Osteopenia and Osteoporosis Assessed by Dual X Absorptiometry in Sickle Cell Anemia Adults Subjects

Background: Sickle cell anemia is the most common genetic disease in sub-Saharan Africa. It is an inherited autosomal recessive disorder characterized by chronic hemolysis secondary to falciformation of red blood cells, also responsible of ischemia, bone infarction and accompanied by serious infections and organic lesions.Normal for weight at birth, Sickle cell anemia subjects have low pre puberty growth compared to normal children and also have compromised bone remodeling balance which results in decrease of bone mass and increase of bone fragility. Several studies have established that 37% to 50% of SCA patients were osteopenic or osteoporotic. This study aims to confirm the existence of bone remodeling disorders with osteoporotic translation and to compare the values found in Congolese sickle cell adults subjects to the general population.Methods: Spine and hip DXA were conducted on 270 SS homozygotes aged 18 to 50 years (121 men and 149 women) and 359 AA homozygotes as controls (138 men and 221 women), aged from 18 to 50 years old, who agreed to participate in the study, considered as a control group. AS heterozygotes were not included in the study.Results: AA subjects shows higher density (BMD) and Bone mineral content (BMC) values. Both SCA and AA controls showed the characteristic curve with peak bone mass at the fourth decade of life, followed by a decay with age. The difference in BMD and BMC with the control population ranged from 7.94% to 26.34% (average of 16.02%) which means -0.8 to -2.7 standard deviations, whereas, compared to the T -score in the Congolese population, was 11.6% to 22.15% less (average of -17.5%) equivalent of -0.9 to -2 standard deviations.The overall decrease in bone mass rate for -2.5 DS of the T-score was: -28.4% and 33.2% for -2 DS of T-score.Conclusion: SCA subjects shows high rate of osteopenia and osteoporosis and are more likely at risk for fractures.

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Is there a role for selective vasodilation in the management of sickle cell disease?

Blood ◽

10.1182/blood.v71.3.597.597 ◽

1988 ◽

Vol 71 (3) ◽

pp. 597-602 ◽

Cited By ~ 18

Author(s):

GP Rodgers ◽

MS Roy ◽

CT Noguchi ◽

AN Schechter

Keyword(s):

Blood Flow ◽

Steady State ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Microvascular Obstruction ◽

Controlled Study ◽

Control Group ◽

Cell Disease ◽

Retinal Arteriolar

Abstract To test the hypothesis that microvascular obstruction to blood flow at the level of the arteriole may be significant in individuals with sickle cell anemia, the ophthalmologic effects of orally administered nifedipine were monitored in 11 steady-state patients. Three patients with evidence of acute peripheral retinal arteriolar occlusion displayed a prompt reperfusion of the involved segment. Two other patients showed fading of retroequatorial red retinal lesions. Color vision performance was improved in six of the nine patients tested. The majority of patients also demonstrated a significant decrease in the amount of blanching of the conjunctiva which reflects improved blood flow to this frequently involved area. Such improvements were not observable in a control group of untreated stable sickle cell subjects. These findings support the hypothesis that inappropriate vasoconstriction or frank vasospasm may be a significant factor in the pathogenesis of the microvascular lesions of sickle cell disease and, further, that selective microvascular entrapment inhibition may offer an additional strategy to the management of this disorder. We believe a larger, placebo-controlled study with nifedipine and similar agents is warranted.

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Primary Hyperparathyroidism in Homozygous Sickle Cell Patients: A Hemolysis-Mediated Hypocalciuric Hypercalcemia Phenotype?

Journal of Clinical Medicine ◽

10.3390/jcm10215179 ◽

2021 ◽

Vol 10 (21) ◽

pp. 5179

Author(s):

Edmat Akhtar Khan ◽

Lynda Cheddani ◽

Camille Saint-Jacques ◽

Rosa Vargas-Poussou ◽

Vincent Frochot ◽

...

Keyword(s):

Primary Hyperparathyroidism ◽

Sickle Cell ◽

Fractional Excretion ◽

Urinary Calcium ◽

High Rate ◽

Calcium Handling ◽

Control Group ◽

Calcium Excretion ◽

Calcium Reabsorption ◽

Chronic Hemolysis

Primary hyperparathyroidism (pHPT) has been reported to have a higher prevalence in sickle cell disease (SCD) patients, including a high rate of recurrence following surgery. However, most patients are asymptomatic at the time of diagnosis, with surprisingly infrequent hypercalciuria, raising the issue of renal calcium handling in SCD patients. We conducted a retrospective study including (1) 64 hypercalcemic pHPT non-SCD patients; (2) 177 SCD patients, divided into two groups of 12 hypercalcemic pHPT and 165 non-pHPT; (3) eight patients with a diagnosis of familial hypocalciuric hypercalcemia (FHH). Demographic and biological parameters at the time of diagnosis were collected and compared between the different groups. Determinants of fasting fractional excretion of calcium (FeCa2+) were also analyzed in non-pHPT SCD patients. Compared to non-SCD pHPT patients, our data show a similar ionized calcium and PTH concentration, with a lower plasmatic calcitriol concentration and a lower daily urinary calcium excretion in pHPT SCD patients (p < 0.0001 in both cases). Fasting FeCa2+ is also surprisingly low in pHPT SCD patients, and thus inadequate to be considered hypercalcemia, recalling the FHH phenotype. FeCa2+ is also low in the non-pHPT SCD control group, and negatively associated with PTH and hemolytic biomarkers such as LDH and low hemoglobin. Our data suggest that the pHPT biochemical phenotype in SCD patients resembles the FHH phenotype, and the fasting FeCa2+ association with chronic hemolysis biomarkers strengthens the view of a potential pharmacological link between hemolytic by-products and calcium reabsorption, potentially through a decreased calcium-sensing receptor (CaSR) activity.

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Up-Regulation of Mir-21 and Mir-130a and Serum Leptin Levels on Leg Ulcers Development in Sickle Cell Anemia

Blood ◽

10.1182/blood-2019-132043 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 975-975

Author(s):

Thais Helena Chaves Batista ◽

Rodrigo Marcionilo Santana ◽

Marcondes José de Vasconcelos Costa Sobreira ◽

Gabriela da Silva Arcanjo ◽

Diego Arruda Falcao ◽

...

Keyword(s):

Sickle Cell ◽

Sickle Cell Anemia ◽

Leg Ulcer ◽

Acute Chest Syndrome ◽

Control Group ◽

Blood Collection ◽

Leg Ulcers ◽

Serum Leptin ◽

Ulcer Group ◽

And Control

Introduction: Leg ulcers (LUs) are a cutaneous complication of sickle cell anemia (SCA), whose etiology is considered multifactorial. In the search for new candidates for modulators of SCA clinical events, recent evidence suggests the significant role of mechanisms related to post-transcriptional regulation, especially microRNAs (miRNAs). Thus, the analysis of miRNAs miR-21 and miR-130a differential expression in patients with SCA becomes an interesting approach, since both act in the regulation of several biological mechanisms related to the pathophysiology of LU, especially the tissue repair process. In addition, these miRNAs have already been related to the regulation of serum leptin levels, a strong angiogenic pleiotropic hormone that acts in the healing process of skin lesions. Therefore, the aim of the study was to investigate the influence of miR-21 and miR-130a and serum leptin levels on the development of LUs in SCA patients. Methods: After analyzing medical records, 60 SCA patients were selected. Patients who presented some of the main clinical manifestations that may have etiology due to the underlying disease (for example: osteonecrosis, stroke, priapism and acute chest syndrome) were not included. Patients with a history of LU were considered cases, and those who did not develop this complication (n=20), were considered control (median age: 26 years, range: 19-61, 50% males). The control group was called "HbSS-Control" and the case group was divided into two subgroups: Active leg ulcer group, composed of 19 patients with active LU at the time of blood collection (median age: 35 years, range: 24-56, 68% males), and healed leg ulcer group, composed of 21 patients with healed LU at the time of blood collection (median age: 34 years, range: 22-52, 43% males). In addition, it was analyzed a group of 10 donors with normal hemoglobin profile (median age: 25 years, range: 20-30, 50% males), identified as "HbAA-Control". Expression levels of miRNAs extracted from peripheral blood, using mirVanaTM PARIS Kit (Invitrogen™) were evaluated by RT-qPCR technique utilizing TaqMan® probes. Serum leptin levels of the patients were evaluated employing the ELISA method (Human Leptin ELISA Kit, Millipore®). Mann-Whitney and Kruskal-Wallis tests were applied to compare continuous variables. Results: Up-regulation of both miRNAs was observed in the active leg ulcer group in contrast to the healed leg ulcer (miR-21: P<0.0001, Figure 1A, Fold change [FC]=14,2; miR-130a: P=0.0004, FC=18,8, Figure 1B) and Control-HbSS groups (miR-21: P<0.0001, FC=34,4, Figure 1A; miR-130a: P=0.0006, FC=15,3, Figure 1B) and the HbAA-Control group (miR-21: P<0.0001, FC=5,8, Figure 1C; miR-130a: P=0.0009, FC=10,9, Figure 1D). However, there was no significant difference between the healed leg ulcer, HbSS-Control and HbAA-Control groups (miR-21: P=0.1829, Figure 1E; miR-130a: P=0.3537; Figure 1F). Furthermore, the active leg ulcer group had lower serum leptin levels when compared to the healed leg ulcer and Control-HbSS groups (P=0.0058; Figure 2A). The levels of leptin in the healed leg ulcer group did not differ from the Control-HbSS group (P=0.5929; Figure 2B). Conclusion: Our results demonstrated an inverse relation between the miRNAs miR-21 and miR-130a expression with serum leptin levels, suggesting that the up-regulation of these miRNAS may be related to the chronicity and healing of LUs in individuals with SCA through decreased of serum leptin levels. Disclosures No relevant conflicts of interest to declare.

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Splenomegaly in Children with Sickle Cell Anemia Receiving Hydroxyurea in Sub-Saharan Africa

Blood ◽

10.1182/blood-2019-129937 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 993-993

Author(s):

Leon Tshilolo ◽

George A. Tomlinson ◽

Patrick T. McGann ◽

Teresa S. Latham ◽

Peter Olupot-Olupot ◽

...

Keyword(s):

Board Of Directors ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Growth Parameters ◽

Sub Saharan Africa ◽

Advisory Committees ◽

Splenic Enlargement ◽

Hydroxyurea Treatment ◽

Lower Blood ◽

Sub Saharan

Introduction. Children with sickle cell anemia enrolled in Realizing Effectiveness Across Continents with Hydroxyurea (REACH, NCT01966731) received open-label hydroxyurea at maximum tolerated dose (MTD) in four countries within sub-Saharan Africa (Tshilolo et al, NEJM 2019;380:121-131). Unlike children in the United States or Europe, a substantial proportion of REACH participants had splenomegaly at enrollment, and more developed splenomegaly while receiving hydroxyurea. Splenic enlargement in association with hydroxyurea treatment in sub-Saharan Africa is previously unrecognized, and its causes and consequences remain unclear. Methods. Palpable splenomegaly was evaluated at both the mid-clavicular and mid-axillary lines at each scheduled and unscheduled sick visit. The size of the spleen, defined as the greatest distance (cm) below the subcostal margin, was recorded in the REDCap trial database at all four clinical sites. Cross-sectional analysis was performed at baseline enrollment using four spleen categories (Not Palpable, 1-4 cm, ≥5 cm, or Splenectomy) with correlations for age, sex, site, growth parameters, alpha-thalassemia trait and G6PD deficiency. This analysis was repeated using the largest spleen size over the first two years on hydroxyurea, but examining two-year laboratory values and also the hydroxyurea dose at MTD, time to MTD, dose-limiting toxicities, and clinical outcomes including acute splenic sequestration, malaria infections, and sepsis. Results. A total of 606 children started hydroxyurea study treatment, including 6 (1.0%) with previous splenectomy, 59 (9.7%) with previous splenic sequestration, and 99 (16.3%) with palpable splenomegaly at enrollment (52 children with 1-4 cm and 47 with ≥5 cm). Large spleens (≥5 cm) were commonly observed at baseline at all clinical sites except Uganda, which identified only 1 child. Compared to those with no palpable spleen, children with large spleens at baseline had similar age and growth parameters, but were significantly more likely to have alpha-thalassemia (78.7% versus 56.2%, P=0.004) and also G6PD deficiency among males (28.0% versus 17.6%, P=0.32). Children with large spleens at enrollment also had a lower hemoglobin (Hb = 6.5 versus 7.3 g/dL, P<0.001) and lower platelet count (platelets = 227 versus 410 x 109/L, P<0.001), but equivalent fetal hemoglobin (HbF = 10.2 versus 9.4%, P=0.82). On hydroxyurea treatment with escalation to MTD, 262 children (43.7%) had palpable splenomegaly recorded, including 120 (20.0%) with spleens ≥5 cm. These large spleens were observed at all four clinical sites, with DRC having the most (52) and Uganda with the least (14). After 24 months of hydroxyurea treatment, laboratory differences were noted according to the cumulative occurrence of splenomegaly including a significantly lower hemoglobin and platelet count, higher absolute reticulocyte count, and lower hydroxyurea dose at MTD (Table). Large spleens were associated with a high cumulative incidence of laboratory dose-limiting toxicities, as well as a significantly higher risk of having clinically symptomatic malaria and receiving blood transfusions (Table). A total of 31 children (5.2%) on hydroxyurea treatment received elective splenectomy, including one partial splenectomy using arterial embolization. Conclusion. Children with sickle cell anemia living in sub-Saharan Africa have an increased risk of having palpable splenomegaly, which is further increased while receiving hydroxyurea treatment. Large spleen at baseline were associated with lower blood counts, consistent with hypersplenism. On hydroxyurea treatment, children with large spleens had significantly lower blood counts and more dose-limiting toxicities, which lowered their eventual hydroxyurea dose at MTD but still led to robust HbF responses. Children with large spleens were also at higher risk of developing malaria infections, receiving transfusions, and requiring surgical splenectomy. Splenic enlargement in association with hydroxyurea treatment was common in children with sickle cell anemia in the REACH trial; its cause remains unclear but the consequences include substantial laboratory toxicity and clinical morbidity. Investigating the etiologies and management of children with chronically enlarged spleens is crucial before expanding hydroxyurea access across Africa for sickle cell anemia. Disclosures Ware: Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Other: Research Drug Donation; Nova Laboratories: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Novartis: Other: DSMB; Agios: Membership on an entity's Board of Directors or advisory committees; Addmedica: Other: Research Drug Donation.

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Exercise-induced hemolysis in sickle cell anemia: shear sensitivity and erythrocyte dehydration

Blood ◽

10.1182/blood.v59.5.1055.1055 ◽

1982 ◽

Vol 59 (5) ◽

pp. 1055-1060 ◽

Cited By ~ 8

Author(s):

OS Platt

Keyword(s):

Sickle Cell ◽

Sickle Cell Anemia ◽

Control Group ◽

Shear Forces ◽

Vigorous Exercise ◽

Shear Rates ◽

Small Vessels ◽

Shear Sensitivity ◽

Chronic Hemolysis ◽

Exercise Induced

Abstract We describe a steady-state patient with sickle cell anemia (SS disease) who developed sporadic hemoglobinuria, historically related to vigorous exercise. We studied him and four other patients with SS disease and demonstrated exercise-induced hemoglobinemia. To see if SS erythrocytes were abnormally fragile when exposed to shear forces that could be generated in small vessels of exercising muscles, we exposed them to physiologic shear rates in a cone-plate viscometer. We show that SS erythrocytes are more shear sensitive than normal erythrocytes. This phenomenon is directly related to the presence of dehydrated cells as demonstrated by the increasing shear sensitivity of increasingly dehydrated cells separated on Stractan density gradients. Normal shear sensitivity could be restored to dehydrated layers by restoring normal hydration. Restoration of shear stability was complete in all layers except for the most dense ISC layer. A control group of patients with SC disease exhibited no exercise-induced hemoglobinemia, no abnormal shear sensitivity of whole blood, and only rare dehydrated ISCs. These studies suggest that the exercise-induced hemolysis in SS patients is related to the lysis of dehydrated, shear-sensitive cells. This same process may also contribute to the chronic hemolysis of SS disease--a phenomenon known to correlate with the numbers of dehydrated ISCs.

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Optimizing hydroxyurea therapy for sickle cell anemia

Hematology ◽

10.1182/asheducation-2015.1.436 ◽

2015 ◽

Vol 2015 (1) ◽

pp. 436-443 ◽

Cited By ~ 19

Author(s):

Russell E. Ware

Keyword(s):

Sickle Cell ◽

Sickle Cell Anemia ◽

Fetal Hemoglobin ◽

Maximum Tolerated Dose ◽

Sub Saharan Africa ◽

Future Research ◽

Published Evidence ◽

Treatment Indications ◽

Hydroxyurea Treatment ◽

Hydroxyurea Therapy

Abstract Hydroxyurea has proven efficacy in numerous clinical trials as a disease-modifying treatment for patients with sickle cell anemia (SCA) but is currently under-used in clinical practice. To improve the effectiveness of hydroxyurea therapy, efforts should be directed toward broadening the clinical treatment indications, optimizing the daily dosage, and emphasizing the benefits of early and extended treatment. Here, various issues related to hydroxyurea treatment are discussed, focusing on both published evidence and clinical experience. Specific guidance is provided regarding important but potentially unfamiliar aspects of hydroxyurea treatment for SCA, such as escalating to maximum tolerated dose, treating in the setting of cerebrovascular disease, switching from chronic transfusions to hydroxyurea, and using serial phlebotomy to alleviate iron overload. Future research directions to optimize hydroxyurea therapy are also discussed, including personalized dosing based on pharmacokinetic modeling, prediction of fetal hemoglobin responses based on pharmacogenomics, and the risks and benefits of hydroxyurea for non-SCA genotypes and during pregnancy/lactation. Another critical initiative is the introduction of hydroxyurea safely and effectively into global regions that have a high disease burden of SCA but limited resources, such as sub-Saharan Africa, the Caribbean, and India. Final considerations emphasize the long-term goal of optimizing hydroxyurea therapy, which is to help treatment become accepted as standard of care for all patients with SCA.

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Evaluation of Hearing and Balance Functions of Patients with Sickle Cell Anemia

Audiology and Neurotology ◽

10.1159/000492171 ◽

2018 ◽

Vol 23 (2) ◽

pp. 122-125 ◽

Cited By ~ 2

Author(s):

Elif Tugba Sarac ◽

Bilgehan Boke ◽

Semsettin Okuyucu

Keyword(s):

Hearing Loss ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Pure Tone ◽

Mixed Type ◽

Normal Hearing ◽

Spontaneous Nystagmus ◽

Control Group ◽

Hearing Thresholds ◽

Significant Difference

Introduction: Sickle cell anemia is a disease characterized by a wide vaso-occlusive incident from micro-vascular incident to muscularactivity. The cochlear function can also get affected by this vaso-occlusion. Objective: It is aimed at determining what kind of effects sickle cell anemia has on hearing and balance system. Methods: This study has been conducted on 46 patients with sickle cell anemia and 45 healthy individuals. For all participants, their pure tone hearing thresholds and videonystagmography (VNG) findings have been determined in 17 frequencies between 125–16.000 Hz. Results: All hearing thresholds between 125 and 16,000 Hz, pure tone averages of patients with sickle cell anemia have been found statistically significant to be higher than the corresponding values in the control group(p < 0.05). The normal hearing rate of patients with sickle cell anemia has been determined to be 71.1% conductive hearing loss (CHL) to be 4.4%, sensorineural hearing loss (SNHL) to be 22.2%, and mixed type hearing loss to be 2.2% in right ear; the normal hearing rate has been determined to be 71.1%, CHL to be 2.2%, SNHL to be 22.2%, and mixed type hearing loss to be 4.4% in left ear. Statistically significant difference has not been found between head shake, spontaneous nystagmus, optokinetic, tracking test batteries, static and dynamic positional tests used in VNG, saccade accuracy and saccade peak velocity, which are saccadic test findings of 2 groups. However, saccadic latency, which is a saccadic test finding, has been determined to be longer in patients with sickle cell anemia in comparison to the control group. Conclusion: While sickle cell anemia causes hearing deficits, it does not have any effect on the central or peripheral vestibular system.

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Evaluation of the concentration of malondialdehyde and nitrite in patients with sickle cell anemia treated or not with hydroxyurea

Einstein (São Paulo) ◽

10.1590/s1679-45082010ao1731 ◽

2010 ◽

Vol 8 (4) ◽

pp. 414-418 ◽

Cited By ~ 6

Author(s):

Darcielle Bruna Dias Elias ◽

Rivelilson Mendes de Freitas ◽

Romélia Pinheiro Gonçalves ◽

Hemerson Yuri Ferreira Magalhães ◽

Jacqueline Holanda de Sousa ◽

...

Keyword(s):

Sickle Cell ◽

Sickle Cell Anemia ◽

Serum Levels ◽

The Other ◽

Control Group ◽

Clinical Variables ◽

Short Period ◽

Significant Difference ◽

Group 2 ◽

Group 1

ABSTRACT Objective: To determine the serum levels of malondialdehyde and nitrite in patients with sickle cell anemia treated or not with hydroxyurea in outpatient's setting. Methods: Of the 65 patients with sickle cell anemia selected for the study, 51 were not treated with hydroxyurea (Group 1), 14 made chronic use of hydroxyurea (Group 2) and 20 individuals had no hemoglobinopathies (Control Group). Results: The Control Group had a lower and more homogeneous concentration of malondialdehyde levels as compared to the other groups. The results of Groups 1 and 2 showed increased values of malondialdehyde levels when compared to the Control Group. Considering the values of Groups 1 and 2, there were no significant changes in the malondialdehyde levels. There was no significant difference in the serum levels of nitrite between the groups. Group 2 presented a statistically significant correlation between serum malondialdehyde levels and the clinical variables investigated. In turn, Group 1 showed correlation only with occurrence of three or more vaso-occlusive crises. There was no correlation between nitrite levels and the clinical variables. Conclusion: The results revealed that during the pathogenesis of sickle cell anemia, an increase in lipid peroxidation was observed. On the other hand, no changes in oxidative parameters were detected during treatment with hydroxyurea, probably due to the short period of treatment of the patients studied.

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Fetal Hemoglobin In Sickle Cell Anemia: Molecular Characterization of the High Fetal Hemoglobin Phenotype In African American Patients

Blood ◽

10.1182/blood.v116.21.2068.2068 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2068-2068

Author(s):

Idowu Akinsheye ◽

Nadia Solovieff ◽

Anita Malek ◽

Duyen A. Ngo ◽

Martin H. Steinberg ◽

...

Keyword(s):

African American ◽

Quantitative Trait Loci ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Quantitative Trait ◽

Binding Sites ◽

Fetal Hemoglobin ◽

Control Group ◽

Trait Loci ◽

Dna Fragment

Abstract Abstract 2068 HbF interferes with deoxygenated HbS polymerization, and is a major genetic modifier of sickle cell anemia severity. In this study, we attempted to identify genetic factors responsible for HbF production in a small group of African American sickle cell anemia patients who have markedly elevated HbF levels. Initially, patients with HbF of more than 11% as determined by HPLC were selected. The following were excluded: age less than 5; MCV greater than 100; presence of HPFH 1 and 2 based on specific gap-PCR tests; other β-globin gene deletions as determined by multiplex ligation-dependent probe amplification (MLPA). We further excluded rare HBG1 and 2 promoter HPFH mutations by nucleotide sequencing. In the end, a unique group of 20 patients were identified for further studies. Their mean age was 16.3 ± 8.3 years; Hb 9.0 ± 1.3 g/dL; MCV 87.9 ± 7.3 fL; and Hb F 17.2 ± 4.8% (range 11–29%). A control group of 30 African American patients were chosen. They had similar age, Hb, and MCV, but their HbF was 5.0 ± 2.5% (range 0.5–8.8%). These patients were examined for the 3 known major HbF quantitative trait loci: the Xmn1 restriction site C/T polymorphism at NT -158 upstream of HBG2; the BCL11A polymorphism on Chr2p16; the HBS1L-MYB intergenic polymorphism on Chr6q23. These 3 HbF quantitative trait loci collectively account for 20–50% of HbF variance in different populations. We found a significant association between high HbF and BCL11A and HBS1L-MYB intergenic region QTLs in these patients, but these account for only 20% of HbF variance (Table). These results were further validated in 590 patients of similar age from the Cooperative Study of Sickle Cell Disease, 57 patients with HbF 20.6 ± 8.2% and 533 patients with HbF 3.1 ± 1.5% (Table). To further explore other possible causes of elevated HbF, we sequenced 8.6 kb DNA fragment between HBG1 and HBD in 15 high HbF and 15 control patients. This DNA fragment includes the 7.2 kb Corfu deletion that is associated with elevated HbF levels and also binding sites for BCL11A. Twenty SNPs were found. The minor allele frequencies were consistently higher in the high HbF group, but the difference was found to be statistically significant only in 4 SNPs, 3 SNPs between positions 49213 and 49994 and 1 SNP at position 54541 (P = 0.001 to 0.04), suggesting that polymorphisms in this region might contribute to HbF expression in African American sickle cell anemia patients. The G→A polymorphism at position 49876 creates a C/EBP binding site which is not present in the major allele. The G→A polymorphism at position 49994 eliminates an AP-1 and NF-E2 binding sites, which are present in the major alleles. All 3 factors are erythroid transcription factors. The possible functional roles of these minor alleles found in significantly higher frequencies in the high HbF patients need to be further investigated. Disclosures: No relevant conflicts of interest to declare.

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A Prospective Pilot Newborn Screening and Treatment Program for Sickle Cell Anemia in the Republic of Angola

Blood ◽

10.1182/blood.v120.21.480.480 ◽

2012 ◽

Vol 120 (21) ◽

pp. 480-480 ◽

Cited By ~ 3

Author(s):

Patrick T. McGann ◽

Margaret G. Ferris ◽

Paulino Macosso ◽

Vysolela de Oliveira ◽

Uma Ramamurthy ◽

...

Keyword(s):

Mortality Rate ◽

Newborn Screening ◽

Capacity Building ◽

Sickle Cell ◽

Treatment Program ◽

Sickle Cell Anemia ◽

Infant Mortality Rate ◽

Sub Saharan Africa ◽

Care And Treatment ◽

The Republic

Abstract Abstract 480 Background: Sickle cell anemia (SCA) is a significant global health problem with >300,000 affected infants born each year in sub-Saharan Africa. Up to 80–90% of all children with SCA in Africa die before five years of age, due to infection or anemia, and usually without the proper diagnosis of SCA. Early identification by newborn screening (NBS), followed by interventions such as pneumococcal immunization and prophylactic penicillin, have dramatically reduced the mortality of children with SCA in the US, but this strategy not yet been established in Africa. A novel public-private partnership involving the Republic of Angola, Chevron Corporation, and Baylor College of Medicine/Texas Children's Hospital was created to develop a pilot NBS and treatment program for SCA, focusing on capacity building and local ownership. Methods: Two large maternity hospitals in the capital city of Luanda, Angola were initially selected for dried blood spot (DBS) collection and analysis, and a third local health center was soon added. Maternity nurses were taught DBS collection and laboratory technicians learned isoelectric focusing (IEF) and capillary electrophoresis (CE) techniques. Identifiers including cell phone numbers are collected onto the Whatman NBS card to facilitate retrieval of affected babies. After collection, DBS were transported to the central NBS laboratory at Hospital Pediátrico David Bernardino (HPDB) for hemoglobin identification by IEF and CE. Demographic data and test results were entered into a unique internet-based electronic data capture system designed with secure password-protection and servers located in Houston, Texas. Results: Since initiation of NBS in July 2011, 17,055 babies have DBS collection and laboratory results: 3,588 (21%) with FAS pattern (sickle cell trait), and 264 (1.55%) with FS (consistent with SCA). Twenty-one samples produced a result other than FA, FAS, or FS, including 10 FAC and 1 FSC. Families of infants with an FS screening result are notified by phone to initiate care and treatment, ideally by age 8 weeks. In the new infant SCA clinic at HPDB, infants receive penicillin prophylaxis and PCV-13 pneumococcal immunization, while parents receive sickle cell education and insecticide-treated bed nets for malaria protection. In the first 6 months, 67.8% of DBS cards had phone numbers documented, but with education and reinforcement, 81.4% of cards had phone numbers in the past 6 months. To date, 220 FS babies are age-eligible for contact and 110 (50%) families have been reached: 104 (47%) have come to the infant SCA clinic, 6 (2.7%) had already died within the first month of life, and 0 refused care. A total of 201 doses of PCV-13 have been provided as per routine vaccination scheduling. After initial visit, the return rate for second immunization is 94% with only 3 babies lost to follow-up including 2 deaths. The calculated first-year mortality rate for all contacted FS babies (6.9%) compares favorably to the national infant mortality rate (9.8%). Conclusions: This prospective pilot study documents that newborn screening for SCA is feasible in a developing country such as Angola. Capacity building and teaching provide local healthcare workers with skills necessary to have a functional NBS program and infant SCA clinic. The sickle cell burden is extremely high in Angola, and contact and retrieval of all affected FS infants remains an ongoing challenge, but families are compliant with clinic appointments and treatment. Early mortality data suggest comprehensive SCA care can save lives, suggesting that expansion of the pilot program is warranted with an eventual national strategy for the diagnosis, care, and treatment of children with SCA in Angola. Disclosures: No relevant conflicts of interest to declare.

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