Apolipoprotein E3 protein as a biomarker of Parkinson's disease

1 . A biomarker for diagnosis, differential diagnosis and screening for a neurodegenerative disease comprising an Apolipoprotein E3 protein in a blood serum sample.

2 . The biomarker of claim 1 , wherein the neurodegenerative disease is Parkinson's disease.

3 . The biomarker of claim 1 , wherein the neurodegenerative disease is Alzheimer's disease.

4 . The biomarker of claim 1 , wherein the neurodegenerative disease is a Parkinson's disease like (PD-Like) or Mixed disorder, such as: Frontotemporal dementia (FTD); Lewy body dementia (LBD); Alcohol related dementia; Semantic dementia; Vascular (Multi-infarct) dementia; Stroke (CVA); Post-irradiation Encephalopathy and Seizures; Vascular (Multi-Infarct) Parkinsonism; Idiopathic Sensory Ataxia; Corticalbasal Ganglionic Degeneration (CBGD); Multiple System Atrophy (MSA); Alzheimer's disease combined with Vascular (Multi-Infarct) dementia; Alzheimer's disease combined with Lewy body dementia; Parkinson's disease combined with Lewy body dementia; Alzheimer's and Parkinson's disease combined with Lewy body dementia; Frontotemporal dementia combined with Chronic Inflammatory Demyelinating Polyneuropathy; Thalamic CVA combined with HX of Lung CA; and Multiple System Atrophy combined with Subdural Hematoma.

5 . The biomarker of claim 1 , wherein the Apolipoprotein E3 protein includes one or more of the amino acid sequences in Tables 2 and 3.

6 . The biomarker of claim 1 , wherein the Apolipoprotein E3 protein includes one or more antigenic determinants of the Apolipoprotein E3 protein, located within one or more of the amino acid sequences in Tables 2 and 3.

7 . The use of the biomarker of claim 1 in a method for screening, diagnosing and/or differentially diagnosing for a neurodegenerative disease comprising:

obtaining a blood, blood serum, or blood plasma sample from a test subject; determining a quantity of an Apolipoprotein E3 protein in the subject sample; and comparing the quantity of an Apolipoprotein E3 protein in the test subject sample with ranges of values of the quantity of an Apolipoprotein E3 protein in samples of normal control subjects; and one or more groups of patients with a neurodegenerative disease,

whereby a quantity of an Apolipoprotein E3 protein in the test subject sample is indicative of a neurodegenerative disease or a normal condition.

8 . The method of claim 7 , wherein the quantity of an Apolipoprotein E3 protein is determined by two-dimensional gel electrophoresis.

9 . The method of claim 8 , wherein the two-dimensional gel electrophoresis comprises a separation by isoelectric point followed by a separation by molecular weight.

10 . The method of claim 8 , wherein the two-dimensional gel is stained and an intensity of the biomarker of claim 1 is proportional to the expression of the biomarker of claim 1 in the serum sample.

11 . The method of claim 7 , wherein the quantity of an Apolipoprotein E3 protein is determined by one or more antibodies to one or more antigenic determinants of an Apolipoprotein E3 protein, located within one or more of the amino acid sequences in Tables 2 and 3.

12 . The method of claim 7 wherein the quantity of an Apolipoprotein E3 protein is determined by one or more of a number of protein quantitative fractionation techniques, including but not limited to gel filtration chromatography, ion exchange chromatography, reverse phase chromatography, affinity chromatography, affinity capture, or 1 dimensional gel or capillary electrophoresis.

13 . The method of claim 7 wherein the ranges of blood serum concentrations of an Apolipoprotein E3 protein in any group of normal controls or neurodegenerative diseases is determined by statistics.

14 . The method of claim 7 wherein the quantity of an Apolipoprotein E3 proteins determined along with the quantity of one or more other biomarkers for diagnosis, differential diagnosis or screening for a neurodegenerative disease.

15 . The method of claim 7 , wherein the screening, diagnosis or differential diagnosis is an adjunct to at least one other diagnostic test for the neurodegenerative disease.

16 . The method of claim 11 wherein the quantity of an Apolipoprotein E3 protein in the subject sample is determined by transferring the protein from a one or two-dimensional gel to a PVDF membrane (Western blot) and contacting the transferred protein with at least one antibody with reactivity to the amino acid sequences in Table 2 and 3.

17 . The method of claim 11 wherein the quantity of an Apolipoprotein E3 protein in the subject sample is determined by any type of immunoassay techniques.