OBJECTIVE To explore the application value of metagenomic next-generation sequencing (mNGS) in the diagnosis and prognosis of patients with non-human immunodeficiency virus (HIV)-infected severe Pneumocystis jirovecii pneumonia (PJP).

METHODS A retrospective analysis was conducted on 17 patients with non-HIV-infected severe PJP diagnosed by mNGS who were admitted to the intensive care unit (ICU) of Beijing Electric Power Hospital from Jan. 2023 to Jul. 2024. Detailed data on the patients′ basic information and outcomes was collected. Patients were divided into the death group and the survival group based on their 28-day survival status after admission to the ICU, and relevant factors affecting the prognosis of non-HIV-infected severe PJP were analyzed.

RESULTS A total of 17 patients with non-HIV-infected severe PJP were enrolled, including 10 males, with an average age of (70.65±12.67) years. Twelve patients were complicated with immunocompromised diseases, and the average time from onset to diagnosis of severe pneumonia caused by P. jirovecii was 6 days. Except for 1 patient who was only infected with P. jirovecii, the remaining patients had mixed infections. After treatment, 9 patients died (52.94%). Compared with the survival group, patients in the death group were older (P=0.082), had high proportion with hypertension (P=0.050), had a long time from onset to diagnosis (P=0.010) and had more patients requiring mechanical ventilation (P=0.057).

CONCLUSIONS Patients with non-HIV-infected severe PJP often have comorbidities that compromise their immune function, primarily presenting with mixed infections and a higher mortality rate. mNGS can rapidly provide etiological basis for such patients. A previous history of hypertension and a longer time from onset and diagnosis are risk factors for poor prognosis in patients with non-HIV-infected severe PJP.