Patent ID: 8916388

Claim:
A method for the detection and determination of Alzheimer's disease in a patient who is suffering from subjectively or objectively detectable cognitive disturbances potentially associated with Alzheimer's disease, the method comprising: (a) detecting and quantitating in a plasma or serum sample from the patient at least one vasodilatory peptide selected from the group consisting of atrial natriuretic peptides ANP and adrenomedullin (ADM), wherein the concentration of ANP is determined by measuring the amount of a midregional segment of proANP (MR-proANP) and the concentration of ADM is determined by measuring the amount of a midregional proADM (MR-proADM) fragment consisting of amino acids 45-92 of preproadrenomedullin; (b) detecting and quantitating in said sample the concentration of a vasoconstrictive peptide, endothelin-1 (ET-1), wherein the concentration of ET-1 peptide in said sample is determined by measuring the amount of a C-terminal proET-1 fragment (CTproET-1) consisting of amino acids 168-212 of pre-proendothelin-1; and (c) determining a ratio index of the concentration(s) of the one or more vasodilatory peptide(s) to the concentration of the endothelin-1 peptide, wherein a ratio index above the corresponding ratio index determined for healthy controls is indicative of Alzheimer's disease, wherein at least one of step (a) and step (b) comprises an immunoassay.