dPAPP-A antigen and antibody
Pregnancy-associated plasma protein-A (PAPP-A) was first identified in serum from pregnant women. Recently it was shown that another form of PAPP-A, namely dPAPP-A, is present in unstable coronary atherosclerotic plaque. It has also been demonstrated that the blood level of dPAPP-A is significantly elevated in patients with unstable angina or acute myocardial infarction in comparison with patients with stable angina as well as control subjects. In addition, dPAPP-A has been shown to be a strong independent marker of risk stratification for patients with acute coronary syndrome (ACS).
The structural difference of dPAPP-A from pregnancy-related htPAPP-A makes it possible to differentiate between these two PAPP-A forms. Antibodies specific to dPAPP-A can be used for the development of immunoassays for precise and selective dPAPP-A measurements in human blood.
Both PAPP-A antigen purified from retroplacental blood and recombinant dPAPP-A are now available. Since the immunoreactivity of the latter is similar to that of the endogenous protein found in atherosclerotic plaque, it can be used as a calibrator or standard in dPAPP-A immunoassays. PAPP-A specific monoclonal antibodies are also offered, suitable for the development of highly sensitive and rapid sandwich-type PAPP-A immunoassays for quantitative detection of PAPP-A in maternal blood as well as for detection of dPAPP-A in the blood of ACS patients.