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 impair humoral response, limiting viral clearance. Thus, COVID-19 convalescent plasma (CCP) therapy appears as a promising approach through the transfer of neutralizing antibodies specific to SARS-CoV-2. We report the effect of CCP in a cohort of 112 patients with hematological malignancies and COVID-19 and a propensity score analysis on subgroups of patients with B-cell lymphoid disease treated (n=81) or not (n=120) with CCP between 1 May 2020 and 1 April 2021. 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 an inverse probability of treatment weighting approach, we observed in anti-CD20–exposed patients with B-cell lymphoid disease a decreased mortality of 63% (95% CI=31%–80%) in the CCP-treated group compared to the CCP-untreated subgroup, confirmed 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.