Detection of autoantibodies reactive with pancreatic islet cell antigenic molecules and/or insulin

A method of screening an undiluted sample of serum or plasma obtained from an animal subject for analyte autoantibodies reactive with the antigenic molecule protein tyrosine phosphatase-like islet cell antigen (IA-2), or one or more variants, analogues, derivatives, antigenic fragments thereof, or fusion molecules comprising two or more directly or indirectly fused antigenic molecule of IA-2, said method comprising:

• (a) immobilizing one or more first sources of antigenic molecules to a solid support in an amount so as to form a monovalent intermediate complex comprising [antigenic molecule of said first source]-[analyte autoantibody] capable of forming a divalent complex with antigenic molecules of the second source, wherein said first source of antigenic molecule is capable of interacting with analyte autoantibodies in a sample of serum or plasma from said subject, or a calibrator and comprises molecules selected from the group consisting of IA-2, one or more variants, analogues, derivatives, antigenic fragments thereof and fusion molecules comprising two or more directly or indirectly fused antigenic molecule of IA-2;
• (b) contacting said immobilized one or more first sources of antigenic molecules with:
• (1) an undiluted sample of serum or plasma from said subject, or said calibrator;
• and
• (2) one or more second sources of antigenic molecules comprising a direct or indirect label, wherein said one of more second sources of antigenic molecules is capable of interacting with analyte autoantibodies in a sample of serum or plasma from said subject, or said calibrator and comprises molecules selected from the group consisting of IA-2, one or more variants, analogues, derivatives, antigenic fragments thereof, and fusion molecules comprising two or more directly or indirectly fused antigenic molecule of IA-2,
• whereby analyte autoantibodies when present in said sample of serum or plasma interact with said first and second sources of antigenic molecules to form one or more divalent complexes comprising [antigenic molecule of said first source]-[analyte autoantibody]-[antigenic molecule of said second source];
• and
• (c) detecting the presence of complexes formed in (b) to provide an indication of analyte autoantibodies present in said sample.

A method of screening a diluted sample of serum or plasma obtained from an animal subject for analyte autoantibodies reactive with the antigenic molecule protein tyrosine phosphatase-like islet cell antigen (IA-2), said method comprising:

• (a) immobilizing one or more first sources of antigenic molecules to a solid support in an amount so as to form a monovalent intermediate complex comprising [antigenic molecule of said first source]-[analyte autoantibody] capable of forming a divalent complex with antigenic molecules of the second source, wherein said first source of antigenic molecule is capable of interacting with analyte autoantibodies in a sample of serum or plasma from said subject, or a calibrator and comprises molecules selected from the group consisting of IA-2, one or more variants, analogues, derivatives, antigenic fragments thereof, and fusion molecules comprising two or more directly or indirectly fused antigenic molecule of IA-2;
• (b) contacting said immobilized one or more first sources of antigenic molecules with:
• (1) a diluted sample of serum or plasma from said subject, or said calibrator;
• and
• (2) one or more second sources of antigenic molecules comprising a direct or indirect label, wherein said one of more second sources of antigenic molecules is capable of interacting with analyte autoantibodies in a sample of serum or plasma from said subject, or said calibrator and comprises molecules selected from the group consisting of IA-2, one or more variants, analogues, derivatives, antigenic fragments thereof, and fusion molecules comprising two or more directly or indirectly fused antigenic molecule of IA-2,
• whereby analyte autoantibodies when present in said sample of serum or plasma interact with said first and second sources of antigenic molecules to form one or more divalent complexes comprising [antigenic molecule of said first source]-[analyte autoantibody]-[antigenic molecule of said second source];
• and
• (c) detecting the presence of complexes formed in (b) to provide an indication of analyte autoantibodies present in said sample.