The Safety Profile of Tumor Necrosis Factor Inhibitors in Ankylosing Spondylitis: Are TNF Inhibitors Safer Than We Thought?

Tumor necrosis factor (TNF) inhibitors significantly improved the treatment options for patients with ankylosing spondylitis. Unfortunately, currently, there is no strategy for sustaining remission of the disease with TNF inhibitors; after discontinuation, a high percentage of patients experience flares in a short time. Therefore, up-to-date, long-term use of TNF inhibitors in patients with ankylosing spondylitis remains necessary. For this reason, the issue of the long-term safety of TNF inhibitors in patients with ankylosing spondylitis raises concerns. Although TNF inhibitors are well established in ankylosing spondylitis treatment, the majority of studies on TNF inhibitors' safety have been performed in patients with rheumatoid arthritis. Until recently, there were very few studies of TNF inhibitors' safety in ankylosing spondylitis. Meanwhile, TNF inhibitors appear to have different safety profiles in ankylosing spondylitis and rheumatoid arthritis. In this review, we describe available data on the occurrence of adverse events associated with TNF inhibitor treatment in ankylosing spondylitis, including serious adverse events, infections, serious infections, tuberculosis, opportunistic infections, hepatitis B reactivation, malignancies, laboratory test abnormalities, autoimmune diseases, paradoxical adverse events, and heart failure.