Conservative treatment of chronic nonbacterial osteomyelitis using zoledronic acid in children

BACKGROUND: Currently, there is no etiological treatment for chronic nonbacterial osteomyelitis. The insufficient efficacy of all available treatment modalities remains a major concern. Among the most effective approaches are genetically engineered therapy and bisphosphonate treatment. Pamidronate is the most frequently reported option in scientific publications. However, given pamidronates’ lower efficacy compared to zoledronic acid, we developed a treatment protocol that includes zoledronic acid at a dose of 0.05 mg/kg every 3 months, three infusions in total, along with active vitamin D metabolites and calcium carbonate. AIM: This study aimed to demonstrate the efficacy of zoledronic acid in the treatment of chronic nonbacterial osteomyelitis. METHODS: The study included 22 children aged 6 to 17 years. A prospective pilot study was conducted to assess the efficacy of zoledronic acid in children with chronic recurrent multifocal osteomyelitis. All patients underwent biopsy with morphological and microbiological verification of the diagnosis, as well as laboratory and imaging assessments before and 3, 6, and 12 months after treatment. Clinical disease activity was assessed using a visual analog scale for pain and the PedsQL 4.0 quality of life questionnaire. RESULTS: Preliminary treatment outcomes in patients receiving this regimen are promising. Pain was significantly reduced, quality of life improved, and the number of bone lesions decreased, with clinical remission achieved in all patients. CONCLUSION: Zoledronic acid rapidly inhibits osteoclast activity, leading to both clinical and radiological remission, as evidenced by decreased pain, reduction of bone marrow edema on MRI, and sclerosis of lytic lesions. Given the reduced osteoclast activity in the post-injection period, this therapy must be combined with active vitamin D metabolites and calcium carbonate to maintain calcium-phosphorus homeostasis.