Image-Based Assessment of Anti-TNF Treatment Outcomes in Pediatric CRMO/CNO: A Single-Center Case Series

Background/Objectives: Chronic recurrent multifocal osteomyelitis/chronic nonbacterial osteomyelitis (CRMO/CNO) is an auto-inflammatory bone disease for which optimal treatment and imaging-based monitoring remain incompletely defined. Methods: We conducted a single-center retrospective review of nine pediatric patients with CRMO/CNO treated with tumor necrosis factor inhibitors (TNFis). Clinical improvement was assessed using Visual Analog Scale (VAS) pain scores, erythrocyte sedimentation rate (ESR), and physical examination findings. Radiographic assessment used longitudinal, site-specific magnetic resonance imaging (MRI) scored with a simplified approach adapted from the Chronic Nonbacterial Osteomyelitis Magnetic Resonance Imaging Scoring (CROMRIS) system. Results: Our cohort was composed of six females and three males with a median age of seven years. TNFi monotherapy was initiated as a first-line therapy (n = 4) or step-up (n = 5). During a median follow-up time of 26 months, treatment was tolerated well, except for the emergence of psoriasis in three patients (n = 3), among whom one necessitated treatment change. Eight patients on TNFis achieved clinical remission, including five with complete resolution of MRI lesions. Conclusions: In this small, single-center case series, TNFi monotherapy was associated with sustained disease control, as reflected by clinical improvement and MRI-documented lesion resolution. These findings emphasize the need for validation of our observations in larger multi-center cohorts.