Study of Interleukin-12 Cytokine and Anti-C1q Antibodies in Lupus Nephritis Patients

Objective: the present study is to evaluate interleukin-12 (IL-12) cytokine and anti-C1q antibodies in lupus nephritis patients and their correlation to systemic lupus erythematosus (SLE) disease activity. Patients: This study included 71 subjects were divided into 3 groups: Group I: 30 patients with lupus nephritis. Group II: 21 patients without lupus nephritis. Group III (control group): 20 healthy subjects. Methods: All subjects were subjected to the following: History taking, clinical examination and relevant laboratory tests, immune profile including ANA, Anti-ds-DNA, anti-C1q and IL-12 were tested in the sera of patients and controls. Renal biopsy was done in lupus nephritis patients. Results: There is significant increase in both anti-C1q and IL-12 levels in all the studied SLE patients. There is highly significant increase in both anti-C1q and IL-12 levels in the studied patients with lupus nephritis. There is a significant increase in both levels of anti-C1q and IL-12 in the studied patients without lupus nephritis. There was a positive correlation between the levels of either anti-C1q or IL-12 and the degree of SLE disease activity index (SLEDAI). There was a positive correlation between the levels of anti-C1q in group I and II with ESR, platelet count, createnine and 24hr urinary proteins (in group I). But there was negative correlation with the Hb level, WBC, C3 and C4. IL-12 level, showed significant positive correlation with WBC, platelet count, creatinine level, ESR and 24-hr urine proteins (in group I), however it showed negative correlation with the Hb level, C3 and C4 .The mean level of anti-C1q in patients with class II (non-proliferative lupus nephritis) and in patients with class III and IV (proliferative lupus nephritis) and in patients with class V (membranous lupus nephritis) showed statistically significant difference between the 3 grades (P < 0.02). The mean level of IL-12 in patients with class II (non-proliferative lupus nephritis) and in patients with class III and IV (proliferative lupus nephritis) and in patients with class V (membranous lupus nephritis) showed statistically significant difference between the 3 grades (P < 0.05). Conclusion: Anti-C1q and IL-12are good biological markers in SLE patients that correlated with disease activity and renal involvement and are a good predictors for development of lupus nephritis.