Nivolumab-Induced Autoimmune Haemolytic Anaemia and Safety of Subsequent Use of Ipilimumab: A Case Report

Autoimmune haemolytic anaemia (AIHA) is a rare immune-related adverse event and appears to be more common with anti-PD1/PDL1 than anti-CTLA4. Little is known about the safety of re-treating with anti-PD1/PDL1 or changing to anti-CTLA4. We present a case of grade 4 AIHA due to nivolumab (PD1-inhibitor) treatment in a patient with melanoma for adjuvant setting after surgery and the safeness of subsequent treatment with ipilimumab (anti-CTLA4). After the remission of AIHA with steroids, ipilimumab was started with the rationale of its different mechanism of action. Fortunately, AIHA did not recur. The mechanism by which checkpoint inhibitors cause AIHA is likely by augmenting or redirecting immune surveillance, especially by activating pre-existing red blood cell autoantibodies, but further studies must be done. To our knowledge, this is the first case published in the literature with the change of immunotherapy treatment to anti-CTLA4.