Neuropsychiatric Immune-related Adverse Events Induced by Pembrolizumab in a Patient with Lung Adenocarcinoma and Systemic Lupus Erythematosus

The patient was a 73-year-old woman with lung adenocarcinoma and systemic lupus erythematosus (SLE) who was treated with pembrolizumab. After six cycles of pembrolizumab, she developed symptoms suggestive of neuropsychiatric SLE, such as resting tremor, confusional state, depression, mood disorder, and anxiety disorder. In addition, her cerebrospinal fluid level of interleukin-6 was elevated. Her symptoms resolved one month after the discontinuation of pembrolizumab. This is the first report of neuropsychiatric symptoms in a patient with lung cancer and SLE on immune checkpoint blockade therapy.