Clinical characteristics and outcomes of COVID-19 in haematopoietic stem-cell transplantation recipients: an observational cohort study

Background Haematopoietic stem-cell transplantation (HSCT) recipients are considered at high risk of poor outcomes after COVID-19 on the basis of their immunosuppressed status, but data from large studies in HSCT recipients are lacking. This study describes the characteristics and outcomes of HSCT recipients after developing COVID-19. Methods In response to the pandemic, the Center for International Blood and Marrow Transplant Research (CIBMTR) implemented a special form for COVID-19-related data capture on March 27, 2020. All patients-irrespective of age, diagnosis, donor type, graft source, or conditioning regimens-were included in the analysis with data cutoff of Aug 12, 2020. The main outcome was overall survival 30 days after a COVID-19 diagnosis. Overall survival probabilities were calculated using Kaplan-Meier estimator. Factors associated with mortality after COVID-19 diagnosis were examined using Cox proportional hazard models. Findings 318 HSCT recipients diagnosed with COVID-19 were reported to the CIBMTR. The median time from HSCT to COVID-19 diagnosis was 17 months (IQR 8-46) for allogeneic HSCT recipients and 23 months (8-51) for autologous HSCT recipients. The median follow-up of survivors was 21 days (IQR 8-41) for allogeneic HSCT recipients and 25 days (12-35) for autologous HSCT recipients. 34 (18%) of 184 allogeneic HSCT recipients were receiving immunosuppression within 6 months of COVID-19 diagnosis. Disease severity was mild in 155 (49%) of 318 patients, while severe disease requiring mechanical ventilation occurred in 45 (14%) of 318 patients-ie, 28 (15%) of 184 allogeneic HSCT recipients and 17 (13%) of 134 autologous HSCT recipients. At 30 days after the diagnosis of COVID-19, overall survival was 68% (95% CI 58-77) for recipients of allogeneic HSCT and 67% (55-78) for recipients of autologous HSCT. Age 50 years or older (hazard ratio 2.53, 95% CI 1.16-5.52; p=0.020); male sex (3.53; 1.44-8.67; p=0.006), and development of COVID-19 within 12 months of transplantation (2.67, 1.33-5.36; p=0.005) were associated with a higher risk of mortality among allogeneic HSCT recipients, and a disease indication of lymphoma was associated with a higher risk of mortality compared with plasma cell disorder or myeloma (2.41, [1.08-5.38]; p=0.033) in autologous HSCT recipients. Interpretation Recipients of autologous and allogeneic HSCT who develop COVID-19 have poor overall survival. These data emphasise the need for stringent surveillance and aggressive treatment measures in HSCT recipients who develop COVID-19. Copyright (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study examined the characteristics and outcomes of HSCT recipients after developing COVID-19. It found that recipients of autologous and allogeneic HSCT who develop COVID-19 have poor overall survival rates. Factors such as age, sex, and time since transplantation were associated with higher risk of mortality in HSCT recipients.