Chronic non-bacterial osteomyelitis (CNO) is a rare disease where the immune system attacks healthy bone, leading to inflammation and destruction. Currently, the use of inflammation markers - which consists of a blood test for erythrocyte sedimentation rate (ESR) and c reactive protein (CRP), a clinical visit, and magnetic resonance imaging (MRI) are used to monitor the state of CNO. However, the reports from these assessments are inconsistent as longitudinal data allowing for a detailed analysis is lacking.Thus, we aim to investigate the association among these disease monitoring modalities using Seattle Children's Hospital CNO research database. The database which contains patients under 21 years old, spanning from January 2014 - January 2021 is one of the largest composed. We hypothesize that an increased presence of lesions, as observed through MRI, correlates with a greater value of inflammation markers and greater physician global assessment (PGA) score. Through blood samples and MRI scans, ESR/CRP values and number of active lesions within 30 days of the visit were recorded. General statistical methods were used to summarize the data and determine correlation. We expect a strong positive correlation between active lesion count and ESR/CRP values. ESR/CRP values measure the rate of inflammation. As inflammation is a common physiological symptom stemming from lesion presence, a positive correlation between these variables must occur. Additionally, we expect a strong positive correlation between active lesion count and PGA scores. PGA scores are determined during clinical visits and are drawn from assessing a patient’s current condition. The prominence/severity of lesions are factored into the PGA score. As CNO lacks a reliable technique to monitor the disease, we expect that the results from this study will shed light on a reliable and robust assessment tool to monitor disease activity.
 

Chronic nonbacterial osteomyelitis (CNO) is an autoinflammatory bone disease associated with persistent bone pain, destruction and pathological fractures. While physical findings and laboratory tests are used in monitoring CNO disease activity, these methods are not yet reliable. Laboratory tests for N-terminal telopeptide (NTx) in the urine and C-terminal telopeptide (CTx) in the serum can be used to measure bone resorption that results from the breakdown of affected bones in CNO. These tests can serve as a useful monitoring marker in CNO patients taking bisphosphonates because these medications work by inhibiting osteoclasts that cause the degradation of bone. We aimed to assess the dynamic change of urinary NTx and serum CTx in children with CNO during and after treatment with bisphosphonates to determine if there is a correlation with disease activity. After IRB approval, we obtained consent from participating patients and families . Blood and urine samples, MRI scans, and clinical data including Physician Global Assessment (PGA) were collected during clinical visits at Seattle Children’s Hospital. We analyzed collected data using descriptive statistics and performed a correlative analysis. Based on our small cohort, we confirmed an initial decrease of NTx and CTx during bisphosphonate treatment in patients with improved PGA scores. After treatment, disease flare among these patients was not clearly correlated with the subsequent increase of these two markers; however, a well-controlled large-scale study is warranted for further confirmation. Results of this study have the potential to improve the efficiency of disease monitoring methods for pediatric CNO.