Background: Hitherto, not very numerous investigations provided so far only few often controversial findings on the importance of interleukin-10 (IL-10) in systemic lupus erythematosus (SLE). The objective of the present investigation was to assess whether there exist practically applicable relations between the serum level of IL-10, clinical and laboratory indicators of activity of the disease and serum levels of selected cytokines or their soluble receptors.
Methods and results: The authors analyzed a group of 23 patients with SLE (23 women and 1 man, median age 37 years). Interleukin-10 and other cytokines were examined by the ELISA method, the clinical activity of the disease was evaluated by the ECLAM system (European Consensus Lupus Activity Measurement). Elevated IL-10 values (> 5 pg/ml) were assessed in 10 (43%) patients. Correlation analysis (Pearson's test, p < 0.05) revealed statistically significant relations between IL-10 levels and the activity of the disease, values of antibody levels against dsDNA and levels of the soluble receptor IL-2 (sIL-2R) in serum. Conversely, no relationship was revealed between values of IL-10 and values of C3 and C4 complement components, IL-1, IL-2, IL-6, sIL-6R, TNF-alpha, sTNFR-alpha and INF-gamma.
Conclusions: Elevated IL-10 serum levels in patients with SLE did not have, with the exception of the index of clinical activity of the disease, antibodies against dsDNA and sIL-2R any statistically significant relations to laboratory indicators of disease activity and levels of selected cytokines and their soluble receptors.