Rituximab suppresses anti-S COVID-19 antibodies in patients with haematological malignancies

While patients with haematological malignancies (HM) are able to mount a persistent antibody response against the spike (S) protein of the SARS-CoV-2 virus, early treatment with rituximab completely abolishes such response, a recent study has found. These findings could help inform coronavirus disease 2019 (COVID-19) vaccination policies for patients with HMs.

Researchers prospectively assessed 45 patients (median age 69 years, 26 men) with HMs and confirmed COVID-19. Antibody levels against the S and nucleocapsid (N) antigens were measured using fluid-phase luciferase-immunoprecipitation assays at 1, 3, and 6 months after the nasal swabs tested negative. A parallel group of 18 COVID-19 patients (median age 54 years, seven men) without HM was also included.

Levels of anti-S antibodies were comparable between patients and controls at the first month after a negative nasal swab test, and remained statistically stable at months 3 and 6. Similarly, anti-N-antibodies had similar between-group levels at all time points except for month 1, during which HM patients showed significant elevation (p=0.016).

Fourteen participants with non-Hodgkin lymphoma were on rituximab treatment, five of whom had received such medication for ≥6 months before COVID-19, while medication was ongoing in the remaining nine. Levels of anti-S antibodies were significantly suppressed in patients with ongoing rituximab than in those whose courses had already ended (month 1: p=0.000039; month 3: p=0.003; month 6: p=0.04).

There were differences in humoral response according to haematologic diagnoses, too. In particular, patients with lymphoma mounted a weaker antibody response compared with any other HM at any time point.