Detection of Toxoplasma gondii in AIDS patients by the polymerase chain reaction.

In recent years, toxoplasmosis has become one of the most frequent and life-threatening opportunistic infections in AIDS patients. Despite strict clinical follow-up and repeated biological examinations, its diagnosis remains difficult to establish in the context of immunodeficiency because of the poor predictive value of serology. The aim of the study was to compare standard methods of diagnosis with the polymerase chain reaction (PCR), in an attempt to investigate the potential usefulness of PCR in the diagnosis of toxoplasmosis. Twelve biological samples (cerebrospinal fluid, bronchoalveolar lavage fluid, one brain biopsy and one liver biopsy) from 11 unselected AIDS patients were tested by PCR. The results showed good correlation (for eight out of 11 patients) between classical methods and PCR, and confirm the value of bronchoalveolar lavage for the diagnosis of toxoplasmosis in AIDS patients. The pathophysiological significance of the presence of Toxoplasma in samples tested is discussed.