Autoantibodies are raised by the body when the immune system attacks the body's own proteins in what is termed an autoimmune disease. Although many autoimmune diseases such as lupus or rheumatoid arthritis have been known for many years, more recently there has been a focus on autoantibodies in diseases traditionally thought of as not being due to an autoimmune response.

For example, Robertson et al have measured autoantibodies to the protein panel MUC1, p53, c-myc and c-erbB2 in serum by ELISA and were able to show a leadtime for cancer detection ranging from 6 to 36 months over current techniques. Wang et al have shown similar results with autoantibodies to peptides in prostate cancer.

The following series of illustrations give a high-level overview of how the immune system raises autoantibodies and how the in-build amplification process enables them to be detected much more easily than traditional biomarkers based on protein expression levels.

	Normal tissue contains many proteins both within cells, on the cell surface, and within the extra-cellular matrix.
	Most cancers start from an errror occuring in a single cell.
	This can cause induce abberant proteins through, for example, an increase in protein expression level, a change in protein sequence, or a change in post-translational modifications.
	The body's immune system responds to these abberant proteins by raising antibodies.
	These antibodies are then amplified and circulate within the serum.
	From there they are detectable on Sense Proteomic's functional protein arrays directly from the blood without the need for a tissue biopsy.