Clinical Clustering with Prognostic Implications in Japanese COVID-19 Patients: Report from Japan COVID-19 Task Force, a Nation-Wide Consortium to Investigate COVID-19 Host Genetics

ObjectiveThe clinical course of COVID-19 is diverse, and the usefulness of phenotyping in predicting the severity or prognosis of the disease has been demonstrated overseas. This study aimed to investigate clinically meaningful phenotypes in Japanese COVID-19 patients using cluster analysis.MethodsA total of 1322 Japanese patients were included in this study. Hierarchical cluster analysis was performed using variables reported to be associated with COVID-19 severity or prognosis.ResultsParticipants were divided into four clusters: Cluster 1, young healthy; Cluster 2, middle-aged; Cluster 3, middle-aged obesity; and Cluster 4, elderly comorbidity. Sore throat, dysosmia and dysgeusia tended to be less frequent, and shortness of breath more frequent in Clusters 3 and 4. Serum lactate dehydrogenase, ferritin, KL-6, D-dimer, and C-reactive protein levels tended to be higher in Clusters 3 and 4. Although Cluster 3 had a similar age as Cluster 2, it tended to have poorer outcomes. Clusters 3 and 4 both tended to exhibit higher rates of oxygen supplementation, intensive care unit admission, and mechanical ventilation, but the mortality rate tended to be lower in Cluster 3.ConclusionsWe identified four clusters with different clinical characteristics and prognosis in a large nationwide series of Japanese COVID-19 patients.