SAT0510 NON-BACTERIAL OSTEITIS IN CHILDREN: PROGNOSTIC FACTORS
Authors: Nuria Heredia Torres, Esmeralda Núñez Cuadros, Rocío Galindo Zavala, Gisela Diaz-Cordobes, Laura Martín Pedraz, Antonio Urda Cardona
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> The incidence of non-bacterial osteitis (NBO), a rare autoinflammatory disease in childhood, has increased over the past few years. Early diagnosis and treatment, as well as an adequate follow-up, are necessary to prevent sequelae and complications. However, prognostic factors of the disease are unknown. <h3>Objectives</h3> To establish the prognostic factors of NBO. <h3>Methods</h3> A retrospective study of NBO, according to Jansson criteria, in children (&lt;14 years) at a tertiary hospital from 2009 to 2018. Descriptive statistics were performed to examine clinical features, diagnoses, treatments and progress of the disease. Furthermore, bivariate analysis was performed in order to investigate factors involved in the remission of the disease (with/out treatment), the number of relapses and sequelae. We considered p&lt;0,1 as <i>s</i><i>ignificance level due to the small sample size</i>. <h3>Results</h3> We reviewed 15 cases. Table shows the descriptive data. The likelihood of remission was found to be associated with the presence of X-ray findings apart from sclerosis/lysis, (80% vs 40%, <i>p 0.07</i>), a high white blood cell count (mm3) (11988.7 ± 3004.9 vs 8915.7 ± 3310.3, p 0.08) and ESR (mm) (58.3 ± 36.3 vs 26.8 ± 17.4, <i>p 0.05</i>) at diagnosis and a longer duration of disease (months) (5.7 ± 1.6 vs 3.1 ± 3.2, <i>p 0.06</i>). In addition, fewer relapses were found among patients with peroneal involvement [0 (0-0) vs 5 (1-6.7), <i>p 0.05</i>], a high white blood cell count at diagnosis (r -0.569, <i>p 0.02</i>) and those who were not treated with pamidronate [0 (0-5) vs 5 (1.2-6.7), <i>p 0.07</i>]. Finally, the lack of sequelae was related to the administration of pamidronate (100% vs 57.1%, <i>p 0.07</i>), younger age at diagnosis (years) (9.08 ± 1.4 vs 11 ± 2, <i>p 0.07</i>) and lesser CRP level at diagnosis (mg/L) [2.9 (2.9-2.9) vs 3.8 (2.9-3.8), <i>p 0.005</i>]. <h3>Conclusion</h3> Advanced cases of NBO, without radiological signs of sclerosis or lysis, were more likely to achieve remission. Elevation of acute phase reactants was related to a better response to treatment and a lower relapse rates, but with a greater probability of sequelae. As described in the literature, bisphosphonates achieve higher rates of clinical and radiological remission. In our study, they are also associated with a lower relapse rates and the lack of sequelae. The last is the main reason to be considered the first treatment choice in NBO. <h3>References</h3> [1] Schnabel A, Range U, Hahn G, Berner R, Hedrich CM. Treatment Response and Longterm Outcomes in Children with Chronic Nonbacterial Osteomyelitis. J Rheumatol. 2017; 44: 1058-1065 [2] Roderick MR, Sen ES, Ramanan AV. Chronic recurrent multifocal osteomyelitis in children and adults: current understanding and areas for development. Rheumatology. 2018; 57:41-48 [3] Zhao Y, Wu EY, Oliver MS, Cooper AM, Basiaga ML, Vora SS, et al. Consensus treatment plans for chronic nonbacterial osteomyelitis refractory to nonsteroidal anti-inflammatory drugs and/or with active spinal lesions. Arthritis Care Res (Hoboken). 2018; 70(8):1228-1237. <h3>Disclosure of Interests</h3> Nuria Heredia Torres: None declared, Esmeralda Núñez Cuadros Grant/research support from: NOVARTIS, ABBVIE, ROCHE (ALWAYS AS SPEAKER), Speakers bureau: NOVARTIS, ABBVIE, ROCHE, Rocío Galindo Zavala Grant/research support from: NOVARTIS, ABBVIE (ALWAYS AS SPEAKER), Speakers bureau: NOVARTIS, ABBVIE, Gisela Diaz-Cordobes Grant/research support from: ABBVIE, ROCHE (ALWAYS AS SPEAKER), Speakers bureau: ABBVIE, ROCHE, Laura Martín Pedraz: None declared, Antonio Urda Cardona Grant/research support from: PFIZER (ALWAYS AS SPEAKER), Speakers bureau: PFIZER