Expert Panel on Liver Stiffness Measurement. Clinical Application of Transient Elastography in the Diagnosis of Liver Fibrosis: an Expert Panel Review and Opinion

Liver stiffness in Fontan patients: the effect of respiration and food intake

Objectives

For several years, patients with single ventricle hearts have been palliated according to the Fontan principle. One well known long-term consequence in these patients is the Fontan-associated liver disease and fibrosis, which occurs due to the chronically increased Central Venous Pressure (CVP) after Fontan palliation. It carries an increased risk of liver cirrhosis and hepatocellular carcinoma over time. Liver elastography (LE) is a non-invasive, safe, and feasible ultrasound method to determine liver stiffness and the stage of liver fibrosis. Usually, this examination must be performed in a sober condition and strict inspiratory hold to optimize the results and may therefore be difficult to perform on children as a routine examination. However, the influence of food intake and respiration on these results in Fontan patients is unclear. To optimize the implementation for this examination especially in children, the effects of food intake and breathing maneuvers on liver stiffness in patients with Fontan circulation were investigated.

Methods

For this prospective study, 25 Fontan patients (group 1) and 50 healthy volunteers (group 2) were examined. The two groups were additionally divided into two age categories (group 1a: 10-19  years; group 1b: 20-29  years; group 2a: 15-19  years; group 2b: 20-25  years). Liver stiffness was measured by liver elastography once before food intake (=T0, with 6 h of fasting). Subsequently the participants consumed a standardized chocolate drink (500  mL) with nutritional distribution corresponding to a standardized meal (600  kcal). Liver stiffness was then determined 15, 30, 45, 60, 90, 120, 150, and 180  min after ingestion. Each measurement of liver stiffness was performed during maximal inspiratory and expiratory holds. The study was reviewed and approved by the responsible ethics committee.

Results

In group 2 there was a significant increase in liver stiffness after food intake at T15, T30, and T45 during inspiration measurements (T0 = 4.0 kPa vs. T15 = 4.9 kPa, difference = 22.5%; T0 = 4.0 kPa vs. T30 = 4.9 kPa difference = 22.5%; T0 = 4.0 kPa vs. T45 = 4.3 kPa difference = 7.5%), as well as during expiration at T15 and T30 (T0 = 4.5 kPa vs. T15 = 5.1 kPa, difference = 14.7%; T0 = 4.5 kPa vs. T30 = 4.9 kPa difference = 7.8%). Whereas in Fontan patients (group 1) liver stiffness did not differ significantly at any time between fasting (T0) and postprandial values. The respiratory maneuvers in the healthy subjects (group 2) differed significantly only before food intake (T0) (group 2: insp = 3.97 kPa vs. exp. = 4.48 kPa difference = 11.3%). In the Fontan group (group 1), there was no significant difference between the respiratory phases at any point. The different age categories showed no significant difference in liver stiffness.

Conclusion

With these results we could demonstrate for the first time that in Fontan patients the time of food intake (i.e., fasting) has no clinical significance for the values obtained in liver elastography. We could also demonstrate that the breathing maneuvers during the examination had only minimal clinical impact on the results of liver elastography in patients with normal circulation and no effect in patients with Fontan-circulation. Consequently, liver elastography for Fontan patients is reliable independently of food intake and breathing maneuvers and can also be performed on younger patients, who are unable to follow breathing commands or longer fasting periods, without any impairment of the results. These results should encourage a routine use of LE in the follow-up of Fontan patients.

Efficacy and safety of elbasvir/grazoprevir treatment for Chinese patients with hepatitis C virus genotype 1b: a retrospective study

OBJECTIVES

To determine the efficacy and safety of elbasvir/grazoprevir (EBR/GZR) treatment in Chinese patients with GT1b chronic hepatitis virus C (HCV) infections.

METHODS

In this retrospective study, 49 treatment-naive patients with chronic GT1b HCV infection were treated with GZR (100 mg) plus EBR (50 mg) for 12 weeks. The viral response was the primary endpoint and fibrosis stage changes during and after treatment, as well as the incidence of treatment-emergent adverse events (TEAE) were secondary endpoints.

RESULTS

After 2-week EBR/GZR treatment, the virologic response rate was 85.1% (80/94) and reached 100% (94/94) after 8 and 12 weeks of therapy. Sustained virologic response (SVR) rates were 100% at the 12, 24 and 48-week follow-ups. Multivariate analysis revealed that the baseline viral load of HCV RNA may affect the rapid 2-week virologic response (OR: 0.36, 95% CI: 0.14-0.92, P=0.034), but did not influence efficacy during further treatment or follow-ups. Fifteen patients with ≥1 TEAE (16.0%) were observed and 7 (7.4%) and 8 (8.5%) patients had mild ALT or AST elevations (1.1-2.5× BL), but no serious drug-related AEs occurred. Liver stiffness measurement (LSM), the AST to platelet ratio index (APRI) and the fibrosis index based on 4 factor (FIB4) scores were consistently reduced, especially in patients with high baseline assessments after 12 weeks' treatment and during follow-ups.

CONCLUSIONS

A 12-week EBR/GZR regimen shows high efficacy and safety in Chinese patients with GT1b HCV infections.

Clinical spectrum of non-alcoholic fatty liver disease in patients with diabetes mellitus

Background

Non-alcoholic fatty liver disease (NAFLD) is increasingly widespread with an overall global estimated prevalence of 25%. Type 2 diabetes Mellitus (T2DM) is a key contributor to NAFLD progression and predicts moderate-severe liver fibrosis and mortality. However, there is currently no uniform consensus on routine NAFLD screening among T2DM patients, and the risk factors of NAFLD and advanced fibrosis among T2DM patients remain to be clarified fully.

Aim

We explored the prevalence, clinical spectrum, and risk factors of NAFLD and liver fibrosis among T2DM patients.

Methods

This is a cross-sectional study that enrolled subjects from a primary care clinic and a diabetes centre in Singapore. Subjects aged 21 to 70 years of all ethnic groups with an established T2DM diagnosis were included. Subjects with chronic liver diseases of other aetiologies were excluded. All subjects underwent transient elastography for hepatic steatosis and fibrosis assessment. Their demographics, anthropometric measurements and clinical parameters were collected. Statistical analysis was performed using STATA/SE16.0 software.

Results

Among 449 enrolled T2DM subjects, 436 with complete data and valid transient elastography results were analysed. Overall, 78.72% (344/436) of the T2DM subjects had NAFLD, of which 13.08% (45/344) had increased liver stiffness. Higher ALT level (OR = 1.08; 95% CI: 1.03–1.14; p = 0.004), obesity (BMI ≥ 27.5 kg/m2, OR = 2.64; 95% CI: 1.28–5.44; p = 0.008) and metabolic syndrome (OR = 4.36; 95% CI 1.40–13.58; p = 0.011) were independent factors associated with increased CAP (NAFLD). Higher AST level (OR = 1.06; 95% CI: 1.02–1.11; p = 0.008), CAP value (OR = 1.02; 95% CI: 1.00–1.03; p = 0.003), lower platelet count (OR = 0.99; 95% CI: 0.98–1.00; p = 0.009) and concomitant hypertension (OR = 4.56; 95% CI: 1.18–17.62; p = 0.028) were independent factors associated with increased liver stiffness.

Conclusions

Our study demonstrated a considerably high prevalence of NAFLD among T2DM patients, with the proportion of advanced liver fibrosis among T2DM NAFLD patients much higher than the general population. Given that NAFLD is largely asymptomatic, increased awareness and vigilance for identifying NAFLD and increased liver stiffness among T2DM patients should be advocated.

Transient Elastography and Ultrasonography: Optimal Evaluation of Liver Fibrosis and Cirrhosis in Patients with Chronic Hepatitis B Concurrent with Nonalcoholic Fatty Liver Disease

Background and Aims

Concordance between transient elastography (TE) and ultrasonography (US) in assessing liver fibrosis in patients with chronic hepatitis B (CHB) and concurrent nonalcoholic fatty liver disease (NAFLD) has been rarely studied. This study aimed to evaluate the individual and combined performances of TE and US in assessing liver fibrosis and cirrhosis.

Patients and Methods

Consecutive CHB patients with NAFLD were prospectively enrolled. TE and US examinations were performed, with liver biopsy as a reference standard. Receiver operating characteristic (ROC) curves were obtained to evaluate the diagnostic performance. Differences between the areas under the ROC curves (AUCs) were compared using DeLong's test.

Results

TE and US scores correlated significantly with the histological fibrosis staging scores. TE was significantly superior to US in the diagnosis of significant fibrosis (AUC, 0.84 vs 0.73; P=0.02), advanced fibrosis (AUC, 0.95 vs 0.76; P<0.001), and cirrhosis (AUC, 0.96 vs 0.71; P<0.001). Combining TE with US did not increase the accuracy of detecting significant fibrosis, advanced cirrhosis, or cirrhosis (P=0.62, P=0.69, and P=0.38, respectively) compared to TE alone. However, TE combined with US significantly increased the positive predictive value for significant fibrosis when compared to TE alone. The optimal cut-off values of TE for predicting advanced fibrosis and cirrhosis were 8.7 kPa and 10.9 kPa, with negative predictive values of 92.4% and 98.7%, respectively.

Conclusions

TE is useful for predicting hepatic fibrosis and excluding cirrhosis in CHB patients with NAFLD. A combination of TE and US does not improve the accuracy in assessing liver fibrosis or cirrhosis.