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Hep C Discussion Forum -> On Treatment -> Genotypes
Post Info TOPIC: Genotypes
Tig


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RE: Genotypes
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Hill,

The genotype determines the type (medications) and length of treatment. It helps to determine the likelihood of success with any given protocol as well. This was particularly true with the Interferon protocols. Now these new all oral treatments are all highly effective, but the need for an accurate genotype remains.



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Tig

68yo GT1A - 5 Mil - A2/F3 - (1996) Intron A - Non Responder, (2013) Peg/Riba/Vic SOT:05/23/13 EOT:12/04/13 SVR 9+ years!

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hill418


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THANK YOU!  What a knowledgeable group.  Seeing my doctor for appt and blood tests on 5/8. Will ask to repeat genotype test and to send to another lab.  Just wondering, why is it important to know genotype?  



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 Hill

53 yo female. genotype 1 and 4;  SGOT 99, SGPT 164. Pre tx vl 234,759/5.35. Dx 1988 HCV. Did interferon 5 million units 3x weekly in 1991.

Tx = 12 weeks Harvoni.  Started 4/8/15.   Undetected as of 5/6/15.  :-)

 
mallani


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Hi Hill,

I can understand your confusion. Genotyping can sometomes be difficult.

The HCV Genotype test uses a fragment of the virus, and is compared with various primers. Older tests just used a fragment of the 5' UTR of the virus. This often led to confusion, as the 5'UTR is identical in Genotypes 1a, 1b and 6.

Newer tests include multiple viral sites. The Core/E1 protein and the central part of the NS5B complex are used as well. This gives an accuracy of about 95% for all Genotypes, from 1 to 6, as well as the various subgroups. If you get a result that shows a mixed genotype, I would want it repeated at a different Lab. Mixed infection with Geno 1 and 4 would be very rare.

Mixed genotypes do occur but form less than 1% of cases using the latest test kits. The most common are 1a/1b, 1a/3b and 1b/3a. In each case, there is one dominant genotype and this is the one that should be treated. The dominant genotype is usually given first.

Genotype 4 and subgroups are mostly found in Egypt and the Middle East.

IMHO, you should ask for a repeat test at a Lab used by a Liver Clinic. It's important to know your Genotype. Good luck.



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Geno 1b, IL28B CT,  x3 prior relapser,  ex-cirrhotic, 75 yo, did 48 weeks with Victrelis/Peg./Riba.  VL 1.28m at start, UNDET. at 8 ,12 ,16 ,24 ,30  and 48 weeks.  EOT 15 Feb 2013 , UNDET. at EOT + 28 weeks. SVR!  Still Undet. at EOT +5 years

Malcolm
Tig


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Hill,

I wanted to wait until you replied regarding your most recent testing. This next bit of information may help to explain it as well. Ultimately your liver specialist can best explain the why how this might occur.

This is a technical article that may help explain more on the possibility of multiple genotypes or quasi-species. This appears to state that one genotype may be more dominant than another and could provide conflicting or changing results. 

 

"If a patient has multiple viral quasispecies or is infected with multiple genotypes, the oligonucleotide primers used to generate the amplicon for genotypic analysis may amplify the viral isolate with the highest concentration in the serum or they may preferentially bind to a particular isolate. In either case, the clinical information generated by genotypic analysis would be limited to that particular isolate and would not provide appropriate insight into mixed infections or populations of viral quasi-species that may be present in the infected patient. Thus, regardless of the method selected to determine viral genotype, the information obtained must be evaluated in the context of the likelihood of other viral quasi-species existing in a patient and that genotyping may need to be repeated as the environment of the patient changes during treatment and disease progression [57]."

http://www.natap.org/2014/HCV/AVT05RV0387Hnatyszyn.pdf

One last article I can provide to you is provided by Hepmag.com on the use and success of Harvoni on GT 4. I hope it puts your mind at ease regarding your current use of it. Good luck.

http://www.hepmag.com/articles/Harvoni_genotype_4_2501_26496.shtml

 



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Tig

68yo GT1A - 5 Mil - A2/F3 - (1996) Intron A - Non Responder, (2013) Peg/Riba/Vic SOT:05/23/13 EOT:12/04/13 SVR 9+ years!

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hill418


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Fourlocos,

Thanks.  If you have the opportunity to ask him, that would be great.  If 4 is like 1 that would be very good news.  

 



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 Hill

53 yo female. genotype 1 and 4;  SGOT 99, SGPT 164. Pre tx vl 234,759/5.35. Dx 1988 HCV. Did interferon 5 million units 3x weekly in 1991.

Tx = 12 weeks Harvoni.  Started 4/8/15.   Undetected as of 5/6/15.  :-)

 
fourlocos


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If I am not mistaken I know a guy at our dog park who is gt4 and he is on Harvoni now.  He said that the type he has is found mostly in Egypt.  And that it is close enough to gt1 that his doctor is using Harvoni.  He had a transplant and had to get treatment.  He had a blood transfusion as a teenager and they figured the donor was from the there?   I am almost sure he said he was 4.

 



-- Edited by fourlocos on Friday 17th of April 2015 12:54:53 AM

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GT 1b first time treating with Harvoni 8 weeks.  4 weeks UND 8 week UND.  8 weeks after treatment UND.

 12 weeks SVR.  Reached 24 weeks SVR!
hill418


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Good points, but it was tested in 2013 and again a few weeks ago.  Both inconclusive.  Weird, I know.  And I live in a relatively urban area, only 20 miles or so north of NYC.  I just worry if I am actually type 4 and this won't work.  



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 Hill

53 yo female. genotype 1 and 4;  SGOT 99, SGPT 164. Pre tx vl 234,759/5.35. Dx 1988 HCV. Did interferon 5 million units 3x weekly in 1991.

Tx = 12 weeks Harvoni.  Started 4/8/15.   Undetected as of 5/6/15.  :-)

 
Tig


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Hello,

Let me ask, when did you last have your genotype tested? They have vastly improved the genotype testing process in the past years. If it has been a number of years since your test was run, that could explain it. Different labs previously had testing procedures far less accurate than those in larger universities, teaching hospitals and the newer mega labs. A sequencing mistake can provide different results or an inconclusive. It all depends on how yours was done. If it has been a long period since you were last tested or had it done in a facility with less sensitive or newly qualified/certified equipment, then your doctor can request a new PCR in a different lab. To my knowledge, it's uncommon to be inconclusive anymore.

That doesn't mean it cant happen though. It is certainly a question you can present to your doctor during your next visit. Good luck.



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Tig

68yo GT1A - 5 Mil - A2/F3 - (1996) Intron A - Non Responder, (2013) Peg/Riba/Vic SOT:05/23/13 EOT:12/04/13 SVR 9+ years!

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hill418


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Hi all.  It seems that most people are genotype 1 or 1a or 1b.  I am inconclusive at 1 or 4.  Is there anyone else either inconclusive or genotype 4?  Wondering if the results differ.  Thanks.



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 Hill

53 yo female. genotype 1 and 4;  SGOT 99, SGPT 164. Pre tx vl 234,759/5.35. Dx 1988 HCV. Did interferon 5 million units 3x weekly in 1991.

Tx = 12 weeks Harvoni.  Started 4/8/15.   Undetected as of 5/6/15.  :-)

 
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