Hypothyroidism as an immune-related adverse event caused by atezolizumab in a patient with muscle spasms: a case report

Abstract

A 60-year-old man with a history of 4 cycles of atezolizumab treatment for non-small cell lung cancer presented to our hospital with a chief complaint of proximal muscle-dominant spasms. Blood tests showed elevated creatine phosphokinase (CPK) of 8450 U/L and hypothyroidism. There was little improvement even after stopping levetiracetam and pregabalin, and no subspinous physical findings of myositis. After levothyroxine was started for hypothyroidism, his muscle cramps and serum CPK level improved. Hypothyroidism as an immune-related adverse event can cause muscle spasms and is important in the differential diagnosis of muscle spasms in patients treated with immune checkpoint inhibitors.

Immune-Related Adverse Events Associated with Atezolizumab: Insights from Real-World Pharmacovigilance Data

“…Disorders of the thyroid are common following immunotherapy and have been found to show a favourable outcome in hepatocellular carcinoma following atezolizumab treatment [ 31 ]. The incidence of hyperthyroidism and hypothyroidism following anti-PD-L1 therapy is reported to be 0.7% and 3.8–5.5%, respectively, and multiple cases of thyroid disorder post-atezolizumab have been reported [ 32 , 33 , 34 ]. Type 1 diabetes mellitus is an underreported and serious irAE if untreated, leading some patients to present with diabetic ketoacidosis [ 35 ].…”