# Challenges in autoimmune polyendocrine syndrome type 2 with the full triad induced by anti-programmed cell death 1: a case report and review of the literature

## TL;DR

An elderly woman developed a rare autoimmune condition with three endocrine disorders after immunotherapy, highlighting the need for careful treatment and hormone replacement.

## Contribution

This case report presents a rare instance of APS-2 with the full triad induced by anti-PD1 therapy.

## Key findings

- APS-2 with the full triad can occur after anti-PD1 treatment in patients without prior autoimmune history.
- Multiple hormone replacement therapy improved outcomes in this patient.
- Components of APS-2 may appear at different times and be life-threatening.

## Abstract

Immune checkpoint inhibitors (ICPis) induce autoimmune diseases, including autoimmune polyendocrine syndrome type 2 (APS-2), which is defined as a combination of at least two of the following endocrinopathies: autoimmune thyroid disease, type 1 diabetes, and Addison’s disease. Cases with the full triad are rare. We present a case of an elderly woman who developed APS-2 with the complete triad shortly after starting anti-programmed cell death 1 (anti-PD1) treatment and review the related literature.

A 60-year-old woman, without any personal or family history of autoimmune and endocrine diseases, started the immunotherapy of anti-PD1 (camrelizumab) for squamous cell carcinoma of the urethral meatus. She developed primary hypothyroidism with elevated antibodies to thyroid peroxidase and thyroglobulin after 25 weeks of treatment, and developed primary adrenal insufficiency with adrenal crisis and fulminant type 1 diabetes with ketoacidosis after 45 weeks. Therefore, this patient met the diagnosis of APS-2 and was given multiple hormone replacement including glucocorticoid, levothyroxine and insulin therapy. Continuous improvement was achieved through regular monitoring and titration of the dosage.

Different components of APS-2 may appear at different time points after anti-PD1 administration, and can be acute and life-threatening. A good prognosis can be obtained by appropriate replacement with multiple hormones.

With the clinical application of ICPis to APS-2, the complexity of its treatment should be paid enough attention.