Use of murine subinoculation for the diagnosis and isolation of toxoplasmosis in HIV-infected patients with persistent lymphadenopathy.
A murine model was used to try to elucidate the importance of Toxoplasma gondii infection in HIV-positive patients. Laboratory mice were inoculated with lymph node homogenates or buffy coats from 30 HIV-infected individuals with persistent lymphadenopathy. Sabin and Feldman dye-tests, direct agglutination tests and indirect immunofluorescence assays (IFA) of serum samples taken from the mice six weeks after inoculation indicated, respectively, that 26.6%, 43.4% and 33.3% of the lymph node inocula and 13.3%, 30.0% and 16.7% of the buffy coat samples had been Toxoplasma-positive. Histological examination of the brains of the infected mice revealed Toxoplasma tachyzoites or bradyzoites in the mice given buffy coat samples from one patient (3.3%) and those given lymph node material from three patients (10%). No protozoa were found in the brains of the control mice, all of which were sero-negative. In contrast to the mouse results, other, concurrent tests failed to detect any signs of toxoplasmosis infection in the patients, except relatively low titres of anti-Toxoplasma antibodies in 11 patients, even though two patients developed brain toxoplasmosis, one 12 and the other 18 months after the study. It appears, therefore, that an animal model can be very useful in the diagnosis of toxoplasmosis in HIV patients.
Diego
J A
JA
Departamento de Medicina Preventiva y Salud Publica, Facultad de Medicina (UAM), Madrid, Spain.
Vazquez
J J
JJ
Penin
P
P
Fernandez
J
J
Sanchez
S
S
Gamallo
C
C
D000386:AIDS-Related Complex / Q000150:complications*; D000293:Adolescent; D000328:Adult; D000818:Animals; D001921:Brain / Q000469:parasitology; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D008297:Male; D051379:Mice; D014122:Toxoplasma / Q000302:isolation & purification; D014124:Toxoplasmosis, Animal / Q000175:diagnosis*