Roche Cobas Ampliprep Test

Hi folks! I haven't been on here in quite a while.  I finally got insurance and my doc had me take the Roche COBAS Ampliprep/COBAS Taqman HCV Test.  I got the results from the lab on Friday.  

The results are Hep C RNA not detected.

I read as much as I could on this forum before posting but either still don't quite understand and/or just need reassurance.  

I was told in 1996 i have anti-bodies and again throughout the years.

I have been convinced for years that I have Hep C.

the test says it has an analytical measurement range of 43-69,000,000 IU/mL  and then in parentheses it says (1.63-7.84 logIU/ml)

next to where it says my results "not" detected" it has a column for "reference range" and nothing is typed there...it is blank.

Any ideas what this means?

Since I got the lab results in the mail Friday I haven't been able to talk to my doctor and as you can imagine i am at my wit's end trying to understand iff this means what i hope it means and if the lack of a reference range is normal.

Thank you for reading and always your responses are appreciated!

sabbath

[sabbath13]

I found a post somewhere on this site that lead me o a GREAT place that really  clarified the tests...and types of tests...

I had a test called a real time polymerase chain reaction (RTPCR) done by Roche COBAS Ampliprep/ COBAS Taqman  HCV Test (to be specific).

I found out that...

"A critically important advance in molecular diagnostics has been the adaptation of real-time PCR methods to quantify HCV RNA. Using TaqMan technology, real-time PCR yields quantitative results with comparable sensitivity to qualitative tests. In addition, real-time PCR can accurately quantify HCV RNA levels over a linear range exceeding 6 logs (ie, 10 IU/mL to 100 million IU/mL) for purposes of therapeutic monitoring (Table 2).36 Therefore, a single test result serves the purpose of both quantitative and qualitative HCV NATs. The assay is faster and more cost-effective than the other techniques and has already replaced other NAT testing platforms at many institutions. However, real-time PCR assays are presently available only as in-house tests."


I am gathering from this paragraph that the test I was given is an advanced test that serves as both qualitative and quantitative in one single test....

I feel from reading this that i really could be HCV free...for real...and have believed for years to be infected....I want to thank

"willing"  for the original post for that link...it helped answer a lot of questions...thank you and i hope by re-posting the above info i have helped someone else out...here is the link to the article:

http://jama.ama-assn.org/cgi/content/full/297/7/724?ck=nck

and if anyone needs clarification as to qualitative vs. quantitative tests this could be helpful...and if you want to know what test you should get I would suggest (from reading this info...) to get this REAL-TIME PCR test...


thank you again...i wish everyone here the best...truly!!!
i am keeping my fingers crossed that this means i really don't have it and somehow this old body of mine fought of that virus!

take care

[sabbath13]

i keep addressing my own post but i want to tag this so others can find the information too :)

i found a another great site about the differences between qualitative and quantitative tests...and it includes the REAL Time PCR tests like the one i had done

http://www.healthnetworklabs.com/media/literature/pdf/PCRq_a.pdf

http://jama.ama-assn.org/cgi/content/full/297/7/724?ck=nck

if you need some answers pleas read these...if you are curious about what test you had and what it all means...please read these links

[sabbath13]

NEW TESTING METHOD FOR HCV VIRAL LOADS
Please note that effective mid-August 2005, the laboratory method used for measuring Hepatitis C quantitative viral loads in the OHSU Molecular Diagnostic Center will be changing (test numbers 102-8804 and 102-8814). In particular, the new HCV viral load test will be utilizing a more sensitive real-time quantitative PCR method that offers several technical and clinical advantages including:
1) Lower detection limit down to 25 international units (IU) per mL of serum
(compared to 600 IU/mL for the old PCR-ELISA quantitative method)
2) Linear reportable range of 6 logs (25 to 25,000,000 IU/mL)
(compared to only 3.1 logs for the old PCR-ELISA method; 12,000 – 17,000,000 IU/mL)
3) Excellent assay precision (reproducibility) as measured by a coefficient of variation (standard deviation divided by mean) of 2.1%
4) Internal control (synthetic template) added to each sample to ensure accurate viral load quantitation and absence of sample-specific PCR inhibitors
In a direct comparison of the quantitative results obtained with the two different methods (n=46), we have found that the HCV viral load values from the new real-time PCR method are, on average, approximately 2-fold (0.3 logs) LOWER than the viral loads determined with the PCR-ELISA method that has been in use in our lab for many years. Please take this assay-dependent bias into consideration when interpreting new viral load values derived from the real-time PCR assay after mid-August 2005.
Because of the relatively poor low-level sensitivity for the old PCR-ELISA method for HCV viral loads (600 IU/mL), a more sensitive qualitative HCV PCR assay had been available with a low-level detection limit of 100 IU/mL of serum. Because of the even better low-level sensitivity of the new real-time quantitative PCR assay for HCV (down to 25 IU/mL), there is no further need for the lab to continue to offer the less sensitive qualitative HCV PCR assay. Effective mid-August 2005, the qualitative HCV PCR assay (test #102-8815) will therefore no longer be available and all requests for the “qualitative” HCV PCR test will instead, receive a quantitative real-time PCR viral load determination (test #102-8804).
Should you have any questions about this change in assay methodology, please call the Molecular Diagnostic Center at 503-494-5400.
Hep C

[wildtruffle]

Hi, I'm in the same situation.  I've received two indeterminate antibody tests and had the same RNA test done recently.  It is not detected and there is a blank Reference Range, too.  It would be nice to know soon any certainty......

[christineelloso]

The NAT result has a flag saying Q_QS INVALID. What does it mean? The manual says Internal Control is invalid. I ran the test again this time Target not Detected. 2 Cobas NAT analyzer I'm using. Everyday there is one result giving this flag but on one machine only. Some problem with the machine or the test?

[RobertBeWell]

The bottom line is, the test could not detect measurable virus.

In all liklihood, you do not have a chronic Hep C infection. You may have been exposed at one time, but approximately 20% of patients are able to rid the body of the virus and thats the end of it.

Congratulations.