Background and aims To study the levels of proinflammatory cytokines (IL6, TNFα, IFN-γ) in systemic lupus erythematosus(SLE) patients as compared to healthy control volunteers and to correlate the levels of cytokines with clinical features in Indian patients

Methods After obtaining Institutional ethical clearance and written informed consent, 88 consecutive SLE patients(newly diagnosed and those in remission) and 60 age and sex matched healthy controls were taken for the study, which was conducted between June to December 2015 in a tertiary care centre. Patients who had overlap syndromes, Mixed connective tissue disorder, antiphospholipid antibody syndrome, secondary Sjogrens syndrome, Lupus flare due to infections and offending drugs,were excluded. A thorough history, clinical examination, baseline biochemical and immunological investigations were done. Serum IL6, TNFα, IFN-γ were estimated in all patients and controls by ELISA. Statistical methods were done using SPSS software.

Results Serum interferon γ levels were higher in patients (mean±SD=25.65±64.81 pg/ml; median 8) than the controls (mean±SD=2.95±10.28 pg/ml, median-0), (p=0.0080). Serum IL6 levels were also higher in patients (mean±SD=143.01±64.94 pg/ml) than controls (mean±SD=69.33±11.7 pg/ml),(p<0.0001). Serum TNF-α were also elevated in patients (mean±SD=427.13±206.49 pg/ml; median 384.5) than controls (mean±SD=236.05±23.53 pg/ml; median 238),(p<0.0001). Interferon γ levels were significantly higher in females, lower in patients with lymphadenopathy and significantly higher in lupus nephritis class III,positively correlated with thrombocytopenia and negatively correlated with ESR, dsDNA, C3, C4. IL6 and TNF α were significantly associated with oral ulcer and alopecia respectively. Both showed a positive correlation with ESR, dsDNA, C3, C4. Cytokines didn’t correlate with SLEDAI.

Conclusions IL6 and TNF α are reliable markers of disease activity, but lack significant clinical correlation.