[Rheumatic adverse events due to immune checkpoint inhibitors].

BACKGROUND: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. CASE DESCRIPTION: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. CONCLUSION: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.