Assessment of biliary fibrosis by transient elastography in patients with PBC and PSC

Transient elastography for the assessment of chronic liver disease: Ready for the clinic?

Transient elastography is a recently developed non-invasive technique for the assessment of hepatic fibrosis. The technique has been subject to rigorous evaluation in a number of studies in patients with chronic liver disease of varying aetiology. Transient elastography has been compared with histological assessment of percutaneous liver biopsy, with high sensitivity and specificity for the diagnosis of cirrhosis, and has also been used to assess pre-cirrhotic disease. However, the cut-off values between different histological stages vary substantially in different studies, patient groups and aetiology of liver disease. More recent studies have examined the possible place of transient elastography in clinical practice, including risk stratification for the development of complications of cirrhosis. This review describes the technique of transient elastography and discusses the interpretation of recent studies, emphasizing its applicability in the clinical setting.

Noninvasive diagnosis of hepatic fibrosis in chronic hepatitis C

Assessment of hepatic fibrosis is important for determining prognosis, guiding management decisions, and monitoring disease. Histological evaluation of liver biopsy specimens is currently considered the reference test for staging hepatic fibrosis. Since liver biopsy carries a small but significant risk, noninvasive tests to assess hepatic fibrosis are desirable. This editorial gives an overview on noninvasive methods currently available to determine hepatic fibrosis and their diagnostic accuracy for predicting significant fibrosis and cirrhosis in chronic hepatitis C. Based on available data, the performance of simple tests derived from routine laboratory parameters appears to be similar to that of more complex and expensive fibrosis panels. Transient elastography seems more accurate than blood tests for diagnosing cirrhosis.

In vivo determination of hepatic stiffness using steady-state free precession magnetic resonance elastography

OBJECTIVE

The objective of this study was to introduce an magnetic resonance elastography (MRE) protocol based on fractional motion encoding and planar wave acquisition for rapid measurements of in vivo human liver stiffness.

MATERIALS AND METHODS

Vibrations of a remote actuator membrane were fed by a rigid rod to the patient's surface beneath the right costal arch resulting in axial shear deflections of the liver. Data acquisition was performed using a balanced steady-state free precession (bSSFP) sequence incorporating oscillating gradients for motion sensitization. Tissue vibrations of frequency fv = 51 Hz were tuned by twice the sequence repetition time (1/fv = 2TR). Twenty axial images acquired by time-resolved through-plane wave encoding were used for planar elasticity reconstruction. The MRE data acquisition was achieved within 4 breathholds of 17 seconds each. The method was applied to 12 healthy volunteers and 2 patients with diffuse liver disease (fibrosis grade 3).

RESULTS

MRE data acquisition was successful in all volunteers and patients. The elastic moduli were measured with values between 1.99 +/- 0.16 and 5.77 +/- 0.88 kPa. Follow-up studies demonstrated the reproducibility of the method and revealed a difference of 0.74 +/- 0.47 kPa (P < 0.05) between the hepatic stiffness of 2 healthy male volunteers.

CONCLUSION

bSSFP combined with fractional MRE enables rapid measurement of liver stiffness in vivo. The used actuation principle supports a 2-dimensional analysis of the strain wave field captured by axial wave images. The measured data indicate individual variations of hepatic stiffness in healthy volunteers.

Sclerosing cholangitis

PURPOSE OF REVIEW

Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by strictures of the biliary tree complicated by cirrhosis and cholangiocarcinoma. It is immune mediated, although the precise aetiology remains unknown.

RECENT FINDINGS

Research into etiopathogenesis and epidemiology, diagnosis of cholangiocarcinoma, associations with inflammatory bowel disease and autoimmune pancreatitis, and medical therapy are discussed.

SUMMARY

Multiple gene polymorphisms associated with primary sclerosing cholangitis have been investigated. Common inflammatory bowel disease-associated polymorphisms do not confer any susceptibility to primary sclerosing cholangitis; the role of intercellular adhesion molecule-1 gene polymorphisms and CCR5 mutations remain unclear. Elevated IgG4 has been demonstrated in a subgroup of primary sclerosing cholangitis patients, which may indicate an overlap with autoimmune pancreatitis and possible responsiveness to steroids. Biliary brush cytology may assist in diagnosis of cholangiocarcinoma, although further clinical indicators are required. Animal studies suggest the superiority of 24-norursodeoxycholic acid over ursodeoxycholic acid in reducing histological disease progress; translational studies in humans are now required.

Cholestasis and cholestatic syndromes

PURPOSE OF REVIEW

This review focuses on the recent advances in cholestatic liver diseases. While there is an emphasis placed on translational and treatment-focused studies, basic science studies with the greatest impact on the field are also covered.

RECENT FINDINGS

Highlights include new discoveries for the role of the farsenoid X receptor and sodium-dependent taurocholate cotransporting polypeptide; new insights into the pathogenesis of progressive familial intrahepatic cholestasis type 1, biliary atresia, intrahepatic cholestasis of pregnancy, and primary biliary cirrhosis; new information for assessing prognosis in biliary atresia and primary biliary cirrhosis; and important clinical trials in intrahepatic cholestasis of pregnancy, primary biliary cirrhosis and primary sclerosing cholangitis.

SUMMARY

The studies of 2006 have furthered our understanding of cholestasis and cholestatic syndromes. While we continue to add to our knowledge of pathogenesis and treatment for many of these diseases, much work remains.

Features associated with success rate and performance of FibroScan measurements for the diagnosis of cirrhosis in HCV patients: a prospective study of 935 patients

BACKGROUND/AIMS

FibroScan, a non-invasive procedure for the diagnosis of cirrhosis, benefits only patients for which at least 10 valid shots are acquired. We investigated features associated with success rate of shots, and performance of FibroScan for the diagnosis of cirrhosis.

METHODS

Liver biopsy and stiffness measurement were performed in HCV patients. AUROCs and mixed logistic models evaluated the influence of patient and operator features on the success of shots and the performance for the diagnosis of cirrhosis.

RESULTS

Nine hundred and thirty five (935) patients were included. Success rate of shots decreased with age, and was lower in obese than in other patients. After adjusting for age and obesity, an operator with at least 50 prior FibroScan exams had a higher success rate in shots. FibroScan performance for the diagnosis of cirrhosis was not influenced by the number of valid shots taken into account and by operator skills.

CONCLUSIONS

After a rapid training, FibroScan provides a reasonable performance for the diagnosis of cirrhosis that is not influenced substantially by any other feature. More patients will benefit from this procedure with no significant loss in performance if only 5 valid shots are requested. These results should emphasize the use of FibroScan even in non-specialized units.

Comparison of test performance profile for blood tests of liver fibrosis in chronic hepatitis C

BACKGROUND/AIMS

We evaluated the test performance profile (TPP) of blood tests of liver fibrosis.

METHODS

Three hundred and fifty-six patients with C chronic hepatitis were included in two centers. Metavir staging of liver specimens by two independent pathologists and the following tests were evaluated: Fibrotest (FT), APRI, FibroMeter (FM), and Hepascore (HS).

RESULTS

Metavir stages were: F0: 4%, F1: 55%, F2: 26%, F3: 11%, and F4: 4%. The AUROCs were not significantly different, respectively, FT, FM, APRI, HS: >or=F2: 0.79, 0.78, 0.76, >or=0.76; F3: 0.81, 0.85, 0.81, 0.81; and F4: 0.86, 0.94, 0.92, 0.89. The TPP relies on the paired comparison of blood-test misclassification based on liver specimen, e.g. FT vs FM, respectively: F0+1: 18 vs 28% (p=0.0003), >or=F2: 43 vs 31% (p=0.004). There was no center effect.

CONCLUSIONS

In those populations, the four blood tests had a similar performance for significant fibrosis (F>or=2), lying in the lower range of published results which is attributable to a low >or=F2 prevalence, and for >or=F3 and F4. However, FM and FT had performance profiles significantly different as a function of fibrosis stages or diagnostic target (fibrosis cut-off). This has to be considered during the interpretation process. Moreover, the performance should be reported with different diagnostic targets.

Résultats et place du Fibroscan® dans le diagnostic non invasif de la fibrose hépatique

BACKGROUND AND AIMS

Diagnosis of liver fibrosis by transient elastography (Fibroscan) is a new and non-invasive method. We report its results, and compare them with the non-invasive biological tests.

RESULTS

Fibroscan is validated for chronic hepatitis C, allowing to diagnose the fibrosis (Métavir) F2, F3 and F4 with areas under the ROC curve of 0.79-0.83, 0.90-0.91 and 0.91-0.97 respectively. The non-invasive diagnosis of the cirrhosis can be made with positive and negative predictive values from 70 to 95% and 77 in 95%. Preliminary data concern the HCV-HIV co-infections, primary biliary cirrhosis, NASH, portal hypertension, and the follow-up of the hepatic fibrosis. These results are altogether comparable to the various non-invasive biological tests, for cirrhosis diagnosis.

CONCLUSIONS

It's remain to determine the respective places of Fibroscan and non-invasive biological tests, in the liver fibrosis diagnosis.

Role of liver biopsy and serum markers of liver fibrosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is common and may progress to end-stage liver disease. Liver-related morbidity and mortality occur almost exclusively in patients whose disease progresses to advanced fibrosis and cirrhosis. Presence and severity of liver fibrosis seem the most important indicators of long-term prognosis. Clinical and biochemical variables may help select NAFLD patients in whom liver biopsy may provide the most prognostic information. Some serum markers of liver fibrosis and imaging techniques aimed at measuring liver stiffness are under investigation as tools to determine severity of liver fibrosis in patients who have NAFLD, but none of them yet can replace liver biopsy.

Accuracy of liver stiffness measurement for the diagnosis of cirrhosis in patients with chronic liver diseases

A proper diagnosis of cirrhosis is essential for the management of patients with chronic liver diseases. We assessed the accuracy of liver stiffness measurement by Fibroscan for the diagnosis of cirrhosis in 1,257 patients with chronic liver diseases of various causes enrolled in a prospective multicenter study as well as clarified causes of discrepancies between liver histology and Fibroscan. One hundred thirty-two patients had unsuitable biopsy specimens, and 118 had unreliable liver stiffness measurements. Because 232 patients overlapped with a previous study, analysis was performed in the 775 new patients then derived in the whole population (1,007; 165 cirrhosis). Diagnostic accuracy was assessed by receiver operator curve (ROC) analysis. Liver samples were re-analyzed in case of discrepancies. The area under the ROC (AUROC) was 0.95 (95% CI, 0.93-0.96) for the diagnosis of cirrhosis in either 775 or 1,007 patients. The cutoff value with optimal diagnosis accuracy was 14.6 kPa in 1,007 patients (positive and negative predictive values, 74% and 96%) with discrepancies among the etiological groups. Eighty patients were misclassified: (1) among 45 patients without cirrhosis with liver stiffness 14.6 kPa or greater, 27 (60%) had extensive fibrosis and 10 (22%) significant perisinusoidal fibrosis; and (2) among 35 patients with cirrhosis and liver stiffness less than 14.6 kPa, 10 (29%) had a macronodular pattern and 25 (71%) either none or mild activity. In conclusion, Fibroscan is a reliable method for the diagnosis of cirrhosis in patients with chronic liver diseases, better at excluding than at predicting cirrhosis using a threshold of 14.6 kPa. False-negatives are mainly attributable to inactive or macronodular cirrhosis.

Transient elastography: a valid alternative to biopsy in patients with chronic liver disease

BACKGROUND

Transient elastography is a novel and non-invasive technique for the evaluation of fibrosis in chronic liver disease. Few studies that exist value the efficacy of transient elastography, mainly in hepatitis C virus-infected patients.

AIM

To evaluate the effectiveness, objectivity, reproducibility and safety of this technique.

METHODS

We included 103 consecutive patients who underwent a liver biopsy in the last 48 months with a wide spectrum of chronic liver diseases. Median stiffness value (expressed as kilopascals - kPa) was kept as representative of the liver elastic modulus. All biopsy specimens were analysed by the same pathologist according to the METAVIR scoring system.

RESULTS

Median value of stiffness in patients with mild or moderate fibrosis (FI and FII), and severe fibrosis or cirrhosis (FIII and FIV) was of 7, 4 +/- 5 and 16, 4 +/- 10 kPa, respectively, with a significant difference between them (P < 0.05). The areas under the receiver operating characteristic curves showed the optimal liver stiffness cut-off values for each group.

CONCLUSIONS

We found a positive correlation between the liver stiffness found by transient elastography and fibrosis stage on biopsy in all patients, independently of the liver disease aetiology. Transient elastography is an easy, quick to perform and safe non-invasive procedure, reliable for assessing liver fibrosis.