Diagnostics & Imaging Week

The viruses that cause respiratory infections are notoriously difficult for physicians to identify. Traditional testing requires multiple individual tests to be performed on a patient sample and can take several days to provide a thorough diagnosis.

Luminex (Austin, Texas) is touting its xTAG Respiratory Viral Panel (RVP) as capable of a quicker diagnosis of these viruses. The company said the assay is the first multiplexed nucleic acid test for respiratory viruses cleared for in vitro diagnostic and can identify viruses that together are responsible for more than 85% of all respiratory viral infections.

The assay received CE-mark approval last year, and the company last week reported receiving FDA clearance for it.

“This test has the ability to completely change the way respiratory viral infections are detected,” Patrick Balthrop, president/CEO of Luminex, said in a conference call. “In just a few hours from taking a single patient sample – our test can detect 12 viruses and subtypes from the common cold, to the flu that together are responsible for 85% of all respiratory viral infections.”

With a non-invasive, painless swab, xTAG RVP tests for:

• Influenza A, influenza A-H1, influenza A-H3 and influenza B, which cause the majority of flu cases in the U.S.;

• Adenovirus, which is responsible for approximately 10 percent of respiratory infections and a subtype of which the Centers for Disease Control (CDC) have recently identified as causing multiple deaths;

• Respiratory syncytial virus (RSV) A and B, the most common cause of bronchiolitis and pneumonia in infants and children;

• Metapneumovirus, a recently-discovered virus that causes flu-like symptoms and is thought to be the second leading cause of respiratory infection in children;

• Parainfluenza 1, 2, and 3, which can cause upper or lower respiratory infections in adults and children and, are thought to be responsible for about half of croup cases and 10-15 percent of bronchiolitis and bronchitis cases; and

• Rhinovirus, which causes the common cold.

“Our test can detect more than one of these viruses at once,” he said. “There’s nothing like it today.”

Because the symptoms of respiratory disease greatly overlap, it can be very difficult to determine whether an illness is caused by a virus, and if so, which specific virus, or bacteria,” said Christine Ginocchio, PhD, director of microbiology/virology and molecular diagnostics at North Shore-LIJ Health System Laboratories (Lake Success, New York). “The xTAG RVP provides results on a broad range of viral pathogens, which will assist in the diagnosis of respiratory infections and help physicians recommend the appropriate treatment quickly. The test also tells us what types of viruses are circulating in our communities, which can assist physicians and public health officials in preventing outbreaks.”

The company said that xTAG RVP’s unique ability to detect influenza A subtypes H1 and H3 will allow it to play an important role in the pandemic influenza monitoring plans of the U.S. Department of Health and Human Services and the World Health Organization. The test will allow public health officials to distinguish H1 and H3 subtypes, which represent the vast majority of Influenza A subtypes, from rarer subtypes.

This way, the few samples that do test positive for Influenza A but cannot be identified as H1 nor H3 subtypes can be flagged for further investigation by the CDC or local public health labs.

The company said that the test also will give physicians a stronger road map for prescribing antibiotics. As of late, some bacteria strains have developed a strong resistance to the disease due to the over prescription of antibiotics.

“The approval of the Luminex xTAG RVP is a critical milestone in the diagnosis, treatment and control of the respiratory viruses that impact millions of individuals every year,” Balthrop said. “In addition to helping improve the surveillance of viruses – both in hospitals and community wide – this test can significantly improve patient care. In a matter of hours, rather than days, xTAG RVP can determine whether a patient has a cold, the flu or another virus, allowing a doctor to prescribe an effective treatment much more quickly.”

ViraCor Laboratories, (Kansas City, Missouri), a specialty molecular diagnostic reference laboratory, has been reported as the first national reference laboratory to offer the xTAG.

“xTAG RVP is a major advancement in respiratory viral testing because it gives doctors fast and accurate results for the nation’s most important respiratory viruses. Up until now, clinicians have been playing a guessing game based largely on a patient’s symptoms,” said Steve Kleiboeker, PHD, VP and chief scientific officer of ViraCor Laboratories. “The high degree of sensitivity and specificity of xTAG RVP helps eliminate incorrect diagnosis by greatly reducing the false negative results that are common with conventional testing methods.”

Luminex develops biological testing technologies with applications throughout the diagnostic and life sciences industries.