Endocrine Abstracts

Nivolumab is the first programmed death 1 (PD-1) immune checkpoint inhibitor. It is approved for use in advanced melanoma and squamous non small cell lung cancer (NSCLC). PD-1 immune checkpoint inhibitors can cause autoimmune disease of endocrine glands, including the thyroid. Here, we present a case of thyroiditis after nivolumab therapy.

A 61 year-old female patient with NSCLC was consulted to endocrinology department for abnormal thyroid function test results. Thyroid hormone results are consistent with hyperthyroidism (TSH: 0.01 μIU/ml, fT₄: 45.4 pmol/l, fT₃: 10.8 pmol/l). Thyroid gland was smooth, non tender and minimally enlarged. She did not have history of prior thyroid dysfunction. In 2006, she was diagnosed with stage III ovarian carcinoma and she received paclitaxel-carboplatin therapy. Relapse occured after seven years in remission and she was given six courses of paclitaxel-carboplatin and four courses of ipilimumab. In March 2015, she was diagnosed with NSCLC and received thirteen weeks of paclitaxel-carboplatin. Then six courses of nivolumab (3 mg/kg) was given fortnightly. Thyroid hormone levels were normal after two courses of nivolumab. Serum TgAb, TPOAb, and TRAb were undetectable. Thyroglobulin levels were >500 ng/ml (0–85) and thyroid ultrasonography showed paranchymal heterogenity and small multiple nodules. Thyroid scintigraphy result was consistent with diffusely reduced uptake but the patient did not give consent to iodine uptake test. Propranolol treatment was given. She was euthyroid approximately 8 weeks later. On follow up one month later, she was found to have an elevated TSH of 81 μIU/ml, low fT₄ of 3.7 pmol/l (12–22), and fT₃ of 1.1 pmol/l (3.1–6.8). L-thyroxine therapy was initiated.

This case demonstrates painless thyroiditis which initially presented as hyperthyroidism and progressed to hypothyroidism under nivolumab therapy. We recommend that all patients on anti-PD1 therapy should be screened for the clinical and laboratory manifestations of thyroid dysfunction.