Comparison of different treatment approaches of pediatric chronic non-bacterial osteomyelitis

Chronic non-bacterial osteomyelitis (CNO) is a chronic inflammatory bone disease which usually manifests in children and adolescents. There are a few data about pathogenesis and treatment. The aim of the study to compare the efficacy of different treatment approaches in pediatric CNO cohort patient. Fifty two children (25 boys and 27 girls) with CNO with average age at the onset of the disease 8.4years (5.4; 11.0), number of foci -3.0 (2.0; 6.0, incl. multifocal cases in 80.8%). Non-steroid anti-inflammatory drugs (NSAID) was the first-line treatment for non-vertebral cases, as well as pamidronate (PAM) for vertebral involvement. Second-line treatment includes sulfasalazine (SSZ), methotrexate (MTX), PAM and tumor necrosis factor- inhibitors (TNF-inh). We evaluated the dynamics of pain, patient's and physician's (MDVAS) assessment with visual-analog scale (VAS) and ability to each medication to achieve remission of CNO activity. According to the NSAID, MTX, SSZ, PAM and TNF-inh groups the following data were registered: patient's VAS: -14.2% (p=0.05), -50.0% (p=0.04), -23.1 (p=0.89), -83.3% (p=0.0001), -73.6% (p=0.0007); painVAS: -21.9% (p=0.01), -18.6% (p=0.13), +36.4 (p=0.89), -79.7% (p=0.00016), -74.1%, (p=0.0015); MDVAS: -13.8% (p=0.13); -56.4% (p=0.09), +30.8% (p=0.89), -74.7%, (p=0.0001), -82.1 (p=0.0015) respectively. The ability of each treatment strategy to achieve the CNO remission was 52.6%, 44.4%, 57,1%, 88.8% and 73.3%, respectively (log-rank test, p=0.001). The efficacy of treatment approaches for CNO depended on the severity of the disease. NSAID, methotrexate, and sulfasalazine were effective in forms without spine involvement, but pamidronate and TNF-a inhibitors were useful in vertebral forms of CNO. Pamidronate and TNF-a inhibitors more extensively suppressed CNO activity. The randomized controlled trials for assessment of the efficacy and safety of these medications is mandatory to confirm these results.