The increased IgM/IgA concentrations against especially the latent EBV protein, EBNA-1, but also IgG/IgA against the lytic EBV protein, EAD, in RA patients compared to HCs are in accordance with previous studies showing elevated levels of IgG against the EBV proteins, EBNA-1, VCA, and EAD in sera from RA patients relative to HCs [10, 11]. This evidence concerns the gene CD40LG and rheumatoid arthritis.