Fibrosis staging in chronic hepatitis C: analysis of discordance between transient elastography and liver biopsy

Abstract

In chronic hepatitis C, transient elastography (TE) accurately identifies cirrhosis, but its ability to assess significant fibrosis (Metavir > or = F2) is variable. Constitutional and liver disease-related factors may influence TE and here we examined the variables associated with differences. Three hundred consecutive hepatitis C virus (HCV)-RNA positive patients had biochemical tests, TE and a biopsy performed on the same day. The Dale model was used to identify the variables associated with discordance between biopsy and elastography results. In 97 patients (34.2%), TE and histological assessment were discordant. Seventy-six of 286 (26.6%) had stage > or =F2 and TE < 7.1 kPa (false negative); 21 of 286 (7.3%) had stage <F2 and TE > or = 7.1 kPa (false positive). No patient with discordant results had cirrhosis. By Dale model, aspartate aminotransferase (AST) was found to be the unique variable significantly related (P = 0.046) with discordance between biopsy and TE. Discordance rate was 43.4% (82 patients) with AST < 1.5 x UNL vs 25.8% (25 patients) with AST > or = 1.5 x UNL (P = 0.004). False negative rate was 43.4 (82 patients) with AST < 1.5 x UNL vs 17.1% (13 patients) with AST > or = 1.5 x UNL (P < 0.001). Areas under the receiver operating characteristic (AUROC) for F > or = 2, according to AST < 1.5 x UNL vs > or = 1.5 x UNL were 0.738 (95% CI: 0.683-0.812) and 0.854(95% CI: 0.754-0.907). Transient elastography is not adequate on its own to rule out or to rule in significant fibrosis, as it is influenced by major variations in biochemical activity of liver disease. Liver stiffness, at low levels of AST, can underestimate fibrosis.

Liver stiffness: a novel parameter for the diagnosis of liver disease

“…It is interesting to learn that in HCV infected patients similar observations have been made. Here, AST was found to be the unique variable significantly related ( P = 0.046) with discordance between biopsy and LS 60. Subanalysis of histological scores with LS values was also very revealing.…”

Feasibility study and control values of transient elastography in healthy children

“…For a reliable examination there should not be an elevated intra-abdominal pressure and no elevated blood pressure because of crying. Recent studies could clearly demonstrate that extrahepatic factors like elevated central venous pressure, elevated blood pressure, obesity, ascites, or extrahepatic cholestasis are significantly influencing LSM [5,9,11,[21][22][23]. Therefore, besides an ultrasound of the liver and a thorough clinical examination to exclude these factors we also recommend to perform TE only in sleeping or sedated infants and small children.…”

“…Since the introduction of TE, the limitations of this method have also become obvious. Extrahepatic factors like elevated blood or central venous pressure, ascites, and obesity influence LSM without influencing the degree of fibrosis [5,9,21,22]. The introduction of a small TE probe, that is also suitable for the small intercostal space of young children and infants, has made TE possible in every age group.…”

Chronic hepatitis C and liver fibrosis

“…In relevant studies [155,156] , ALT levels correlated with Fibroscan ® values. Conversely, another study showed that low AST is a variable associated with discordance between Fibroscan ® measurement and liver biopsy for diagnosis of significant fibrosis [157] . The authors concluded that Fibroscan ® is influenced by major variations in biochemical activity of liver disease in CHC and that liver stiffness, at low levels of AST, can underestimate fibrosis.…”