Ustekinumab may have therapeutic effects on autoimmune thyroid disease.

Interleukin (IL)-12 and IL-23 play crucial roles in initiating and maintaining autoimmunity, which is implicated in autoimmune thyroid disease (AITD). This study evaluated the effect of ustekinumab, a biologic agent targeting IL-12/23, on AITD in patients with inflammatory bowel disease (IBD). A total of 203 IBD patients and 58 age- and sex-matched healthy controls underwent comprehensive thyroid examinations including biochemical tests and sonography. Among the IBD patients, 127 received biologic therapy and 76 did not; 91 were treated with infliximab, 26 with adalimumab, and 10 with ustekinumab. Compared with healthy controls, patients with IBD exhibited impaired thyroid structure and a higher incidence of AITD. The incidence of AITD was lower and thyroid structure was better preserved in IBD patients receiving biologic therapy than in those not receiving it. When thyroid findings were analyzed by biologic type, ustekinumab-treated patients had the lowest AITD incidence, lower anti-thyroid peroxidase levels, and more favorable sonographic features compared with adalimumab and infliximab groups. These findings suggest that ustekinumab may have a protective or therapeutic effect on the thyroid gland and may be a potential treatment option in patients with AITD.