The concurrence of ankylosing spondylitis (AS) in a patient with mixed connective tissue disease (MCTD) is rarely described in the literature. Significant and sustained efficacy with tumor necrosis factor (TNF)-alpha blockers has been demonstrated in AS patients. However, evidence to date has revealed associated side effects, including antinuclear antibody induction and development of a lupus-like syndrome. Several authors have reported lupus-like manifestations in MCTD patients treated with TNF-alpha blockers used to control peripheral polyarthritis. In our case report, we demonstrate a good response to etanercept therapy for refractory sacroiliitis in a patient with coexisting AS and MCTD, without development of a lupus-like syndrome. This demonstrates that etanercept therapy may be an appropriate therapeutic agent for sacroiliitis in MCTD patients, as it is in AS alone.
Female ; Humans ; Immunoglobulin G/*therapeutic use ; Magnetic Resonance Imaging ; Middle Aged ; Mixed Connective Tissue Disease/complications/*drug therapy/*pathology ; Receptors, Tumor Necrosis Factor/*therapeutic use ; Sacroiliac Joint/*drug effects/*pathology ; Spondylitis, Ankylosing/complications/*drug therapy/*pathology ; Treatment Outcome