Amyloid beta aggregates in cerebro spinal fluid as biomarkers for alzheimer's disease

A method for assessing increased probability of not having Alzheimer's disease in a subject under assessment comprising the steps of:

• obtaining the level of Aβ40 aggregates in a biological sample from said subject;
• and
• determining that said subject has an increased probability of not having Alzheimer's disease if said subject does not show clinical cognitive impairment and if said Aβ40 aggregate level is the same as or lower than a control level threshold;
• wherein said control level threshold is calculated from data comprising the levels of Aβ40 aggregates in biological samples from a plurality of cognitively normal control subjects;
• wherein said subject under assessment and said control subjects are of a same species;
• and
• wherein all of said biological samples comprise CSF and none of said biological samples comprises brain tissue, a fraction of brain tissue or brain homogenate.

A method for assisting in assessing increased probability of not having Alzheimer's disease in a subject under assessment comprising the steps of:

• measuring the level of Aβ40 aggregates in a biological sample from said subject;
• and
• communicating said Aβ40 aggregate level to a different entity;
• wherein said different entity determines that said subject has an increased probability of not having Alzheimer's disease if said subject does not show clinical cognitive impairment and if said Aβ40 aggregate level is the same as or lower than a control level threshold;
• wherein said control level threshold is calculated from data comprising the levels of Aβ40 aggregates in biological samples from a plurality of cognitively normal control subjects;
• wherein said subject under assessment and said control subjects are of a same species;
• and
• wherein all of said biological samples comprise CSF and none of said biological samples comprises brain tissue, a fraction of brain tissue or brain homogenate.

A method for assessing increased probability of MCI progressing to Alzheimer's disease in a subject under assessment comprising the steps of:

• obtaining the level of Aβ40 aggregates in a biological sample from said subject, determining that said subject has an increased probability of MCI progressing to Alzheimer's disease if said Aβ40 aggregate level is higher than a control level threshold,
• wherein said control level threshold is calculated from data comprising the levels of Aβ40 aggregates in biological samples from a plurality of cognitively normal control subjects;
• wherein said subject under assessment and said control subjects are of a same species;
• and
• wherein all of said biological samples comprise CSF, and wherein none of said biological samples comprise brain tissue, a fraction of brain tissue or brain homogenate.

A method for assisting in assessing increased probability of MCI progressing to Alzheimer's disease in a subject under assessment comprising the steps of:

• measuring the level of Aβ40 aggregates in a biological sample from said subject;
• and
• communicating said Aβ40 aggregate level to a different entity;
• wherein said different entity determines that said subject has an increased probability of MCI progressing to Alzheimer's disease if said Aβ40 aggregate level is higher than a control level threshold;
• wherein said control level threshold is calculated from data comprising the levels of Aβ40 aggregates in biological samples from a plurality of cognitively normal control subjects;
• wherein said subject under assessment and said control subjects are of a same species;
• and
• wherein all of said biological samples comprise CSF and none of said biological samples comprises brain tissue, a fraction of brain tissue or brain homogenate.