College of American Pathologists
Printable Version

  A testing first: moderate complexity PCR for H1N1


CAP Today




February 2010
Feature Story

With its announcement Jan. 4 of a PCR test for H1N1 that can be run in less than an hour, Cepheid accelerates the trend to make molecular the standard for flu testing. The Xpert Flu A Panel test, which runs on Cepheid’s GeneXpert, will for the first time allow labs certified as moderate complexity under CLIA to perform the test. As with earlier PCR assays from Roche Diagnostics, Quest subsidiary Focus Diagnostics, Gen-Probe, and other companies, the Food and Drug Administration has issued Cepheid an emergency use authorization for the test.

About 3,000 hospital-based moderate-complexity labs could benefit from the new assay, estimates David Persing, MD, PhD, executive vice president and chief medical and technology officer at Cepheid. “Many high-complexity labs only run tests on a batched basis once or twice a day. So from a pragmatic standpoint, a moderate-complexity test is something that can be offered around the clock. It is easy to set up and anybody in the lab can run it.”

CLIA uses 12 criteria to assess complexity, Dr. Persing notes, and one of the most stringent is that the test cannot require a quantitative pipetting step. Anything involving extracting and purifying would automatically be high complexity, and all those steps of purifying, transferring, and setting up the reaction have to be done automatically in the cartridge. The quantitative pipetting happens inside GeneXpert.

To date, Cepheid is the only company that has a moderate-complexity PCR test of any kind, he adds. “This is the only PCR test that can be run on demand on a stat basis and be available 24/7.” Cepheid expects to obtain 510(k) clearance for a test that will include the ability to detect influenza A, B, and H1N1 separately.

The price is lower than most other PCR tests, according to Dr. Persing. The basic cartridge is produced in large quantities and lists at about $38, while the instrumentation ranges from a single module system, for as low as $27,000, up to a 48-unit system. “Our larger customers have recently had such high volumes that they have purchased our Infinity system, a fully automated, random-access, on-demand molecular system that runs any test on the menu.”

“The Infinity was available before we announced the H1N1 test, but many knew that we were working on this and that we were committed to coming out with an influenza product that would serve them for every season to come.” All of the Infinity customers are high-complexity labs but have chosen the system primarily from an operator use standpoint. “Within a couple months of installation, many of them are running these Infinities on a 24/7 basis.”

Dr. Persing believes insurers and health systems will be adjusting to a new day in rapid molecular testing. “Reimbursement is going to be a challenge irrespective of the underlying technology,” Dr. Persing says. “We’ve suffered for many years with insensitive technologies, such as the antigen test, that are really only alive and still in use because they’re quick. Insurers need to recognize that PCR is the new gold standard for influenza detection.”

—Anne Paxton


Related Links Related Links