The info below comes from a couple of documents from.
All of these sites are good places to start finding Info on HepC
Viruses are microscopic and are so small that around 30 billion would fit on a full stop.
Although it is much easier to talk of the hepatitis C virus as if it is a single organism, in fact it is a group of viruses, similar enough to be called hepatitis C virus, yet different enough to be classified into subgroups.
Several identifiable ‘families’ of hepatitis C virus have been observed around the world, differing slightly from each other in their DNA sequencing (genetic makeup). The most commonly used classification system lists these ‘families’ as HCV genotype 1, 2, 3, 4,5,6.
Within each genotype, difference between viruses exists – too small to be seen as a different new genotype but significant enough and measurable, thus making the term sub-type applicable. These lesser classifications are described as HCV subtype 1a or 1b, etc.
Among the viruses that make up a person’s HCV infection, individual viruses will differ from each other very slightly. The differences are incredibly minute and not significant enough to form a distinct sub-type. Instead they form what’s known as quasi-species.
It is believed that within an HCV sub-type, several million quasispecies would exist. Scientists predict that people who have hepatitis C have billions of actual viruses circulating within their body. Although there may be one or two predominant sub-types, the infection as a whole is not a single entity and is composed of many different quasispecies.
HCV genotypes and subtypes are distributed differently in different parts of the world, and certain genotypes predominate in certain areas. Genotypes 1-3 are widely distributed throughout the world. Subtype 1a is prevalent in North and South America, Europe, and Australia. Subtype 1b is common in North America and Europe, and is also found in parts of Asia. Genotype 2 is present in most developed countries, but is less common than genotype 1. Some studies suggest that different types of HCV may be associated with different transmission routes. Subtype 3a appears to be prevalent among injection drug users and it is believed that they were introduced into North American and the United Kingdom with the widespread use of heroin in the 1960s.
Prediction of Treatment Response
Genotype information is important because it can be used as a predictor of a positive treatment outcome or response. The sustained virological response rates for pegylated interferon plus ribavirin are much higher in genotype 2 and 3 compared with genotype 1.
Other predictors of treatment response include:
• Age of Patient – younger patients respond more favorably especially people under 30 years old.
• Sex of Patient – women are more likely to respond to therapy than men
• Histological (health of the liver) – people with minimal damage respond better to treatment
• Viral Load – the lower the viral load (less than 800,000 IU/mL) the more likely one is to respond to current medications
• Obesity or high Body Mass Index is associated with lower treatment response rates
• Steatosis or fatty liver reduces the chance of responding to treatment.
• Race - Caucasians and Asians respond better to current HCV medications.
Genotype and Treatment Response
Genotype 1 is considered the most difficult to treat with current HCV medications. However, treatment response rates with the newer forms of pegylated interferon plus ribavirin have been remarkably high--up to a 51% sustained virological response rate (SVR – undetectable viral load six months post treatment). Genotype 2 and 3 respond even better to current medications -up to 80%.
There is some evidence that genotype 2 responds better to current HCV therapies than genotype 3, but this needs to be confirmed in prospective studies. The reason that a particular genotype responds to treatment differently is unknown, but it is speculated that specific genotypes of the hepatitis C virus live longer or shorter than others. For example, it has been theorized that genotype 2 and 3 of the hepatitis C virus do not live as long (viral lifecycle) as genotype 1 thus making eradication of genotype 2 and 3 easier.
Genotype and Treatment Duration
Genotype is also a factor in the period of time required to treat with current HCV medications. Generally, genotype 1 is treated for 48 weeks and genotype 2 and 3 are treated for 24 weeks.
However, there are studies underway to determine the most optimal treatment duration based on certain factors. For instance, some experts believe that people with genotype 1, high viral load should be treated for 72 weeks instead of 48 weeks to maximize treatment response rates. There are also studies evaluating treating people with genotype 2 for 12 weeks and genotype 3 for 48 weeks.
Genotype and HCV Medication Dosage
Genotype information is also important for establishing the appropriate dose of ribavirin. For instance, people with genotype 2 and 3 are given 800 mg a day of ribavirin (flat dose), whereas the ribavirin dose for people with genotype 1 is dosed by body weight.
A person can become infected with more than one genotype. Data is almost non-existent on being infected with more than one genotype, but some experts believe it may effect treatment response and HCV disease progression.
WOW! Can't add a thing to what CS said! Just good luck to you!
Get a biopsy to determine current damage, get a good liver specialist to discuss treatment options!
I, too, am geno 3. I began tx on 3/3. 180mcg Peg and 800mg Riba. 2 shots of Peg down and on day 9 with Riba! whoo-hoo!
Spend time researching this site and ASK QUESTIONS! LOTS of Questions!
My husband is a type 2. You're better off being a 2 or 3 than a 1. The medicine has to do more work to get into the hard shell of the cell if you're a type 1. If you are 2 or 3, it has less work to do to get inside the shell because the cell is softer.
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