Serum and urinary cytokine levels of SLE patients.

Systemic lupus erythematosus (SLE) is a chronic, relapsing, polysystemic autoimmune disease with various clinical signs. The prognosis of SLE patients is influenced by neuropsychiatric and renal involvement. Lupus nephritis (LN) is present in 40-60% of patients. Classical laboratory parameters are not sensitive and specific in prediction renal flares, over the last few years there has been a growing interest in searching novel lupus biomarkers predicting future flares. Our goal was to detect serum and urinary level of cytokines in 36 patients with lupus nephritis (34 female and 2 male, mean age: 43.36 +/- 11.53 years), 23 patients with SLE without renal involvement (19 women and 4 men, mean age: 54 +/- 8.71) (both groups followed by the 3rd Department of Internal Medicine, Division of Clinical Immunology, University of Debrecen) and 30 healthy controls (23 female and 7 male, mean age: 45.5 +/- 12.4). Serum IL-1 (interleukin), IL-2 (both p < 0.05), IL-6, IL-13 and IFN-gamma (p < 0.001) levels were significantly higher in lupus nephritis patients, as compared to patients with SLE without renal involvement and healthy controls. Urinary level of IL-1 and TNF-alpha were significantly higher in SLE patients without renal disease (p = 0.012 and p < 0.001), while urinary IFN-gamma was significantly higher in LN patients (p = 0.002). Measurement of IL-6 level in SLE patients could help to predict future renal involvement of SLE patients.