BACKGROUND: Little is known about characteristics of seasonal human coronavirus (HCoV) (NL63, 229E, OC43 and HKU1) after allogeneic stem cell transplantation (allo-HCT).
PATIENTS AND METHODS: this is a collaborative Spanish and European bone marrow transplantation groups retrospective multicentre study, which included allo-HCT recipients (adults and children) with upper and/or lower respiratory tract disease (U/LRTD) caused by seasonal HCoV diagnosed through multiplex PCR assays from January 2012 to January 2019.
RESULTS: We included 402 allo-HCT recipients who developed 449 HCoV U/LRTD episodes. Median age of recipients was 46 years (range 0.3-73.8 years). HCoV episodes were diagnosed at a median of 222 days after transplantation. The most common HCoV subtype was OC43 (n=170, 38%). LRTD involvement occurred in 121 episodes (27%). HCoV infection frequently required hospitalization (18%), oxygen administration (13%) and intensive care unit (ICU) admission (3%). Three-month overall mortality after HCoV detection was 7% in the whole cohort and 16% in those with LRTD. We identified 3 conditions associated with higher mortality in recipients with LRTD: absolute lymphocyte count <0.1 x10 9/mL [hazard ratio (HR), 10.8], corticosteroid (HR 4.68) and ICU admission (HR 8.22) (p<0.01).
CONCLUSIONS: Seasonal HCoV after allo-HCT may involve the LRTD in many instances, leading to a significant morbidity.