Abstract: The invention provides a method for assessing risk of a neurodegenerative disease or disorder in a subject. The method comprises comparing a level of anti-&bgr;-amyloid-42 (A&bgr;42) antibody in a biological sample from a subject to a normal level, wherein a lower level in the biological sample from the subject indicates the risk of the disease or disorder. In a specific embodiment, the disease or disorder is Alzheimer's Disease (AD).

Abstract: The invention provides a method for assessing risk of a neurodegenerative disease or disorder in a subject. The method comprises comparing a level of anti-amyloid peptide antibody in a biological sample from a subject to a normal level, wherein a lower level in the biological sample from the subject indicates the presence of the disease or disorder. In a specific embodiment, the disease or disorder is Alzheimer's Disease (AD); in a further specific embodiment, the amyloid peptide is &bgr;-amyloid-42 (A&bgr;42).

Abstract: The present invention relates to an isolated protein or polypeptide capable of production by T cells and capable of ultimately activating production of B cells. The present invention further provides an isolated DNA molecule encoding the protein or polypeptide capable of production by T cells and capable of ultimately activating production of B cells. The isolated DNA molecule can be inserted as a heterologous DNA in an expression vector forming a recombinant DNA expression system for producing the protein or polypeptide. Likewise, the heterologous DNA can be incorporated in a cell to achieve this objective. The isolated protein or polypeptide of the present invention can be combined with a pharmaceutically-acceptable carrier or used alone for administration to mammals for activating production of B cells.