The clinical characteristics and prognosis of patients with SAPHO syndrome--a real-world cohort study

ObjectivesWe aimed to analyze the clinical characteristics and outcomes of patients with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.MethodsThe clinical records of 64 patients with SAPHO syndrome were collected, and the treatment and outcomes of 27 patients were followed up. The patients were divided into three groups according to the site of bone lesions: only anterior chest wall (ACW) involvement, only spinal involvement, and bone lesion involvement at both sites. The clinical characteristics and outcomes were compared. The clinical characteristics of the patients with and without peripheral joint involvement were compared.ResultsAmong all patients, 31.25% (20/64) had only ACW involvement, 15.63% (10/64) had only spinal involvement, and 53.12% (34/64) had both ACW and spinal involvement. Peripheral joint involvement was observed in 25.00% (16/64) of the patients. Patients with only spinal involvement were older than those with only ACW involvement (p = 0.006). Patients with both ACW and spinal involvement were older than those with only ACW involvement (p = 0.002) and had a longer diagnosis delay (p = 0.015). Patients with peripheral joint involvement were younger than those without peripheral joint involvement (p = 0.028). During follow-up, 88.89% (24/27) of patients had good outcomes. Twenty-two patients were treated with non-steroidal anti-inflammatory drugs + Iguratimod (IGU), and the outcomes of 90.91% (20/22) improved.ConclusionsA relationship may exist between the sites of bone lesions and clinical characteristics of patients with SAPHO syndrome. The clinical outcomes of these patients may be good, and IGU may be effective in treating SAPHO syndrome.Key Points center dot This study is the first long-term follow-up on the effectiveness of iguratimod in treating patients with SAPHO.center dot This study revealed that patients with SAPHO and different bone lesion sites may present with different clinical characteristics.