Three cases of anti-TNF induced myositis and literature review.

Anti-tumor necrosis factor (anti-TNF) drugs are frequently preferred in the treatment of rheumatologic diseases and other inflammatory diseases. The development of myositis after using anti-TNF is a rare clinical condition. Here we aimed to report cases who developed myositis after using anti-TNF and review the current literature. We report two cases of rheumatoid arthritis (RA) and a case of ankylosing spondylitis (AS) developed idiopathic inflammatory myopathy following anti-TNF therapy. In conclusion, myositis could develop during anti-TNF therapy, so these patients should be evaluated carefully initially for myositis and should be closely monitored due to the potential for developing myositis in treatment process.