Nivolumab-induced polyarthritis.

Kodama S, et al. BMJ Case Rep 2017. doi:10.1136/bcr-2017-223387 Description A 48-year-old Japanese woman with non-small cell lung adenocarcinoma (cT3N2M1b) received nivolumab (an immune checkpoint inhibitor) at a dosage of 3 mg/kg every 2 weeks. Treatment with nivolumab was effective. The primary tumour as well as metastases to the lymph nodes and spine almost completely disappeared, as shown on positron emission tomography-CT before treatment (figure 1A) and 4 months after treatment (figure 1B). However, she developed sustained pain and swelling in the shoulders and knees bilaterally after only one infusion of nivolumab, and active inflammation was detected in the shoulder joints bilaterally (figure 1B). She had no personal and family histories of autoimmune disease. Serum C-reactive protein level was 2.1 mg/L. Serum matrix metalloproteinase-3 was elevated at 209 ng/mL (normal <60). Antinuclear antibody, rheumatoid factor and anti-cyclic citrullinated peptide antibody were negative. Ultrasonography confirmed shoulder tenosynovitis and bursitis (figure 2). The arthritis responded well to low-dose prednisone, and she could continue to receive nivolumab. General physicians are encountering an increasing number of immune-related adverse events with increased use of immune checkpoint inhibitors. Our case provides instructive images demonstrating both the efficacy of immune checkpoint inhibitors and the associated immune-related adverse events.