ABSTRACT Introduction: Hemoglobinopathy Sβ-thalassemia (HbSβ-thal) has a wide range of clinical and laboratory severity. There is limited information on the natural history of HbSβ-thal and its modulating factors. We described the molecular, hematological, and clinical characteristics of a cohort of children with HbSβ-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 β-thal mutations were identified. The incidence of HbSβ-thal in the state was 1 per 22,250 newborns. The most common βS-haplotypes were CAR and Benin. The most frequent βthal-haplotypes were V, II, and I. Coexistence of 3.7 kb HBA1/HBA2 deletion was present in 21.3 % of children. β-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 HbSβ0-thal, IVS-I-5 G>A, and IVS-I-110 G>A. Children with HbSβ+-intermediate phenotypes had a more severe laboratory and clinical profile when compared with those with HbSβ+-mild ones. βS-haplotypes and α-thalassemia did not meaningfully influence the phenotype of children with HbSβ-thal. Conclusion: The early identification of b-thalassemia alleles may help the clinical management of these children. © 2023 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier España, S.L.U. This is an open access article under the CC BY-NC-ND license Introduction Sβthalassemia Sβ thalassemia HbSβthal HbSβ thal (HbSβ-thal severity factors molecular hematological Gerais Brazil Methods records sequencing PCRRFLP, PCRRFLP PCR RFLP, RFLP PCR-RFLP gapPCR, gapPCR gap PCR, gap-PCR MLPA Results Eightynine Eighty nine study βthal β identified 22250 22 250 22,25 newborns βShaplotypes βS haplotypes Benin βthalhaplotypes V II I 37 3 7 3. HBA1HBA2 HBAHBA HBA1 HBA2 HBA HBA1/HBA 213 21 21. βthalassemia features general 10 patientyears patient years HbSβ0thal, HbSβ0thal HbSβ0 thal, HbSβ0-thal IVSI5 IVSI IVS 5 IVS-I- G&gtA, GgtA G&gt A, G gt A G>A IVSI110 110 IVS-I-11 G&gtA. A. HbSβ+intermediate HbSβintermediate HbSβ+ intermediate HbSβ+mild HbSβmild mild ones αthalassemia α HbSβthal. thal. Conclusion bthalassemia b 202 Hematologia Celular España SLU S L U S.L.U BYNCND BY NC ND 2225 2 25 22,2 HBA1HBA IVS-I gtA G&gtA Ggt IVSI11 11 IVS-I-1 20 222 22, IVSI1

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.

ABSTRACT Cerebrovascular disease, particularly stroke, is one of the most severe clinical complications associated with sickle cell disease and is a significant cause of morbidity in both children and adults. Over the past two decades, considerable advances have been made in the understanding of its natural history and enabled early identification and treatment of children at the highest risk. Transcranial Doppler screening and regular blood transfusions have markedly reduced the risk of stroke in children. However, transcranial Doppler has a limited positive predictive value and the pathophysiology of cerebrovascular disease is not completely understood. In this review, we will focus on the current state of knowledge about risk factors associated with ischemic stroke in patients with sickle cell disease. A search of PubMed was performed to identify studies. Full texts of the included articles were reviewed and data were summarized in a table. The coinheritance of alpha-thalassemia plays a protective role against ischemic stroke. The influence of other genetic risk factors is controversial, still preliminary, and requires confirmatory studies. Recent advances have established the reticulocyte count as the most important laboratory risk factor. Clinical features associated with acute hypoxemia as well as silent infarcts seem to influence the development of strokes in children. However, transcranial Doppler remains the only available clinical prognostic tool to have been validated. If our understanding of the many risk factors associated with stroke advances further, it may be possible to develop useful tools to detect patients at the highest risk early, improving the selection of children requiring intensification therapy.

ABSTRACT Background: The etiology of stroke, a severe complication of sickle cell anemia, involves inflammatory processes. However, the pathogenetic mechanisms are unknown. The aim of this study was to evaluate the influence of interleukin-10 polymorphisms and haplotypes on the risk of acute cerebral ischemia and high-risk transcranial Doppler in 395 children with sickle cell anemia from the state of Minas Gerais, Brazil. Methods: Interleukin-10 haplotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and sequencing. The outcomes studied were acute cerebral ischemia and high-risk transcranial Doppler. Clinical data were retrieved from the children's records. Results: There was no statistically significant difference in the frequencies of polymorphisms and haplotypes between children with and without acute cerebral ischemia or children with or without high-risk transcranial Doppler. These data are consistent with a previous report that showed an absence of association between interleukin-10 plasma levels and high-risk transcranial Doppler velocity in children with sickle cell anemia. Conclusion: Interleukin-10 haplotypes were not associated with the risk of acute cerebral ischemia or high-risk transcranial Doppler velocity in children with sickle cell anemia from the state of Minas Gerais, Brazil.

ABSTRACT INTRODUCTION: The hemoglobin FSD is very uncommon in newborn screening programs for sickle cell disease. In the program of Minas Gerais, Brazil, the clinical course of children with hemoglobin SD was observed to be heterogeneous. The objective of this study was to estimate the incidence (1999-2012) and to describe the natural history of a cohort of newborns with hemoglobin SD. METHODS: Isoelectric focusing was the primary method used in newborn screening. Polymerase chain reaction-restriction fragment length polymorphism and gene sequencing were used to identify mutant alleles and for haplotyping. Gap-polymerase chain reaction was used to detect alpha-thalassemia. RESULTS: Eleven cases of hemoglobin S/D-Punjab and eight of Hb S-Korle Bu were detected. Other variants with hemoglobin D mobility were not identified. All hemoglobin D-Punjab and hemoglobin Korle Bu alleles were associated with haplotype I. Among the children with hemoglobin S/D-Punjab, there were four with the ßS CAR haplotype, six with the Benin haplotype, and one atypical. Results of laboratory tests for hemoglobin S/D-Punjab and hemoglobin S-Korle Bu were: hemoglobin 8.0 and 12.3 g/dL (p-value <0.001), leukocyte count 13.9 × 109/L and 10.5 × 109/L (p-value = 0.003), reticulocytes 7.5% and 1.0% (p-value <0.001), hemoglobin F concentration 16.1% and 6.9% (p-value = 0.001) and oxygen saturation 91.9% and 97% (p-value = 0.002), respectively. Only hemoglobin S/D-Punjab children had acute pain crises and needed blood transfusions or hydroxyurea. Those with the Benin ßS haplotype had higher total hemoglobin and hemoglobin F concentrations compared to the CAR haplotype. Transcranial Doppler was normal in all children. CONCLUSION: The clinical course and blood cell counts of children with hemoglobin S/D-Punjab were very similar to those of hemoglobin SS children. In contrast, children with hemoglobin S-Korle Bu had clinical course and blood cell counts like children with the sickle cell trait.

Cyanosis in an apparently healthy newborn baby may be caused by hemoglobin variants associated with the formation of methemoglobin, collectively known as M hemoglobins. They should not be confused with genetic alterations in methemoglobin reductase enzyme systems of red cells since treatment and prognosis are completely different. A newborn male child was noted to be significantly cyanotic at birth and is the basis for this report. Hemoglobin isoelectric focusing, acid and alkaline gel electrophoresis, and HBA/HBB gene sequencing were performed for the child, both parents and a sister. The newborn child was treated with methylene blue in an intensive care unit fearing that he had a defective reductase system and exposure to oxidant drugs or toxins. Newborn hemoglobin screening with high performance liquid chromatography was abnormal on the 10th and 45th days but no conclusive diagnosis was reached. Cyanosis persisted up to four years of age with no other symptoms. Hemoglobin M Iwate [alpha2 87(F8) His>Tyr, HBA2:c.262C>T] was detected. It was not present in the child's presumed mother, father, sister, and brother. The analysis of 15 short tandem repeats in the trio demonstrated a de novo mutation occurrence (p-value < 1 × 10 -8). The family was reassured that no further action was necessary and genetic counseling was provided. Methemoglobins should be considered for differential diagnosis of cyanosis in newborns even if no familial cases are detected. Except for cosmetic consequences, the clinical course of patients with hemoglobin M Iwate is unremarkable.