Autoimmunity was prevalent in T1D-CD individuals, who showed more comorbidities than controls (χ2 25.4, P < .001), particularly the CD_FIRST (P < .001).<h4>Conclusion</h4>In children with T1D-CD, worse glucometabolic control is associated with an increase in fold anti-TTG IgA and with worse Marsh grade. Here, CD79A is linked to type 1 diabetes mellitus.