Measurement and clinical significance of circulating PAPP-A in ACS patients.
BACKGROUND
The rupture of coronary atherosclerotic plaque and subsequent thrombus formation are major events underlying acute coronary syndromes (ACS). Pregnancy associated plasma protein A (PAPP-A), a biomarker of plaque rupture, has been studied in patients with ACS. This review aimed to provide an overview of clinical utility of PAPP-A in ACS patients and analytical issues adhering to immunological PAPP-A measurement.


METHODS
The literature relating to PAPP-A in ACS, the molecular structure and immunodetection of PAPP-A was reviewed. PubMed was used to search the relevant articles published from 1974 to 2006.


RESULTS
Higher PAPP-A concentrations have been found in patients with ACS than in patients with stable angina and subjects without coronary artery disease. Elevated PAPP-A concentrations have also been shown to associate with adverse cardiac events in ACS patients. The prognostic value of PAPP-A appears to be independent of cardiac troponins. Noteworthy, the PAPP-A form that accounts for increase in ACS is uncomplexed with the proform of eosinophil major basic protein (proMBP). However, PAPP-A assays applied in clinical studies published thus far detect total PAPP-A. Consequently, the clinical value may be non-optimal when total PAPP-A is measured in ACS patients. In addition, the clinical value can also be affected by the analytical factors that exert an effect on the performance of PAPP-A assays.


CONCLUSIONS
PAPP-A appears to be a very promising biomarker useful in the clinical management of ACS patients. However, more prospective and interventional studies with carefully established immunoassays are required to validate its clinical utility.
Qin
Qiu-Ping
QP
Innotrac Diagnostics, Biolinja 12, 20750 Turku, Finland. qiuping.qin@innotrac.fi
Wittfooth
Saara
S
Pettersson
Kim
K
D000208:Acute Disease; D003327:Coronary Disease / Q000097:blood*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D013577:Syndrome
D011266:Pregnancy-Associated Plasma Protein-A