[PROBLEMS] To provide a pharmaceutical composition for treating and/or preventing abnormalities of bone metabolism, which targets a protein encoded by a gene that can be strongly expressed in osteoclasts. [MEANS FOR SOLVING PROBLEMS] To provide a pharmaceutical composition containing an antibody that can recognize human Siglec-15 specifically and has an activity of inhibiting the formation of osteoclasts； and others.本發明係提供一種骨代謝異常治療及/或預防用醫藥組成物，其係以在破骨細胞中高度表現之基因所編碼之蛋白質作為標的。本發明之解決手段為提供含有抗體之醫藥組成物等，該抗體具有特異地識別人類Siglec-15，並抑制破骨細胞之形成的活性。
