He probably got it for CVID. You’d have to test chronically low on IgG immunoglobulin levels. Often people with CVID experience higher levels of inflammation, and SFN is a common complication. But they prescribe it for the CVID, not the SFN in that case. Sometimes you can get an insurance company to pay for it for SFN.
I guess I just answered my own question re: autoimmunity. If he has CVID that’s likely the cause of his SFN, not autoimmunity.
Post Edited (dcd2103) : 5/29/2020 4:50:16 PM (GMT-6)