Long-Term Outcomes of COVID-19 and Risk Factors for Prolonged or Persistent COVID-19 in Lymphoma Patients: A Multicenter, Retrospective Cohort Study

Background: Patients with hematologic malignancies exhibit persistent severe acute respiratory syndrome coronavirus 2 positivity over long periods after coronavirus disease 2019 (COVID-19) diagnosis. However, the frequency of, risk factors for, and prognosis of prolonged COVID-19 in immunocompromised patients remain unclear. Therefore, we investigated the long-term outcomes of COVID-19 in lymphoma patients and identified the associated factors and impact of prolonged COVID-19 on mortality.

Methods: A multicenter retrospective cohort study of 583 lymphoma patients was conducted in 3 tertiary hospitals in South Korea. Patients receiving lymphoma treatment who were quarantined after obtaining a diagnosis of COVID-19 by polymerase chain reaction (PCR) or antigen test from August 2021 to September 2022 were examined.

Results: Overall, 115 patients (19.7%) were diagnosed with COVID-19. Among 77 patients with clinical data, 24 had prolonged COVID-19. Patients in the prolonged COVID-19 group showed higher rates of receiving rituximab maintenance therapy following bendamustine and rituximab (BR) treatment for follicular lymphoma. This group did not show significant differences in clinical presentation within 30 days of COVID-19 diagnosis; however, it showed higher rates of re-admission due to COVID-19 pneumonia compared with the non-prolonged COVID-19 group. BR treatment followed by rituximab maintenance therapy is one of the risk factors for persistent PCR positivity, delayed or persistent pneumonia, and COVID-19 related admission after quarantine period. Prolonged COVID-19 was an independent risk factor for 1-year mortality.

Conclusion: Prolonged COVID-19 was more frequent in lymphoma patients who received BR treatment followed by rituximab maintenance therapy and associated with unfavorable long-term outcomes and higher 1-year mortality.