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.

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.

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.

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.

Polymorphisms in genes that affect the variation of lipid levels in a Brazilian pediatric population with sickle cell disease: rs662799 APOA5 and rs964184 ZPR1.

This cross-sectional study investigated associations between SNPs in metabolizing lipid genes, alpha-thalassemia and laboratory parameters in two forms of sickle cell disease (SCD), sickle cell anemia (SCA) and hemoglobin SC disease (HbSC) in a pediatric population. Among the groups SCA and HbSC was found a higher proportion of increased triglycerides (TG) in SCA. High levels of TG were significantly associated with lower hemoglobin (p = 0.006) and HDL-C (p = 0.037), higher white blood cell count (p = 0.027), LDH (p = 0.004) and bilirubins (p < 0.05) in SCD. Patients with HDL-C ≤40 mg/dL had higher markers hemolytic levels. Therapy of HU significantly influenced several hematological and biochemical parameters but not lipid fractions. Genotypes of the APOA5 rs662799 were not associated with lipid levels. The G-risk allele rs964184/ZPRI ZNF259/ZPR1 gene (GC + GG genotypes) was associated with increased levels of TG in children ≥10 years old (p = 0.045) and the atherogenic ratio TG/HDL-C (p = 0.032) in SCD. The use of HU improves levels of hemolysis and inflammation markers in SCD with high TG and, while not interfering with lipid levels, seems to overlap the effect of the G-risk allele in on them. This study reported for the first time that rs964184 SNP could be a genetic modifier of TG in SCD.

Evidence for interactions between inflammatory markers and renin-angiotensin system molecules in the occurrence of albuminuria in children with sickle cell anemia.

Sickle cell anemia (SCA) is an important cause of chronic kidney disease, but its pathophysiology is not completely understood. The aim of this study was to compare inflammatory biomarkers in urine samples of SCA children with and without albuminuria, and to explore correlations with renin-angiotensin system (RAS) molecules. A cross-sectional study of 213 children selected from the Minas Gerais state cohort were assigned to two groups: Group 1-89 children with SCA who had albuminuria; Group 2-124 children with SCA and normal albuminuria matched by age and sex with group 1. A subset of 89 children was prospectively followed for a median time of 1.1 year. Inflammatory biomarkers (chemokines and cytokines) in urine were measured using cytometric beads array, and RAS molecules were measured by ELISA. Children with albuminuria had significantly higher urinary levels of IP-10/CXCL10, MCP-1/CCL2, MIG/CXCL9, IL-8/CXCL8, IL-12p70, TNF, IL-10, and IL-6 than patients with normal albuminuria. In the correlation analysis, albumin/creatinine ratio was significantly and positively correlated with IP-10/CXCL10, MCP-1/CCL2, MIG/CXCL9, IL-8/CXCL8, TNF, IL-10, and IL-6. Significant correlations were found between inflammatory and RAS molecules. In the prospective analysis, cumulative risk of persistent albuminuria was higher for children with urinary levels of IP-10/CXCL10 or IL-6 above the 50th percentile. Our data showed that inflammatory markers and RAS molecules might contribute to the occurrence of albuminuria in children with SCA, suggesting that both pathways interact in sickle cell nephropathy.

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.

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.

Clinical and Genetic Predictors of Priapism in Sickle Cell Disease: Results from the Recipient Epidemiology and Donor Evaluation Study III Brazil Cohort Study.

INTRODUCTION: Priapism is the persistent and painful erection of the penis and is a common sickle cell disease (SCD) complication. AIM: The goal of this study was to characterize clinical and genetic factors associated with priapism within a large multi-center SCD cohort in Brazil. METHODS: Cases with priapism were compared to SCD type-matched controls within defined age strata to identify clinical outcomes associated with priapism. Whole blood single nucleotide polymorphism genotyping was performed using a customized array, and a genome-wide association study (GWAS) was conducted to identify single nucleotide polymorphisms associated with priapism. MAIN OUTCOME MEASURE: Of the 1,314 male patients in the cohort, 188 experienced priapism (14.3%). RESULTS: Priapism was more common among older patients (P = .006) and more severe SCD genotypes such as homozygous SS (P < .0001). In the genotype- and age-matched analyses, associations with priapism were found for pulmonary hypertension (P = .05) and avascular necrosis (P = .01). The GWAS suggested replication of a previously reported candidate gene association of priapism for the gene transforming growth factor beta receptor 3 (TGFBR3) (P = 2 × 10-4). CLINICAL IMPLICATIONS: Older patients with more severe genotypes are at higher risk of priapism, and there is a lack of consensus on standard treatment strategies for priapism in SCD. STRENGTHS & LIMITATIONS: This study characterizes SCD patients with any history of priapism from a large multi-center cohort. Replication of the GWAS in an independent cohort is required to validate the results. CONCLUSION: These findings extend the understanding of risk factors associated with priapism in SCD and identify genetic markers to be investigated in future studies to further elucidate priapism pathophysiology. Ozahata M, Page GP, Guo Y, et al. Clinical and Genetic Predictors of Priapism in Sickle Cell Disease: Results from the Recipient Epidemiology and Donor Evaluation Study III Brazil Cohort Study. J Sex Med 2019;16:1988-1999.

Reticulocyte count is the most important predictor of acute cerebral ischemia and high-risk transcranial Doppler in a newborn cohort of 395 children with sickle cell anemia.

Stroke is a severe clinical manifestation of sickle cell anemia (SCA). Despite the prognostic relevance of transcranial Doppler (TCD), more accurate tools to assess stroke risk in children with SCA are required. Here, we describe the effect of clinical, laboratory, and molecular features on the risk of stroke and high-risk TCD in children from the newborn cohort of Minas Gerais, Brazil. Outcomes studied were acute cerebral ischemia and high-risk TCD. Clinical and hematological data were retrieved from children's records. Genetic markers, which were known for their association with stroke risk, were genotyped by polymerase chain reaction/restriction fragment length polymorphism and sequencing. The cumulative incidence of acute cerebral ischemia by the age of 8 years was 7.4 % and that of high-risk TCD by the age of 11.5 years was 14.2 %. The final multivariate model for acute cerebral ischemia risk included high white blood cell count and reticulocyte count, acute chest syndrome rate, and the single nucleotide polymorphisms (SNPs) TEK rs489347 and TNF-α rs1800629. The model for high-risk TCD included high reticulocyte count and the SNPs TEK rs489347 and TGFBR3 rs284875. Children with risk factors should be considered for intensive risk monitoring and for intervention therapy.

Glucose-6-Phosphate Dehydrogenase Deficiency in Brazilian Children With Sickle Cell Anemia is not Associated With Clinical Ischemic Stroke or High-Risk Transcranial Doppler.

BACKGROUND: Stroke is a severe complication of sickle cell anemia (SCA). The role of glucose-6-phosphate dehydrogenase (G6PD) deficiency in the development of stroke in children with SCA is controversial. PROCEDURE: The aim of this study was to investigate the association of clinical ischemic stroke, high-risk transcranial Doppler measurements (TCD), and hematological features with molecular variants usually linked to G6PD deficiency or with the biochemical activity of G6PD in a cohort of 395 Brazilian children with SCA. G6PD activity was quantitatively determined using an enzymatic-colorimetric assay. G6PD mutations were determined by PCR-RFLP and sequencing. Clinical and hematological data were retrieved from the children's records. RESULTS: The prevalence of molecularly defined deficiency (hereafter, molecular deficiency) was 4.3% (95% confidence interval: 2.3-6.3%). The mean G6PD activity was 16.88 U/g hemoglobin (Hb) (standard error of the mean [SEM] 0.28) in the group without G6PD molecular deficiency and 8.43 (SEM 1.01) U/g Hb in the group with G6PD A(-) molecular deficiency. G6PD molecular deficiency was not associated with any hematological features. No effects of G6PD molecular deficiency on clinical ischemic stroke or high-risk TCD were detected. The mean G6PD activity was similar in children who had clinical ischemic stroke and in those without stroke. Similar results were obtained in analyses comparing children who had high-risk TCD and those without high-risk TCD. CONCLUSIONS: Our study demonstrated that G6PD molecular deficiency was not associated either with clinical ischemic stroke or high-risk TCD. Similarly, we found no associations between G6PD enzyme activity and stroke or high-risk TCD. Small sample size precludes definitive conclusions.

Association of alpha-thalassemia, TNF-alpha (-308G>A) and VCAM-1 (c.1238G>C) gene polymorphisms with cerebrovascular disease in a newborn cohort of 411 children with sickle cell anemia.

Cerebrovascular disease (CVD) is a severe complication associated with sickle cell anemia. Abnormal transcranial Doppler (TCD) identifies some children at high risk, but other markers would be helpful. This cohort study was aimed at evaluating the effects of genetic biomarkers on the risk of developing CVD in children from Minas Gerais, Brazil. Clinical and hematological data were retrieved from children's records. Outcomes studied were overt ischemic stroke and CVD (overt ischemic stroke, transient ischemic attack, abnormal TCD, or abnormal cerebral angiography). Out of 411 children, 386 (93.9%) had SS genotype, 23 (5.6%) had Sß(0)-thal and two had severe Sß(+)-thal (0.5%). Frequency of CVD was lower in Sß-thal group (p=0.05). No effect of VCAM-1 polymorphism on stroke or CVD risks was detected. Cumulative incidence of stroke was significantly higher for children with TNF-α A allele (p=0.02) and lower for children with HBA deletion (p=0.02). However, no association between CVD and TNF-α -308G>A was found. CVD cumulative incidence was significantly lower for children with HBA deletion (p=0.004). This study found no association between VCAM1 c.1238G>C and stroke. An association between stroke and TNF-α -308A allele has been suggested. Our results have confirmed the protective role of HBA deletion against stroke and CVD.

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.

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.