Analysis of BCL11A gene polymorphisms and hemolysis parameters in patients with sickle-cell disease

Abstract

Introduction: Patients with sickle-cell disease (SCD) present chronic hemolysis with increased serum biomarkers. Genetic polymorphisms of the BLC11A gene modulate fetal hemoglobin (HbF), thus reducing hemolysis. Objective: To associate the polymorphisms of BCL11A gene with the hemolysis markers: reticulocyte, bilirubin, uric acid, lactate dehydrogenase (LDH), and methemoglobin (MetHb) in SCD patients. Methods: The study included 45 patients with SCD of both sexes using hydroxyurea (HU), treated at a Hospital in Fortaleza, Ceará, Brazil, along with 80 healthy individuals as the control group. MetHb, uric acid, and bilirubin measurements were carried out with the spectrophotometric method, and LDH with a kinetic method, a reticulocyte count by a manual method; and evaluation of BCL11A polymorphisms, in real time polymerase chain reaction (PCR). Data were analyzed using the statistical software GraphPad Prism. The level of significance was set at < 5%. Results: In region rs7557939 of the BCL11A gene genotype, A/G showed a significant increase of MetHb (p = 0.0297), and the A/A genotype showed high concentration of LDH (p = 0.0316) in the same region. The use of HU at doses ≥ 10 mg/kg/day showed a decrease of LDH (p = 0.02), and treatment for > 50 months was linked to the reticulocyte count (p = 0.0155). Conclusion: Polymorphisms in the rs7557939 region of the BCL11A gene appear to somehow interfere in the clinical setting of patients with SCD, suggesting relation with the concentration of MetHb and LDH. This study pioneered an investigation into the association of hemolysis biomarkers with BCL11A gene polymorphisms in SCD.