ABSTRACT
Estudamos 55 pacientes com sindrome da imunodeficiência adquirida (SIDA) e neurotoxoplasmose (grupo 1); 37 pacientes com SIDA e comprometimento neurológico por outra etiologia (grupo 2) e 18 indivíduos anti-HIV negativos com manifestações neurológicas (grupo 3), pesquisando IgG, IgA e IgM anti-Toxoplasma gondii, no soro, líquor e saliva, utilizando teste ELISA, para fins diagnósticos. O valor preditivo negativo do teste para o encontro de IgG no soro foi 100 por cento e no líquor, 92,4 por cento. Não houve diferença entre os três grupos quanto aos anticorpos IgA neste material. Para IgA, no líquor, o teste alcançou 72,7 por cento de especificidade (p<0,05). Na saliva, apenas o encontro de IgG mostrou correlação com o diagnóstico de neurotoxoplasmose. Enfatizamos que a ausência de anticorpos IgG anti-T. gondii no soro e líquor depõe fortemente contra o diagnóstico de neurotoxoplasmose e que imunoglobulinas IgA específicas no líquor e IgG na saliva podem representar dois marcadores auxiliares para o diagnóstico diferencial da encefalite toxoplásmica na SIDA.
Subject(s)
Animals , Humans , Male , Female , AIDS-Related Opportunistic Infections/immunology , Antibodies, Protozoan/analysis , Immunoglobulin Isotypes/analysis , Toxoplasma/immunology , Toxoplasmosis, Cerebral/immunology , AIDS-Related Opportunistic Infections/diagnosis , Antibodies, Protozoan/blood , Antibodies, Protozoan/cerebrospinal fluid , Biomarkers/blood , Biomarkers/cerebrospinal fluid , Enzyme-Linked Immunosorbent Assay , Immunoglobulin A/blood , Immunoglobulin A/cerebrospinal fluid , Immunoglobulin G/blood , Immunoglobulin G/cerebrospinal fluid , Immunoglobulin M/blood , Immunoglobulin M/cerebrospinal fluid , Predictive Value of Tests , Saliva/chemistry , Toxoplasmosis, Cerebral/diagnosisABSTRACT
Active infection by T. gondii was evaluated by immunoassay for soluble SAG-1 (p30), the major surface antigen from T. gondii, specific antibodies and immune complexes in human cerebrospinal fluid (CSF) samples. A total of 263 samples of CSF were collected from hospitalized patients presenting neurological disorders and analyzed for antibodies to HIV. Patients were divided into two groups: HIV positive (n = 96) or HIV negative (n =167). The results of the assays showed that 45 of all samples were positive for soluble SAG-1. Toxoplasma Ag/Ab immune complexes were detected in 19 of the CSF samples and 62 were positive for T. gondii- specific IgG. A combination of these assays in the presence of clinical findings consistent with active Toxoplasma infection may predict the presence of toxoplasmic encephalitis. Moreover, detection of soluble SAG-1 in the CSF of these individuals appears consistent with active infection.