Severe acute respiratory syndrome coronavirus 2 infection in the stem cell transplant recipient - clinical spectrum and outcome.

Purpose of review Focusing on large multicenter cohorts reported over the last months, this review aims at summarizing the available evidence by July 2021 on the impact of coronavirus disease 2019 (COVID-19) on hematopoietic stem cell transplant (HSCT) recipients in terms of epidemiology, clinical features, and outcome. Recent findings The incidence of COVID-19 in institutional cohorts varied according to different regions and study periods from 0.4% to 8.3%. Clinical presentation was overall comparable to other immunocompromised hosts and the general population. Microbiologically confirmed superinfection occurred in 13-25% of recipients, with most episodes due to hospital-acquired bacteria and few reported cases of COVID-19-associated aspergillosis. Prolonged nasopharyngeal severe acute respiratory syndrome coronavirus 2 shedding has been demonstrated for as long as 210 days. Mortality rates were similar across studies (14.8-28.4%) and did not markedly differ from those observed in nontransplant hematological patients during the first wave. Older age and shorter time from transplantation were associated with mortality, as well as underlying disease status and amount of immunosuppression. No outcome differences were found in most studies between allogeneic and autologous procedures. Summary Considerable advances have been achieved in the characterization of COVID-19 in the HSCT population, although uncertainties remain in the optimal therapeutic management.