Fig. 1

Plasma IgA levels in cohorts I and II. The graphs illustrate significantly higher IgA levels in AD patients compared to NC in cohort I (A) and cohort II (B), significantly higher IgA levels in AD patients compared to NC in APOEε4 non-carriers (−APOEε4) in cohort I (C), unaltered IgA levels in AD patients compared to NC in APOEε4 carriers (+APOEε4) in cohort I (D), and significantly higher IgA levels in AD patients compared to NC in APOEε4 non-carriers in cohort II (E). Data were analysed using Student’s t-test and are presented as mean ± SD. ns, not significant. *Significant at p ≤ 0.05 level. **Significant at p ≤ 0.01 level. ***Significant at p ≤ 0.001 level