Pneumocystis jiroveci pneumonia in immunocompromised patients: Delayed diagnosis and poor outcomes in non-HIV-infected individuals

Background: Pneumocystis jiroveci pneumonia (PJP) is a life-threatening disease in immunocompromised patients. Improved knowledge about the varied characteristics and management in different populations may guide treatment. Methods: We evaluated the clinical characteristics, management, and outcomes of patients with PJP diagnosed by nested polymerase chain reaction at a medical center in southern Taiwan from 2008 to 2011. The risk factors of mortality among non-human immunodeficiency virus (HIV)-infected patients were analyzed. Results: During the study period, there were 43 cases of PJP, and the common underlying diseases were HIV infection (23 patients, median CD4 count: 19/μl) and malignancy. The HIV-infected patients had a younger age (36.9±13.7 vs. 50.2±16.2 years, p=0.006), a lower body mass index (19.9±2.3 vs. 22.0±3.7kg/m², p=0.035), a longer duration of symptoms before admission (24±29 vs. 7±15 days, p=0.035), and a lower pneumonia severity index (56±25 vs. 99±35, p<0.001) than non-HIV-infected patients. A delay between admission and starting antimicrobial therapy for PJP (10±10 days vs. 1±3 days, p=0.004) and a high crude mortality (12/20, 60% vs. 2/23, 9%, p=0.001) were noted in non-HIV-infected patients. In the univariate analysis, the risk factors for mortality were a low lymphocyte count (p<0.05) and shock during hospitalization (p=0.004). Conclusion: A delay in the initiation of antimicrobial therapy for PJP and severe pneumonia were more common in the non-HIV-infected patients and were most likely related to the poor prognosis. The utilization of sensitive diagnostic tools to facilitate early diagnosis and treatment may improve the clinical outcomes of non-HIV-infected patients with PJP.