Abstract: FR-PO584
Hyponatremia Due to Nivolumab-Induced Sequential Primary Adrenal Insufficiency and Hypothyroidism
Session Information
- Trainee Case Reports - III
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 902 Fluid and Electrolytes: Clinical
Authors
- Son, Raku, St. Luke's international hospital, Tokyo, tokyo, Japan
- Nagahama, Masahiko, St. Luke's international hospital, Tokyo, tokyo, Japan
- Nakayama, Masaaki, St. Luke's international hospital, Tokyo, tokyo, Japan
Introduction
Hyponatremia is the most common electrolyte disorders in lung cancer patients. Here we present a case of hyponatremia due to both primary adrenal insufficiency and hypothyroidism in a patient treated by nivolumab, a novel and increasingly used immune checkpoint agent.
Case Description
A 77-year old Asian man diagnosed as Stage IV non-small cell lung cancer on 6 courses of nivolumab for 4 months presented with 1-week general malaise. Laboratory test showed serum sodium (S-Na) 122 mEq/L. Cortisol, renin, aldosterone were 1.31 microg/dL, 1.1 ng/ml/hr and 23 pg/ml, respectively. Brain MRI denied hypophysitis. Positron emission tomography (PET) scan showed no adrenal metastasis but raised suspect of thyroiditis, though TSH was within normal limit. After treatment with hydrocortisone for primary adrenal insufficiency, S-Na was improved to 136 mEq/L. One month after discharge, laboratory follow-up revealed TSH of 62.7 micro IU/ml with low free T4 and T3. Levothyroxine was started but TSH remained high at 99.9 micro IU/ml. Two months after discharge he again presented with S-Na 121 mEq/L accompanied with loss of appetite. Laboratory test revealed cortisol 23.23 microg/dL, renin 7.5 ng/ml/hr and aldosterone 115 pg/ml. We increased both levothyroxine and hydrocortisone and S-Na returned to 135 mEq/L.
Discussion
Hyponatremia in lung cancer patients is commonly attributed to SIADH or hypovolemia. However, immune checkpoint agent including nivolumab can cause hypophysitis, primary adrenal insufficiency and hypothyroidism, or even more than one as in our patient. Any patient on a checkpoint inhibitor presenting with hyponatremia should undergo full work-up of endocrine disorders.