Background Interleukin-6 (IL-6) is a Pro-Inflammatory cytokine with many biological activities. IL-6 is mainly involved in immunity and inflammatory process. It induces the terminal differentiation of B lymphocytes into antibody-forming cells and the differentiation of T cells into effector cells. Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by antibodies to nuclear and cytoplasmic antigens, multisystem inflammation, protean clinical manifestations, and relapsing course. We designed a study to establish the correlation between IL-6 and the severity of SLE.

Methods About 52 SLE-diagnosed patients were recruited based on the 1997 Updated American College of Rheumatology Revised Criteria for Classification of SLE in our centre. Their venous blood was taken and centrifuged at 4500RPM for about 5mins, and the serum was collected. ELISA test was done on these sera, and the data obtained was recorded in the form of a scatter plot and statistics, in which any ‘P’ value of >0.05 was significant. The severity of the subject’s SLE was quantified using BILAG Index. The index allocates alphabetic scores to each of the ten organ-based systems, and then a total score is calculated.

Results We found a direct correlation between the level of IL-6(statistically significant P=0.005) and the severity of the SLE. The IL-6 mean value was taken as 132.6pg/ml, while a linear scatter plot was obtained. Pearson correlation coefficient showed a linear correlation between the two variables. Thus, the higher the IL-6 levels, the higher the BILAG score.

Conclusions Serum IL-6 levels can be used to screen, diagnose, and act as a prognostic factor in the development and progression of SLE. These findings may open the opportunity for a new horizon in the early detection and treatment of SLE patients, which will greatly implicate the disease’s complications and the cost of treating it.