RESUMO
OBJECTIVE: To investigate a possible association between human T cell leukemia/lymphoma virus type I (HTLV-I) and polymyositis (PM). METHODS: Sera and muscle biopsy samples from 9 Jamaican PM patients were compared with specimens from American HTLV-I positive PM patients and normal controls. Sera were evaluated for HTLV antibodies by enzyme-linked immunosorbent assay and Western blot. The biopsy samples were analyzed for HTLV-I/II DNA by polymerase chain reaction and were also immunohistochemically stained for HTLV gp46 envelope protein. RESULTS: Seven of the 8 Jamaican PM patients from whom sera were available were HTLV-I seropositive. The muscle biopsies of all 9 Jamaican patients demonstrated severe lymphocytic infiltration, cellular degeneration, myofiber atrophy, and fibrosis. Each muscle biopsy specimen contained HTLV-I DNA. Two of 6 samples demonstrated intense staining for HTLV-I gp46 in many of the invading mononuclear cells and weak staining for HTLV-I gp46 in many of the other specimens were weakly positive for gp46 in rare mononuclear cells. All controls specimens were negative for the presence of HTLV-I DNA and protein. CONClUSION: HTLV-I is associated with an inflammatory muscle disease characterized by direct invasion of the affected muscle by HTLV-I-infected mononuclear cells.(AU)
