ビスホスフォネート経口製剤が著効したSAPHO症候群の1例

Efficacy of Oral Alendronate in the Treatment of SAPHO Syndrome. Case Report

　SAPHO症候群の骨病変にビスホスフォネート（BP）経口製剤が著効した1例を報告する．症例は50歳の女性で，40歳時に掌蹠膿疱症と診断されていた．左大腿近位部痛を主訴とし，単純X線写真で大腿骨近位部に骨肥厚と溶骨像を認めた．非ステロイド性消炎鎮痛薬は無効であったがアレンドロン酸（5mg/日）の経口投与により疼痛は消失し，溶骨像は硬化像に変化した．尿中Ⅰ型コラーゲン架橋N-テロペプチドは治療前の66％減となった．骨吸収マーカーが高値を示すSAPHO症候群に対してBP経口製剤が奏効する可能性がある．

　Introduction. In other countries bisphosphonates (BPs) have recently been used intravenously to treat SAPHO syndrome, but in Japan intravenous administration of BPs is usually restricted to cancer patients. We report a case of SAPHO syndrome successfully treated by oral administration of a BP.

　Case. A 50-year-old woman with a history of palmoplantar pustulosis complained of pain in the left thigh. A plain radiograph revealed cortical hyperostosis and focal osteolytic changes in the proximal femur, and a diagnosis of aseptic osteomyelitis was made by incisional biopsy. Oral alendronate (5mg/day) was started, and 3 weeks later the severe pain was relieved. Oral alendronate was continued for more than 1 year, and prominent sclerotic changes were observed in the bone lesion. The patient's increased urinary excretion of NTX decreased dramatically after the oral alendronate therapy.

　Conclusion. Oral BPs may be an effective treatment for SAPHO syndrome in patients with increased levels of bone resorption markers.