Hepatitis C Virus Viral Load Ultrasensitive Testing

Reported by Jules Levin

November 9-13, 2001, Dallas

    After I sent out the report on the TMA ultrasensitive viral load test reported on here at AASLD, I received  this note from LabCorp. I thought you would like to see it.

    The information below (the TMA study I reported toy you that was presented here at AASLD) compared a highly sensitive TMA qualitative test to LabCorp/NGI's highly sensitive quantitative test (apples/oranges)

    Our Hepatitis C Virus quantitative test (Hepatitis C Virus SuperQuant) has a sensitivity of 100 copies / 39 IU's w/ a dynamic range to 5 million copies / 2 million IUs. Our Hepatitis C Virus qualitative RNA test (Hepatitis C Virus UltraQual) has a sensitivity of 5-8 copies / 2 IU's. The UltraQual test is the most sensitive qualitative test commercially available in the world. I'm surprised this test was not compared to TMA since it to is an ultra sensitive qualitative test.

    In fact, on September 21st LabCorp's National Genetics Institute announced the FDA approval of the Hepatitis C Virus and HIV UltraQual tests for use in the screening of source plasma. This is the same Hepatitis C Virus UltraQual test that we offer diagnostically. Because this was FDA approved in the screening market it has been scrutinized heavily by the FDA and its claims and purpose have been upheld/endorsed.

    LabCorp purchased NGI last fall and we have been making these exquisite tests available to all clinicians.   NGI has completed the clinical trial work for all Hepatitis C Virus drugs w/ the exception of one using these highly sensitive qualitative and quantitative RNA tests. We also announced yesterday the availability of the most sensitive Hepatitis C Virus RNA quantitative test (Hepatitis C Virus QuantaSure) w/ a sensitivity of 5-8 copies / 2 IU's to 5 million copies / 2 million IUs.

    PERFORMANCE OF TRANSCRIPTION MEDIATED AMPLIFICATION (TMA) IN THE DETERMINATION OF VIROLOGICAL RESPONSE TO TREATMENT IN PATIENTS WITH CHRONIC HEPATITIS C abstract 207

    This is the program abstract, I will check tomorrow to see if poster is different. Remember, this test is in clinical development and not yet FDA approved. But its my understanding that the test can be accessed through certain commercial labs and may be reimburseable: Quest - order code 37273N; Specialty Labs - order code 7516

     Emilia Hadziyannis, Fotini Spanou, Aggeliki Kostamena, Savvas Savvas, Stephanos J Hadziyannis, Acad Dept of Medicine, Hippokration Gen Hosp, Athens Greece

    A sensitive qualitative Hepatitis C Virus RNA assay based on transcription mediated amplification (TMA) has recently been introduced in research and clinical laboratories. TMA has a sensitivity level of 25-50 Hepatitis C Virus RNA copies/ml, 2-3 times lower than other widely used assays. We evaluated the performance of TMA (VersantTM , Bayer) in the determination of long term response to therapy (monotherapy or combination therapy) in patients with chronic hepatitis C (CHC) at the end of treatment (ET). Materials and Methods: 47 treated patients, 10 sustained responders, 29 relapsed responders and 8 non-responders, were included. Sera from all of them were obtained at the end of treatment and were tested with a sensitive PCR assay, either in house by AmplicorTM, Roche or at National Genetics Institute (NGI). Aliquots, stored at 70o were thawed before tested with TMA. TMA was performed according to the manufacturers instructions.

    The results were compared. Results:TMA classified 21% of relapsed responders as non responders at the end of therapy. There was 100% concordance between the results of TMA and PCR for the groups of non-responders and long-term responders to treatment. The results were further analyzed in relationship to baseline viral levels, Hepatitis C Virus genotype and type of therapy. Conclusions: 1)The results of this study indicate that the virological response at the end of treatment should be determined by the TMA assay which reclassifies approximately 1/5 of relapsed virological responders to non responders 2) These findings have practical application in monitoring and tailoring therapy in chronic hepatitis C.