Correlation of CT Findings and Clinical Characteristics of Pneumocystis Pneumonia in Patients with Acquired Immunodeficiency Syndrome

Background: Pneumocystis pneumonia (PCP) is the most common opportunistic infection, and it is difficult to diagnose as PCP. The aim of this study was to assess whether CT findings or clinical characteristics contribute to early diagnosis of PCP. Method: Twenty-six patients with AIDS and PCP received medical treatment at the Kurume University Hospital between 1999 and 2018. None of the patients with AIDS had been diagnosed as HIV positive until the episode of PCP. In this study, the correlation between computed tomography (CT) findings and clinical characteristics were analyzed in patients with AIDS and PCP. The number of patients with PCP is not that high in Japan; therefore, it is difficult to diagnose patients with PCP in the clinic. Results: This study included 24 men and 2 women, and the mean age was 47.8 years. The mean CD4 cell count was 65.7 cells/μl, HIV-viral load was 680 × 104 copy, β-D-glucan (βDG) level was 234 pg/ml, and mean time till diagnosis was 41.3 days; 14 patients had hypoxemia. Twelve patients had PCP, 10 had cytomegalovirus (CMV) infection, 2 had Cryptococcus infection, 1 had Entamoeba histolytica infection, 1 had non-tuberculous mycobacteria infection, and 1 had Toxoplasma infection. CT images of the patients showed 10 cases with ground-glass opacity (GGO), 13 with consolidation, 1 with small nodules, 2 with a cavity, and 1 with cyst formation. Nine cases revealed peripheral distribution with peripheral sparing, 1 had pleural fluid, and 6 had lymph node enlargement. The mean time till diagnosis and cough were significantly correlated with lymphadenopathy. Patients with consolidation were more likely to be infected with CMV. Conclusion: GGO, combined with peripheral distribution and peripheral sparing, was the most common CT finding. When consolidation was present in PCP patients as shown in CT images, the patients were more likely to be infected with CMV.