Long-standing type 1 diabetes: patients with adult-onset develop celiac-specific immunoreactivity more frequently than patients with childhood-onset diabetes, in a disease duration-dependent manner.

To assess the frequency of celiac-associated humoral autoimmunity in patients with long-standing childhood- and adult-onset type 1 diabetes (LDM1) and whether it occurs more frequently as the disease progresses. IgA-/IgG-anti-tissue transglutaminase (IgA-tTG and IgG-tTG) and IgA-/IgG-deamidated gliadin (DGP) antibodies were analyzed in 277 LDM1 sera (120 females; disease duration 19.3 ± 12.3 years, range 5.0-54.0 years). Of the 277 patients, 147 were childhood-onset LDM1 ((CH)LDM1) and 130 adult-onset LDM1 ((AD)LDM1); 6.1 % LDM1 sera were tTG- and/or DGP-antibody-positive, with a lower frequency among (CH)LDM1 as compared with (AD)LDM1 patients (3.4 vs 9.2 %, p = 0.048). Celiac-associated immunoreactivity was significantly more frequent in LDM1 with >15 years of disease duration (9.4 vs 2.9 % in those with ≤15 years, p = 0.042) and among them in (AD)LDM1 (14.7 vs 4.2 % (CH)LDM1, p = 0.043). Celiac disease humoral immunoreactivity should be screened not only at diabetes onset, but also in long-standing patients, especially adults with disease duration >15 years.