Abstract
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 assgciations with clinical disease activity.
Methods
We measured blood concentrations of interleukin-1 R (IL-1p), 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-1beta (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-1beta, 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-1beta 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.