Clinical features of anti-PIT-1 hypophysitis: A new aspect of paraneoplastic autoimmune condition
Shin Urai, Genzo Iguchi, Keitaro Kanie, Hironori Bando, Masaaki Yamamoto, Yuka Oi, Yuya Kashitani, Keiji Iida, Maki Kanzawa, Hidenori Fukuoka, Michiko Takahashi, Yasushi Shintani, Wataru Ogawa, Yutaka Takahashi- Endocrinology
- General Medicine
- Endocrinology, Diabetes and Metabolism
Abstract
The pathogenesis of anti-pituitary-specific transcription factor 1 (PIT-1) hypophysitis was gradually revealed as cases emerged. Our comprehensive analysis, including all reported cases, identified a new instance of anti-PIT-1 hypophysitis post-immune checkpoint inhibitor therapy. All nine patients exhibited extremely low GH, PRL, and TSH levels; two had a slightly atrophic pituitary gland; four had thymoma, and five had malignant neoplasms of diffuse large B-cell lymphoma (DLBCL) and other origins. Patients with thymoma showed multiple autoimmune diseases. HLA-A*24:02 and/or A*02:06 were present in six and DR53 in five cases analyzed. High anti-PIT-1 antibody titers and ectopic PIT-1 expression in the cytosol and nucleus of the tumor tissues were observed in patients with thymoma or DLBCL, whereas it was exclusively observed in the nuclei of a bladder cancer patient. These findings provide new insights into the pathophysiology of paraneoplastic autoimmune hypophysitis.