[Hypothyroidism and immunotherapy using interferon or interleukin for metastatic renal adenocarcinoma]

The authors report a case of hypothyroidism occurring during cytokine treatment of metastatic renal cancer. This is a relatively rare complication of immunotherapy, whose aetiopathogenesis remains unclear. Possible hypotheses include an autoimmune process or direct toxicity. Thyroid function tests at the start of immunotherapy and regular monitoring are therefore recommended during treatment with interferon and/or interleukin. If hypothyroidism is not recognised, its clinical symptoms and signs could be attributed to cytokine toxicity, leading to unwarranted discontinuation of treatment when L-thyroxin replacement therapy would have been sufficient.