COMBINED USE OF BLOOD AND OROPHARYNGEAL SAMPLES FOR NONINVASIVE DIAGNOSIS OF PNEUMOCYSTIS-CARINII PNEUMONIA USING THE POLYMERASE-CHAIN-REACTION

To evaluate the clinical use of a polymerase chain reaction (PCR) assa y for diagnosis of Pneumocystis carinii pneumonia (PCP) using samples collected noninvasively, the Internal Transcribed Spacers (ITSs) neste d PCR was performed on 148 samples from 40 subjects. Bronchoalveolar l avage (BAL) fluid sera, gargled oropharyngeal washes, and peripheral b lood mononuclear cells (PBMC) from 14 AIDS patients (mean age, 35.6 ye ars; mean CD4+ cell count, 49.2 cells/mm(3)) with proven PCP and from 13 HIV-seropositive controls (mean age, 34.6 years; mean CD4 + cell co unt, 107.3 cells/mm(3)) with other AIDS-related opportunistic infectio ns were evaluated. Sera and oropharyngeal samples were also collected from 13 HIV-seronegative health care personnel working in an infectiou s disease ward for use as negative controls. The ITSs nested PCR confi rmed the morphological diagnosis of PCP in all patients when BAL fluid was tested (100% sensitivity). This technique also detected Pneumocys tis carinii DNA in oropharyngeal samples from 78.6% of patients, in se ra from 71.4% of patients, in PBMC from 35.7% of patients. When all re sults obtained after ITSs nested PCR were considered together for the same patient, the sensitivity for PCP diagnosis was 100% for blood and oropharyngeal samples (gargled saline), as confirmed by subsequent BA L. All samples collected noninvasively from 26 of 26 controls were neg ative using ITSs nested PCR (100% specificity).