Long-term Clinical Outcomes in Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis Syndrome

Abstract

Objective: To assess the outcome of empirical therapeutic interventions for synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. Methods: The clinical features and treatment outcomes of a cohort of 21 patients diagnosed with SAPHO in Western Australia were reviewed retrospectively. Results: All 21 patients met published diagnostic criteria; 20 (95%) were Caucasian, and the median age was 47 years. The median follow-up was 6 years (range, 2 to 32 years). Three patients (14%) received no treatment; 18 (86%) required conventional synthetic disease-modifying antirheumatic drug (DMARDs). Thirteen (62%) had an initial good response to methotrexate; 8 relapsed and progressed to biologic DMARDs (bDMARDs) during a period of 14 years. Of the 13 recipients on a tumor necrosis factor inhibitor, 11 (85%) continued treatment for a median of 4 years (range, 1 to 14 years), whereas none of 3 recipients of interleukin 17/23 continued treatment (median, 4 months). Higher Physician Global Assessment scores (better outcomes) were observed in bDMARD recipients (mean, 7.06±2.24 [SD]) compared with non-bDMARD recipients (mean, 5.63±2.50; P=.1672) after a median of 3 years of therapy. Conclusion: This study describes the broad range of clinical manifestations in SAPHO, variable courses over time, and inconsistent outcomes with diverse empirical therapies. Moderately good long-term treatment outcomes were observed in most recipients of tumor necrosis factor inhibitor. Poorer outcomes were observed with bisphosphonates and interleukin 17/23 axis inhibitors; however, low numbers preclude robust comparison. Suboptimal treatment may be associated with poorer clinical outcomes and greater skeletal damage. Trial Registration: Australian and New Zealand Clinical Trials Registry: ACTRN12619000445178