ABSTRACT
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.
Subject(s)
Albuminuria/physiopathology , Anemia, Sickle Cell/complications , Glomerular Filtration Rate/physiology , Adolescent , Adult , Child , Child, Preschool , Cohort Studies , Female , Humans , Infant , Male , Prevalence , Risk Factors , Young AdultABSTRACT
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 1.1â¯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.
