In AD patients with concomitant CD, IgA-anti-TG1 responses were as prevalent as in the CD patients but more common compared to controls (p < 0.05) or AD patients (p < 0.005), indicating that IgA-anti-TG1 and IgA-anti-TG3 responses were associated with CD and not AD. The gene discussed is CD79A; the disease is Alzheimer disease.