PCR detection of Toxoplasma gondii DNA in CSF for the differential diagnosis of AIDS-related focal brain lesions.
To evaluate whether the detection of Toxoplasma gondii DNA in CSF could contribute to the differential diagnosis of AIDS-related focal brain lesions, CSF samples from 88 HIV-infected patients (56 with focal brain lesions and 32 without) were tested prospectively by a nested PCR for the B1 gene of T. gondii. The assay had a detection limit of 10 trophozoite equivalents. Six of 18 patients with toxoplasmic encephalitis, but none of the 70 patients with other disorders, were PCR-positive (33.3% sensitivity and 100% specificity). Considering only those patients with cerebral toxoplasmosis from whom CSF was collected before or during the first week of antitoxoplasmic therapy, sensitivity rose to 50%. This was higher than the sensitivity in patients whose CSF was collected after the first week of treatment (odds ratio (OR) of 7.0; 95% CI: 0.46-218.2). The administration of antitoxoplasmic prophylaxis did not affect the PCR results. Patients with a poor response to therapy had a higher probability of detectable T. gondii DNA in their CSF (OR of 5.0; 95% CI: 0.37-86.6). All patients with other central nervous system disorders were PCR-negative. Despite the moderate sensitivity, the high specificity and positive predictive value (100%) make this assay a useful tool in the differential diagnosis of AIDS-related focal brain lesions as part of a series of CSF and neuroradiological examinations.
Cingolani
A
A
Department of Infectious Diseases, Catholic University, Rome, Italy.
De Luca
A
A
Ammassari
A
A
Murri
R
R
Linzalone
A
A
Grillo
R
R
Antinori
A
A
D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis* / Q000188:drug therapy; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D003049:Coccidiostats / Q000627:therapeutic use; D015331:Cohort Studies; D016001:Confidence Intervals; D016054:DNA, Protozoan / Q000134:cerebrospinal fluid*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013129:Spinal Puncture; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D016781:Toxoplasmosis, Cerebral / Q000175:diagnosis* / Q000188:drug therapy
D000913:Antibodies, Protozoan; D003049:Coccidiostats; D016054:DNA, Protozoan; D007074:Immunoglobulin G