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.

Improved detection of JC virus DNA in cerebrospinal fluid for diagnosis of AIDS-related progressive multifocal leukoencephalopathy.

Several methods to increase the sensitivity of JC virus (JCV) DNA detection in cerebrospinal fluid (CSF) for a noninvasive diagnosis of AIDS-related progressive multifocal leukoencephalopathy (PML) were investigated. When CSF collected at clinical presentation was tested, JCV DNA was detected in 8 of 19 patients with PML by standard PCR (sensitivity, 42%; 95% confidence interval [CI], 21 to 66%) and in 14 of 19 by nested PCR (sensitivity, 74% [95% CI, 49 to 90%]; P = 0.014 [McNemar's test]. For multiple serial CSF samples, standard PCR yielded JCV DNA for 11 of 19 PML patients (sensitivity, 58% [95% CI, 34 to 79%]) and nested PCR yielded JCV DNA for 17 of 19 patients (sensitivity, 90% [95% CI, 66 to 98%]; P = 0.014). The majority of the false-negative samples were found to contain PCR inhibitors. Standard PCR did not detect JCV DNA in CSF from any of the 83 AIDS patients with other diagnosis (100% specificity [95% CI, 95 to 100%]); JCV DNA was found in CSF from one control patient by nested PCR (99% specificity [95% CI, 93 to 100%]).

Aerosolized pentamidine, cotrimoxazole and dapsone-pyrimethamine for primary prophylaxis of Pneumocystis carinii pneumonia and toxoplasmic encephalitis.

OBJECTIVE: To investigate the efficacy and safety of three regimens for primary prophylaxis of Pneumocystis carinii pneumonia (PCP) and toxoplasmic encephalitis (TE) and to evaluate their effect on survival in patients with HIV infection. DESIGN: Randomized, open label, prospective trial. SETTING: A single Infectious Diseases Department in Italy. PATIENTS: HIV-infected patients (n = 197) with a CD4 count < 200 x 10(6)/l and without previous PCP or TE. INTERVENTIONS: Patients were randomly assigned to receive (1) aerosolized pentamidine (AP; 300 mg monthly), (2) cotrimoxazole (CTX; 160 mg trimethoprim and 800 mg sulfamethoxazole every other day), or (3) dapsone-pyrimethamine (DP; 100 mg weekly dapsone and 25 mg biweekly pyrimethamine). MAIN OUTCOME MEASURES: PCP, TE, death, and drug-limiting toxicity. Considering difference in PCP occurrence the trial was interrupted on June 1992. Observation was prolonged until June 1994 for TE and survival. RESULTS: Intention-to-treat analysis yielded PCP rates of 10.2 per 100 person-years in the AP, 2.0 in the CTX, and 32.1 in the DP group [adjusted relative risk of DP versus CTX: 17.5; 95% confidence interval (CI), 2.2-139.6; P = 0.007]. TE rates in patients with positive Toxoplasma serology were 25.6 per 100 person-years in the AP, 8.9 in the CTX and 9.4 in the DP group. In 'on treatment' analysis, no episode of TE developed in the DP group, and rates were 34.7 per 100 person-years in the AP and 2.5 in the CTX group (AP versus CTX: P = 0.01; AP versus DP: P = 0.004). The adjusted risk of mortality for the DP group was 2.8 times that of the CTX group in the first part of the study (95% CI, 1.1-7.3; P = 0.037), and 1.8 times (95% CI, 1.1-2.9; P = 0.02) in the prolonged follow-up. No significant difference in the occurrence of serious adverse reactions was observed between the three treatment groups. CONCLUSIONS: Intermittent CTX was more effective than low-dose DP and showed a slight but not significant advantage on AP for primary PCP prophylaxis. DP was associated with a shorter survival. Both CTX and DP resulted in a significant reduction in the risk of TE.

Evaluation of cerebrospinal fluid EBV-DNA and IL-10 as markers for in vivo diagnosis of AIDS-related primary central nervous system lymphoma.

Acquired immunodeficiency syndrome (AIDS)-related primary central nervous system lymphoma (PCNSL) is almost always associated with the Epstein-Barr virus (EBV), and EBV-DNA in cerebrospinal fluid (CSF) has been indicated as a useful tumour marker for this HIV-related neoplasm. AIDS lymphomas also show an enhanced production of IL-10 which is generally associated with the presence of EBV in lymphoma cells. We performed a prospective study in 19 HIV seropositive patients with brain mass lesions, and in 21 other AIDS patients with or without other neurological disorders, to assess the in vivo diagnostic value of EBV-DNA and of IL-10 levels in the CSF for primary lymphoma of the central nervous system (CNS). EBV-DNA was detected by a nested polymerase chain reaction (PCR) in the CSF from seven of eight patients with PCNSL, diagnosed by brain biopsy (87.5% sensitivity) and in none of the 11 controls with brain mass lesions (100% specificity) and of the other 21 AIDS patients with or without neurological disorders. The only patient with PCNSL without detectable EBV-DNA in the CSF was also negative for EBV-DNA in the lymphoma tissue, whereas the samples of the other seven brain lymphomas were all positive for EBV-DNA by nested PCR. Therefore 100% of patients with an EBV-positive primary CNS lymphoma had detectable EBV-DNA in the CSF. No patient from the control group without PCNSL with EBV-negative CSF developed a lymphoma after a mean follow-up of 157 +/- 173 d. IL-10 levels in the CSF from the patients with PCNSL were not significantly different from those in the other groups of patients with AIDS. Due to uniformly high levels in the CSF from AIDS patients, IL-10 is not a useful diagnostic marker for AIDS-related brain lymphoma. The detection of EBV-DNA from the CSF by nested PCR is an extremely sensitive and specific diagnostic tool for AIDS-related PCNSL and should be further evaluated as a possible alternative in patients from whom brain biopsy is not advisable.

Fluconazole for primary prophylaxis of AIDS-associated cryptococcosis: a case-control study.

In order to verify whether fluconazole has a prophylactive effect against the occurrence of cryptococcosis in HIV-infected patients and to identify other factors capable of increasing or reducing the risk of this infection, we arranged a case-control study of 17 patients with cryptococcal infection. 34 controls were selected, matched by presence of an AIDS-defining event, CD4 cell count, and date of T-cell phenotyping. No significant difference in exposure to fluconazole, in total days of treatment, or in total dose administered was observed between cases and controls. However, control patients took a significantly higher average daily dosage of fluconazole and a linear tendency in risk reduction (p = 0.04) in relation to increasing dosage was observed. Antiretroviral therapy and an average daily fluconazole dose exceeding 150 mg both each reduced the risk of a cryptococcal infection.