Polymyositis Mediated by T Lymphocytes That Express the γ/δ Receptor

Abstract

The invasion and destruction of nonnecrotic muscle fibers by CD8+ cytotoxic T cells is considered a hallmark of polymyositis. In the cases of polymyositis reported so far, the autoinvasive CD8+ T cells expressed the common form of T-cell receptor for the recognition of antigen, the so-called α/β T-cell receptor. We describe a 69-year-old man with polymyositis mediated by CD4—, CD8— T cells expressing the recently discovered, uncommon γ/δ T-cell receptor.