Luminex Corporation announced that it has performed computer-based sequence analysis of the US swine flu patient isolates and compared them to the primer sequences of the company’s xTAG RVP assay. In the interest of providing information to its customers and to public health labs, the company is reporting these interim computer-based results and will provide further updates once actual patient samples have been tested with the RVP assay. xTAG RVP is the only commercially available FDA-cleared test that can distinguish different subtypes of the flu virus. A computer-based analysis of the swine flu sequences compared to the primers in the xTAG RVP product indicate that a swine flu positive patient sample is likely to be correctly identified by the portion of the RVP assay which detects the flu A matrix gene. However, the H1 subtyping portion of the RVP assay is not predicted to identify the swine flu H1 gene, even though the Atlanta Center for Disease Control and Prevention (CDC) has identified the swine flu strain as an H1 subtype strain. The reason for this finding is that the new swine flu strain is significantly different from normal, seasonal H1 subtype flu A. Luminex is working with its customers and other public health labs to identify patient samples to empirically confirm these computer-based sequence analysis results. Luminex will provide further information once these results are complete. “If our prediction based on sequence analysis is confirmed, RVP should prove to be very useful for swine flu surveillance programs,” said Patrick Balthrop, chief executive officer of Luminex. “A test which can identify the virus, but which provides a different result from that seen with a normal, seasonal H1 flu A sample, is the type of test required for effective surveillance programs. Our preliminary results suggest that xTAG RVP could provide that type of result. We are working hard to verify this sequence-based analysis with real patient samples and will provide further updates as soon as possible.” The Luminex xTAG RVP was developed by Luminex Molecular Diagnostics and was cleared by the FDA in January of 2008. Luminex’s unique multiplexing xMAP Technology is the key to delivering the capability to determine subtypes from one sample, enabling the RVP assay to simultaneously detect 12 respiratory viruses and subtypes at the DNA/RNA level in a matter of hours. The package insert for xTAG RVP instructs the user how to proceed in case of encountering an “unsubtypeable” flu A sample. These instructions include contacting a public health lab to conduct follow-up analysis of the sample to identify if the patient is infected with a flu A strain which could pose a pandemic threat, such as swine flu.