How do you use total IgG levels, if at all, to guide plasma exchange for myasthenia gravis exacerbations?

I do not routinely measure total IgG levels before the first and after the last session of PLEX in MG exacerbations, and I do not use this lab to determine the number of required PLEX sessions, but I understand the rationale of the question, and I believe that this topic requires further study. I only found one recent publication about the predictive value of AchR ab and total IgG reduction after PLEX (see below). In a small retrospective study of 21 patients treated with PLEX for MG exacerbations, authors from Japan found that the group which showed favorable response to PLEX (n=11) had an average reduction of AchR antibody titer and total IgG of about 57-59% after PLEX, whereas the group with unfavorable response (n=10) had approximately ...