Hello, I also have a rare disorder - Pachymeningitis, which is basically inflammation comprised of Over active B cells all over my dura. I was originally diagnosed with a small meningioma in the cavernous sinus area. Treated with gamma knife but returned after 5 years so treated once again with gamma knife however they treated it for 4.5 hours instead of standard 90 mins. I didn’t feel well for 2 years. Then mRI showed inflammation all over my dura. Doctors did a craniotomy to biopsy the tissue and found ‘Pachymeningitis’. Treated with prednisone for 2 months then came right back after I stopped prednisone taper down. So Rituximab infusion was done for 1x weekly for 4 weeks. The first time they load you up with an allergy medication and Tylenol. It went well. I felt better but so far had to have Rituximab infusion about once a year or year 1/2. It grows back slowly. I do have to be very careful since our immune system is compromised. I’ve had 4 treatments so far since 2017 and doing well. Wear mask even double mask and wash hands often. Hope this helps.