The effect of interleukin-1β and interleukin-6 genetic polymorphisms on sickle cell disease course in childhood: an Egyptian study

Introduction Sickle cell disease (SCD) is a chronic inflammatory disorder characterized by altered levels of several inflammatory cytokines, which may be regulated by genetic polymorphisms and could be associated with diverse clinical presentations. Interleukin 1β (IL-1) and interleukin 6 (IL-6) have a pivotal role in the pathogenesis of many acute and chronic diseases, and their genetic alterations have been considered as molecular contributors to several inflammatory disorders. The current study aimed to define the impact of IL-1β and IL-6 genetic polymorphisms on the clinical course of the disease in a cohort of pediatric SCD patients. Material and methods Genotyping of IL-1β +3954 C/T and IL-6 –174 G/C polymorphisms was performed by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) technique for 84 SCD patients and 100 age- and gender-matched unrelated healthy controls. Results The polymorphic genotypes of IL-6 –174 G/C were associated with patients suffering from repeated, severe attacks of vaso-occlusion (VOC) requiring hospitalization (p = 0.023 and p = 0.03 respectively), while no significant differences were noted between SCD patients harboring the wild or the polymorphic genotypes of IL-1β +3954 C/T and their demographic, clinical or laboratory characteristics. Conclusions IL-6 –174 G/C polymorphism could be considered as a molecular predictor for recurrent, severe attacks of vascular occlusion in Egyptian SCD patients. Considering the important roles of cytokines in SCD pathophysiology, further investigations in larger cohorts are recommended for better characterization of individual variations in immune regulatory genes and identification of novel markers for disease complications and morbidity.