SERUM LEVELS OF INTERLEUKIN-6 AND TUMOR-NECROSIS-FACTOR-ALPHA ARE NOTCORRELATED TO DISEASE-ACTIVITY IN PATIENTS WITH RHEUMATOID-ARTHRITIS AFTER TREATMENT WITH LOW-DOSE METHOTREXATE

Cytokines are major mediators of inflammatory responses in rheumatoid arthritis. Some of them have been shown to correlate with the disease activity and thus are proposed to be used for monitoring patients. The refore the effects of a low-dose therapy with methotrexate on serum co ncentrations of interleukin-6 (IL-6) and tumour-necrosis-factor-alpha (TNF-alpha) were examined in eight patients with seropositive rheumato id arthritis. Serum levels of IL-6 and TNF-alpha were significantly el evated in patients compared to healthy controls. Before the onset of M TX treatment IL-6 concentrations were correlated to the c-reactive pro tein (P < 0.05) but the correlation was abolished after treatment. For TNF-alpha no correlations neither before nor after treatment were obs erved. Both cytokines remained substantially elevated after MTX treatm ent despite a clear reduction in disease activity. Thus we suggest tha t one of the effects of MTX might be the inhibition of some of the act ions of IL-6 and TNF-alpha.