CD40LG and Alzheimer disease: However, the anti-ATCAY IgM levels were positively correlated with the levels of anti-ATCAY IgG (rs = 0.248, p = 0.004, Supplementary Fig. 3C), and the anti-ATCAY IgG/IgM ratio was higher in patients with AD than that in the NC group (Supplementary Fig. 3B).