Giant Cell Arteritis Associated With PD-1 Inhibitor Use

A 74-year-old woman with metastatic neuroendocrine tumor presented with unilateral vision loss while receiving nivolumab therapy. An ophthalmologic examination and transcranial Doppler were concerning for giant cell arteritis (GCA). Empiric pulse dose steroids were started, and temporal artery biopsy was consistent with GCA. Her immunotherapy was stopped in the setting of suspected immune-related adverse events from nivolumab, and her course was complicated by steroid-induced hyperglycemia. Tocilizumab was used as a steroid-sparing agent without relapse of GCA. Although rare, GCA induced by immune checkpoint inhibitors is an important consideration for patients who are receiving immunotherapy and can result in limited chemotherapeutic options and life expectancy.