Role of PCR for diagnosing Pneumocystis jirovecii pneumonia in HIV-infected individuals in a tertiary care hospital in India

Objectives : In developing countries like India, the diagnosis of Pneumocystis jirovecii infection is often made either by conventional staining or clinically. This study was planned to know the utility of polymerase chain reaction (PCR) in diagnosing Pneumocystis jirovecii pneumonia (PJP) in human immunodeficiency virus (HIV)-infected patients, to compare the PCR results with that of staining techniques and also to correlate the results with clinical condition of patients. Materials and Methods: A prospective study included 50 HIV-infected adult in-patients with symptoms of lower respiratory tract infection. Induced sputum, bronchoalveolar lavage or tracheal aspirate were proceeded for both staining and PCR for mitochondrial large subunit rRNA gene of P. jirovecii. Results: In our study PCR results correlated with staining findings in 14% (7/50) of cases. Another 20% (10/50) cases could be diagnosed only with PCR, where staining was negative for the presence of P. jirovecii. When compared with clinical evidence of disease, PCR showed 93.7% sensitivity and 94.1% specificity. Presence of dyspnea and CD ₄ count showed statistical significance (P<0.05) in PCP-diagnosed patients. Conclusions: PCR can be used for early and accurate diagnosis of PCP in HIV-infected patients.