Imaging patterns of Pneumocystis jirovecii pneumonia in HIV-positive and renal transplant patients – a multicentre study. Â Â Swiss Medical Weekly
Christe et al. aimed to explore the computed tomography (CT) and chest X-ray (CXRs) imaging features of Pneumocystis jirovecii pneumonia (PJP) in immunocompromised patients from two well-defined cohorts, the Swiss HIV Cohort Study (SHCS) and renal transplant recipients (RTRs) included in the Swiss Transplant Cohort Study (STCS).
From 2005 to 2012, 84 patients with PJP (RTR n = 24; HIV n = 60) were included in this retrospective multicentre study. 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.
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).
In conclusion, the PJP radiological CT findings in renal transplant patients were dominated by multifocal consolidation and solid nodularities, whereas in the HIV population more classic subpleural sparing was present. A common feature in both groups was ground glass opacification. Of note, pulmonary cysts, previously described as a hallmark feature in PJP, were present in only 4% of the HIV-positive patients and in none of the RTRs. With the advance of prophylaxis in high-risk groups, this classic complication is now an infrequent finding. Based on the differing imaging manifestations of PJP in transplant recipients and HIV-positive patients, it is of utmost importance for radiologists to be aware of the spectrum of patterns in the context of different underlying diseases and to show high awareness in high-risk groups.