Alloimmunization in children with sickle cell disease: A tertiary care experience

Abstract

IntroductionPatients with sickle cell disease (SCD) show a high prevalence of red blood cell (RBC) alloimmunization, however, few studies have focused on children. The present study was undertaken to determine the prevalence of alloimmunization and autoimmunity in children with SCD and to assess any correlation with age, number of transfusions received, and the number and frequency of crisis. Material & methodsSixty children affected with homozygous SCD, aged between five to eighteen years and having received more than one packed red blood cell (PRBC) transfusion were enrolled in the study.The preliminary tests included antiglobulin test (indirect and direct), alloantibody screening by three panel, antibody typing using 11 panel and auto-control test to detect autoantibodies. ResultsDirect antiglobulin test was negative in all the 60 patients, whereas indirect antiglobulin test was positive in 4/60 (6.6%) patients. Specific typing of alloantibodies revealed anti-D and anti-Kell antibodies in 2 (3.3%) each. Patients with alloantibody (4) had a higher mean age at onset of first symptom (7.05 ± 2.12 years) and age at first transfusion (7.5 ± 2.12 years) as compared to those without alloantibody, (4.48 ± 3.09 and 4.91 ± 3.12 years respectively). Patients with alloantibody received more PRBC transfusions, maintained low hemoglobin, required higher doses of hydroxyurea and also had a larger liver and spleen. ConclusionThe present study found a low prevalence of antibodies in patients with SCD. Patients presenting with symptoms of SCD at younger age received hydroxyurea at an earlier age. Starting hydroxyurea at an earlier age may decrease subsequent alloantibodies development. Larger studies to compare groups of patients related to administration of hydroxyurea are required to confirm this hypothesis.