Evaluation of intrathecal synthesis of specific IgG antibodies against Toxoplasma gondii in the diagnosis assessment of presumptive toxoplasma encephalitis in AIDS patients.
The diagnosis of neurotoxoplasmosis in patients with acquired immunodeficiency syndrome is mainly based on tomographic or magnetic resonance findings and on the response to specific treatment. We studied 55 patients with AIDS and neurotoxoplasmosis according to these diagnostic criteria (group 1), 37 patients with AIDS and neurological involvement of other etiology (group 2), and 16 anti-HIV-negative individuals with neurological manifestations (group 3). Serum and cerebrospinal fluid were examined for the presence of anti-T. gondii IgG, by indirect immunofluorescence. In 72 of them, the total amounts of these antibodies were determined in order to assess local production of anti-T. gondii antibodies in the central nervous system and to correlate their titers with infection activity in patients with AIDS and neurotoxoplasmosis. IgG titers > or = 1/64 in cerebrospinal fluid reached 100% specificity for the diagnosis of neurotoxoplasmosis in AIDS. Evidence of local synthesis of these antibodies was detected in 42.8% of patients of group 1, in 29.1% of patients of group 2 and in no patient of group 3. The test showed 70.8% specificity and therefore was not useful in our study for the differential diagnosis of neurotoxoplasmosis in patients with AIDS.
Borges
Aercio Sebastião
AS
Centro de Ciências Biomédicas da Faculdade de Medicina da Universidade Federal de Uberlândia, Uberlândia, MG, Brasil. aerciosb@uol.com.br
Figueiredo
José Fernando de Castro
JF
D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis* / Q000276:immunology; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis* / Q000097:blood / Q000134:cerebrospinal fluid; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000097:blood / Q000134:cerebrospinal fluid; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014122:Toxoplasma / Q000276:immunology*; D016781:Toxoplasmosis, Cerebral / Q000175:diagnosis* / Q000276:immunology
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G