Study of Serum Complement 3 Split Product iC3b /C3 Ratio in a Cohort of Systemic Lupus Erythematosus Patients

Abstract

Abstract Background Systemic lupus erythematosus (SLE) is a chronic autoimmune systemic disease that causes widespread multi organ inflammation. The exact cause of SLE remains unclear; however, genetic, hormonal, and environmental factors contribute to the development of the disease. Aim of the Work The aim of this study is to measure the ratio of complement split product iC3b to C3 and its relation to disease activity and lupus nephritis in a cohort of SLE patients. Patients and Methods This study is a Cross sectional case control study conducted in internal medicine and Rheumatology unit, Ain Shams university hospital and Rheumatology unit, Maadi military hospital. Our study included. Results The present study shows that female were (76%) in active group of SLE patients and (60%) in inactive group while male were (24%) and (40%) respectively. with no significant difference. The mean of Disease Duration was (5.66 ± 1.97) with a range from 3 and 10 years in active group of SLE patients and (5.08 ± 1.54) with a range from 3 and 9 years in inactive group. with no significant difference. Regarding clinical manifestations of SLE the present study shows that active group of SLE patients had statistically highly significant increase in incidence of lupus nephritis, arthritis, serositis, oral ulcers, malar rash (p < 0.001) with significant increase in incidence of alopecia and neurological manifestations (p < 0.05). The current study shows that active group of SLE patients had statistically significantly higher mean ESR, anti-DNA titre, 24hr urinary proteins, serum creatinine, serum urea, and GFR levels (p = 0.000) than inactive group, Also active group had significant leucopenia, anemia (p = 0.000, 0.005 respectively) and C3 was significantly more consumed than inactive group (p < 0.05) Conclusion The ratio of complement split product iC3b to C3 concentrations correlates with the extent of SLE disease activity more than C3 alone. Furthermore, the iC3b:C3 ratio may discriminate between patients with lupus nephritis and patients without lupus nephritis. Detection of SLE disease activity and lupus nephritis by iC3b/C3 ratio help to make a proper decision in management to induce remission.