Ingested (oral) rituximab inhibits EAE.

Background: Blocking CD20 can inhibit autoimmune diseases such as multiple sclerosis (MS) and rheumatoid arthritis (RA).

Objective: We examined whether an antibody against CD20, rituximab (RTX) (Rituxan®), used clinically in oncology, MS and RA would have similar anti-inflammatory effects in EAE after oral administration.

Design/methods: B6 mice were immunized with MOG peptide 35-55 and gavaged with control saline or RTX during ongoing disease. Splenocytes or CD4(+) T cells from control fed or RTX fed mice were adoptively transferred into active MOG peptide 35-55 immunized recipient mice during ongoing disease. Actively fed and recipient mice were examined for disease inhibition, inflammation, and cytokine responses.

Results: Ingested (oral) RTX inhibited ongoing disease and decreased inflammation. Adoptively transferred cells from RTX fed donors protected against actively induced disease and decreased inflammation. There was a decrease in Th1-like cytokines IFN-γ and IL-12, IL-17 and TNF-α in active fed and adoptively treated recipients without upregulation of counter-regulatory cytokines.

Conclusions: Ingested (orally administered) RTX can inhibit disease, CNS inflammation, decrease pro-inflammatory IL-17 and Th1-like cytokines without increases in Th2-like anti-inflammatory cytokines.