A New Marker
When I spoke with the diaDexus rep the other day on the telephone, he told me the PLAC test, a new test that measures lipoprotein-associated phospholipase A2 (Lp-PLA2), is being done in forty labs across the US, with another added every two weeks. A new instrument platform is added every two months, he said.
The PLAC test was approved by the FDA as a risk marker for coronary heart disease (CHD) in 2003 and is already performed by reference laboratories. The science of the test is interesting: Lp--PLA2 is an enzyme associated with rupture-prone arterial plaque. It's a more specific marker than cholesterol or LDL in predicting a heart attack or stroke. With those values, it gives doctors a better risk assessment.
The PLAC test may very well be the best new test to hit the market in years. I don't really know. I forwarded literature to our hospitalist, who seems intrigued. But it's arrival has me wondering, what role does the laboratory have in promoting new technology?
I think a big one, with physician support. The joke around here is that we have to wait until one of the doctors reads an article to add a test to our menu. But it's not far from the truth. They are, after all, the people who order lab tests.
There is already a need for CHD markers. It's a sure bet that physicians will be interested in those that are more sensitive and more specific. Our role is to identify the best test, not to decide what a doctor should be looking for.
Understanding this can help us ask the right questions, such as "I see this test is similar to this one, but it has greater sensitivity. Should we think about bringing it in-house?" In the case of the PLAC test, I'll wait and see.