Clinical characteristics and prognosis of immunosuppressed inpatients with COVID-19 in Japan.

INTRODUCTION We aimed to analyze the clinical characteristics and outcomes of immunosuppressed inpatients with coronavirus disease 2019 (COVID-19). METHODS In this observational study, we utilized a large nationwide registry of hospitalized patients with COVID-19 in Japan. Patients' baseline characteristics and outcomes were compared according to the immunosuppressed states of the patients. The impact of different therapeutic agents on the clinical courses of the patients was evaluated. RESULTS Data of 14,760 patients were included, and 887 (5.9%) were immunosuppressed. The immunosuppressed state of the patient resulted from solid tumor (43.3%, n = 384), chemotherapy within 3 months (15.6%, n = 138), collagen disease (16.9%, n = 150), use of immunosuppressive agents (16.0%, n = 142), and metastatic solid tumor (13.5%, n = 120). Immunosuppressed patients were older and had a higher severity of illness at admission and during hospitalization than non-immunosuppressed patients. The mortality rates for major diseases causing immunosuppression were as follows: solid tumor, 12.5% (48/384; P < 0.001; relative risk [RR], 3.41); metastatic solid tumor, 31.7% (38/120; P < 0.001; RR, 8.43); leukemia, 23.1% (9/39; P < 0.001; RR, 5.87); lymphoma, 33.3% (20/60; P < 0.001; RR, 8.63); and collagen disease, 15.3% (23/150; P < 0.001; RR 3.97). Underlying diseases with high mortality rates were not necessarily associated with high rates of invasive supportive care. CONCLUSIONS The prognosis of immunosuppressed COVID-19 inpatients varied according to the different immunosuppressed states. Multiple factors, including the severity of the underlying diseases, might have affected their invasive supportive care indications.