Interleukin-1\u03b2 and interleukin-6 gene polymorphisms in Egyptian sickle cell disease patients

Abstract

BackgroundSickle cell disease (SCD) is a disorder characterized by a heterogeneous clinical outcome. Interleukin-1β (IL-1β) and interleukin-6 (IL-6) are important mediators of inflammatory response. Genetic modifiers that alter cytokine levels may contribute to the clinical variability of SCD. The present study investigated the associations of IL-1β + 3954 C>T and IL-6 (− 174G>C and − 597 G>A) gene polymorphisms with clinical and laboratory data in SCD patients. The study was conducted on 100 SCD patients (59 sickle cell anemia patients “SS” and 41 sickle beta thalassemia patients “Sβ”). Fifty age- and sex-matched healthy volunteers were included as a control group. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used for the detection of IL-1β and IL-6 gene polymorphisms.ResultsThe homomutant genotypes of IL-1β (+ 3954 C>T), IL-6 (− 174G>C), and IL-6 (− 597 G>A) were infrequently presented among SCD patients and control group. No significant differences were detected between SS, Sβ patients, and control group as regards the genotypic frequencies and allele distributions of the studied polymorphisms. As regards the clinical complications, the mutant genotypes of IL-1β (+ 3954 C>T) had a significantly higher frequency among Sβ patients with splenomegaly. Hemoglobin is significantly lower in SS patients with mutant allele (AA and GA) for IL-6 (− 597 G>A) (P = 0.005), while Sβ patients with mutant genotype for IL-6 (− 597 G>A) had significantly higher total leucocytic count (P = 0.031).ConclusionIL-1β (+ 3954 C>T), IL-6 (− 174G>C), and IL-6 (− 597G>A) polymorphisms are not associated with disease phenotype. However, IL6 polymorphism (− 597 G>A) might predispose to underlying inflammatory process.