Risk factors for Pneumocystis jiroveci pneumonia in glomerulonephritis patients receiving immunosuppressants

Objective Pneumocystis jiroveci pneumonia (PJP) infection is a rare but lethal complication in immunocompromised hosts. However, risk factors for PJP infection in glomerulonephritis (GN) patients receiving immunosuppressants are unknown. Methods From August 2009 to July 2010, we encountered a cluster occurrence of PJP infection in our renal biopsy patients. Seven of 73 GN patients under immunosuppressant agents developed PJP infection, which were diagnosed by the Giemsa and Gomori's methenamine silver stains of the bronchoalveolar lavage specimen.Results The average time of PJP onset was 2.4 months after immunosuppressant initiation. We found that the immunosuppressant regimens were equal between patients with and without the development of PJP infection regarding the daily dose per body weight, treatment duration, and accumulative dose per body weight. Logistic regression analysis indicated that high serum creatinine, low hemoglobin, and low absolute lymphocyte count at immunosuppressant initiation, and high chronicity indices of kidney pathology were predictors of PJP infection. In addition, patients with PJP infection had persistently worse renal function, more severe anemia, and more severe lymphocytopenia as compared to those without. Conclusion Prophylactic therapy for P. jiroveci and immunosuppressant dose reduction should be considered in GN patients with high chronicity of their kidney diseases and/or persistent lymphocytopenia.