Rituximab Treatment and Immune Response

Effects on B Cells and Humoral Immunity

Rituximab treatment can lead to permanent elimination of some memory B cells, negatively affecting humoral immunity in certain patients, as evidenced by incomplete recovery patterns 1
Depletion of circulating B cells is maintained for at least 6-12 months in most patients 2
Rituximab alters the composition of remaining B cells in lymph nodes, with a higher percentage of switched memory B cells (IgD-CD27+) 1

Rituximab significantly reduces responses to vaccines, including SARS-CoV-2 vaccines (only 39% seroconversion compared to 100% in controls) and tetanus vaccine (only 9% of rituximab-treated patients had a ≥4-fold rise in antibody titers) 1
Impaired immune response to influenza vaccines is associated with persistent memory B-cell depletion 3
Patients vaccinated 6 months after rituximab had ~20% seropositivity rate, while those vaccinated 1 year after rituximab had ~50% seropositivity rate 1
Rituximab causes profound B-cell depletion leading to increased infection risk 4

Monitoring for signs of infection is crucial in patients treated with rituximab 4