Autoimmune phenomena and disease in cancer patients treated with immune checkpoint inhibitors

The discovery and approved treatment with immune checkpoint inhibitors (ICIs) for a variety of cancers has changed dramatically the morbidity and mortality rates for these patients. Despite the obvious benefits, their use is associated with unique immune-related adverse effects (irAEs), including autoimmune conditions such as: inflammatory arthritis, myositis, vasculitis and Sicca syndrome. The appearance of ICIs-induced autoimmune irAE requires from oncologists and rheumatologists a different approach to the identification and treatment of these conditions, which may differ from the classic and traditional approach to rheumatologic diseases. It should be taken into consideration that ICIs therapy in patients with preexisting autoimmunity could be possible, but with a cost of causing disease exacerbation. In this extensive review, we present the autoimmune irAEs, mostly as phenomena, but also as classic autoimmune diseases as well as therapeutic options for the side effects.