Frequency and Prognosis of COVID-19 in The Course of Autologous Stem Cell Transplantation

This study aimed to retrospectively determine the frequency and prognosis of coronavirus disease 2019 (COVID-19) in patients who underwent an autologous stem cell transplantation (ASCT) during the pandemic and to evaluate the effects of possible factors on outcomes. The demographic characteristics, diagnoses, COVID-19 status, vaccination status, COVID-19-related mortality (CRM), non-relapse mortality (NRM), and overall survival (OS) of patients who underwent an ASCT in our center between March 2020 and June 2022 were investigated. Of the 153 patients who underwent ASCT consecutively, 146 patients were included in this study and the rest were excluded. The median age of the 146 patients was 55 years (20–78 years), and the median follow-up time after ASCT was 17.4 months. The common diagnoses were multiple myeloma and other plasma cell disorders (44.5%, n = 65) and Hodgkin lymphoma (15.1%, n = 22). Of the patients, 8.9% (n = 13) had COVID-19 before ASCT and 24.0% (n = 35) after ASCT, and 6.2% (n = 9) had CRM. Unvaccinated patients constituted 25.3% (n = 37). Moreover, 19.2% patients were vaccinated at least once before ASCT n = 28), 44.5% (n = 65) got vaccinated after ASCT, and 11.0% (n = 16) got vaccinated both before and after ASCT. The cumulative CRM after 3, 6, 9, and 12 months was 2.0% [95% confidence interval (CI): 0.04 vs 3.96], 5.0% (95% CI: 1.08–8.92), 6.0% (95% CI: 2.08–9.92), and 6.0% (95% CI: 3.08–10.92), respectively. Patients with ≥3 doses of vaccination had favorable CRM (P = 0.01), NRM (P = 0.001), and OS (P < 0.001). Age ≥60 years, non-Hodgkin lymphoma, and a total vaccination dose of ≤2 were independently associated with a poorer OS and higher NRM. A total vaccination dose of ≤2 was an independent factor for increased CRM (hazard ratio: 9.69; 95% CI: 1.20–78.15; P = 0.03). COVID-19 is an important cause of mortality in the post-ASCT period. The mortality risk was higher during the 6 months after ASCT. Those who received at least two doses of the vaccine exhibited improved outcomes. Booster doses after ASCT might have a positive impact.