I think there are subsets who will respond differently. Systrom/Oaklander believe there is a small fiber neuropathy subset (based on skin biopsy) where whatever has gone wrong in the biological process has damaged nerve fibers. So if you are in a subset where there is physical damage, it is going to be a long process to repair that damage when the "factor in the blood" is removed. They associate SFN with impaired cardiac return and hypoxia.
Statement in abstract from Oaklander about SFN, hypoxia, and impaired cardiac return.
Source : Chapter 10 - Dysimmune small fiber neuropathies - 1 May 2020