The systematic evaluation of undiagnosed CD among all AD patients allowed for the detection of three subjects without a previous diagnosis of CD who were positive for IgA anti-tTG at high concentrations at screening; in particular two females with SLE (69.4 AU/mL and 190.8 AU/mL, respectively) and one female with pSS (111.5 AU/mL). This evidence concerns the gene TGM2 and systemic lupus erythematosus.