PROBLEM TO BE SOLVED: To provide antibodies specific to α2β1 integrin and their uses, including humanized anti-alpha 2 (α2) integrin antibodies, showing improved ADCC and/or CDC effector function, and methods of treatment with anti-α2 integrin antibodies.SOLUTION: The present invention provides humanized anti-α2 integrin antibodies comprising a heavy chain variable region, a light chain variable region, a human light chain constant region and a variant human IgG1 heavy chain constant region, wherein a specific amino acid in the IgG1 heavy chain constant region is varied.SELECTED DRAWING: None【課題】改善されたＡＤＣＣ及び／又はＣＤＣのエフェクター機能を示す、ヒト化抗アルファ２(α２)インテグリン抗体及び抗α２インテグリン抗体を用いた処置方法を含む、α２β１インテグリンに特異的な抗体及びそれらの使用方法の提供。【解決手段】重鎖可変領域、軽鎖可変領域、ヒト軽鎖定常領域及び変異ヒトＩｇＧ１重鎖定常領域を含む親ヒト化抗α２インテグリン抗体に対し、ＩｇＧ１重鎖定常領域の特定のアミノ酸が変異した、ヒト化抗α２インテグリン抗体。【選択図】なし
