TUMOR-NECROSIS-FACTOR-ALPHA (TNF-ALPHA), INTERLEUKIN-6 (IL-6) AND THEIR SOLUBLE RECEPTORS (STNF-ALPHA-RP55 AND SIL-6R) SERUM LEVELS IN SYSTEMIC LUPUS ERYTHEMATODES

WE investigated a possible association between serum concentrations of tumour necrosis factor alpha(TNF-alpha), interleukin-6 (IL-6) and the ir soluble receptors (sTNF-alpha-Rp55 and sIL-6R) using an enzyme-link ed immunosorbent assay (ELISA) in 55 patients with systemic lupus eryt hematodes (SLE) and 16 healthy controls. We also examined a possible a ssociation between the serum levels of these peptides and SLE activity , as well as TNF-alpha and IL-6 concentrations and the levels of their soluble receptors. The median concentrations of TNF-alpha, sTNF-alpha -Rp55 and IL-6 were significantly higher in SLE patients than in norma l individuals. In contrast, there was no difference between the serum level of sIL-6R in both groups. We found positive correlations between the serum concentrations of TNF-alpha and IL-6 as well as their solub le receptors and disease activity. There were also correlations betwee n TNF-alpha and sTNF-alpha-Rp55 as well as IL-6 and sIL-6R serum level s in SLE patients but there were no such correlations in the normal co ntrol group. In conclusion, an increase in the serum levels of TNF-alp ha, sTNF-alpha-Rp55 and IL-6 may become useful markers for SLE activit y. Patients with SLE have sIL-6R serum concentration similar to that a s in normal individuals. However, it correlates with disease activity and the level of IL-6.