Pneumocystis jirovecii pneumonia in patients with and without human immunodeficiency virus infection.

BACKGROUND AND PURPOSE Pneumocystis jirovecii pneumonia is an opportunistic infection capable of causing life-threatening pneumonia in immunocompromised patients. To elucidate the clinical presentation and outcome of this disease in Taiwan, we analyzed the patients with P. jirovecii pneumonia during a 34-month period. METHODS We collected data retrospectively from patients with P. jirovecii pneumonia at a medical center in northern Taiwan between January 2004 and October 2006. The diagnosis was made by nested polymerase chain reaction (PCR) analysis of expectorated sputum. Demographics, clinical characteristics, laboratory findings, and outcomes were compared between patients with and without human immunodeficiency virus (HIV) infection. RESULTS Forty nine patients were included in this study. The most common underlying diseases were HIV and malignancies. The mean (+/- standard deviation) age of the 49 patients was 54 +/- 20.2 years (range, 5 to 96 years). The mean CD4+ T-lymphocyte count was 110 cells/microL (range, 0-670 cells/microL). Although the mean CD4+ T-lymphocyte count of the non-HIV group was higher than that of the HIV group (165 +/- 78 cells/microL vs 57.5 +/- 97 cells/microL), statistical significance was not obtained (p=0.087). Arterial oxygenation (ratio of arterial oxygenation to fraction of inspired oxygen) was less than 200 mm Hg in 28 patients. Lactate dehydrogenase levels were higher than the normal range in 15 patients. A significantly higher proportion of patients died in the group without HIV compared with the HIV-infected patients (17/34 [50.0%] vs 1/15 [6.7%]; p=0.004). CONCLUSION P. jirovecii pneumonia remains a significant problem for immunocompromised patients. The mortality rate for patients without HIV infection was high (50%). Greater alertness with regard to early detection of P. jirovecii in HIV-negative immunosuppressed patients with the application of nested PCR may improve the clinical management and outcome.