ELEVATED TH1 CYTOKINE MESSENGER-RNA IN SKIN BIOPSIES AND PERIPHERAL-CIRCULATION IN PATIENTS WITH ERYTHEMA-NODOSUM

It is generally believed that erythema nodosum is the result of an imm unologic attack centered within the subcutaneous fat. This belief, how ever, is based on indirect evidence. The aim of this study was to anal yze whether erythema nodosum could represent an example of a polarized Th1 or Th2 immune response. We have studied herein, by semiquantitati ve coupled reverse transcription-polymerase chain reaction the Th1 (IL -2, IFN-gamma) and Th2 (IL-4, IL-10) cytokine gene expression in skin biopsies and peripheral blood from eleven patients with erythema nodos um. As controls, we studied skin and peripheral blood from nine health y subjects. We found expression of Th1 cytokines in most erythema nodo sum skin Lesions as well as in their peripheral blood. Both Th1 and Th 2 cytokine gene expressions were scarcely or not detected in the skin and peripheral blood of control subjects. These results directly demon strate that a polarized Th1 immune response occurs in the skin lesions of erythema nodosum patients regardless of the wide variety of provok ing agents.