PROBLEM TO BE SOLVED: To provide a detection method of an index substance capable of monitoring easily peritoneal deterioration in peritoneal dialysis.SOLUTION: There is provided a detection method of an index substance for detecting an index substance from a specimen such as sampled dialysis drainage from peritoneal dialysis. In the detection method of the index substance, the index substance is fibulin-1 which is detected at least during peritoneal deterioration in an organism from which the specimen is sampled, or whose concentration is increased definitely following progress of the peritoneal deterioration.SELECTED DRAWING: Figure 3【課題】腹膜透析における腹膜劣化を簡便にモニターできる指標物質の検出方法を提供することを目的とする。【解決手段】採取された腹膜透析の透析排液等の検体中から指標物質を検出する指標物質の検出方法であって、前記指標物質は、前記検体を採取した生物において少なくとも腹膜劣化時に検出され、もしくは腹膜劣化の進行に伴って濃度の増大が確認されるファイブリン-1である指標物質の検出方法である。【選択図】図３
