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HCV Viral Load Ultrasensitive Testing
Reported by Jules Levin
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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 HCV
quantitative test (HCV SuperQuant) has a sensitivity of 100 copies / 39 IU's
w/ a dynamic range to 5 million copies / 2 million IUs. Our HCV qualitative
RNA test (HCV 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 HCV and HIV UltraQual tests for use in the screening
of source plasma. This is the same HCV 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 HCV 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 HCV RNA quantitative test (HCV 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 HCV 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 HCV 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, HCV 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.
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