CD40LG and rheumatoid arthritis: We found inverse correlations between age at onset of the RA patients and antibody titers, such as bacterin-specific IgM (R = −0.55, p = 0.01), VtaA9-specific IgM (R = −0.41, p = 0.05), and close to significance for VtaA10-specific IgM (R = −0.40, p = 0.06; Figures 2A–C, respectively; Spearman's rank correlations).