What is the difference between Genotype 1a and 1b?

[sljl]

I have had many labs and one report said I had Genotype 1a and another one said it was Genotype 1b.  Does anyone know what is the difference?

I was treated with interferon/ribavirin combo for 48 weeks which ended in Sept 2011.  Unfortunately, my undetected virus came roaring back 3 months later with 1.4 million RNA PCR and 6.17 RNA log IU/ml  

This month, my labs came back with 4.6 million RNA PCR and 6.66 RNA log IU/ml. This rapid increase is alarming me and I am waiting for a non interferon treatment as I had difficulties with interferon.

[sljl]

Yes, I have had 3 liver biopsies and the latest one was in 2010 showing Fibrosis stage 2 moderate.  Hence, my GI in Georgia started me on treatment.  

My current doctor (as I have moved to Florida) is my primary doc and didn't test for genotype only viral load.  I will be seeing a hepatologist in Sept and inquire about determining genotype and the best course of treatment.  

I know, I don't want to wait.  I was hoping to get into clinical trials with Gilead's sofosbuvir but it is for previous trial subjects or for another genotype.
I'm still checking on clinicaltrials.gov frequently.

sljl

[HectorSF]

"This month, my labs came back with 4.6 million RNA PCR and 6.66 RNA log IU/ml. This rapid increase is alarming me"

This is no reason to worry about the amount of your viral load. Viral loads go up and down all the time. It has no impact on the progression of your liver disease or being cured. Besides you can't change it anyway so why worry about something you can do nothing about? Either you are chronically infected with hepatitis C and have a viral load or you are not infected and don't have a chronic hepatitis C infection.

You will only need to be aware of your viral load when you are treating. It will show how responsive you are to treatment. Basically the faster it drops the better your chance of SVR.

Your doctor should redo the test if he/she doesn't know if you are 1a or 1b. Treatment is the same for both as treatment is based on the genotype. Depending on which treatment you do 1a or 1b can be a advantage or a disadvantage. But it doesn't make a huge difference. Stage of your liver disease makes the most difference. For example a person with cirrhosis generally has far less chance of SVR vs someone with mild to moderate fibrosis. Not that it is impossible just less likely to happen the more advanced cirrhosis is. To the point of decompensation where the risk out weights the benefit.

As Can-do said, it may be a few years before new therapy is available for treatment experienced genotype 1s. A biopsy will tell you if you can wait for new treatments or should treat sooner.

Good luck.
Hector

[pooh55811]

Can-do-man addressed your question about 1a and 1b.

You said you want to wait for the all oral treatments. Do you know what your liver fibrosis stage is? If you do not know your liver fibrosis stage, it would be a good idea to get a liver biopsy so that you will know. This is especially important if you are considering waiting for all orals, which may not be available for treatment experienced patients for quite a  while, perhaps years. You would not want to be sitting around waiting for future all oral treatments if you are at Stage 3 or Stage 4. One does not want to risk becoming cirrhotic while waiting for treatment and, if one is already cirrhotic, one does not want to risk decompensating before treatment.

I know you said you will see your Hepatologist in Sept. and most likely a liver biopsy will be discussed then.

[sljl]

Thank you so much.  I did check the website you referenced and I also found that Abbott Labs has FDA approval for tests to differentiate the various geno types:

http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm357982.htm

[can-do-man]

Bill1954 talked about this in this thread,

"The ‘a’ in genotype 1a refers to the subtype of the disease; 1a is the most prevalent in North America, while 1b has historically been more prevalent in Europe, I believe. In terms of disease management they’re both treated as one disease, and both difficult to get rid of, unfortunately. Janis and Friends site has ore info on genotyping here:

http://janis7hepc.com/hepatitis_c_genotypes_news.htm

~~~~~~~~~~~~~~~~
Most of us learn about Hepatitis C as one disease, however in actuality it's really several different strains of a virus. They are all similar enough to be called hepatitis C virus, yet different enough to be classified into subgroups."

http://www.medhelp.org/posts/Hepatitis-C/Difference-between--genotype-1-and-1a/show/1208231
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That said there are some people that have both a and b.

It doesn't make a difference when it comes to the way one treats, though there has been some studies that show at least with the PI's 1b has a slightly better outcome......... As for you rise in viral load that means nothing so know need to let that worry you........ Best to you