RESUMO
OBJECTIVE: To evaluate the effect of methotrexate (MTX) in combination with prednizone on cytokine levels, acute phase proteins and thiobarbituric acid reactive substances (TBAR--an indicator of peroxidative damage to tissue lipids) in the blood of rheumatoid arthritis (RA) patients and to investigate their associations with clinical disease activity. METHODS: We measured blood concentrations of interleukin-1 beta (IL-1 beta), interleukin- 6 (IL-6), TBARs and classical clinical and laboratory indices of disease activity in 36 RA subjects before and after 3 and 6 month treatment with MTX and prednizone. Only RA subjects who stopped any disease-modifying anti rheumatic drugs treatment for last 3 months were included in the study. Baseline cytokine and TBARs levels were compared with those obtained with 20 healthy controls. RESULTS: Compared to controls RA subjects had elevated levels of circulating IL-1 beta (63.3 +/- 47.6 vs 13.7 +/- 7.8 pg/ml, p<0.01), IL-6 (147.2 +/- 76.5 vs 15.9 +/- 13.3 pg/ml, p<0.001) and TBARs (3.11 +/- 0.42 vs 1.34 +/- 0.45 nmol/1, p<0.001) concentrations. MTX in combination with prednizone improved patient clinical status that was accompanied by 1.96-, 1.25-, and 1.35-fold decrease in IL-1 beta, IL-6 and TBARs after 6 month treatment (p<0.001), respectively. Although, IL-1 and IL-6 revealed a few correlations with classical indices of disease activity no association was found between patient clinical status improvement and cytokine changes over 6 month treatment. CONCLUSIONS: MTX in combination with prednizone decreases blood levels of IL-1 beta and IL-6 and inhibits the intensity of free radical- mediated processes in RA subjects. Monitoring of plasma concentrations of these cytokines could not predict the treatment efficacy.
