Researchers with the Veterans Affairs Palo Alto Health Care System (VAPAHCS) in California conducted a retrospective observational study to identify certain predictors that could help determine successful markers for treatment in patients with chronic hepatitis C (HCV).
After examining data from 5,944 HCV patients of the VAPAHCS system, Lisa I. Backus, principal investigator, and her team found particular variables to help predict viral clearance. They screened the blood of HCV-infected patients who were on a combination of pegylated interferon and ribavirin, three months post-treatment to establish whether the virus had been diminished. They found that the type of interferon used in treatment was a contributor to the eventual outcome of therapy. Specifically, patients treated with pegylated interferon 2A were 40% more likely to achieve viral clearance than those receiving the 2B form.
Another important finding was related to genotype, which is the genetic makeup of an organism or virus. Researchers found that patients with HCV genotype 2 were more apt to respond to therapy than those with genotype 3. In addition, genotype 1 patients had the lowest rate of sustained virologic response (SVR), a common measure of HCV clearance and treatment success. The SVR rates for genotypes 1, 2 and 3 were 20%, 52% and 43%, respectively. Researchers also found that low cholesterol levels could be a predictor of unsuccessful treatment.
In addition, the researchers determined that the SVR rates of genotype 1 patients were affected by the greatest number of variables. Such patients with liver disease, low cholesterol, diabetes, low hemoglobin or low platelet count or who were African-Americans tended to have a lower probability of SVR. Conversely, low-level HCV viremia (virus in the bloodstream), elevated levels of alanine aminotransferase (ALT, a common measurement of liver function) and therapy with pegylated interferon 2A, instead of 2B, may predict greater SVR. As for the other genotypes, the authors concluded that, "few of these factors affect the rate for genotype 2 patients, and even fewer do so for genotype 3 patients."
The study, "Predictors of Response of U.S. Veterans to Treatment for the Hepatitis C Virus," was published in the July 2007 issue of Hepatology.
Source: HealthDay News, July 6, 2007