HTLV-1 polymyositis.

The case is described of an HTLV-1 seropositive Jamaican woman who presented with signs and symptoms of polymyositis and myelopathy. A muscle biopsy showed features of myositis with a mononuclear inflammatory infiltrate, variation in fibre size and evidence of regeneration. Immunocytochemistry showed the mononuclear cells were composed of macrophages and T-lymphocytes suggesting a cell-mediated response. Multiplex PCR demonstrated the presence of the HTLV-1 tax gene within the muscle.