B cell depletion – how it works

I have done some talks on B cell depletion and especially on rituximab, but I’ve never found an illustrative model to explain how B cell depletion works, so far.


Rituximab or an other monoclonal anti CD20 antibody binds to CD20, which is widely expressed on the surface of B cells. Already early pre-B cells carry CD20. All B cells do with the exception of plasma cells. And also stem cells and pro B cells don’t express CD20. Plasma cells produce antibodies. The exact mode of action of rituximab still is unclear.


Stem cell / pro B cell / pre B cell / immature B cell / mature B cell / activated B cell / memory cell / plasma cell
The marked cells carry CD20.


Imagine there’s a big company, stem cell and pro B cell represent the CEO, pre B to memory cells represent the research and development (R&D) department, plasma cells stand for production. Plasma cells still produce known antibodies. But there’s no development of new antibodies. That’s the reason why you have to get vaccinated [pneumococcal conjugate vaccine (PCV 7) (e.g.Prevena)] before receiving rituximab.