Circulating interleukin 10 and interleukin-6 serum levels in rheumatoid arthritis patients treated with methotrexate or gold salts: preliminary report.

In order to evaluate the relationship between serum concentrations of interleukin-10 (IL-10), IL-6, and acute phase proteins in rheumatoid arthritis (RA) patients treated with methotrexate (MTX) or intramuscular gold (IMG) we determined IL-10, IL-6, C-reactive protein (CRP), alpha-1-acid glycoprotein (AGP) and alpha-1-antichymotrypsin (ACT) in the sera of 35 RA patients. IL-10 and IL-6 levels were evaluated using an enzyme-linked immunoassay (ELISA). AGP and ACT level were measured using rocket immunoelectrophoresis. IL-10 serum level was not increased in RA patients as compared to controls (58.7 +/- 18.1 pg/ml vs. 57.2 +/- 11.9 pg/ml). IL-6 level was significantly elevated (91.6 +/- 46.9 pg/ml vs. 45 +/- 19 pg/ml, p < 0.05). CRP was significantly increased as compared to healthy controls (35 +/- 19 mg/l vs. 3 +/- 2 mg/l, p < 0.05). Patients treated with MTX or IMG presented an increased level of IL-10 and decreased amounts of IL-6, as compared to those treated with NSAID only. However, only changes between patients treated with IMG and NSAID were found to be statistically significant. A good negative correlation between IL-10 and IL-6 serum level was found (r = -0.75, p < 0.05). A positive significant correlation between IL-6 serum level and CRP (r = 0.62, p < 0.05), AGP (r = 0.78, p < 0.05) and ACT (r = 0.45, p < 0.05) was established.(ABSTRACT TRUNCATED AT 250 WORDS)