Abstract: Objective To study the clinical characteristics, diagnosis and treatment of Pneumocystis carini pneumonia(PCP). Methods The retrospective analyses of 19 inpatients who were diagnosed with PCP in Beijing Chaoyang Hospital from 2004 to 2008 were performed, and the literature was reviewed with regard to clinical profiles. Results Of the19 PCP patients, 12 were male and 7 female. The average age was(41.53±9.22) years. Five patients(26.3%) were co-infected with human immunodeficiency virus(HIV). The remaining 14 non-HIV-infected patients had underlying diseases. Seven patients had a sudden onset; others had a gradual onset. Twelve of 19 patients had normal or mildly coarse breath sounds on auscultation; 5/19 patients had rales at the bottom of lung. 2/17 of the patients had inspiratory crackles which is considered to be related with fibrosis of lung. The most common abnormal chest radiological findings were bilateral diffuse interstitial infiltrations, patchy shadows or ground-glass. Seven patients were found positive for PC in their sputum or bronchoalveolar lavage fluid(BALF) by Gomori methenamine silver stain(GMS), 7 patients were proved positive for PC in their sputum or bronchoalveolar lavage fluid by polymerase chain reaction(PCR ), and one patient was also proved positive for PC in transbronchial lung biopsy(TBLB). All patients were treated with trimethoprim-sulfamethoxazole and 84.2%(16/19) of the patients were treated with corticosteroids concomitantly. Five patients died; 3 of 5 patients succumbed to MODS, 2 succumbed to ARDS. Overall crude mortality was 26.3%. Conclusion Being infected with HIV much frequently and increasing immuno-suppressive therapy(such as organ transplantations and tumor therapy), PCP does not belong to rare diseases. The mortality of PCP was high despite appropriate treatment, because of lack of specific clinical characteristics. Chemoprophylaxis should be considered in populations at high risks.

Key words: pneumocystis pneumonia, acquired immunodeficiency syndrome(AIDS), nonHIV immunodeficiency