Markers of disease severity amongst homozygous sickle cell anaemia attending the outpatient clinic at Bowen University Teaching Hospital, Ogbomoso

Abstract

Introduction: Genetic, cellular and molecular modifiers are responsible for the notoriously variable sickle cell phenotype. Haemoglobin F is a principal modulator of the SCD phenotype. Haemoglobin F inhibits the polymerization of Haemoglobin S and ameliorates the secondary effects of sickling. We measured the Haemoglobin F(HbF) in our population and compared it with other markers associated with clinical severity and clinical status of the patients. Methods: we randomly selected 40 Hemoglobin S(HbS) patients who have never taken hydroxyurea. We measured hemoglobin F levels, packed cell volume (PCV) and reticulocyte count to serve as markers for hemolysis, neutrophils, platelets and MCHC to serve as markers for clinical severity. We searched for a relationship between these laboratory features and frequency of vaso-occlusive crises, transfusion history and number of hospital visits per year. They were compared with twenty healthy Hemoglobin A (HbA) controls. Results: Packed cell volume was significantly lower and the reticulocyte was significantly higher in the Haemoglobin S compared with the controls. The platelet count of the sickle cell anaemia patients was more than twice the number of the controls. The mean hemoglobin F level was 7.1± 3.5 %. The hemoglobin F was negatively correlated with the platelet count but positively correlated with the total white cell count and haematocrit but there was no significant correlation between hemoglobin F and clinical features. Conclusion: The fetal hemoglobin level may not be the only modifier responsible for phenotype in population of hemoglobin S.