The management of COVID-19 in hematopoietic cell transplant (HCT) recipients represents a special challenge given the variable states of immune dysregulation and altered vaccine efficacy in this population. A systematic search (Ovid Medline and Embase on 1 June 2021) was needed to better understand the presenting features, prognostic factors, and treatment options. Of 897 records, 29 studies were identified in our search. Most studies reporting on adults and pediatric recipients described signs and symptoms that were typical of COVID-19. Overall, the mortality rates were high, with 21% of adults and 6% of pediatric HCT recipients succumbing to COVID-19. The factors reported to be associated with increased mortality included age (HR = 1.21, 95% CI 1.03-1.43, p = 0.02), ICU admission (HR = 4.42, 95% CI 2.25-8.65, p < 0.001 and HR = 2.26, 95% CI 1.22-4.20, p = 0.01 for allogeneic and autologous HCT recipients), and low platelet count (OR = 21.37, 95% CI 1.71-267.11, p = 0.01). Performance status was associated with decreased mortality (HR = 0.83, 95% CI 0.74-0.93, p = 0.001). A broad range of treatments was described, although no controlled studies were identified. The risk of bias, using the Newcastle-Ottawa scale, was low. Patients undergoing HCT are at a high risk of severe morbidity and mortality associated with COVID-19. Controlled studies investigating potential treatments are required to determine the efficacy and safety in this population.
Keywords: COVID-19; hematopoietic cell transplant; meta-analysis; mortality; systematic review; treatment.