Liver biopsy

Sampling variability of computer-aided fractal-corrected measures of liver fibrosis in needle biopsy specimens

AIM: To assess the sampling variability of computer-aided, fractal-corrected measures of fibrosis in liver biopsies.

METHODS: Samples were derived from six to eight different parts of livers removed from 12 patients with clinically and histologically proven cirrhosis undergoing orthotopic liver transplantation. Sirius red-stained sections with a thickness of 2 μm were digitized using a computer-aided image analysis system that automatically measures the surface of fibrosis, as well as its outline perimeter, fractal surface and outline dimensions, wrinkledness, and Hurst coefficient.

RESULTS: We found a high degree of inter-sample variability in the measurements of the surface [coefficient of variation (CV) = 43% ± 13%] and wrinkledness (CV = 28% ± 9%) of fibrosis, but the inter-sample variability of Hurst’s exponent was low (CV = 14% ± 2%).

CONCLUSION: This study suggests that Hurst’s exponent might be used in clinical practice as the best histological estimate of fibrosis in the whole organ, and evidences the fact that biopsy sections, which are fundamental for the qualitative diagnosis of chronic hepatitis, play a key role in the quantitative estimate of architectural changes in liver tissue.

Elevation of Nepsilon-(carboxymethyl)lysine-modified advanced glycation end products in chronic liver disease is an indicator of liver cirrhosis

OBJECTIVES

Progression of liver fibrosis to cirrhosis is a dire consequence of chronic liver diseases (CLD). Nepsilon-(carboxymethyl)lysine (CML)-modified advanced glycation end products (AGEs) in patients with CLD could reflect the degree of severity of the disease.

DESIGN AND METHODS

In 110 patients with CLD and 124 healthy controls, CML serum levels and their diagnostic sensitivity and specificity were determined and compared to hyaluronan (HA).

RESULTS

Serum levels of CML were significantly affected by the stage of liver cirrhosis and were closely associated with liver function capacity. CML correlated positively with HA (r = 0.639, P < 0.0001). In ROC analysis, the diagnostic sensitivity and specificity in distinguishing healthy controls from liver disease patients for CML (AUC 0.908; 95%-CI 0.863-0.942, cut-off 640 ng/mL, sensitivity 74.5% and specificity 97.6%) resembled HA (AUC 0.948; 95%-CI 0.907-0.974; cut-off 50 ng/mL, sensitivity 80.7% and specificity 97.9%). The combination of CML and HA shows an AUC of 0.932; 95%-CI 0.888-0.962; sensitivity 82.6%; and specificity 95.8%.

CONCLUSIONS

Our data suggest that serum levels of CML could provide a supplementary diagnostic marker for advanced stages of liver cirrhosis. However, the quality of interaction needs further investigation.

Liver fibrosis and tissue architectural change measurement using fractal-rectified metrics and Hurst’s exponent

AIM: To provide the accurate alternative metrical means of monitoring the effects of new antiviral drugs on the reversal of newly formed collagen.

METHODS: Digitized histological biopsy sections taken from 209 patients with chronic C virus hepatitis with different grade of fibrosis or cirrhosis, were measured by means of a new, rapid, user-friendly, fully computer-aided method based on the international system meter rectified using fractal principles.

RESULTS: The following were described: geometric perimeter, area and wrinkledness of fibrosis; the collation of the Knodell, Sheuer, Ishak and METAVIR scores with fractal-rectified metric measurements; the meaning of the physical composition of fibrosis in relation to the magnitude of collagen islets; the intra- and inter-biopsy sample variability of these parameters; the “staging” of biopsy sections indicating the pathway covered by fibrosis formation towards its maximum known value; the quantitative liver tissue architectural changes with the Hurst exponent.

CONCLUSION: Our model provides the first metrical evaluations of the geometric properties of fibrosis and the quantitative architectural changes of the liver tissue. The representativeness of histological sections of the whole liver is also discussed in the light of the results obtained with the Hurst coefficient.

Serum markers detect the presence of liver fibrosis: a cohort study

BACKGROUND & AIMS

Histologic examination of a liver biopsy specimen is regarded as the reference standard for detecting liver fibrosis. Biopsy can be painful and hazardous, and assessment is subjective and prone to sampling error. We developed a panel of sensitive automated immunoassays to detect matrix constituents and mediators of matrix remodeling in serum to evaluate their performance in the detection of liver fibrosis.

METHODS

In an international multicenter cohort study, serum levels of 9 surrogate markers of liver fibrosis were compared with fibrosis stage in liver biopsy specimens obtained from 1021 subjects with chronic liver disease. Discriminant analysis of a test set of samples was used to identify an algorithm combining age, hyaluronic acid, amino-terminal propeptide of type III collagen, and tissue inhibitor of matrix metalloproteinase 1 that was subsequently evaluated using a validation set of biopsy specimens and serum samples.

RESULTS

The algorithm detected fibrosis (sensitivity, 90%) and accurately detected the absence of fibrosis (negative predictive value for significant fibrosis, 92%; area under the curve of a receiver operating characteristic plot, .804; standard error, .02; P < .0001; 95% confidence interval, .758-.851). Performance was excellent for alcoholic liver disease and nonalcoholic fatty liver disease. The algorithm performed equally well in comparison with each of the pathologists. In contrast, pathologists' agreement over histologic scores ranged from very good to moderate (kappa = .97-.46).

CONCLUSIONS

Assessment of liver fibrosis with multiple serum markers used in combination is sensitive, specific, and reproducible, suggesting they may be used in conjunction with liver biopsy to assess a range of chronic liver diseases.

Liver biopsy: when, how, by whom, and where?

Liver biopsy remains an important diagnostic tool in the management of liver disease. Complications, though infrequent, are potentially disastrous. Risks and discomfort can be minimized with good technique, although prospective data to prove the superiority of one method over another are often lacking. Image direction is preferred in all cases, as is a transjugular approach when bleeding risks are judged to be high. Bleeding is essentially a random event. Outpatient liver biopsy is appropriate in almost every instance if immediate hospitalization facilities are available. It should be more widely practiced. Liver biopsies should only be done if, after thoughtful assessment, benefits are thought to exceed risks.