Imaging patterns of Pneumocystis jirovecii pneumonia in HIV-positive and renal transplant patients - a multicentre study.

To investigate differences in chest computed tomography (CT) and chest radiographs (CXRs) of Pneumocystis jirovecii pneumonia (PJP) between renal transplant recipients (RTRs) and human immunodeficiency virus (HIV)-positive patients. From 2005 to 2012, 84 patients with PJP (RTR n = 24; HIV n = 60) were included in this retrospective multicentre study. Written informed consent was obtained. CT scans and CXRs were recorded within 2 weeks after the onset of symptoms. PJP diagnosis was confirmed either by cytology/histology or successful empirical treatment. Two blinded radiologists analysed the conventional chest films and CT images, and recorded the radiological lung parenchyma patterns, lymph node enlargement and pleural pathologies (pneumothorax, effusion). The radiological features of the two subgroups were compared. Consolidations and solid nodules prevailed on CT in RTRs (91.7 ± 5.6% vs 58.3 ± 6.4% with HIV, p = 0.019 and 91.7 ± 5.6% vs 51.6 ± 6.5% with HIV, p = 0.005). HIV-positive patients with PJP showed more atelectasis (41.7 ± 6.4% vs 4.2 ± 4.1% in RTRs, p = 0.017) and hilar lymph node enlargement (23.3 ± 5.5% vs 0.0 ± 0.0% in RTRs, p = 0.088). Ground glass opacification was found in all cases. Pneumothorax was a rare complication, occurring in 3% of the HIV-positive patients; no pneumothorax was found in the RTRs. On CXR, the basal lungs were more affected in HIV-positive patients as compared with RTRs (p = 0.024). PJP on CT differs substantially between RTRs and HIV-positive patients. Physicians should be aware of such differences in order not to delay treatment, particularly in renal transplant recipients.