Abstract: An object is to provide a leucine-rich ?2 glycoprotein composition comprising leucine-rich ?2 glycoprotein and having excellent preservation stability. The object can be achieved by a leucine-rich ?2 glycoprotein composition comprising leucine-rich ?2 glycoprotein and having a pH of 7.0 to 9.3.

Abstract: An object of the present invention is to provide a measurement method and a reagent for measurement which can measure LRG in a biological sample simply in a short time. The present inventors have intensively studied to achieve the object and made findings that LRG in a biological sample can be measured simply in a short time by an immunoagglutination measurement method in which the biological sample is brought into contact with insoluble carrier particles carrying a first anti-LRG monoclonal antibody and insoluble carrier particles carrying a second anti-LRG monoclonal antibody in a liquid phase, and the invention has been thus completed.

Abstract: Provided is a method of testing Alzheimer's disease using serum or plasma as a sample. It is found that a ?-amyloid peptide added to a blood sample is degraded. The degradation activity thereof was compared between the blood samples of normal subjects and Alzheimer's disease patients, and it is also found that the degradation activity is significantly higher in the blood of the normal subjects.

Abstract: Provided is a method of testing Alzheimer's disease using serum or plasma as a sample. It is found that a ?-amyloid peptide added to a blood sample is degraded. The degradation activity thereof was compared between the blood samples of normal subjects and Alzheimer's disease patients, and it is also found that the degradation activity is significantly higher in the blood of the normal subjects.

Abstract: The present invention is intended to devise a process of measuring ?-amyloid in a biological sample such as blood and to apply the process to diagnosis of Alzheimer's disease. It is possible to assay Alzheimer's disease by measuring a total amount of ?-amyloid 1-42 and ?-amyloid 1-42 fragments each of which retains a C-terminal site of the ?-amyloid 1-42 in the biological sample by an immunological assay in which an antibody which recognizes the C-terminal site of ?-amyloid 1-42 is used. It is preferable that the immunological assay be a competitive immunological assay.