Clinical Significance:
Amyloid B-Protein is a peptide that ranges in size from 28-43 amino acids. Most fragments have the same biological activity as the whole molecule. Amyloid B-Protein causes vascular and cerebral plaque formation. Insoluble fibrils of Amyloid B-Protein accumulate in adrenal blood vessels and un neutritic placques. Occurrence of placques are present in normal brain but in a much less dense degree as in Alzheimer’s disease patients. Amyloid B-Protein is also found in elevated levels in patients with Down’s Syndrome. Substance P has been found to counteract the effects of Amyloid B-Protein.
Reference Range:
20- 80 pg/mL
Procedure:
Amyloid Protein is measured by a specific radioimmunoassay procedure that measures all fragments from 1-40 amino acids.
Patient Preparation:
No specific patient preparation is required as Amyloid B-Protein is increased by the quantity and density of placques.
Specimen Collection:
3mL EDTA plasma should be collected and separated as soon as possible. Freeze EDTA plasma immediately after separation. Minimum specimen size is 1 ml.
Special Specimens:
For tumor/tissue and various fluids (i.e. CSF, peritoneal, synovial, etc.) contact the Institute for requirements and special handling.
Shipping Instructions:
Ship specimens frozen in dry ice.
References:
1. Whitson JS, Selkoe DJ and Cotman CW. Amyloid B-Protein enhances the survival of hippocampal neurons in vitro. Science 243: 1488-1490, 1989.
2. Yankner BA, Mesulam M-M. Beta-Amyloid and the pathogenesis of alzheimer’s disease. N Eng J Med 325: 1849-1857, 1991.