ABSTRACT
Background: Patients with hematological malignancies are at a higher risk of developing severe form and protracted course of COVID-19. Remdesivir, an inhibitor of RNA polymerase was identified early as a promising therapeutic regimen for COVID-19, while convalescent plasma (CP) therapy with anti-SARS-CoV-2 antibodies can aid the treatment of COVID-19 in B-cell depleted patients. Aims: Here we investigated whether the combination of externally administered immunoglobulins (Ig) via CP therapy and specific inhibition of viral replication might be sufficient to effectively treat B-cell depleted patients with COVID-19. Methods: We enrolled a series of 20 consecutive patients who suffered from various hematological malignancies with profound B-cell lymphopenia and COVID-19 pneumonia between December 2020 and May 2021. These patients demonstrated a profound B-cell lymphopenia based on flow cytometry analysis of peripheral blood lymphocyte subpopulations. Consequently, they showed undetectable baseline anti-SARS-CoV-2 Ig levels before CP therapy according to anti-SARS-CoV-2 nucleocapsid-and S1-RBD-specific total Ig tests. Each patient received a complete course of remdesivir and at least one unit (200 ml) of AB0 compatible convalescent plasma during their treatment for COVID-19. Results: Previous anti-CD20 therapy resulted in a more prolonged SARS-CoV-2 PCR positivity compared to other causes of Bcell lymphopenia (p=0.004). Timing of CP therapy showed a significant impact on the clinical outcome. Simultaneous use of remdesivir and CP reduced time period for oxygen weaning after diagnosis (p=0.017), length of hospital stay (p=0.007), and PCR positivity (p=0.012) compared to patients who received remdesivir and CP consecutively. In addition, time from the diagnosis to CP therapy affected the length of oxygen dependency (p<0.001) and hospital stay (p<0.0001). In those cases where there were at least ten days from the diagnosis to plasma administration, oxygen dependency was prolonged vs. patients with shorter interval (p<0.001). Summary/Conclusion: Via combined administration of remdesivir and CP, we experienced an overwhelming survival rate in COVID-19 patients with hematological malignancies. Inhibition of viral replication with passive immunization proved to be efficient and safe. Our results suggest the clear benefit of early administration of CP to avoid protracted COVID-19 disease in patients with B-cell lymphopenia.