Effect of interleukin-1β gene polymorphisms on clinicopathological features and disease activity of systemic lupus erythematosus

Abstract

Background Systemic lupus erythematosus (SLE) is responsible for severe disability and represents a major cause of chronic illness. Interleukin (IL)1β is a proinflammatory cytokine. We aimed to explore the possible associations of IL1β-511C/T (rs16944) and IL1β +3954C/T (rs1143634) gene polymorphisms with SLE, and to detect whether these polymorphisms are associated with disease activity of SLE. Moreover, we aimed to clarify the effect of these polymorphisms on clinical and biochemical parameters of SLE. Patients and methods Polymorphisms of IL1β-511 and IL1β +3954 genes were assessed in a case-control study comprising 110 patients with SLE and 90 controls. Disease activities were assessed by systemic lupus erythematosus disease activity index (SLEDAI). Serum IL-1β was estimated using an enzyme-linked immune sorbent assay. Genetic variants were genotyped using PCR-restriction fragment length polymorphism. Results Our results revealed higher values of IL1β in patients with SLE. In addition, there was a significant positive correlation between IL-1β serum level and SLEDAI score. The CT genotype distribution was significantly higher in patients with SLE than controls. Regarding IL1β +3954 gene polymorphisms, our results showed nonsignificant difference between control and SLE groups. In an attempt to estimate the diagnostic power of serum IL1β serum in differentiating patients with SLE from the control group, we found that the sensitivity was 94.5%, and the specificity was 99%. In conclusion, the CT genotype distribution of IL1β-511 was significantly higher in patients with SLE than controls. However, there was a nonsignificant difference regarding IL1β +3954 gene mutation.

Keywords

• interleukin1β single nucleotide polymorphisms
• systemic lupus erythematosus
• systemic lupus erythematosus disease activity index