Endocrine Abstracts

Ipilimumab is an immunomodulating agent for the treatment of metastatic melanoma. Ipilimumab is a human mAb which works by inhibiting cytotoxic T-lymphocyte antigen 4 (CTLA-4).

CTLA4 typically works to down-regulate the T-cell response and protects self-antigens from recognition by the immune system. Since the T-cells are no longer down-regulated by this antigen, they are allowed to proliferate, thereby helping to prevent melanoma tumor evasion. As a result of the up-regulation of the immune system, immune-mediated adverse effects have been reported including colitis, dermatitis, hepatitis and hypophysitis. Typically, these effects are treated with high-dose steroids and most eventually resolve.

We present two cases of female patients referred to our department with manifestations of hyperthyroidism. They were 66 and 61 years old without autoimmune background. Hyperthyroism ocurred 1 month after their fourth dose of ipilimumab for metastatic malignant melanoma. Hyperthyroidism was initially controlled by steroids but with recurrence 2 and 4 months respectively after the beginning of steroid therapy. Clinical, biological presentation was usual with elevated TRAK. Curiously, there was no hypervascularization at presentation but only at recurrence.

There have been no reported cases of Grave’s hyperthyroidism with ipilimumab therapy to our knowledge but only two cases of euthyroid ophtalmopathy. We discuss the presentation of these cases in the light of classical Grave’s diseases and previous reports of autoimmune endocrinopathies.