Aa
Lab Corp no longer offering <10 PCR.
Scared the c**p outa me for sure. As most of you know I dropped the RIBA a few weeks ago. Well I did a PCR, checking on break thru. When I called my lab lady she read the results saying "<43" HCV RNA not detected." I'm LIKE, what's this <43?? She doesn't know, she said it was the same test we've been doing from the start which is the 10 to 100,000,000 . (been UND <10 from week 2) Of course I'm thinking of the confusion during the Telaprivir trials and others. Well I'm a LITTLE worried at this point so she starts making calls trying to find something out. That was yesterday, got the word this morn. Lab Crop has stopped the 10-100,000,000 and in it's place is using a 43-69,000,000. The L.Corp lady told my lady that they considered this test more reliable and consistant. I am still UND. jerry
MEDICAL PROFESSIONAL
The answer is in my post above:
The Labcorp code for the NGI Quantasure is LC 140639.
Once you are UND you might as well use the cheaper HCV NGI Ultraqual,
LC code 140609, it has the same sensitivity. thus if you are UND, you are very UND
The Labcorp code for the NGI Quantasure is LC 140639.
Once you are UND you might as well use the cheaper HCV NGI Ultraqual,
LC code 140609, it has the same sensitivity. thus if you are UND, you are very UND
==============================================================
quote from HR:
They key aspect is that this standard is used by all labs, so that the same patient gets approx the same value regardless by which assay he is measured.
=============================================================
HR, I understand how the same patient gets approx the same value regardless by which assay he is measured by.
But doesn't the difference in actual iU/ml numbers between the tests have some clinical significance?
Amplicor HCV Monitor v2.0 ............. 1 IU/mL=0.9 copies/mL
Cobas Amplicor HCV Monitor v2.0 ... 1 IU/mL=2.7 copies/mL
Versant HCV RNA 3.0 Quantitative ... 1 IU/mL=5.2 copies/mL
Cx HCV RNA Quantitative ............... 1 IU/mL=3.8 copies/mL
SuperQuant ..................................... 1 IU/mL=3.4 copies/m
How about if a patients lab/Dr used a different baseline vl test, than the 12 wk test with its minimum 2 log drop cutoff point. Not uncommon for the baseline test to be a less sensitive test with reflex to genotype. Using different VL assay (just like orleans LabCorp did) could conceivably for some patients, make the difference to continue tx or stop as a non responder if going by IU/mL.
Low Vl 600,000, is it figured in iU/ml or copies/virions ?
So what would a Doctor do, use the actual iU/ml value on the test results, or research the copies factor number of the test used, and then translate to copies for his decisions on TX? Is it common for Hepatologist to do this ?
quote from HR:
They key aspect is that this standard is used by all labs, so that the same patient gets approx the same value regardless by which assay he is measured.
=============================================================
HR, I understand how the same patient gets approx the same value regardless by which assay he is measured by.
But doesn't the difference in actual iU/ml numbers between the tests have some clinical significance?
Amplicor HCV Monitor v2.0 ............. 1 IU/mL=0.9 copies/mL
Cobas Amplicor HCV Monitor v2.0 ... 1 IU/mL=2.7 copies/mL
Versant HCV RNA 3.0 Quantitative ... 1 IU/mL=5.2 copies/mL
Cx HCV RNA Quantitative ............... 1 IU/mL=3.8 copies/mL
SuperQuant ..................................... 1 IU/mL=3.4 copies/m
How about if a patients lab/Dr used a different baseline vl test, than the 12 wk test with its minimum 2 log drop cutoff point. Not uncommon for the baseline test to be a less sensitive test with reflex to genotype. Using different VL assay (just like orleans LabCorp did) could conceivably for some patients, make the difference to continue tx or stop as a non responder if going by IU/mL.
Low Vl 600,000, is it figured in iU/ml or copies/virions ?
So what would a Doctor do, use the actual iU/ml value on the test results, or research the copies factor number of the test used, and then translate to copies for his decisions on TX? Is it common for Hepatologist to do this ?
I'm confused @ 12 weeks und used Lab corp 140639 ; now week 24 coming up what lab corp lab is necessary?
HR
From Standardization of Hepatitis C Virus RNA Quantification
Jean-Michel Pawlotsky,1,2 Magali Bouvier-Alias,1 Christophe Hezode,3 Francoise Darthuy,1 Jocelyne Remire,1 And Daniel Dhumeaux2,3
The situation has changed recently with the publication of 2 studies involving more than 1,700 treatment-naive patients with chronic hepatitis C and showing a significant benefit of combination therapy with IFN-a, 3 MU 3 times per week subcutaneously, and ribavirin, 1,000 to 1,200 mg/d orally, compared with the same dose of IFN-a alone.11,12 In these reports, both pretreatment viral load and the HCV genotype were independent predictors of sustained HCV RNA clearance after combination therapy.1
The cut-off point defining “high” and “low” pre-treatment viral loads was established as the HCV RNA load discriminating best between sustained virologic responders and nonresponders in the 2 studies.11,12
Both teams used the Superquant assay (National Genetics Institute, Los Angeles, CA),
an “inhouse” competitive PCR-based technique using multiple PCR cycles performed in a central laboratory.14 From these data the decision threshold was established at 2,000,000 copies/mL (i.e., 6.3 log10 copies/mL).11,12
More recently, the same authors reanalyzed their database and used the study group median viral load (i.e., 3,500,000 copies/mL or 6.5 log10 copies/mL) as the decision threshold.15
Unfortunately, these recommendations have been inapplicable on a global level, because most laboratories worldwide use commercial assays such as Amplicor HCV Monitor and Quantiplex HCV RNA.
Indeed, in the absence of standardized HCV RNA quantification units, 1 copy/mL in Monitor, 1 genome equivalent (Eq)/mL in Quantiplex, and 1 copy/mL in Superquant do not represent the same amount of HCV RNA in a clinical sample, these units having been defined independently, with quantified standards of different natures, lengths, and sequences. In addition, the same units can also vary from one version of a commercial assay to the next.16 Thus, 2,000,000 or 3,500,000 copies/mL in Superquant may not be 2,000,000 or 3,500,000 copies or Eq/mL in assays other than Superquant, meaning that these assays cannot be used to tailor the duration of combined treatment unless the exact correspondence between the various units has been established.
In other words HR its all your fault. -LOL
You know I am joking. It is ironic though.
So IUs came about because no one could work out how to convert from SuperQuant copies to whatever the other tests were using.
And this the bit I don’t understand
“do not represent the same amount of HCV RNA in a clinical sample,”
Why not. Either you detect a copy or you are detecting something that looks like a copy.
But 1 copy should be the same no matter what.
Or have I missed something
CS
From Standardization of Hepatitis C Virus RNA Quantification
Jean-Michel Pawlotsky,1,2 Magali Bouvier-Alias,1 Christophe Hezode,3 Francoise Darthuy,1 Jocelyne Remire,1 And Daniel Dhumeaux2,3
The situation has changed recently with the publication of 2 studies involving more than 1,700 treatment-naive patients with chronic hepatitis C and showing a significant benefit of combination therapy with IFN-a, 3 MU 3 times per week subcutaneously, and ribavirin, 1,000 to 1,200 mg/d orally, compared with the same dose of IFN-a alone.11,12 In these reports, both pretreatment viral load and the HCV genotype were independent predictors of sustained HCV RNA clearance after combination therapy.1
The cut-off point defining “high” and “low” pre-treatment viral loads was established as the HCV RNA load discriminating best between sustained virologic responders and nonresponders in the 2 studies.11,12
Both teams used the Superquant assay (National Genetics Institute, Los Angeles, CA),
an “inhouse” competitive PCR-based technique using multiple PCR cycles performed in a central laboratory.14 From these data the decision threshold was established at 2,000,000 copies/mL (i.e., 6.3 log10 copies/mL).11,12
More recently, the same authors reanalyzed their database and used the study group median viral load (i.e., 3,500,000 copies/mL or 6.5 log10 copies/mL) as the decision threshold.15
Unfortunately, these recommendations have been inapplicable on a global level, because most laboratories worldwide use commercial assays such as Amplicor HCV Monitor and Quantiplex HCV RNA.
Indeed, in the absence of standardized HCV RNA quantification units, 1 copy/mL in Monitor, 1 genome equivalent (Eq)/mL in Quantiplex, and 1 copy/mL in Superquant do not represent the same amount of HCV RNA in a clinical sample, these units having been defined independently, with quantified standards of different natures, lengths, and sequences. In addition, the same units can also vary from one version of a commercial assay to the next.16 Thus, 2,000,000 or 3,500,000 copies/mL in Superquant may not be 2,000,000 or 3,500,000 copies or Eq/mL in assays other than Superquant, meaning that these assays cannot be used to tailor the duration of combined treatment unless the exact correspondence between the various units has been established.
In other words HR its all your fault. -LOL
You know I am joking. It is ironic though.
So IUs came about because no one could work out how to convert from SuperQuant copies to whatever the other tests were using.
And this the bit I don’t understand
“do not represent the same amount of HCV RNA in a clinical sample,”
Why not. Either you detect a copy or you are detecting something that looks like a copy.
But 1 copy should be the same no matter what.
Or have I missed something
CS
MEDICAL PROFESSIONAL
Here is the root of the iU/copy difference;
The WHO standard, intended to be later used as a cross laboratory internal standard in 1999, used a genotype 1 sample that was "assigned' a value of 100000 "international units". That was an underestimate of the actual viral load, unfortunately, and the producers of this standard should have made an effort to determine the absolute Vl in copies or virions/ml , something that was regrettably not available to them. Thus this number in iu is always short/only a fraction of the actual virion number. It would have been possible to determine the true copy number of this sample with good efforts and then assign one copy to be one international unit. They key aspect is that this standard is used by all labs, so that the same patient gets approx the same value regardless by which assay he is measured. That is very good and important. But they could have "assigned" the true number to this standard, not an estimate, that turned out to be too low.
The WHO standard, intended to be later used as a cross laboratory internal standard in 1999, used a genotype 1 sample that was "assigned' a value of 100000 "international units". That was an underestimate of the actual viral load, unfortunately, and the producers of this standard should have made an effort to determine the absolute Vl in copies or virions/ml , something that was regrettably not available to them. Thus this number in iu is always short/only a fraction of the actual virion number. It would have been possible to determine the true copy number of this sample with good efforts and then assign one copy to be one international unit. They key aspect is that this standard is used by all labs, so that the same patient gets approx the same value regardless by which assay he is measured. That is very good and important. But they could have "assigned" the true number to this standard, not an estimate, that turned out to be too low.
MEDICAL PROFESSIONAL
Here is the abstract of the paper mentioned, I have the actual Journal in fron of me. I do however not see anything that fits the above remark by CS.
Standardization of hepatitis C virus RNA quantification.Pawlotsky JM, Bouvier-Alias M, Hezode C, Darthuy F, Remire J, Dhumeaux D.
Department of Bacteriology and Virology, Hôpital Henri Mondor, Université Paris XII, Créteil, France. jean-michel.***@****-hop-paris.fr
It was recently recommended that hepatitis C virus (HCV) RNA quantification be used to tailor the duration of combined interferon alfa (IFN-alpha)/ribavirin therapy in patients infected by HCV genotypes 1, 4, and 5. This recommendation has been difficult to implement in the absence of standardized quantitative units for HCV RNA. The aim of this work was to define clinically relevant HCV RNA loads in standardized international units (IU), for use in routine clinical and research applications based on standardized quantitative assays. Two hepatitis C virus RNA quantitative assays were used: (1) the Superquant assay (National Genetics Institute, Los Angeles, CA), for which possibly relevant thresholds were established; and (2) the semi-automated Cobas Amplicor HCV Monitor assay version 2.0 (Cobas v2.0, Roche Molecular Systems, Pleasanton, CA) that measures HCV RNA loads in IU/mL. Quantification in the Cobas v2.0 assay was linear over the entire range of values tested, including viral loads higher than 850,000 IU/mL after 100-fold dilution. The accuracy and precision of the measures in IU/mL were satisfactory with Cobas v2.0. The results obtained with Superquant and Cobas v2.0 correlated (r =.932; P <.0001). A value of 2,000,000 copies/mL (6.3 log(10) copies/mL) with Superquant was converted to nearly 800,000 IU/mL (5.9 log(10) IU/mL). In conclusion, all HCV RNA quantitative assays should give HCV RNA loads in international units and be validated with appropriate calibrated panels; 800,000 IU/mL in any of these assays should be used as the decision threshold to tailor the IFN-alpha/ribavirin treatment duration in patients infected by HCV genotypes 1, 4, and 5.
Standardization of hepatitis C virus RNA quantification.Pawlotsky JM, Bouvier-Alias M, Hezode C, Darthuy F, Remire J, Dhumeaux D.
Department of Bacteriology and Virology, Hôpital Henri Mondor, Université Paris XII, Créteil, France. jean-michel.***@****-hop-paris.fr
It was recently recommended that hepatitis C virus (HCV) RNA quantification be used to tailor the duration of combined interferon alfa (IFN-alpha)/ribavirin therapy in patients infected by HCV genotypes 1, 4, and 5. This recommendation has been difficult to implement in the absence of standardized quantitative units for HCV RNA. The aim of this work was to define clinically relevant HCV RNA loads in standardized international units (IU), for use in routine clinical and research applications based on standardized quantitative assays. Two hepatitis C virus RNA quantitative assays were used: (1) the Superquant assay (National Genetics Institute, Los Angeles, CA), for which possibly relevant thresholds were established; and (2) the semi-automated Cobas Amplicor HCV Monitor assay version 2.0 (Cobas v2.0, Roche Molecular Systems, Pleasanton, CA) that measures HCV RNA loads in IU/mL. Quantification in the Cobas v2.0 assay was linear over the entire range of values tested, including viral loads higher than 850,000 IU/mL after 100-fold dilution. The accuracy and precision of the measures in IU/mL were satisfactory with Cobas v2.0. The results obtained with Superquant and Cobas v2.0 correlated (r =.932; P <.0001). A value of 2,000,000 copies/mL (6.3 log(10) copies/mL) with Superquant was converted to nearly 800,000 IU/mL (5.9 log(10) IU/mL). In conclusion, all HCV RNA quantitative assays should give HCV RNA loads in international units and be validated with appropriate calibrated panels; 800,000 IU/mL in any of these assays should be used as the decision threshold to tailor the IFN-alpha/ribavirin treatment duration in patients infected by HCV genotypes 1, 4, and 5.
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