HTLV-1 associated polymyositis in Jamaica

The clinical, laboratory and epidemiological characteristics of 38 adult Ja maican patients with polymyositis were evaluated. Twenty-four patients (63% ) were human T-lymphotropic virus 1 (HTLV-1) seropositive and 14 patients ( 37%) were HTLV-1 seronegative. Polymyositis runs a more protracted course i n seropositive patients who had more frequent hospital admissions and a sig nificantly longer duration of symptoms prior to presentation. Joint swellin g, chest pain and dyspnoea were more frequent complaints among the seronega tive patients. There was no significant difference between the two serologi cal groups in muscle enzyme levels, antinuclear antibody positivity or freq uency of Jo-1 antibodies. HTLV-1 infection may define a subgroup of polymyo sitis patients with a more insidious presentation and poorer response to co rticosteroid therapy.