デノスマブによる顎骨壊死の1症例

A case of osteonecrosis of the mandible related to denosumab

はじめに

　ビスホスホネートなどの強力な骨吸収抑制剤は骨粗鬆症，骨転移性悪性腫瘍など幅広い疾患に臨床応用されている。近年この合併症の1つとして骨吸収抑制薬関連顎骨壊死（anti-resortive agents-related osteonecrosis of the jaw：ARONJ）が報告され注意が喚起されている^1-4）。一方，デノスマブなどの長期間作用が持続する分子標的薬が新しく開発され，骨粗鬆症の治療薬として臨床応用されている^5-7）。今回われわれはデノスマブに関連する下顎骨壊死の1症例を経験したので，若干の文献的な考察を加えて報告する。

　Anti-resortive agents including Bisphosphonate（BP）are widely used in the management of metastatic bone disease and osteoporosis. Recently, there have been reports of osteonecrosis of the jaws as a complication of anti resortive agents-related osteonecrosis of the jaw（ARONJ）. Denosmab is a monoclonal antibody against to receptor activator of nuclear factor k B ligand.

　A 75-year-old woman with osteoporosis, who had received denosumab from July 2016 through January 2017, presented with a swelling and purulent discharge from a fistula in the left submandibular region. Physical examination revealed ulceration over the left mandible and a devitalized bone exposed around the left mandibular canine. CT of the lesion revealed an extensive radiolucent area in the left and right sides of the mandible. ARONJ was diagnosed. Denosmab was discontinued, and surgical intervention was carried out, followed by antibiotic therapy and oral care management. Complete recovery from the lesion was observed 4 months after initial treatment.