Association of ZBTB38 gene polymorphism (rs724016) with height and fetal hemoglobin in individuals with sickle cell anemia.

Objectives: Our study evaluated the association of the polymorphism rs724016 in the ZBTB38 gene, previously associated with height in other populations, with predictors of height, clinical outcomes, and laboratory parameters in sickle cell anemia (SCA). Methods: Cross-sectional study with individuals with SCA and aged between 3 and 20 years. Clinical, laboratory, molecular, and bone age (BA) data were evaluated. Levels of IGF-1 and IGFBP-3 were adjusted for BA, target height (TH) was calculated as the mean parental height standard deviation score (SDS), and predicted adult height (PAH) SDS was calculated using BA. Results: We evaluated 80 individuals with SCA. The homozygous genotype of the G allele of rs724016 was associated with a lower height SDS (p < 0.001) and, in a additive genetic model, was negatively associated with HbF levels (p = 0.016). Lower adjusted IGF-1 levels were associated with co-inheritance of alpha-thalassemia and with the absence of HU therapy. Elevated HbF levels were associated with a lower deficit in adjusted growth potential (TH minus PAH). Conclusion: Our analysis shows that SNP rs724016 in the ZBTB38 is associated with shorter height and lower HbF levels, an important modifier of SCA.

Evaluation of blood cell count using an automatic hematology analyzer to optimize collection of peripheral blood progenitor cells by leukapheresis.

BACKGROUND: Autologous stem cell transplantation is a treatment modality for several diseases. Prediction of successful mobilization may be useful to optimize hematopoietic stem cell collection. STUDY DESIGN AND METHODS: This was a retrospective study with data from transplantation candidates between September 2015 and December 2021 being analyzed. The medical record of each patient was reviewed to mine mobilization information. The laboratory data analyzed were CD34+ cell enumeration and pre-collection peripheral blood cell count. The primary outcome, good mobilization, was defined as a CD34+ cell count ≥20/µL. RESULTS: This study included 807 patients. Increased patient weight, low mean corpuscular volume, high nucleated red blood cells, peripheral blood mononuclear cell and immature granulocyte counts were significantly associated with good mobilization. In addition, patients diagnosed with multiple myeloma were two times more likely to be good mobilizers than patients with lymphoma. The model was applied to a validation set to identify patients who underwent apheresis (CD34+ cell count ≥10 µL), resulting in a sensitivity of 69 %, a specificity of 95 %, positive predictive value of 98 %, and a negative predictive value of 50 %. CONCLUSION: Success in mobilization was greater in patients who underwent the first mobilization cycle and who had a diagnosis of multiple myeloma. Furthermore, higher body weight, and nucleated red blood cells, immature granulocytes and mononuclear cell counts, as well as low mean corpuscular volumes, were associated with successful mobilization.

Clinical, laboratory, and molecular characteristics of a cohort of children with hemoglobinopathy S/beta-thalassemia.

INTRODUCTION: Hemoglobinopathy Sß-thalassemia (HbSß-thal) has a wide range of clinical and laboratory severity. There is limited information on the natural history of HbSß-thal and its modulating factors. We described the molecular, hematological, and clinical characteristics of a cohort of children with HbSß-thal and estimated its incidence in Minas Gerais, Brazil. METHODS: Laboratory and clinical data were retrieved from medical records. Molecular analysis was performed by HBB gene sequencing, PCR-RFLP, gap-PCR, and MLPA. RESULTS: Eighty-nine children were included in the study. Fourteen alleles of ß-thal mutations were identified. The incidence of HbSß-thal in the state was 1 per 22,250 newborns. The most common ßS-haplotypes were CAR and Benin. The most frequent ßthal-haplotypes were V, II, and I. Coexistence of 3.7 kb HBA1/HBA2 deletion was present in 21.3 % of children. ß-thalassemia mutations were associated with several clinical and laboratory features. In general, the incidence of clinical events per 100 patient-years was similar for children with HbSß0-thal, IVS-I-5 G>A, and IVS-I-110 G>A. Children with HbSß+-intermediate phenotypes had a more severe laboratory and clinical profile when compared with those with HbSß+-mild ones. ßS-haplotypes and α-thalassemia did not meaningfully influence the phenotype of children with HbSß-thal. CONCLUSION: The early identification of ß-thalassemia alleles may help the clinical management of these children.

Estimated glomerular filtration rate in Brazilian adults with sickle cell disease: results from the REDS-III multicenter cohort study.

Chronic kidney disease (CKD) has a significant impact on sickle cell disease (SCD) morbidity and mortality. Early identification of individuals at highest risk of developing CKD may allow therapeutic intervention to prevent worse outcomes. This study aimed to evaluate the prevalence and risk factors for reduced estimated glomerular filtration rate (eGFR) among adults with SCD in Brazil. Participants in the REDS-III multicenter SCD cohort with more severe genotypes aged ≥ 18 years with at least two serum creatinine values were analyzed. The eGFR was calculated using the Jamaica Sickle Cell Cohort Study GFR equation. The eGFR categories were defined according to the K/DOQI. Participants with eGFR ≥ 90 were compared to those with those with eGFR < 90. Among the 870 participants, 647 (74.4%) had eGFR ≥ 90, 211 (24.3%) had eGFR 60 to 89, six (0.7%) had eGFR 30 to 59, and six (0.7%) had ESRD. Male sex (OR: 37.3; 95%CI: 22.4-65.1), higher age (OR: 1.04; 95%CI: 1.02-1.06), higher diastolic blood pressure (OR: 1.03; 95%CI: 1.009-1.06), lower Hb (OR: 0.80; 95%CI: 0.68-0.93), and lower reticulocytes (OR: 0.94; 95%CI: 0.89-0.99) levels were independently associated with eGFR < 90. There was a trend towards higher odds of death in participants with eGFR < 90 (OR: 1.8; 95%CI: 0.95-3.32; p = 0.065). In turn, participants with eGFR < 60 had a 12.2 (95%CI: 2.1-96.9) times higher odds for death when compared to those with eGFR ≥ 60. In this study, eGFR < 90 was observed in one-quarter of adults. Older age, male sex, higher diastolic blood pressure, lower hemoglobin, and lower reticulocyte levels were associated with occurrence of eGFR < 90. Estimated GFR < 60 increased the risk of mortality.

Pharmacogenomic markers of glucocorticoid response in congenital adrenal hyperplasia.

Glucocorticoids (GC) replacement are the mainstay treatment for 21-hydroxylase deficiency (21-OHD), the most common cause of congenital adrenal hyperplasia (CAH), in its classical form. There are novel insights into the genetic basis of the GC action diversity that point to an important role for GC receptor (GR) gene polymorphisms, suggesting a possible modulation in occurrence of metabolic disorders, what may be relevant to clinical management of 21-OHD. The aim of this study was to investigate whether the five GR gene polymorphisms Tth111I, ER22, 23EK, BclI, 9ß (rs10052957, rs6189, rs6190, rs41423247, rs6198) and their combination into haplotypes are associated to different GC response in a cohort of classic 21-OHD subjects. GR genotype-phenotype associations were explored after a dexamethasone suppression test using very low-doses (VLD-DST), 20 and 40 µg/m². The final sample (n = 28) was selected based on the 102 individuals' previous genotypes classification, according to literature data of GC sensitivity or resistance. Thus, only patients with GC increased resistance (n = 18) or increased sensitivity (n = 10) profiles were selected. Out of 28 subjects aged 12 (2-34) years enrolled in this study, 75% were females, 75% presented the salt-wasting form (SW) and 25% the simple virilizing form (SV). Subjects who carried Tth111I and 9ß, associated or not to the ER22/23EK variants, showed an impaired DST response. Results did not differ significantly according to gender or body mass index. SV subjects with GC hypersensitivity-genotypes showed decreased average cortisol levels compared to those with GC resistance-genotypes (p = 0.0023). The Tth111I + 9ß/ Wild or Tth111I + ER22/23EK + 9ß/ Wild genotypes were associated to GC resistance in this population. This finding may be relevant given the challenges posed by therapeutic management with GC in CAH.

Fetal hemoglobin-boosting haplotypes of BCL11A gene and HBS1L-MYB intergenic region in the prediction of clinical and hematological outcomes in a cohort of children with sickle cell anemia.

Single nucleotide polymorphisms (SNPs) of BCL11A gene and HBS1L-MYB intergenic region (named HMIP-2) affect both fetal hemoglobin (HbF) concentration and clinical outcomes in patients with sickle cell anemia (SCA). However, no previous study has examined the interaction among these SNPs in the regulation of HbF. We examined whether HbF-boosting haplotypes combining alleles of functional SNPs of BCL11A and HMIP-2 were associated with clinical outcomes and hematological parameters, and whether they interact to regulate HbF in a cohort of Brazilian children with SCA. The minor haplotype of BCL11A ("TCA", an allele combination of rs1427407, rs766432, and rs4671393) was associated with higher HbF, hemoglobin and lower reticulocytes count compared to reference haplotype "GAG". The minor haplotype of HMIP-2 ("CGC", an allele combination of rs9399137, rs4895441, and rs9494145) was associated with higher HbF and hemoglobin compared to reference haplotype "TAT". Subjects carrying minor haplotypes showed reduced rate of clinical complications compared to reference haplotypes. Non-carriers of both minor haplotypes for BCL11A and HMIP-2 showed the lowest HbF concentration. Subjects carrying only the minor haplotype of BCL11A showed significantly higher HbF concentration than non-carriers of any minor haplotype, which showed no significant difference compared to subjects carrying only the minor haplotype of HMIP-2. Interestingly, subjects carrying both minor haplotypes of BCL11A ("TCA") and HMIP-2 ("CGC") showed significantly higher HbF levels than subjects carrying only the minor haplotype of BCL11A. Our novel findings suggest that HbF-boosting haplotypes of BCL11A and HMIP-2 can predict clinical outcomes and may interact to regulate HbF in patients with SCA.

Is Severity Score Associated With Indication for Hematopoietic Stem Cell Transplantation in Individuals With Sickle Cell Anemia?

Manifestations of sickle cell disease (SCD) begin early in childhood and cause morbidity and decreased life expectancy. Hematopoietic stem cell transplantation (HSCT) is curative but associated with risk of mortality attributable to the transplant. This risk should be counterbalanced with SCD morbidity and mortality. A severity score using a Bayesian network model was previously validated to predict the risk of death in adult individuals with SCD. The objective of this study is to calculate the severity scores of participants in a multicenter cohort of Brazilians with SCD, using a previously published Bayesian network-derived score, associated with risk of death and then compare the severity scores between participants with and without an indication for HSCT as defined by the Brazilian Ministry of Health (MoH) criteria. This is an observational, retrospective study. We analyzed 2063 individuals with sickle cell anemia from the Recipient Epidemiology and Donor Evaluation Study-III Brazil SCD cohort and applied a Bayesian network-derived score to compare candidates and non-candidates for HSCT according to the Brazilian MoH transplant criteria. Classical statistical methods were used to analyze data and make comparisons. We compared severity scores between cohort members with (n = 431) and without (n = 1632) HSCT indications according to Brazilian MoH. Scores were not different in adult participants with ≥1 HSCT indication when compared to those with no indication (mean 0.342 versus 0.292; median 0.194 versus 0.183, P = .354) and receiver operating characteristic curves did not demonstrate an obvious threshold to differentiate participants with or without HSCT indications. Severity score may predict risk of death but does not differentiate HSCT candidates. Current indications should be evaluated to ensure that patients with more severe disease who might benefit from HSCT are appropriately identified.

Association between inflammatory molecules, nitric oxide metabolites and leg ulcers in individuals with sickle cell anemia

Abstract Introduction Leg ulcers (LUs) are relatively common in patients with sickle cell anemia (SCA). The role of inflammation and nitric oxide (NO) pathways in the pathophysiology of the LU is not understood. Objective The aim of this study was to verify the association between inflammatory molecules and nitric oxide metabolites (NOx) and the occurrence of the LU in patients with SCA. Method It was a cross-sectional study on adult participants with SCA followed at Fundação Hemominas, a public blood center in Brazil. Eligible participants were recruited and included in one of two groups: Group 1, comprised of cases with SCA (Hb SS) and at least one LU at the time of inclusion in the study and Group 2, comprised of controls with SCA without a history of LU, matched by sex and age to cases. Participants were interviewed to obtain sociodemographic data and blood samples were collected. Clinical and laboratory data were abstracted from medical records. Nitric oxide metabolites (NOx) and inflammatory molecules were quantified using an immunoassay and Multiplex xMAP® technology, respectively. Eighty-seven individuals were included, ranging in age from 17 to 61 years (mean 40 ± 10.7 years); 30 had LU and 57 were controls without LU. Results Participants with LU had significantly higher levels of interleukin 8 (IL-8), IL-10, IL-15, NOx and platelet and white blood cell (WBC) counts, when compared to those without LU. Participants with LU had a significantly higher risk of having a history of osteomyelitis and a higher use of antiseptic soap in bathing, when compared to those without LU. Conclusion In conclusion, our results showed that NOx, inflammatory molecules and hematological features were associated with LU in Brazilian adults with SCA.

Evaluation of insertion/deletion (I/D) polymorphisms of ACE gene and circulating levels of angiotensin II in congenital anomalies of the kidney and urinary tract.

BACKGROUND: Congenital Anomalies of the Kidney and the Urinary Tract (CAKUT) are defined as a heterogeneous group of anomalies that resulted from defects in kidney and urinary tract embryogenesis. CAKUT have a complex etiology. Genetic, epigenetic and environmental factors have been investigated in this context. Angiotensin II is a potent vasoconstrictor and exerts an important role in kidney embryogenesis. The angiotensin-converting enzyme (ACE) converts Angiotensin I into Angiotensin II (Ang II) and ACE gene has insertion/deletion (I/D) polymorphisms that have been evaluated in several nephropathies. This study aimed to evaluate whether the I/D polymorphisms of ACE gene and the circulating levels of Ang II are associated with any CAKUT phenotype or CAKUT in general. METHODS AND RESULTS: Our study was performed with 225 pediatric patients diagnosed with CAKUT and 210 age-and-sex matched healthy controls. ACE I/D alleles were analysed by real-time polymerase chain reaction (RT-PCR). The distribution of ACE I/D polymorphisms were compared between CAKUT patients and healthy controls, as well between ureteropelvic junction obstruction (UPJO), vesicoureteral reflux (VUR), multicystic dysplastic kidney (MCDK) phenotypes and control group. No statistical association was detected between ACE I/D polymorphism and CAKUT and UPJO, VUR, and MCDK phenotypes. In a subset of 80 CAKUT patients and 80 controls, plasma levels of Ang II were measured. No significant differences were found between CAKUT patients and controls, even in regard to comparisons of UPJO, VUR and MCDK with control group. CONCLUSION: Although CAKUT is a complex disease and the ACE gene may exert a role in kidney embryogenesis, CAKUT was not associated with any ACE I/D polymorphisms nor with differences in plasma levels of Ang II in this Brazilian pediatric population.

Association between inflammatory molecules, nitric oxide metabolites and leg ulcers in individuals with sickle cell anemia.

INTRODUCTION: Leg ulcers (LUs) are relatively common in patients with sickle cell anemia (SCA). The role of inflammation and nitric oxide (NO) pathways in the pathophysiology of the LU is not understood. OBJECTIVE: The aim of this study was to verify the association between inflammatory molecules and nitric oxide metabolites (NOx) and the occurrence of the LU in patients with SCA. METHOD: It was a cross-sectional study on adult participants with SCA followed at Fundação Hemominas, a public blood center in Brazil. Eligible participants were recruited and included in one of two groups: Group 1, comprised of cases with SCA (Hb SS) and at least one LU at the time of inclusion in the study and Group 2, comprised of controls with SCA without a history of LU, matched by sex and age to cases. Participants were interviewed to obtain sociodemographic data and blood samples were collected. Clinical and laboratory data were abstracted from medical records. Nitric oxide metabolites (NOx) and inflammatory molecules were quantified using an immunoassay and Multiplex xMAP® technology, respectively. Eighty-seven individuals were included, ranging in age from 17 to 61 years (mean 40 ±â€¯10.7 years); 30 had LU and 57 were controls without LU. RESULTS: Participants with LU had significantly higher levels of interleukin 8 (IL-8), IL-10, IL-15, NOx and platelet and white blood cell (WBC) counts, when compared to those without LU. Participants with LU had a significantly higher risk of having a history of osteomyelitis and a higher use of antiseptic soap in bathing, when compared to those without LU. CONCLUSION: In conclusion, our results showed that NOx, inflammatory molecules and hematological features were associated with LU in Brazilian adults with SCA.

Glucocorticoid receptor Gene (NR3C1) Polymorphisms and Haplotypes in patients with congenital adrenal hyperplasia.

BACKGROUND: Lifelong glucocorticoid (GC) replacement is the mainstay treatment of congenital adrenal hyperplasia (CAH) due to classic 21-hydroxylase deficiency (21-OHD). Challenges posed by therapeutic management of these patients are well known, but novel insights into the variability in clinical response to GC highlight a role for single nucleotide polymorphisms (SNPs) of the glucocorticoid receptor gene (NR3C1). AIM: To assess whether six commonly studied NR3C1 SNPs, which were previously associated with modified response to GC, are associated with CAH. We further assessed the linkage disequilibrium (LD) among these NR3C1 SNPs and their combination into haplotypes. METHODS: Genotypes were determined by Taqman allele discrimination assays for Tth111I (rs10052957), ER22 (rs6189), 23 EK (rs6190), N363S (rs56149945), BclI (rs41423247) and 9ß (rs6198) in a Brazilian cohort of 102 unrelated 21-OHD patients and 163 unrelated healthy subjects (controls). Haplotypes were estimated using Haplo.stats, and LD among SNPs using Haploview. RESULTS: Heterozygous subjects for Tth111I were more frequent in 21-OHD patients (P = 0.004), while heterozygous for BclI were more frequent in controls (P = 0.049). We found a strong LD among the six NR3C1 SNPs, and four out of six common haplotypes contained the Tth111I-variant. Although we found no significant differences in overall haplotype analysis, the BclI-haplotype was less frequent among 21-OHD patients (P = 0.0180). CONCLUSIONS: BclI-haplotype was less common and heterozygous for Tth111I were more frequent in 21-OHD patients, while heterozygous for BclI were more frequent in controls. Our novel findings may contribute to further clinical studies on the prognostic value of NR3C1 haplotypes towards individualized treatment for 21-OHD patients.

Influence of laboratory procedures on postthawing cell viability and hematopoietic engraftment after autologous peripheral blood stem cell transplantation.

BACKGROUND: The kinetics of hematopoietic recovery after autologous stem cell transplantation (ASCT) may be affected by laboratory procedures. The aim of this study was to evaluate the influence of characteristics of the cryopreserved units of peripheral blood stem cells (PBSC) on postthawing cell viability and engraftment outcomes after ASCT. STUDY DESIGN AND METHODS: This was a retrospective cohort study including individuals referred for ASCT. Cryopreservation was conducted at a single processing facility between 2014 and 2019, and patients received clinical care at six transplant centers. Covariates and outcome data were retrieved from participants' records. RESULTS: The study population comprised 619 patients (345 [55.7%] male). Median age was 53 years. Multiple myeloma was the most common diagnosis (62.7%). Higher preapheresis CD34+ cell count, lower nucleated cell (NC) concentration per cryobag, and composition of the cryoprotectant solution (5% dimethyl sulfoxide [DMSO] and 6% hydroxyethyl starch) were statistically significantly associated with higher postthawing cell viability. The linear regression model for time to neutrophil and platelet engraftment included the infused CD34+ cell dose and the composition of the cryoprotectant solution. Patients who had PBSC cryopreserved using 10% DMSO solution presented six times higher odds (odds ratio [OR] = 6.9; 95% confidence interval [CI]: 2.2-21.1; p = .001) of delayed neutrophil engraftment (>14 days) and two times higher odds (OR = 2.3, 95%CI: 1.4-3.7; p = .001) of prolonged hospitalization (>18 days). DISCUSSION: The study showed that mobilization efficacy, NC concentration, and the composition of the cryoprotectant solution significantly affected postthawing cell viability. In addition, the composition of the cryoprotectant solution significantly impacted engraftment outcomes and time of hospitalization after ASCT.

10-year analysis of human immunodeficiency virus incidence in first-time and repeat donors in Brazil.

BACKGROUND AND OBJECTIVES: Incidence in first-time and repeat blood donors is an important measure of transfusion-transmitted HIV infection (TT-HIV) risk. This study assessed HIV incidence over time at four large blood centres in Brazil. MATERIALS AND METHODS: Donations were screened and confirmed using serological assays for HIV from 2007 to 2016, and additionally screened by nucleic acid testing from 2011 forward. Limiting antigen (LAg) avidity testing was conducted on HIV seroreactive samples from first-time donors to classify whether an infection was recently acquired. We calculated incidence in first-time donors using the mean duration of recent infection and in repeat donors using classical methods. Time and demographic trends were assessed using Poisson regression. RESULTS: Over the 10-year period, HIV incidence in first-time donors was highest in Recife (45·1/100 000 person-years (105 py)) followed by São Paulo (32·2/105 py) and then Belo Horizonte (23·3/105 py), and in repeat donors was highest in Recife (33·2/105 py), Belo Horizonte (27·5/105 py) and São Paulo (17·0/105 py). Results from Rio de Janeiro were available from 2013 to 2016 with incidence in first-time donors of 35·9/105 py and repeat donors from 2011 to 2016 of 29·2/105 py. Incidence varied by other donor demographics. When incidence was considered in 2-year intervals, no significant trend was evident. Overall residual risk of TT-HIV was 5·46 and 7·41 per million units of pRBC and FFP transfused, respectively. CONCLUSION: HIV incidence in both first-time and repeat donors varied by region in Brazil. Clear secular trends were not evident.

Association of HIV infection with clinical and laboratory characteristics of sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is a multisystem disorder characterized by a wide spectrum of clinical manifestations and severity. Studies investigating potential effects of co-morbid human immunodeficiency virus (HIV) and SCD have produced conflicting results, and additional investigations are needed to elucidate whether the interaction between the two disease states might impact both HIV and SCD clinical outcomes. The association of HIV infection with clinical and laboratory characteristics of patients with SCD was assessed. METHODS: This nested case-control study included individuals with SCD with HIV treated at six Brazilian SCD centers. Clinical and laboratory data were abstracted from medical records. HIV positive participants were compared to age, gender, center, and SCD genotype matched HIV negative participants (ratio 1:4). Individual clinical outcomes as well as a composite outcome of any SCD complication and a composite outcome of any HIV-related complication were compared between the two groups. RESULTS: Fifteen HIV positive participants were included, 12 (80%) alive and 3 (20%) deceased. Most of the HIV positive patients had HbSS (60%; n = 9), 53% (n = 8) were female, and mean age was 30 ± 13 years. The frequency of individual SCD complications of acute chest syndrome/pneumonia, sepsis/bacteremia, pyelonephritis, ischemic stroke, hemorrhagic stroke, abnormal transcranial Doppler (TCD), and pulmonary hypertension was higher in HIV positive participants when compared to HIV negative, although analyzed individually none were statistically significant. HIV positive participants had significantly higher risk of any SCD complication and of a composite HIV-related complication compared to the HIV negative group (HR = 4.6; 95%CI 1.1-19.6; P = 0.04 and HR = 7.7; 95%CI 1.5-40.2; P = 0.02, respectively). There was a non-significant trend towards higher risk of any infections in participants with HIV positive (HR = 3.5; 95%CI 0.92-13.4; P = 0.07). Laboratory parameters levels were not significantly different in individuals with and without HIV. CONCLUSIONS: In summary, our study in SCD patients shows that those with HIV have an increased risk of any SCD complication and HIV-related complications, as well as a suggestive but not significantly increased risk of infections.

Blood utilization and characteristics of patients treated with chronic transfusion therapy in a large cohort of Brazilian patients with sickle cell disease.

BACKGROUND: Red blood cell (RBC) transfusions are used in sickle cell disease (SCD) to treat acute complications or as chronic transfusion therapy (CTT) to prevent severe manifestations. The objectives of this study were to describe blood utilization and adverse events (AEs) associated with RBCs in the Brazilian SCD population and compare characteristics of patients treated or not with CTT. STUDY DESIGN AND METHODS: A SCD cohort was established at six Brazilian centers. Medical and blood bank records were abstracted for clinical and transfusion history. Two controls not treated with CTT matched on center, SCD genotype, sex, and age were selected for each CTT case within the cohort to compare characteristics between the two groups. RESULTS: Most of the 2794-member cohort had received a transfusion (75.0% of children and 89.2% of adults) with 29.2% of patients receiving transfusion in the prior year. There were 170 (10.6%) children and 115 (9.2%) adults treated with CTT. Children not treated with CTT were more likely to have pain and acute chest hospitalizations in the prior year (25.3% vs. 11.9%, p = 0.0003; and 22.0% vs. 10.7%, p = 0.002, respectively). Both iron overload and alloimmunization were more common in CTT cases compared to controls (65.6% vs. 17.0% and 36.2% vs. 15.9%, respectively). A higher proportion of adults treated with CTT demonstrated oxygen saturation of greater than 95% compared to controls not treated (51.1% vs. 39.2%), while there was no difference in oxygenation between children treated or not. Of 4501 transfusion episodes, 28 (0.62%) AEs were reported. There was no difference in AEs associated with transfusions for acute indications versus CTT. CONCLUSION: Red blood cell transfusion was common in Brazilian SCD patients, with utilization driven by CTT. Transfusion reactions were not common; however, alloimmunization and iron overload were frequent among those on CTT, highlighting the need for novel clinical strategies to mitigate these risks.

Functional polymorphisms of BCL11A and HBS1L-MYB genes affect both fetal hemoglobin level and clinical outcomes in a cohort of children with sickle cell anemia.

Fetal hemoglobin (HbF) ameliorates clinical severity of sickle cell anemia (SCA). The major loci regulating HbF levels are HBB cluster, BCL11A, and HMIP-2 (HBS1L-MYB). However, the impact of noncoding single-nucleotide polymorphisms (SNPs) in these loci on clinical outcomes and their functional role on regulating HbF levels should be better elucidated. Therefore, we performed comprehensive association analyses of 14 noncoding SNPs in five loci with HbF levels and with clinical outcomes in a cohort of 250 children with SCA from Southeastern Brazil, and further performed functional annotation of these SNPs. We found SNPs independently associated with HbF levels: rs4671393 in BCL11A (ß-coefficient = 0.28), rs9399137 in HMIP-2A (ß-coefficient = 0.16), and rs4895441 in HMIP-2B (ß-coefficient = 0.15). Patients carrying minor (HbF-boosting) alleles for rs1427407, rs93979137, rs4895441, rs9402686, and rs9494145 showed reduced count of reticulocytes (p < 0.01), while those carrying the T allele of rs9494145 showed lower white blood cell count (p = 0.002). Carriers of the minor allele for rs9402686 showed higher peripheral saturation of oxygen (p = 0.002). Patients carrying minor alleles in BCL11A showed lower risk of transfusion incidence rate ratio (IRR ≥ 1.3; p < 0.0001). This effect was independent of HbF effect (p = 0.005). Carriers of minor alleles for rs9399137 and rs9402686 showed lower risk of acute chest syndrome (IRR > 1.3; p ≤ 0.01). Carriers of the reference allele for rs4671393 showed lower risk of infections (IRR = 1.16; p = 0.01). In conclusion, patients carrying HbF-boosting alleles of BCL11A and HMIP-2 were associated with milder clinical phenotypes. Higher HbF concentration may underlie this effect.