@dervish
Long-lived plasma cells (LLPCs) are specialized immune cells that reside primarily in the bone marrow and act as the body's long-term "memory" for antibodies. While most plasma cells die shortly after an infection clears, LLPCs can survive for decades, or even a lifetime, providing continuous protection against pathogens you have already encountered.
LLPCs are the reason why a single course of vaccinations (like measles or polio) can protect you for your entire life. However, they can also be a double-edged sword; in autoimmune diseases, LLPCs can mistakenly produce "autoantibodies" that attack the body's own tissues, and because these cells are so hardy, they can be very difficult to eliminate with standard treatments.
They are why rituxan doesn't seem to work for everyone. There are no treatments that go after them as well but the risk is the more of your immune system you are taking out to get rid of the anti-mag You're also increasing your risk of infections and possibly cancer.