Role of CD8 lymphocytes and neutrophilic alveolitis in Pneumocystis jiroveci pneumonia.

We described the characteristics of bronchoalveolar inflammatory cells and their correlation with lung injury in patients with Pneumocystis jiroveci pneumonia. We reviewed all cases of patients with Pneumocystis jiroveci pneumonia in newly diagnosed HIV infected patients admitted to a large metropolitan referral hospital during June 2003 to December 2004. Nine patients (5M, 4F) with Pneumocystis jiroveci pneumonia diagnosed with bronchoscopy and cytological examination of bronchoalveolar lavage (BAL) were identified. There was a positive correlation between peripheral CD8 count and BAL neutrophilia and negative correlation with hypoxemia. Although the number patients in this case series is small, our findings suggest that CD8 cells and alveolar neutrophilic inflammation have a role in lung injury in Pneumocystis jiroveci pneumonia. These findings are consistent with data from animal studies.