ステロイド剤が女性関節リウマチ患者の骨型アルカリホスファターゼ（BAP）に与える影響

Effect of a Corticosteroid on the Serum Bone-specific Alkaline Phosphatase (BAP) Level in Female Rheumatoid Arthritis Patients

　ステロイド剤が関節リウマチ患者(RA)の血中骨型アルカリホスファターゼ(BAP)値にどのような影響を与えるかを検討した．女性RA患者131例(ステロイド内服63例，非内服68例)を対象に年齢別，罹病期間別，炎症反応別(ESR，CRP)にBAP値を測定した．その結果，ステロイド内服の有無にかかわらず，各項目とも進行に従いBAP値は上昇していた．ステロイドは骨代謝回転を抑制する働きがあり，ステロイド内服例のBAP値は非内服例に比べ低値となっていた．このため，骨密度が減少していてもBAP値が低値になることがあり，注意を要すると考えられた．

　Objective：The aim of this study was to evaluate the effect of a corticosteroid on the serum bone-specific alkaline phosphatase (BAP) level of 131 female rheumatoid arthritis (RA) patients.　Methods：We measured the serum BAP level of 63 female RA patients (aged 30―81 years) who were treated with a corticosteroid and 68 female RA patients (aged 31―86 years) who were not treated with a corticosteroid.　Results：The serum BAP levels of the patients as a whole increased with age, disease duration, the erythrocyte sedimentation rate, and C-reactive protein level.　The serum BAP levels of the corticosteroid group were significantly lower than in the group not treated with a corticosteroid.　Conclusion：BAP was a useful marker of bone loss in the RA patients.　However, we have to notice that the BAP levels of the corticosteroid group may decrease compared with non-treated group because corticosteroid suppresses the BAP.