Levels of cytokine inhibitors: a possible marker of disease activity in childhood dermatomyositis and polymyositis.

The levels of cytokines and of their inhibitors were assessed by ELISA in serum samples from 3 children with dermatomyositis (DM) and polymyositis (PM) who were followed for several years. We observed normal levels of IL-6 and TNF alpha, but increased concentrations of IL-1Ra and TNF-sR75 at disease onset, which was followed by a decrease in the levels of IL-1Ra and TNF-sR75 in the patients with a favorable disease outcome. In contrast, in the one patient who relapsed no correlation with the levels of cytokines or of their inhibitors could be established. These results suggest that cytokine inhibitors such as IL-1Ra and TNF-sR may be useful additional parameters for monitoring the evolution of DM and PM.