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 confirmed 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 a death group and a survival group based on their survival status 28 days 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 with comorbidities that compromised their immune function experienced an average of 6 days from onset to confirmed diagnosis of severe PJP. 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 old (P=0.082), had high proportion with hypertension (P=0.050), a long time from onset to confirmed diagnosis (P=0.010) and a great number 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 history of hypertension and a longer interval between onset and diagnosis are risk factors for poor prognosis in patients with non-HIV-infected severe PJP.