Further support for a role for Th2-like cytokines in blister formation of pemphigus

Pemphigus vulgaris and pemphigus foliaceus are commonly known as antibody-m ediated bullous diseases. However, recently a role for infiltrating cells a s contributors to the pathogenesis of these diseases has been suggested. Th e aims of our study were to characterize the immunophenotype of the cellula r infiltrate of pemphigus lesional skin and to study the cytokines secreted . We have therefore performed an immunohistochemical study with a large pan el of monoclonal antibodies (to CD3, CD4, CD8, CD25, CD30, myeloperoxidase, eosinophil cationic protein EG2, tryptase, human interleukin (IL)-2, human IL-4, human IL-5, human IL-6, human IL-8, and interferon (IFN)-gamma using the alkaline phosphatase-antialkaline phosphatase procedure on lesional an d uninvolved skin of six patients with clinical, histological, and immunofl uorescent proven pemphigus. We also performed RT-PCR in order to demonstrat e mRNA expression of the cytokines of interest. Our results suggest the pre sence of a T cell population with a prevalent Th2-like cytokine pattern in lesional skin. In addition, we demonstrate a consistent number of granulocy tes and mast cells that show clear signs of activation. These data suggest the involvement of an inflammatory infiltrate in the production of pemphigu s lesions. In particular, we assume that Th2 cells may be implicated in the very early stages of autoimmune response, concluding that they exert broad activity in blister formation. (C) 2000 Academic Press.