Immune-related myocarditis in two patients receiving camrelizumab therapy and document analysis

Introduction Camrelizumab is an antibody against programmed death protein 1 (PD-1) and is one of immune checkpoint inhibitors (ICI). ICI may lead to autoimmune myocarditis, which has a variety of clinical manifestations and usually has a poor prognosis. This article will discuss these clinical manifestations through 2 cases of ICI-related myocarditis caused by carrelizumab. Case report We reviewed the patients who received tumor treatment in our hospital from September 2019 to June 2020. A total of 155 patients received camrelizumab treatment. there were 2 cases of acute myocarditis, accounting for 1.29%, and 8 cases of new-onset arrhythmia. Here we present 2 cases of active myocarditis in a 69-year-old man with primary liver cancer and a 75-year-old man with non-small-cell lung cancer after treatment with camrelizumab. Management and outcome: The first patient presented with severe heart failure and died of malignant arrhythmia after being treated with glucocorticoid. The second patient presented with numbness of the extremities, weakness, and mild dyspnea. The symptoms gradually improved after treatment with glucocorticoid. The Naranjo scores of these two cases were 6 and 7, which suggested that myocarditis was probably caused by carrelizumab. Discussion ICI has been successfully used to treat a variety of malignant tumors with good results. However, blocking immune checkpoints by ICI may lead to autoimmune myocarditis with a poor prognosis. Early detection of cardiotoxicity may be possible through the patient's clinical manifestations and some commonly used cardiac examination methods.