Several different blood tests can be useful for identifying clinically significant fibrosis and cirrhosis in patients infected with hepatitis C virus, now that liver biopsy is no longer recommended for that purpose, according to a report published online June 3 in Annals of Internal Medicine.
Liver biopsy used to be recommended before antiviral therapy was initiated for HCV because the treatment was used primarily in patients at highest risk for disease progression. But "the increased effectiveness of antiviral treatments has resulted in broadening of treatment indications to encompass patients at lower risk for disease progression, calling into question the need to obtain detailed pretreatment prognostic information with an invasive test," said Dr. Roger Chou and Ngoc Wasson of Oregon Health & Science University, Portland.
Dr. Roger Chou
Moreover, biopsy is avoided because it is subject to sampling error; inconsistency in the interpretation of the results; and complications including bleeding, severe pain, and infection. "However, given the adverse effects and costs associated with current antiviral therapies, knowing the degree of liver fibrosis can still provide important information and allow for more informed treatment decisions," the investigators said.
They assessed the accuracy of less invasive alternatives to liver biopsy – specifically, blood tests that aim to identify fibrosis and cirrhosis – in a review of the literature commissioned by the Agency for Healthcare Research and Quality.
The researchers selected 172 English-language studies of HCV-infected patients, excluding posttransplant patients, those coinfected with HIV or hepatitis B virus, patients receiving hemodialysis, and children. "We did not pool results because of differences across studies in populations evaluated, differences in how fibrosis and cirrhosis were defined, and methodological limitations in the studies," Dr. Chou and Ms. Wasson said.
Many of the 30 blood tests included in the analysis were found to be "moderately useful at commonly used cutoffs" in identifying fibrosis and cirrhosis. These included simple platelet counts, the age-platelet index, the aspartate aminotransferase/platelet ratio index (APRI), the FibroIndex, the FibroTest, and the Forns index.
The GUCI (Göteborg University Cirrhosis Index) and the Lok index were slightly less useful, but still more accurate than the remaining 20-odd tests assessed, they noted (Ann. Intern. Med. 2013 June 3 [10.7326/0003-4819-158-11-201306040-00005]).
More complicated indexes that incorporate the results of a variety of tests, particularly indexes that rely on tests that are not routine, were no more accurate at predicting fibrosis or cirrhosis than many of the simpler, more readily available blood tests, the investigators said.
Their findings remained robust in sensitivity analyses that categorized the data according to the quality of the study, type of methodology, and characteristics of the study population.
This study was supported by the Agency for Healthcare Research and Quality.