Associated diseases and their effects on disease course in patients with chronic non-bacterial osteomyelitis: retrospective experience from a single center

Abstract

Objective: Chronic non-bacterial osteomyelitis (CNO) is a rare autoinflammatory bone disease associated with other chronic inflammatory diseases such as familial Mediterranean fever (FMF), juvenile idiopathic arthritis (JIA), spondylarthropathies, inflammatory bowel disease (IBD), and pyoderma gangrenosum. We aimed to describe the clinical and follow-up characteristics of patients with CNO and to compare findings between patients with and without comorbidities. Methods: The clinical records of patients with CNO who were followed up in our pediatric rheumatology clinic between 2018 and 2023 were reviewed. Patients were divided into two groups according to the presence or absence of comorbidities. The clinical, laboratory, and radiological characteristics and treatments of the groups were compared. Results: The study included 40 patients (65% male) diagnosed with CNO. The median (IQR) age at symptom onset was 10 (6.4) and at diagnosis was 11.5 (5.9) years. Fourteen (35%) patients had comorbidities. The comorbidities were FMF (n = 9), IBD (n = 3), uveitis (n = 3), psoriasis (n = 1) and acne conglabatae (n = 2). The group with comorbidities had higher number of bones involved (3 or more bones) (78.6% versus 42.3%) (p = 0.028), and 78.6% of patients with comorbidities received biologic treatment, while only 23.1% of patients without comorbidities were treated with biologics (p = 0.001). Conclusion: Familial Mediterranean fever, uveitis, IBD, psoriasis and acne conglabata were found to be the clinical conditions associated with CNO. Patients with CNO who had comorbidities appeared to have a more severe phenotype of the disease accompanied with more bone involvement and requiring more biologic treatment. (Table presented.)