Concurrent presence of nonendocrine autoimmune diseases with Hashimotos thyroiditis: a systematic assessment on more than 5000 consecutive patients
M. Centanni1,2, M. Santaguida1, S Del Duca1, M. Cellini1,2, L. Gargano2, N. Brusca1,2 & C. Virili1
Systematic studies on the association of autoimmune thyroiditis (AIT), as pivotal disease and nonendocrine autoimmune diseases (NEAD) are scarce and mostly based only on the presence of circulating autoantibodies. In a large cohort of consecutive outpatients, AIT was diagnosed in 1541 (28.2%) and whenever additional autoimmune disorders were suspected, they underwent further screening. Diagnostic criteria were according with the Consensus Conferences for each suspected autoimmune disease. The association AIT+NEAD was detected in 250/1541 (16.2%) patients (227 W and 23 M; W/M 10:1; median age=39 years). Of these, 64 patients (25.6%) had more than one autoimmune disease associated with AIT. The most frequent associated disease was chronic atrophic gastritis (CAG) (34.8%), followed by nonsegmental vitiligo (22.3%), celiac disease (11.0%), anti-phospholipids syndrome and multiple sclerosis (7.6%). Although most of patients with multiple autoimmune disorders were adult to old, 9.9% of them had a second autoimmune disease before the age of 30 years. In this group the most frequent diseases associated with thyroiditis were vitiligo (39%) and celiac disease (26%), while CAG was less observed (13%). Peculiar characteristics of patients with AIT+NEAD were thyroxine malabsorption, chronic unexplained anemia and recurrent pregnancy loss (RPL). Thyroxine malabsorption was indeed higher than in patients with isolated thyroid diseases (31 vs 12.3%; P<0.0001; OR=3.60). RPL was observed in 6.9% of patients with AIT+NEAD as compared with 1.7% found in patients with isolated thyroid diseases (P<0.0001; OR=4.06). Unexplained anemia was found in 2.2% of patients with isolated thyroid diseases and in 18.3% of patients with AIT+NEAD (P<0.0001; OR=8.23). In conclusion: i) 1 patient out of 6 has NEAD associated with AIT and 1/10 of them is younger than 30 years; ii) atrophic gastritis, vitiligo and celiac diseases are the most frequent autoimmune disorders associated with AIT, being their prevalence age-related; iii) the presence of thyroxine malabsorption, chronic unexplained anemia and recurrent pregnancy loss in patients with AIT should induce to look for other autoimmune diseases.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This work was supported, however funding details are unavailable.