Release patterns of pregnancy associated plasma protein A (PAPP-A) in patients with acute coronary syndromes

Pregnancy associated plasma protein A (PAPP-A) has recently been shown to be associated with acute coronary syndromes (ACS). The goal of this study was to investigate its release patterns in patients with ACS.

PAPP-A concentrations in plasma samples serially collected after admissions from 15 patients with ACS were measured. The levels of PAPP-A were compared with a reference range determined from 80 normal subjects. The associations between PAPP-A and myoglobin (Mb), C-reactive protein (CRP), fatty-acid-binding protein (FABP) and creatine kinase MB (CK-MB) were determined.

Various release patterns were observed with 2-10-fold changes of PAPP-A in the different patients. Increases in PAPP-A levels above the reference range could appear early at 2 h or late at 30 h after onset of chest pain. Only in 4 of the 15 cases were significantly elevated PAPP-A levels detected before 6 h after onset. Elevations early after admission showed rapid decline whereas later elevations were more persistent. No associations between PAPP-A and Mb, CRP, FABP and CK-MB were found. However, a weak but significant association to cardiac troponin I (cTn I) was found.

PAPP-A is an additional marker for ACS, but does not seem to be a useful early marker for acute myocardial infarction (AMI). The possible clinical utility of PAPP-A calls for extensive studies of chest pain patients using serial sampling combined with short- and long-term outcome studies.