Patented aptamers for C-reactive protein detection: a review about their use in clinical diagnostics

C-reactive protein (CRP) is a homopentameric oligoprotein composed of monomeric subunits that are about 21 kD each. The form of detectable native CRP in validated assays was developed in 2007 and from that time has been considered as an excellent biomarker for peripheral artery disease and/or atherosclerosis, as well as a cardiovascular disease marker for risk prediction. The improvements in the detection of CRP levels could predict significantly the population that have increased risk of stroke being the modulation of CRP levels as a therapeutical outcome for prevention of cardiovascular diseases. Nowadays antibodies that specifically bind CRP, as monoclonal anti-CRP antibodies, are available from commercial sources. Aptamers are biomolecules conformed principally by RNA or DNA, able to adopt secondary structures that can bind to epitopes from oligopeptides or complete proteins. The sensitivity and accuracy of aptamers has let to consider them as more efficient to identify proteins than just antibodies. These properties have become the base for testing these molecules for different uses. A battery of patented aptamers has been developed for detecting and/or measuring CRP. In this sense, aptamers against CRP (CRP-apt) would help to modulate CRP physiological actions at systemic, tissue, cellular and molecular levels by using appropriate experimental designs. This kind of studies would lead to fully understand which systems are regulated by the protein, what disturbances are produced if the CRP is missing or overexpressed. Finally, we hallmark other applications of CRP in terms of patents for both basic and applied research.