Researchers from the University of North Carolina at Chapel Hill recently completed a study to determine the significance of genetics as a contributing factor to viral clearance among hemophilia patients infected with the hepatitis C virus (HCV). Patients are considered to be “cleared” of the virus when molecular tests (assays) show no detectable levels of HCV in the bloodstream.
The investigators, led by Michael W. Fried, MD, examined 257 pairs of siblings who had hemophilia and evidence of HCV infection but who were HIV-negative. They looked for genetic patterns that could contribute to either spontaneous and treatment-induced clearance of HCV or progression of liver disease.
When HCV disease characteristics typically found in randomly paired, unrelated hemophilia patients were compared with those of the siblings, authors reported some noteworthy, if not dramatic, findings.
Matching disease characteristics (concordance) for spontaneous clearance was twice as high (8.8% vs. 4.3%) in siblings with HCV and hemophilia as in the randomly paired individuals. Concordance for treatment-generated HCV clearance among the sibling pairs was more than double that of the random pairs. Concordance for advanced liver disease was higher among siblings (4.0% vs. 2.3%).Overall, the researchers concluded that these and other results were not statistically significant. They were therefore reluctant to overstate the study’s implications.
“Concordance rates and heritability estimates for spontaneous and treatment-related viral clearance indicate that genetic factors have a modest influence on the outcome of hepatitis C, although shared environmental factors cannot be excluded. Investigations to map candidate disease-susceptibility genes associated with these characteristics must be approached with caution,” reported study authors.
The study, “Hemophilic Siblings with Chronic Hepatitis C: Familial Aggregation of Spontaneous and Treatment-Related Viral Clearance,” was published in the September 2006 issue of Gastroenterology.
Source: HIVandhepatitis.com, published online on September 15, 2006