PAPP-A

PAPP-A (Pregnancy Associated Plasma Protein A)
is a 740 kDa protein produced primarily by the
placenta during pregnancy; infact this protein is
usually present in the serum, but its concentration
rises in maternal serum as gestation time
progresses. PAPP-A concentration levels in
maternal serum are indicative of threatened
abortion, preterm birth, intrauterine growth
restriction and others.
Many studies have shown a decrease in PAPP-A
concentration in case of trisomy disorders,
particularly in Down's Syndrome (Trisomy 21).
PAPP-A protein can be found in the serum in a
heterotetrameric dimer with ProMBP form (most
important during pregnancy) or in a dimeric form
associated with coronary and cardiac conditions;
Diametra PAPP-A ELISA is designed specifically for
the testing of the heterotetrameric form.
When evaluation of this protein is done it is often
compared to the Multiple of Medians (MoM) and
represented as a percent of an in-house establish
median. Without easy access to an IRP, ELISA
method is an easier way to evaluate the
concentration of PAPP-A in the serum and to
compare the results from different laboratories.