Serologic evidence of toxoplasmosis among patients with polymyositis

Abstract The prevalence and quantity of anti-Toxoplasma antibodies were greater in a group of 10 patients with polymyositis than in patients with other inflammatory muscle diseases or other diseases. Eight of these patients with polymyositis had positive Sabin-Feldman tests. Complement-fixing antibodies, usually associated with recent infection, were present in five of them. These patients had no other findings suggestive of acute toxoplasmosis except for myocarditis, which occurred in one. The prevalence of positive serologic findings was not related to age, birthplace or steroid therapy. Most positive results in patients with polymyositis occurred in those who had had the disease for 1 year or less. Sequential antibody titers were obtained in four patients with polymyositis. All had unusually elevated antibody titers early in the disease with a fall in titers after several months. Attempts at isolation of T. gondii from three of these patients failed. Three patients were treated with pyrimethamine and sulfonamides; one died within weeks and the other two showed gradual improvement within months.