[Rheumatic adverse events due to immune checkpoint inhibitors]

Oncological survival and quality-of-life improved significantly after introduction of immune checkpoint inhibitors (ICIs). Immunotherapy, however, also decreases immunotolerance, potentially inducing autoimmune reactions. This can result in symptoms mimicking rheumatic diseases.

Patient A, 51-years-old, female, was treated with adjuvant nivolumab for metastatic melanoma. After 9 months, she developed arthritis. Prednisone 30 mg/ day and methotrexate significantly improved arthritis, followed by prednisone tapering. Patient B, 75-year-old, male with metastatic melanoma treated with Ipilimumab/Nivolumab developed malaise and reduced muscle strength shortly after treatment start. Patient was suspected of myositis/myocarditis, treated with methylprednisolone, which resulted in a rapid improvement.

ICIs can cause rheumatic adverse events, resulting in decreased quality of life that may require immunesuppressive treatment. Disruption or cessation of ICIs may occur. These adverse events demand low-threshold rheumatological referral and collaboration between oncologist and rheumatologist. Further research must indicate the most effective immunosuppressive therapies with minimized negative oncological impact.