ProMBP

Pregnancy-associated plasma protein A and its endogenous inhibitor, the proform of eosinophil major basic protein (proMBP), are related to complexstenosis morphology in patients with stable angina pectoris.

[5] Nonstandard abbreviations: PAPP-A, pregnancy-associated plasma protein A; ACS, acute coronary syndrome; proMBP, proform of eosinophil major basic protein; FPAPP-A, free form of PAPP-A; TPAPP-A, total PAPP-A; cTnI, cardiac troponin I; ECG, electrocardiogram; CRP, C-reactive protein; FDA, US Food and Drug Administration; RR, risk ratio.

We analyzed the effect of increasing concentrations of PAPP-A/proMBP by the addition of purified PAPP-A/ proMBP (0 to 180 mg/L) to a reaction containing 1 nmol/L active PAPP-A.

QF-II was cleaved efficiently by recombinant PAPP-A, but not by an inactive mutated PAPP-A variant (E483Q) (25) or PAPP-A/ proMBP complex purified from pregnancy serum (21) (Fig.

The PAPP-A/proMBP assay imprecision was studied with pooled pregnancy serum diluted with BSA-TSA buffer to achieve PAPP-A/ proMBP concentrations relevant in ACS (mean PAPP-A/ proMBP concentrations, 3.1 mIU/L and 10.0 mN/L).

The calibration curves for the total PAPP-A and PAPP-A/ proMBP assays are shown in Fig.

In particular, PAPP-A in serum of patients with atherosclerotic disease appears to be present as a homodimer, making it difficult to measure PAPP-A as marker for coronary syndromes/ atherosclerosis by immunoassays that are designed to detect molecules in pregnancy serum via a sandwich formed by 2 antibodies, one specific for PAPP-A and the other specific for proMBP (10, 17).

[4] Nonstandard abbreviations: PAPP-A, pregnancy-associated plasma protein-A; IGF, insulin-like growth factor; proMBP, proform of eosinophil major basic protein; PAD, peripheral arterial disease; tHcy, total homocysteine; (hs-)CRP, (high-sensitivity) C-reactive protein; and eGFR, estimated glomerular filtration rate.