In-vitro synthesis of antibodies to Toxoplasma gondii by lymphocytes from HIV-1-infected patients.

Toxoplasma-specific in-vitro antibody production by peripheral blood lymphocytes (PBL) was investigated in 124 adults infected with human immunodeficiency virus (HIV-1). PBL from 20 of 21 patients with cerebral toxoplasmosis showed spontaneous in-vitro secretion of antibodies to Toxoplasma gondii antigens. Among 103 HIV-1-infected patients without signs or symptoms of toxoplasmosis, PBL from 19 produced toxoplasma-specific antibodies in vitro; 5 of these patients, who discontinued prophylaxis for toxoplasmic encephalitis, showed in-vitro antibody production 3-15 months before the diagnosis of toxoplasmic encephalitis. In-vitro production of toxoplasma-specific antibodies could improve the diagnosis of toxoplasmic encephalitis in HIV-1-infected patients.