Study: US elastography may best biopsy in diagnosis of liver fibrosis
Ultrasound-based transient elastography (TE) provides excellent diagnostic accuracy for detecting cirrhosis due to recurrent infection with hepatitis C virus (HCV) infection following liver transplantation, according to a study published in the March issue of Liver Transplantation.

The World Health Organization estimates that chronic HCV affects up to 170 million people worldwide and could lead to more severe liver diseases such as cirrhosis and liver cancer. An average 6,000 liver transplants are performed in the U.S. each year, according to experts. Medical evidence shows that liver transplantation recipients who are HCV RNA-positive at the time of transplantation are at risk of reinfection with HCV. Moreover, studies have determined that fibrotic tissue can develop more quickly in the transplanted liver resulting in rapid progression of cirrhosis and graft failure.

“The current gold standard for determining liver disease severity and progression is liver biopsy,” said Jayant A. Talwalkar, MD, of the Mayo Clinic in Rochester, Minn., in a statement. “However, biopsy following liver transplantation may not accurately determine fibrosis severity and noninvasive imaging technology has advanced to more accurately assess the severity of liver injury which includes an indirect assessment of elevated portal pressure.” A prior study reported liver biopsy can understage cirrhosis in up to 30 percent of cases.

Talwalkar and colleagues conducted a meta-analysis of existing research and reviewed studies of the diagnostic accuracy of ultrasound-based TE to assess the performance of TE compared to liver biopsy in detecting severe hepatic fibrosis caused by recurrent HCV post-transplantation.

Six studies were identified, with five studies that evaluated significant fibrosis and cirrhosis. Analysis of the pooled estimates showed TE had a sensitivity and specificity of 83 percent, respectively, for detecting fibrosis. Of the five studies analyzing TE for detecting cirrhosis, sensitivity estimates were 98 percent and specificity estimates were 84 percent.

The researchers noted that TE can detect early increases in portal venous pressures, which may yield more information regarding disease severity than biopsy alone.

In some cases, specifically those in which a low TE value excludes cirrhosis, patients may be able to avoid biopsy, the researchers suggested.

“Ultrasound-based TE provides excellent diagnostic accuracy for identifying cirrhosis caused by recurrent HCV following liver transplantation,” concluded Talwalkar et al. “Further studies that confirm our results could highlight the importance of TE as a diagnostic tool for liver transplant recipients infected with HCV.”