CD40LG and primary progressive multiple sclerosis: In general, a low IgM positivity frequency of ≤ 10% was observed for most EBV proteins/peptides in the different patient cohorts, with only untreated PPMS patients having > 10% positivity for gp350/220 (20%), gh/gL/gp42 (30%) and VCA gp125 (30%, Supplementary Table 3).