Convalescent Plasma Improves Overall Survival in Patients with B-Cell Lymphoid Malignancies and COVID-19:  A Longitudinal Cohort and Propensity Score Analysis

Patients with hematological malignancies and COVID-19 display a high mortality rate. In such patients, immunosuppression due to underlying disease and previous specific treatment impairs humoral response, limiting viral clearance. Thus, COVID-19 convalescent plasma (CCP) therapy appears to be a promising approach through the transfer of neutralizing antibodies specific to SARS-CoV-2.Our study reports the effect of CCP in a cohort of patients with hematological malignancies and COVID-19 between 1 May 2020 and 1 April 2021. Overall, 112 hospitalized patients with severe COVID-19 (83 B-cell neoplasm, 19 plasma cell neoplasm, and 10 myeloid neoplasm) were included. The overall survival of the whole cohort was 65% [56–74.9] and 77.5% [68.5–87.7] for patients with B-cell neoplasm. Prior anti-CD20 monoclonal antibodies therapy was associated with better overall survival whereas age, high blood pressure, and COVID-19 severity were associated with a poor outcome after CCP transfusion. A retrospective analysis in the subgroup of COVID-19 patients with B-cell neoplasm treated with CCP (n=81) was compared to a similar group of patients (n=120) treated only with standard of care. An inverse probability of treatment weighting (IPTW) approach, performed to limit confusion and immortality bias, revealed a decreased mortality of 63% (95% CI=31%–80%) in the main analysis and 50% (95% CI=28%–66%) in the overall population of the CCP-treated group of patients with similar findings in the other sensitivity analyses.Convalescent plasma may be beneficial in COVID-19 patients with B-cell neoplasm who are unable to mount a humoral immune response. Comparing CCP to other passive immunotherapy approaches such as anti-SARS-CoV-2 monoclonal antibodies is warranted.