Rituximab is a treatment for some autoimmune disorders and Lymphoma.
It helped a lot with my POTS and fatigue, it is harder to evaluate its effect on my SFN's sensory symptoms because it is mainly numbness and reduced sensation, and not pain.
My sensory SFN symptoms progressed slowly, the autonomic problems began almost 20 years ago.
I don't have any specific autoimmune diagnosis, but I have been having many problems that are common in Sjogren syndrome and other autoimmune disorders.
10 years ago I had Lymphoma (which is more common in some autoimmune disorders), I felt a lot better for a couple of years after the chemotherapy which included Rituximab, so my doctors thought it is worth trying Rituximab again.