echocardiography. Histopathological evaluations were performed in lung, liver, spleen, and kidney tissues. HbS mice displayed elevated hemolysis markers and white blood cell counts, with some increases more pronounced in older adults. After extended in vivo hypoxia, hemoglobin, platelet counts, and white blood cell counts decreased significantly in HbS mice, whereas they remained stable in HbA mice. Cytokine analyses showed increased TNF-alpha in HbS mice. Kidney function assays revealed worsened kidney function in HbS mice. The von Frey assay showed a lower threshold to response in the HbS mice than controls, with more noticeable differences in males. Echocardiography in HbS mice suggested left ventricular hypertrophy and dilatation. Plethysmography suggested obstructive lung disease and inflammatory changes in HbS mice. Histopathological studies showed vascular congestion, increased iron deposition, and disruption of normal tissue architecture in HbS mice. These data correlate with clinical manifestations in SCD patients and highlight analyses and groups to be included in preclinical therapeutic studies., (Published by Elsevier Inc.)

Objectives: Heterozygous hemoglobin variants are known to cause method- and variant-specific interference with hemoglobin A1c (HbA1c) quantitation. Less attention has been paid to the role of other hemoglobin variants in confounding HbA1c testing. Here we evaluated the frequency with which enzymatic (ENZ) and immunoassay (IA) HbA1c quantitation methods, i.e., those unable to routinely detect the presence of hemoglobin variants, were used within our healthcare system for HbA1c analysis in patients with elevated fetal hemoglobin as well as compound heterozygous and homozygous variants., Design & Methods: This analysis was enabled by automated review of HbA1c result history, implemented to promote detection of variants prior to HbA1c result reporting., Results: During a 54-week period, 319,290 HbA1c analyses were performed. We observed 110 unique patient cases (0.03% problem identification rate) in which HbA1c testing was ordered in the presence of either a homozygous or compound heterozygous hemoglobin variant or elevated hemoglobin F beyond the tolerance of the method. Among the 110 cases identified, 55 (50%) showed a compound heterozygous or homozygous hemoglobin variant while 55 (50%) showed elevated hemoglobin F. Of those cases involving a compound heterozygous or homozygous variant, 8/55 (15%) involved patients who had one or more ENZ or IA HbA1c results reported previously within our system. Of the 55 total compound heterozygous or homozygous variants identified, 37 (67%) were hemoglobin E, 10 (18%) hemoglobin S/C, 4 (7%) hemoglobin S, 2 (4%) hemoglobin C, 1 (2%) hemoglobin Camden, and 1 (2%) unidentified variant., Conclusions: Exclusive use of methods unable to routinely detect the presence of hemoglobin variants may lead to reporting of HbA1c results that are not clinically meaningful., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Background: Automated red cell exchange (RCE) is a common treatment for patients with sickle cell disease (SCD). Two key parameters are used to determine the volume of blood for RCE to reduce sickle hemoglobin (eg, HbS): fraction of cells remaining (FCR) and target hematocrit. We evaluated how the calculated FCR-using the manufacturer's algorithm-impacted blood utilization and incidence of acute care encounters., Study Design and Methods: Retrospective chart review was conducted of 15 adults with SCD who underwent chronic RCE from July 1, 2015 to August 31, 2019. Blood utilization and acute care encounters were compared across three time periods: (a) when a fixed FCR of 30% was used (12 months); (b) transition period during which physicians made ad hoc changes to the FCR (25 months); (c) algorithm phase when a procedural FCR between 30% and 50% was selected using an algorithm generated by the manufacturer's built-in software to target a HbS fraction of 8% post-procedure (12 months). Wilcoxon signed rank test was used to determine statistical significance., Results: Median blood utilization per procedure decreased from 2398 mL (interquartile range [IQR]: 2271-2759 mL) during the fixed FCR phase to 1887 mL (IQR: 1495-2241 mL) during the algorithm phase (P < 0.001). Similarly, median number of units transfused decreased from 10 (9-11) to 7 (5-9) during the respective phases (P < 0.001). Visits to the emergency department were 1 (0-4) in the fixed FCR phase and 0 (0-3) in the algorithm phase., Conclusion: Algorithm-based selection of a procedural FCR significantly reduced blood utilization (~21%) without appearing to increase acute care encounters., (© 2022 Wiley Periodicals LLC.)

Background and Objectives: Red cell antigen genotyping is commonly performed on patients requiring chronic transfusion support, such as sickle cell disease and thalassaemia. The Immucor HEA BeadChip™ test, in addition to assessing red cell antigen expression, can also detect the haemoglobin S (HbS) mutation. Our aim was to compare HbS results using HEA BeadChip™ performed at the Australian Red Cross Lifeblood with conventional haemoglobin studies., Materials and Methods: Patients with thalassaemia and sickle cell trait (SCT) or disease (SCD) referred for red cell genotyping between 2017 and 2019 were assessed. The HbS result obtained from HEA BeadChip™ was compared with that obtained from high-performance liquid chromatography (HPLC) performed by the referring pathology provider., Results: One-hundred and nineteen cases had comparable HPLC and HEA BeadChip™ results. On HEA BeadChip™ testing, 40 cases showed a negative HbS result, 31 cases showed HbS+ and 47 cases showed HbS++. There was one case with 'low signal' result. Of the negative HbS cases, there was none with SCT. The HbS+ group comprised a mixture of SCT and SCD due to compound heterozygosity for HbS and β-thalassaemia mutations. The HbS++ group comprised predominantly SCD due to homozygosity for HbS., Conclusion: HEA BeadChip™ is an accurate screening test for the detection of HbS. There were no false positives or false negatives. The identification of donors with the HbS mutation through the targeted genotyping programme would enable early intervention, improved donor management and reduced wastage., (© 2022 International Society of Blood Transfusion.)

Background: Blood-brain barrier (BBB) disruption may lead to endothelium dysfunction and inflammation in sickle cell disease (SCD). However, abnormalities of BBB in SCD, especially in pediatric patients for whom contrast agent administration less than optimal, have not been fully characterized., Purpose: To examine BBB permeability to water in a group of pediatric SCD participants using a non-invasive magnetic resonance imaging technique. We hypothesized that SCD participants will have increased BBB permeability., Study Type: Prospective cross-sectional., Population: Twenty-six pediatric participants (10 ± 1 years, 15F/11M) were enrolled, including 21 SCD participants and 5 sickle cell trait (SCT) participants, who were siblings of SCD patients., Field Strength/sequence: 3 T. Water extraction with phase-contrast arterial spin tagging with echo-planer imaging, phase-contrast and T 1 -weighted magnetization-prepared rapid acquisition of gradient echo., Assessment: Water extraction fraction (E), BBB permeability-surface area product (PS), cerebral blood flow, hematological measures (hemoglobin, hematocrit, hemoglobin S), neuropsychological scores (including domains of intellectual ability, attention and executive function, academic achievement and adaptive function, and a composite score). Regions of interest were drawn by Z.L. (6 years of experience)., Statistical Tests: Wilcoxon rank sum test and chi-square test for group comparison of demographics. Multiple linear regression analysis of PS with diagnostic category (SCD or SCT), hematological measures, and neuropsychological scores. A two-tailed P value of 0.05 or less was considered statistically significant., Results: Compared with SCT participants, SCD participants had a significantly higher BBB permeability to water (SCD: 207.0 ± 33.3 mL/100 g/minute, SCT: 171.2 ± 27.2 mL/100 g/minute). SCD participants with typically more severe phenotypes also had a significantly leakier BBB than those with typically milder phenotypes (severe: 217.3 ± 31.7 mL/100 g/minute, mild: 193.3 ± 31.8 mL/100 g/minute). Furthermore, more severe BBB disruption was associated with worse hematological symptoms, including lower hemoglobin concentrations (β = -8.84, 95% confidence interval [CI] [-14.69, -3.00]), lower hematocrits (β = -2.96, 95% CI [-4.84, -1.08]), and higher hemoglobin S fraction (β = 0.77, 95% CI [0.014, 1.53])., Data Conclusion: These findings support a potential role for BBB dysfunction in SCD pathogenesis of ischemic injury., Level of Evidence: 2 TECHNICAL EFFICACY: Stage 2., (© 2021 International Society for Magnetic Resonance in Medicine.)

Alleviating anaemia in patients with sickle cell disease (SCD) is crucial in managing acute complications, mitigating end-organ damage and preventing early mortality. Some disease-modifying and curative therapies have increased haemoglobin (Hb) levels to exceed 100 g/l, a threshold above which complications from red blood cell (RBC) transfusions have occurred, raising concern about whole-blood viscosity-related complications with these therapies. Here we discuss the rationale behind this limit, the effect of viscosity on blood flow and the applicability of this Hb threshold to therapies for SCD beyond RBC transfusions., (© 2021 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Voxelotor is a novel agent in the management of sickle cell disease. It is an inhibitor of Hb S ( HBB : c.20A>T) polymerization that reversibly binds to hemoglobin (Hb), stabilizing it in the oxygenated state that has been shown to reduce hemolysis and to improve anemia. Four patients in our institution are receiving treatment with Voxelotor as part of clinical studies. All four showed a characteristic change in the appearance of Hb S by high performance liquid chromatography (HPLC) soon after commencing treatment. A second peak was identified eluting at the Hb D window. Cellulose acetate membrane and agar gel electrophoresis only identified a band at the Hb S position. The patients' Hb level or clinical conditions were not adversely affected. Our findings indicate that patients receiving Voxelotor invariably display this unique pattern by HPLC. As there will be an increasing number of patients treated with this agent, it is important to be aware of this characteristic HPLC appearance for diagnostic and treatment monitoring purposes.

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

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

Background: Although effectiveness of hydroxyurea (HU) in sickle cell disease is well established, unanswered questions persist about its use in African children. We determined real-life issues of acceptability, availability, and monitoring of HU use in Nigeria., Methods: A retrospective longitudinal review of laboratory data of patients on HU was done from case files, followed by a cross-sectional survey that captured families' perception of medication and clinic adherence, laboratory tests, benefits, side effects, and acceptability., Results: One hundred sixteen patients (1.2-17 years) received HU (mean ± SD = 18.5 ± 4.3 mg/kg/day) in 33 months. Eighty-nine had laboratory analysis. Dose escalation was the initial goal, but only 80% of patients had some form of it. Parents reported improvement in general well-being and reduction in bone pain episodes, hospital admissions, and blood transfusion. While most parents (89.5%) reported satisfaction with HU, 61% reported dissatisfaction with daily drug use, and the frequency and cost of monitoring. Sixteen percent voluntarily stopped therapy. Adherence to daily HU was 88.8%, doctor's appointments 24.5%, hematology tests 18.9%, and organ function tests 37.4%. There were no significant toxicities. Significant increases in hemoglobin, hemoglobin F and mean corpuscular volume, and reduction in absolute neutrophil count occurred despite inconsistent dose escalation., Conclusion: HU (10-15 mg/kg/day starting dose) is safe and seems effective and acceptable to parents. Parental commitment to therapy, pre-HU education (that continues during therapy), provision of affordable HU, and subsidized laboratory tests are important considerations for initiating therapy. Special HU clinics may facilitate dose escalation and reduce frequency of monitoring. Studies are needed on feasibility of maximum tolerable dose HU protocols in sub-Saharan Africa without compromising safety., (© 2021 Wiley Periodicals LLC.)

The majority of the global population of sickle cell disease (SCD) patients resides in Africa. Individuals with this condition are at great risk of serious infections and early mortality secondary to splenic dysfunction without preventative measures. This review investigated the spectrum of splenic complications encountered in SCD among populations in Africa. We systematically searched several databases for all articles published through March 3, 2020. We included 55 studies from 14 African countries. This review reveals the difference in frequency of splenic complications in SCD in Africa when compared with their counterparts in the United State and Europe. While several studies (n = 45) described splenomegaly with a prevalence of 12% to 73% among children, and 4% to 50% among adults with HbSS, the reported prevalence for acute splenic sequestration crisis (n = 6 studies) and hypersplenism (n = 4 studies) was <10% and <5% respectively. A total of 30 surgical splenectomy was reported across eight studies. Only two (3.7%) studies provided data on spleen function. A conflicting pattern was observed amongst studies that evaluated the relationship between splenomegaly and the presence of bacterial and malaria infections. This review reveals the paucity of studies describing the role of SCD-induced splenic dysfunction in morbidity and infection related mortality in Africa., (© 2020 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Sickle cell disease (SCD) is a group of common, life-threatening disorders caused by a point mutation in the β globin gene. Early diagnosis through newborn and early childhood screening, parental education, and preventive treatments are known to reduce mortality. However, the cost and complexity of conventional diagnostic methods limit the feasibility of early diagnosis for SCD in resource-limited areas worldwide. Although several point-of-care tests are commercially available, most are antibody-based tests, which cannot be used in patients who have recently received a blood transfusion. Here, we describe the development of a rapid, low-cost nucleic acid test that uses real-time fluorescence to detect the point mutation encoding hemoglobin S (HbS) in one round of isothermal recombinase polymerase amplification (RPA). When tested with a set of clinical samples from SCD patients and healthy volunteers, our assay demonstrated 100% sensitivity for both the β A globin and β S globin alleles and 94.7 and 97.1% specificities for the β A globin allele and β S globin allele, respectively ( n = 91). Finally, we demonstrate proof-of-concept sample-to-answer genotyping of genomic DNA from capillary blood using an alkaline lysis procedure and direct input of diluted lysate into RPA. The workflow is performed in <30 min at a cost of <$5 USD on a commercially available benchtop fluorimeter and an open-source miniature fluorimeter. This study demonstrates the potential utility of a rapid, sample-to-answer nucleic acid test for SCD that may be implemented near the point of care and could be adapted to other disease-causing point mutations in genomic DNA.

Background: Sickle cell disease (SCD) is a monogenic disorder due to point mutation in the β-globin gene resulting in substitution of Valine for Glutamic acid. The SCD is prevalent in P. falciparum endemic regions such as western Kenya. Carriage of different sickle cell genotypes may influence haematological parameter during malaria. Children resident in malaria holoendemic regions suffer more from malaria-related complications and this is moderated by the presence of the SCD. In the current study, we determined the association between sickle cell genotypes and haematological parameters in children with P. falciparum malaria resident in Kisumu County in Western Kenya., Methodology: Children (n = 217, aged 1-192 months) with acute febrile condition were recruited at Jaramogi Oginga Odinga Teaching and Referral Hospital. Chi-square (χ2) analysis was used to determine differences between proportions. Differences in haematological parameters were compared across groups using Kruskal Wallis test and between groups using Mann Whitney U test. Multivariate logistic regression analysis controlling for infection status was used to determine the association between sickle cell genotypes and haematological parameters., Results: Using HbAA as the reference group, multivariate logistic regression analysis revealed that carriage of HbSS was associated with reduced haemoglobin [OR = 0.310, 95% CI = 0.101-0.956, P = 0.041], reduced haematocrit [OR = 0.318, 95% CI = 0.128-0.793, P = 0.014], reduced RBC count [OR = 0.124, 95% CI = 0.045-0.337, P = 0.001], reduced MCHC [OR = 0.325, 95% CI = 0.118-0.892, P = 0.029], increased leucocytosis [OR = 9.283, 95% CI = 3.167-27.210, P = 0.001] and reduced monocytosis [OR = 0.319, 95% CI = 0.123-0.830, P = 0.019]. However, carriage of HbAS was only associated with increased micro-platelets [OR = 3.629, 95% CI = 1.291-8.276, P = 0.012]., Conclusion: Results show that carriage of HbSS in children influence the levels of haemoglobin, haematocrit, RBC, MCHC, WBC and Monocytes. Therefore prior knowledge of HbSS should be considered to improve clinical management of haematological alterations during malaria in children.

Objectives: Voxelotor was recently approved for use in the United States as a treatment for sickle cell disease (SCD) and has been shown to interfere with the quantitation of hemoglobin (Hb) S percentage. This study aimed to determine the effect of voxelotor on the quantitation of hemoglobin variant levels in patients with multiple SCD genotypes., Methods: In vitro experiments were performed to assess the impact of voxelotor treatment on hemoglobin variant testing. Whole blood samples were incubated with voxelotor and then analyzed by routinely used quantitative and qualitative clinical laboratory methods (high-performance liquid chromatography [HPLC], capillary zone electrophoresis [CZE], and acid and alkaline electrophoresis)., Results: Voxelotor modified the α-globin chain of multiple hemoglobins, including HbA, HbS, HbC, HbD-Punjab, HbE, HbA2, and HbF. These voxelotor-hemoglobin complexes prevented accurate quantitation of multiple hemoglobin species, including HbS, by HPLC and CZE., Conclusions: Technical limitations in quantifying HbS percentage may preclude the use of HPLC or CZE for monitoring patients treated with voxelotor. Furthermore, it is unclear whether HbS-voxelotor complexes are clinically equivalent to HbS. Consensus guidelines for reporting hemoglobin variant percentages for patients taking voxelotor are needed, as these values are necessary for determining the number of RBC units to exchange in acute situations., (© American Society for Clinical Pathology, 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Many hypotheses have been proposed to explain how a glutamate to valine substitution in sickle haemoglobin (HbS) can cause sickle cell disease (SCD). We propose and document a new mechanism in which elevated tyrosine phosphorylation of Band 3 initiates sequelae that cause vaso-occlusion and the symptoms of SCD. In this mechanism, denaturation of HbS and release of heme generate intracellular oxidants which cause inhibition of erythrocyte tyrosine phosphatases, thus permitting constitutive tyrosine phosphorylation of Band 3. This phosphorylation in turn induces dissociation of the spectrin-actin cytoskeleton from the membrane, leading to membrane weakening, discharge of membrane-derived microparticles (which initiate the coagulation cascade) and release of cell-free HbS (which consumes nitric oxide) and activates the endothelium to express adhesion receptors). These processes promote vaso-occlusive events which cause SCD. We further show that inhibitors of Syk tyrosine kinase block Band 3 tyrosine phosphorylation, prevent release of cell-free Hb, inhibit discharge of membrane-derived microparticles, increase sickle cell deformability, reduce sickle cell adhesion to human endothelial cells, and enhance sickle cell flow through microcapillaries. In view of reports that imatinib (a Syk inhibitor) successfully treats symptoms of sickle cell disease, we suggest that Syk tyrosine kinase inhibitors warrant repurposing as potential treatments for SCD., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)

Background: Lipid peroxidation plays a very important role in sickle cell pathophysiology. The formation of malondialdehyde (MDA) in patients with sickle cell disease (SCD) may lead to endothelial dysfunction. Nitric oxide (NO) is a known vasodilator which plays a role in endothelial function. The current study determined the association between MDA and NO metabolites (NOx), trace elements, and antioxidant enzymes (SOD and CAT) in patients with SCD. The ratio of MDA/NOx was also determined as an index of oxidative stress in the study groups., Methods: This was a cross-sectional study involving 90 patients with SCD and 50 "healthy" controls. Blood samples (n = 140) were collected from the study groups. The plasma, sera, and red cells were kept at -20°C for biochemical analyses. Hemoglobin (Hb) and NOx levels were determined in the plasma using Labsystem Multiskan MS and Griess reagent system, respectively. Super oxide dismutase (SOD) and catalase (CAT) levels were determined in the red cells using assay kits from Cayman chemicals. Lipid peroxidation biomarker MDA was determined in the sera using the TBARS assay. Levels of iron (Fe), copper (Cu), and zinc (Zn) were also determined in the sera using Variant 240FS. MDA and NOx ratio was computed for the study groups and compared., Results: Levels of Hb, NOx, SOD, CAT, and Zn were significantly lower in the patients with SCD (P < .001). MDA, Fe, and MDA/ NOx ratio were, however, significantly higher in the patients with SCD (P < .001). There was no significant correlation between MDA and NOx, SOD, CAT, Fe, and Zn in the study groups. MDA, however, correlated positively and significantly with Cu in the HbSS patients with vaso-occlusive crises (VOC). Gender did not affect the levels of oxidative stress markers., Conclusions: Findings from this study suggest a link between lipid peroxidation and Cu in HbSS patients with VOC. Increased MDA/NOx ratio may contribute to sickle cell pathophysiology by promoting oxidative stress., (© 2020 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals, Inc.)

While there is ample evidence suggesting that carriers of heterozygous hemoglobin S and C are protected from life-threatening malaria, little is known about the underlying biochemical mechanisms at the single cell level. Using nanofocused scanning X-ray fluorescence microscopy, we quantify the spatial distribution of individual elements in subcellular compartments, including Fe, S, P, Zn, and Cu, in Plasmodium falciparum -infected ( P. falciparum -infected) erythrocytes carrying the wild type or variant hemoglobins. Our data indicate that heterozygous hemoglobin S and C significantly modulate biochemical reactions in parasitized erythrocytes, such as aberrant hemozoin mineralization and a delay in hemoglobin degradation. The label-free scanning X-ray fluorescence imaging has great potential to quantify the spatial distribution of elements in subcellular compartments of P. falciparum -infected erythrocytes and unravel the biochemical mechanisms underpinning disease and protective traits.

Nearly 7% of the world's population live with a hemoglobin variant. Hemoglobins S, C, and E are the most common and significant hemoglobin variants worldwide. Sickle cell disease, caused by hemoglobin S, is highly prevalent in sub-Saharan Africa and in tribal populations of Central India. Hemoglobin C is common in West Africa, and hemoglobin E is common in Southeast Asia. Screening for significant hemoglobin disorders is not currently feasible in many low-income countries with the high disease burden. Lack of early diagnosis leads to preventable high morbidity and mortality in children born with hemoglobin variants in low-resource settings. Here, we describe HemeChip, the first miniaturized, paper-based, microchip electrophoresis platform for identifying the most common hemoglobin variants easily and affordably at the point-of-care in low-resource settings. HemeChip test works with a drop of blood. HemeChip system guides the user step-by-step through the test procedure with animated on-screen instructions. Hemoglobin identification and quantification is automatically performed, and hemoglobin types and percentages are displayed in an easily understandable, objective way. We show the feasibility and high accuracy of HemeChip via testing 768 subjects by clinical sites in the United States, Central India, sub-Saharan Africa, and Southeast Asia. Validation studies include hemoglobin E testing in Bangkok, Thailand, and hemoglobin S testing in Chhattisgarh, India, and in Kano, Nigeria, where the sickle cell disease burden is the highest in the world. Tests were performed by local users, including healthcare workers and clinical laboratory personnel. Study design, methods, and results are presented according to the Standards for Reporting Diagnostic Accuracy (STARD). HemeChip correctly identified all subjects with hemoglobin S, C, and E variants with 100% sensitivity, and displayed an overall diagnostic accuracy of 98.4% in comparison to reference standard methods. HemeChip is a versatile, mass-producible microchip electrophoresis platform that addresses a major unmet need of decentralized hemoglobin analysis in resource-limited settings.

Objective: To use the spatial distribution of the sickle cell trait (SCT) to analyze the frequency of hemoglobin S (HbS) carriers in Sergipe., Methods: The sample consisted of all individuals born in Sergipe from October 2011 to October 2012 who underwent neonatal screening in the public health system. Tests were carried out in basic health units and forwarded to the University Hospital laboratory, where they were analyzed. We used spatial autocorrelation (Moran's index) to assess the spatial distribution of heterozygous individuals with hemoglobinopathies., Results: Among 32,906 newborns, 1,202 showed other types of hemoglobin besides Hemoglobin A. We found a positive correlation between the percentage of black and multiracial people and the incidence of SCT. Most SCT cases occurred in the cities of Aracaju (n=273; 22.7%), Nossa Senhora do Socorro (n=102; 8.4%), São Cristóvão (n=58; 4.8%), Itabaiana (n=39; 4.2%), Lagarto (n=37; 4.01%), and Estância (n=46; 4.9%)., Conclusions: The spatial distribution analysis identified regions in the state with a high frequency of HbS carriers. This information is important health care planning. This method can be applied to detect other places that need health units to guide and care for sickle cell disease patients and their families.

Background: Sickle cell trait and sickle cell disease are thought to be independent risk factors for CKD, but the trajectory and predictors of kidney function decline in patients with these phenotypes are not well understood., Methods: Our multicenter, observational study used registry data (collected January 2005 through June 2018) and included adult black patients with sickle cell trait or disease (exposures) or normal hemoglobin phenotype (reference) status (ascertained by electrophoresis) and at least 1 year of follow-up and three eGFR values. We used linear mixed models to evaluate the difference in the mean change in eGFR per year., Results: We identified 1251 patients with sickle cell trait, 230 with sickle cell disease, and 8729 reference patients, with a median follow-up of 8 years. After adjustment, eGFR declined significantly faster in patients with sickle cell trait or sickle cell disease compared with reference patients; it also declined significantly faster in patients with sickle cell disease than in patients with sickle cell trait. Male sex, diabetes mellitus, and baseline eGFR ≥90 ml/min per 1.73 m 2 were associated with faster eGFR decline for both phenotypes. In sickle cell trait, low hemoglobin S and elevated hemoglobin A were associated with faster eGFR decline, but elevated hemoglobins F and A 2 were renoprotective., Conclusions: Sickle cell trait and disease are associated with faster eGFR decline in black patients, with faster decline in sickle cell disease. Low hemoglobin S was associated with faster eGFR decline in sickle cell trait but may be confounded by concurrent hemoglobinopathies. Prospective and mechanistic studies are needed to develop best practices to attenuate eGFR decline in such patients., (Copyright © 2020 by the American Society of Nephrology.)

Objectives: Sickle cell anemia is the commonest genetic disorder in India, and the frequency of the sickle cell gene is very high in the remote tribal areas where facilities are generally limited. Therefore, a rapid and affordable point-of-care test for sickle cell disease is needed., Methods: The diagnostic accuracy of HemoTypeSC was evaluated against automated high-performance liquid chromatography (HPLC) as the gold standard for its efficacy in a newborn screening program., Results: A total of 1,559 individuals (980 newborns and 579 adults) from four participating centers were analyzed by both methods. HemoTypeSC correctly identified 209 of 211 total hemoglobin (Hb) SS cases, for a 99.1%/99.9% total HbSS sensitivity/specificity. Overall, HemoTypeSC exhibited sensitivity and specificity of 98.1% and 99.1% for all possible phenotypes (HbAA, HbAS, and HbSS) detected. HPLC is relatively expensive and not available in most laboratories in remote tribal areas., Conclusions: We conclude that the rapid, point-of-care testing device HemoTypeSC test is suitable for population and newborn screening for the HbS phenotype., (© American Society for Clinical Pathology, 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: Angiopoietin-2 (Ang-2) is a multifaceted cytokine that functions in both angiogenesis and inflammation. A proangiogenic state has been found in adults with sickle cell disease (SCD), mainly because of elevated Ang-2 levels. We determined Ang-2 level in 40 children and adolescents with SCD compared with 40 healthy controls and assessed its relation to retinopathy as well as carotid intimamedia thickness (CIMT)., Methods: Hematologic profile, serum ferritin, and serum Ang-2 were measured. CIMT was assessed using high-resolution ultrasound. Fundus examination was performed followed by fundus fluorescein angiography. Optical coherence tomography angiography (OCTA) was used to find small vascular changes not clinically manifested., Results: Ang-2 levels and CIMT were significantly higher in SCD patients compared with controls. The incidence of nonproliferative retinopathy was 45%. SCD patients with retinopathy were older in age with a history of sickling crisis of >3 attacks per year and had a higher incidence of sickle cell anemia than sickle β-thalassemia. Ang-2 cutoff value 9000 pg/mL could significantly detect the presence of retinopathy among SCD patients with 100% sensitivity and specificity. Serum Ang-2 levels were positively correlated with HbS and CIMT. Logistic regression analysis revealed that Ang-2 and HbS significantly contribute to retinopathy among patients with SCD., Conclusions: Elevated Ang-2 highlights the role of angiogenesis in the pathophysiology of SCD and may be considered a promising marker for screening of patients at risk of sickle retinopathy and vascular dysfunction.

Background: Normal saline has been the fluid of choice for resuscitation, rehydration and fluid replacement during plasma or red cell exchange/cytapheresis. There are increased concerns about its clinical effects and data showing it causes more haemolysis in vitro than buffered solutions such as Plasma-Lyte A., Methods: We investigated whether normal saline or Plasma-Lyte A was associated with greater haemolysis during hours of in vitro incubation with both normal red cells and samples from patients with sickle cell anaemia., Results: Sickle red cells haemolysed more than normal red cells did in both crystalloid solutions. The results of 24-hour exposure to saline were particularly striking (median of 163 mg/dl (IQ range 105-247) for sickle red cells vs. 53 (48-92) for normal red cells (P < 0·0001). In patient samples containing variable quantities of haemoglobin S red cells, increased haemoglobin S was associated with increased haemolysis. This effect was greater for normal saline than Plasma-Lyte A (P = 0·12)., Conclusions: These in vitro models demonstrate that short-term ex vivo exposure of sickle red cells to normal saline leads to greater haemolysis than short-term exposure of normal red cells, and this effect is exacerbated by normal saline. Whether use of normal saline causes increased haemolysis in vivo is unknown. Given recent evidence that normal saline increases renal failure and mortality in critically ill patients, further studies are urgently needed., (© 2019 International Society of Blood Transfusion.)

After reacting with hydrogen peroxide (H 2 O 2 ), sickle-cell hemoglobin (HbS, βE6V) remains longer in a highly oxidizing ferryl form (HbFe 4+ =O) and induces irreversible oxidation of "hot-spot" amino acids, including βCys-93. To control the damaging ferryl heme, here we constructed three HbS variants. The first contained a redox-active Tyr in β subunits (F41Y), a substitution present in Hb Mequon; the second contained the Asp (K82D) found in the β cleft of Hb Providence; and the third had both of these β substitutions. Both the single Tyr-41 and Asp-82 constructs lowered the oxygen affinity of HbS but had little or no effects on autoxidation or heme loss kinetics. In the presence of H 2 O 2 , both rHbS βF41Y and βF41Y/K82D enhanced ferryl Hb reduction by providing a pathway for electrons to reduce the heme via the Tyr-41 side chain. MS analysis of βCys-93 revealed moderate inhibition of thiol oxidation in the HbS single F41Y variant and dramatic 3- to 8-fold inhibition of cysteic acid formation in rHbS βK82D and βF41Y/K82D, respectively. Under hypoxia, βK82D and βF41Y/K82D HbS substitutions increased the delay time by ∼250 and 600 s before the onset of polymerization compared with the rHbS control and rHbS βF41Y, respectively. Moreover, at 60 °C, rHbS βK82D exhibited superior structural stability. Asp-82 also enhanced the function of Tyr as a redox-active amino acid in the rHbS βF41Y/K82D variant. We conclude that the βK82D and βF41Y substitutions add significant resistance to oxidative stress and anti-sickling properties to HbS and therefore could be potential genome-editing targets.

Sickle cell disease (SCD) is a common, life-threatening genetic disorder that is best managed when diagnosed early by newborn screening. However, SCD is most prevalent in low-resource regions of the world where newborn screening is rare and diagnosis at the point-of-care is challenging. In many such regions, the majority of affected children die, undiagnosed, before the age of 5 years. A rapid and affordable point-of-care test for SCD is needed. The diagnostic accuracy of HemoTypeSC, a point-of-care immunoassay, for SCD was evaluated in individuals who had SCD, hemoglobin C disease, the related carrier (trait) states, or a normal hemoglobin phenotype. Children and adults participated in low-, medium- and high-resource environments (Ghana [n = 383], Martinique [n = 46], and USA [n = 158]). Paired blood specimens were obtained for HemoTypeSC and a reference diagnostic assay. HemoTypeSC testing was performed at the site of blood collection, and the reference test was performed in a laboratory at each site. In 587 participants, across all study sites, HemoTypeSC had an overall sensitivity of 99.5% and specificity of 99.9% across all hemoglobin phenotypes. The test had 100% sensitivity and specificity for sickle cell anemia. Sensitivity and specificity for detection of normal and trait states were >99%. HemoTypeSC is an inexpensive (<$2 per test), accurate, and rapid point-of-care test that can be used in resource-limited regions with a high prevalence of SCD to provide timely diagnosis and support newborn screening programs., (© 2018 Wiley Periodicals, Inc.)

Purpose: This study aimed to determine the association between sickle cell trait (SCT) as a binary variable and hemoglobin S percentage as a stratified categorical variable with aerobic and anaerobic fitness., Methods: This retrospective cohort study included all recruits who entered US Air Force Basic Training between January 2009 and December 2014. Fitness parameters among recruits with and without SCT were compared using a standardized fitness assessment of a 1.5-mile timed run, 1 min of push-ups, and 1 min of sit-ups. Performance was further compared by stratifying those with SCT by their hemoglobin S percentage (20%-29.99%, 30%-39.99%, and ≥40%)., Results: Of all recruits (N = 210,461) who entered training during the surveillance period, 2161 (1.0%) had SCT. After adjusting for age, sex, race, body mass index, and ambient temperature while conducting the fitness assessment, recruits with SCT were slower on their initial run than their peers without SCT by a mean (standard error) of 9.4 s (2.6 s) (P < 0.001) and completed 0.5 (0.3) fewer push-ups (P < 0.05); sit-up completion was statistically equivalent between the two groups. When retested 6 wk later, recruits with SCT improved their run time by a margin of 4.3 s (2.1 s) over their counterparts without SCT (P < 0.05). Baseline physical fitness was largely consistent across strata of hemoglobin S percentages; increased percentages were modestly correlated with faster run times (R = 0.374) and fewer push-ups (R = 0.339)., Conclusions: As compared with their peers, recruits with SCT had slightly inferior aerobic fitness and similar anaerobic fitness at the outset of basic training, and gaps further narrowed over 6 wk of training. Stratifying recruits by their hemoglobin S percentage did not dramatically change the strength or direction of association.

Background: The main goal of newborn screening (NBS) for sickle cell disease (SCD) is to detect affected neonates so that specific preventive care can be implemented. High-performance liquid chromatography (HPLC) used for NBS has high sensitivity and specificity, but we lack guidelines for quantitative hemoglobin (Hb) fraction interpretation. The purpose of this study was to determine cutoff values to standardize quantitative interpretation in SCD NBS for different clinical situation such as, red blood cell transfusion or beta-thalassemia, which can be real screening pitfalls., Methods: Retrospective study of 75,026 samples from the neonatal screening program analyzed in our laboratory. Precise HbA and HbS percentages at birth were recorded and median values established for each gestational age, allowing percentage results to be expressed in normal gestation-specific multiples of the median (MoM). Three threshold values of clinical interest were determined., Results: High levels of HbA (>2.5 MoM) allowed identification of newborns who received transfusions. Low levels of HbS (≤0.7 MoM) allowed detection of the association between HbS and other mutations of the beta-globin gene (i.e., HbHope, β0-thalassemia, etc.). An HbA/HbS ratio <0.5 to distinguish healthy carriers from SCD with S/β+-thalassemia. The screening accuracy for each threshold was established. The screening accuracy of low-level HbA, which is determinant in identifying the subgroup of patients at risk of β-thalassemia, will be determined prospectively., Conclusions: This new approach introduces tools for a quantitative interpretation in SCD NBS by HPLC methods and could allow standardization of interpretation between centers., (© 2018 Wiley Periodicals, Inc.)

Approximately 3500 children with sickle cell disease (SCD) are born in Brazil each year, but the burden of SCD morbidity is not fully characterised. A large, multi-centre cohort was established to characterise clinical outcomes in the Brazilian SCD population and create the infrastructure to perform genotype-phenotype association studies. Eligible patients were randomly selected from participating sites and recruited at routine visits. A biorepository of blood samples was created and comprehensive demographic and clinical outcome data were entered in a centralized electronic database. Peripheral blood genome-wide single nucleotide polymorphism (SNP) genotyping was performed using a customized Transfusion Medicine (TM) Array. A total of 2795 participants at six Brazilian sites were enrolled between 2013 and 2015. The cohort included slight predominance of children <18 years (55·9%) and females (53·0%). Haemoglobin (Hb) SS was the most common SCD genotype (70·7%), followed by HbSC (23%), Sβ0 (3·0%) and Sβ+ (2·9%). SNP data from the TM Array were analysed to evaluate the genetic ancestry of the cohort and revealed significant admixture among the population. Demographics and clinical complications, stratified by age and SCD genotype, are summarized and future studies in this cohort are discussed., (© 2018 British Society for Haematology and John Wiley & Sons Ltd.)

Background: Pre- and post-transfusion hemoglobin S (HbS) levels are used to document the efficacy of red blood cell exchange (RCE) in patients with sickle cell disease (SCD). In case of urgent RCE a 24/7 short turn-around time (STAT) analysis, with the ability to identify and quantify HbS, is warranted. The use of TOSOH G8 (Tosoh Europe) is evaluated for this purpose, using the variant HbA1c mode., Methods: Analytical performance of the HbS analysis on TOSOH G8 in variant HbA1c mode was evaluated, including assessment of imprecision and linearity for HbS. In addition, a comparison study between TOSOH G8 and Minicap Flex Piercing (FP) system CZE (Sebia) using 32 HbS samples (HbS range: 9%-93%) was carried out to evaluate analytical and clinical concordance., Results: Total HbS imprecision was 1.77% and 0.31% for a sickle cell trait and a sickle cell anemia sample, respectively. An acceptable linearity (HbS range: 6%-88%) was observed (R 2  > .99). Passing-Bablok regression analysis showed a significant proportional bias; however, a good analytical concordance (r > .95) was found. Our results suggested that TOSOH G8 underestimated HbS results compared with those of Minicap FP system (mean difference: -3.54%), especially in samples with a high HbS concentration., Conclusion: Hemoglobin S results obtained with TOSOH G8 in variant HbA1c mode are clinically acceptable to monitor urgent RCE. The observed underestimation will not alter clinical decision-making., (© 2018 Wiley Periodicals, Inc.)

We here report the case of a 18 year old patient with two brothers who died from sickle cell anemia. He had a 5-day history of diffuse bone pain. He had drunk a preparation containing lead to obtain an analgesic effect without improvement. Radiographic examination showed a condensation due to the presence of lead in the digestive tract, associated with aseptic osteonecrosis of the two femoral heads on the X-ray of the pelvis (A) and of the vertebrae in H on the X-ray of the dorso-lumbar spine (B). These signs were suggestive of sickle cell anemia. The diagnosis was confirmed by hemoglobin electrophoresis test showing haemoglobin S at 79%.

Background: A prior practice survey revealed variations in the management of patients with sickle cell disease (SCD) and stressed the need for comprehensive guidelines. Here we discuss: 1) common indications for red blood cell exchange (RCE), 2) options for access, 3) how to prepare the red blood cells (RBCs) to be used for RCE, 4) target hemoglobin (Hb) and/or hematocrit (Hct) and HbS level, 5) RBC depletion/RCE, and 6) some complications that may ensue., Study Design and Methods: Fifteen physicians actively practicing apheresis from 14 institutions representing different areas within the United States discussed how they manage RCE for patients with SCD., Results: Simple transfusion is recommended to treat symptomatic anemia with Hb level of less than 9 g/dL. RCE is indicated to prevent or treat complications arising from the presence of HbS. The most important goals are reduction of HbS while also preventing hyperviscosity. The usual goals are a target HbS level of not more than 30% and Hct level of less than 30%., Conclusion: Although a consensus as to protocol details may not be possible, there are areas of agreement in the management of these patients, for example, that it is optimal to avoid hyperviscosity and iron overload, that a target Hb S level in the range of 30% is generally desirable, and that RCE as an acute treatment for pain crisis in the absence of other acute or chronic conditions is ordinarily discouraged., (© 2018 AABB.)

Objectives: We evaluated the effect of diabetes on sickle hemoglobin (HbS) measurement on two common clinical hemoglobin separation platforms., Methods: We performed a method comparison between the Bio-Rad Variant II high-performance liquid chromatography (HPLC) and Sebia Capillarys 2 Flex Piercing capillary electrophoresis (CE) using clinical specimens from 38 patients without hemoglobin variants and 57 patients with sickle cell trait (AS) (HbA1c%, 4.1%-15.4%). We investigated the effect of intermethod Hb% differences on result interpretation by a panel of expert clinical observers., Results: In diabetic specimens, HPLC undermeasured HbS% up to 7.4% vs CE, due to S1c eluting closely with A0 in HPLC. This increased concern for underlying α-thalassemia in diabetic patients with AS based on HPLC results. HPLC P2% was linearly related to HbA1c% and can be a screen for diabetic AS samples., Conclusions: Glycosylation can interfere with HbS% measurement by HPLC. Susceptible specimens should be identified and preferentially analyzed via CE.

Background: Newborn screening for sickle cell anemia is necessary in Africa where the disease is more frequent. Hemoglobin electrophoresis is used for screening, but is limited by a high cost and difficult access. Sickling test (Emmel test), which is more affordable and technically more accessible, is often requested for prenatal assessment of pregnant women in West African areas to reserve screening for newborns from mothers in whom the positive sickling test attests the presence of hemoglobin S. This study aims to evaluate the number of undetected sickle cell anemia newborns by a screening policy targeting only newborns from mothers in whom a sickling test would have been positive., Methods: From 2010 to 2012, in Bamako, Mali, West Africa, 2489 newborns were routinely screened for sickle cell anemia at the umbilical cord or heel by isoelectrofocusing and, if necessary, by high-performance liquid chromatography. These newborns were born from 2420 mothers whose hemoglobin was studied by isoelectrofocusing. The data was recorded and processed using Excel software version 14.0.0. We calculated the frequency of the sickle cell gene in mothers and newborns as well as the number of SCA newborns from heterozygous or C homozygous mothers., Results: Of the 2489 newborns, 16 had sickle cell anemia (6 SS and 10 SC); 198 had the sickle cell trait; 139 were AC and 1 was CC. Of the 10 newborns with SC profile, 3 were born from mothers not carrying the S gene but the C gene of hemoglobin and in which an Emmel test would have been negative., Conclusion: Targeted newborn screening, based on the results of sickling test in pregnant women, would misdiagnose more than one of six sickle cell anemia newborns who would not benefit from early care. Cost-effectiveness studies of routine newborn screening for sickle cell anemia should lead to a better screening strategy in contexts where hemoglobin S and other hemoglobin defect genes coexist., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Hemoglobinopathies evolved as a protective mechanism against malaria, which exhibit selective advantage in the heterozygous state. However, in a homozygous recessive condition, it poses a serious socioeconomic burden. Sickle cell anemia is an autosomal recessive hemoglobinopathy associated with erythrocytes sickling, vaso-occlusive crisis (VOC), as well as multi-organ failure and death. The coinheritance of other hemoglobinopathies is known to substantially modulate the clinical manifestation of sickle cell anemia. In the present study, we aimed to analyze the coinheritance of β-thalassemia (β-thal) in Hb S (HBB: c.20A>T) patients. The study includes 918 sickle cell anemia patients from 10 ethnic populations of Chhattisgarh State, India. Complete blood counts (CBCs) and hemoglobin (Hb) high performance liquid chromatography (HPLC) fractionation data were collected from patient record books. We observed Hb S-β-thal in all the analyzed populations. Interestingly, high frequencies of Hb S-β-thal have been observed in Satnami (53.8%), Rawat (47.1%), Gond (35.1%) and Panika (30.6%) populations. Inter-population comparison of hematological parameters [Hb F (p < 0.001), Hb A 2 (p < 0.001), Hb (p = 0.03) and red blood cell distribution width (RDW) (p < 0.001)] revealed significant differences. We also observed that mean Hb F levels were significantly higher in Hb S compared to Hb S-β-thal patients in the respective populations. Our study highlights the higher prevalence of β-thal as well as the compound heterozygosity for Hb S and β-thal in various populations of Chhattisgarh State, India.

Background: Hemoglobin S percentages are used in the management of patients who have sickle cell disease. However, hemoglobin S measurements often are not routinely or rapidly performed. Rapid and accurate methods to estimate hemoglobin S levels after simple transfusion may improve the care of patients with sickle cell disease., Study Design and Methods: A comprehensive review of the electronic medical record identified 24 stable patients with sickle cell disease who received simple red blood cell transfusions and had hemoglobin S measurements before and after the transfusion that were less than 72 hours apart. Examination of these patients identified 62 separate transfusions that met our criteria. Three simple equations that utilized complete blood count values and readily available information from the medical record were used to predict the post-transfusion hemoglobin S level after transfusion (Equation 1: predicted post-transfusion hemoglobin = pre-transfusion hemoglobin S × [pre-transfusion hemoglobin/post-transfusion hemoglobin]; Equation 2: predicted post-transfusion hemoglobin S = pre-transfusion hemoglobin S × [pre-transfusion hematocrit/post-transfusion hematocrit]; and Equation 3: predicted post-transfusion hemoglobin S = pre-transfusion hemoglobin S × total pre-transfusion hemoglobin/[total pre-transfusion hemoglobin + (red blood cell volume × 20)])., Results: The predicted hemoglobin S values for all three equations showed a highly significant correlation with the measured post-hemoglobin S value. The coefficient of determination (R 2 ) for Equations 1, 2, and 3 was 0.95, 0.92, and 0.97, respectively. Predicting the post-transfusion hemoglobin S value using estimates of the patient's total hemoglobin and the transfused hemoglobin (Equation 3) was the most precise., Conclusion: Reductions in hemoglobin S values in patients with sickle cell disease who receive simple red blood cell transfusions can be reliably predicted using complete blood cell measurements and simple arithmetic equations., (© 2017 AABB.)

Hemoglobinopathies are a group of hereditary diseases that cause quantitative or qualitative changes in the shape, function or synthesis of hemoglobin. One of the most common is sickle cell anemia, which, due to sickling of erythrocytes, causes vaso-occlusive phenomena. Among the possible ocular manifestations, the most representative is retinopathy, which can lead to blindness if left untreated. Therefore, periodic ophthalmologic monitoring of these patients is important for early diagnosis and adequate therapeutic management, which can be done localy by treating the lesions in the eyes, or systemically.

Mixed donor chimerism after hematopoietic cell transplantation for sickle cell disease (SCD) can result in resolution of disease symptoms, but symptoms recur when donor chimerism is critically low. The relationship between chimerism, hemoglobin S (HbS) level, and symptomatic disease was correlated retrospectively in 95 patients who had chimerism reports available at day 100 and at 1 and 2 years after transplantation. Recurrent disease was defined as recurrence of vaso-occlusive crises, acute chest syndrome, stroke, and/or HbS levels > 50%. Thirty-five patients maintained full donor chimerism (myeloid or whole blood) through 2 years. Donor chimerism was less than 10% (defined as graft failure) in 13 patients during this period. Mixed chimerism was reported in the remaining 47 patients (range, 10% to 94%). The lowest documented donor chimerism without symptomatic disease was 26%. Of 12 surviving patients with recurrent disease, 2 had recurrence of symptoms before documented graft failure (donor chimerism of 11% and 17%, respectively). Three patients underwent second transplantation for graft failure. None received donor leukocyte infusion to maintain mixed chimerism or prevent graft failure. We conclude stable donor chimerism greater than 25% is associated with resolution of SCD-related symptoms, and HbS levels in transplant recipients should be interpreted in context of the sickle trait status of the donors., (Copyright © 2017 The American Society for Blood and Marrow Transplantation. All rights reserved.)

Sickle cell disease poses a public health problem in Senegal. It mainly affects children and adolescents. This study aimed to determine the epidemiological, clinical and hematological profiles of homozygous (SS) sickle cell disease in a cohort of children followed-up at the Peace Hospital in Ziguinchor. We conducted a retrospective study of the medical records from children with sickle cell disease. All patients aged between 2 months and 21 years with sickle cell disease SS during the intercritical period, hospitalized during the study period from 1 st January 2015 to 31 August 2017 were included in our study. Compound heterozygous patients (SC, S Beta Thalassemia) were not included. We collected 46 medical records of patients with sickle cell disease SS (20 girls and 26 boys). The average age of children was 8,0 years [11 months-21 years]. Approximately 1/3 of children (39.1%) had an age less than or equal to 5 years. There was an ethnic diversity showing a predominance of the Diola (30.2%) followed by the Mandinga (27.9%) and the Poular (25.6%). The average age of children with first crisis was 35,5 months [7-192 months]. More than 1/3 of children (41.3%) had had first crisis before their second anniversary. In the child, first crisis was dominated by vaso-occlusive crisis (32.6%) followed by hand-foot syndrome (30.4%). Clinical signs during the intercritical period were pallor 95.6%), jaundice (36.9%) and splenomegaly (21.7%). Mean white blood cell count was 12465 leucocytes/mm 3 [5340-26900]. Hyperleukocytosis greater than 10 000 leucocytes/mm 3 was found in 34 patients (73.9%). All patients had anemia with an average hemoglobin of 08,6 g/dl [05,7-11,8]. Hemoglobin S rate ranged between 54.6 and 98.4%. Diagnosis and medical management of sickle cell disease SS are delayed in Ziguinchor. Neonatal screening may lead to improve early management of patients in the region.