Invasive and non-invasive assessment of portal hypertension.

Portal hypertension is the central driver of complications in patients with chronic liver diseases and cirrhosis. The diagnosis of portal hypertension has important prognostic and clinical implications. In particular, screening for varices in patients with portal hypertension can effectively reduce the morbidity and mortality of variceal bleeding. In this article, we review the invasive and non-invasive methods to assess portal hypertension. Hepatic venous pressure gradient remains the gold standard to measure portal pressure but is invasive and seldom performed outside expert centers and research settings. In recent years, a number of non-invasive tests of fibrosis have shown good correlation with liver histology. They also show promise in identifying patients with portal hypertension and large varices. As a result, the latest Baveno VI consensus guidelines endorse the use of liver stiffness measurement by transient elastography and platelet count as initial assessment to select patients for varices screening. On the other hand, the performance of non-invasive tests in assessing the response to non-selective beta-blockers or transjugular intrahepatic portosystemic shunting is either suboptimal or unclear.

Application of the combined FibroMeter vibration-controlled transient elastography algorithm in Chinese patients with non-alcoholic fatty liver disease.

BACKGROUND AND AIM: The FibroMeter vibration-controlled transient elastography (FM VCTE) is a new formula combining the serum test FM and liver stiffness measurement (LSM) by VCTE. We tested the accuracy and utility of FM VCTE for fibrosis staging in patients with non-alcoholic fatty liver disease (NAFLD). METHODS: Two hundred fifteen NAFLD patients with LSM, FM NAFLD, FM VCTE, and other serum tests (aspartate aminotransferase-to-platelet ratio index, fibrosis-4 index, BARD score, NAFLD fibrosis score, and aspartate aminotransferase-to-alanine aminotransferase ratio) performed 1 day before liver biopsy were evaluated. RESULTS: Sixty-nine (32.1%) and 43 (20.0%) patients had F2-4 and F3-4, respectively. LSM had higher diagnostic accuracy (area under receiver-operating characteristics curves [AUROC] 0.851 for F2-4, 0.940 for F3-4; Obuchowski index 0.937 ± 0.007) than all evaluated serum tests, while FM NAFLD was the most accurate serum test (AUROC 0.775 and 0.774; Obuchowski index 0.891 ± 0.013). FM VCTE had similar accuracy to LSM (AUROC 0.855 and 0.901; Obuchowski index 0.927 ± 0.009). LSM had excellent negative predictive values of 92.4% and 99.2% to exclude F2-4 and F3-4, but the positive predictive values (PPV) were only 71.4% and 61.0%, respectively. In patients with high LSM, the use of FM VCTE improved the PPV from 71.4% to 84.4% for F2-4 and from 61.0% to 88.9% for F3-4. Liver biopsy could be spared in around 50-65% of patients. CONCLUSIONS: Liver stiffness measurement alone can confidently exclude significant and advanced fibrosis in NAFLD patients. Using FM VCTE in patients with high liver stiffness can increase the positive predictive value to rule in F2-4 and F3-4.

Histological severity and clinical outcomes of nonalcoholic fatty liver disease in nonobese patients.

Although nonalcoholic fatty liver disease (NAFLD) is closely linked to obesity, around 10%-20% of nonobese Americans and Asians still develop NAFLD. Data on this special group are limited. We therefore studied the severity and clinical outcomes of nonobese NAFLD patients. Consecutive NAFLD patients who underwent liver biopsy were prospectively recruited. We used the NASH Clinical Research Network system to score the histology. The Asian body mass index cutoff of 25 kg/m2 was used to define nonobese NAFLD. Among 307 recruited NAFLD patients, 72 (23.5%) were nonobese. Compared to obese patients, nonobese patients had lower NAFLD activity score (3.3 ± 1.3 vs. 3.8 ± 1.2; P = 0.019), mainly contributed by steatosis (1.7 ± 0.8 vs. 2.0 ± 0.8; P = 0.014) and presence of hepatocyte ballooning (60.9% vs. 73.4%; P = 0.045). Similarly, nonobese patients had lower fibrosis stage (1.3 ± 1.5 vs. 1.7 ± 1.4; P = 0.004), serum cytokeratin-18 fragments (283 vs. 404 U/L; P < 0.001) and liver stiffness measurement by transient elastography (6.3 vs. 8.6 kilopascals; P < 0.001). By multivariate analysis in nonobese patients, only elevated serum triglyceride level was independently associated with higher NAFLD activity score (adjusted odds ratio [OR], 1.644; P = 0.021), whereas elevated creatinine level was the only factor associated with advanced fibrosis (adjusted OR, 1.044; P = 0.025). After a median follow-up of 49 months, 6 patients died, 2 developed hepatocellular carcinoma, and 1 had liver failure, all of whom were in the obese group. CONCLUSION: Nonobese NAFLD patients tend to have less-severe disease and may have a better prognosis than obese patients. Hypertriglyceridemia and higher creatinine are the key factors associated with advanced liver disease in nonobese patients. (Hepatology 2017;65:54-64).

Prevalence and Severity of Nonalcoholic Fatty Liver Disease in Non-Obese Patients: A Population Study Using Proton-Magnetic Resonance Spectroscopy.

OBJECTIVES: Some studies suggest that non-obese patients with nonalcoholic fatty liver disease (NAFLD) may have more severe disease. We aim to study the epidemiology and severity of non-obese NAFLD. METHODS: A total of 911 community subjects were randomly recruited from the census database of the Hong Kong Government. Intrahepatic triglycerides (IHTG) and liver fibrosis were assessed by proton-magnetic resonance spectroscopy and transient elastography, respectively. The Asian body mass index cutoff of 25 kg/m(2) was used to define non-obese NAFLD. RESULTS: The prevalence of NAFLD was 19.3% in non-obese subjects and 60.5% in obese subjects (P<0.001). Compared with obese NAFLD patients, non-obese NAFLD patients had similar IHTG content (median 9.8% vs. 9.9%; P=0.100) but lower cytokeratin-18 fragments (149 vs. 182 IU/l; P=0.019) and liver stiffness (4.6 vs. 5.6 kPa; P<0.001). The G allele at the patatin-like phospholipase domain-containing protein 3 gene (PNPLA3 rs738409) was more common in non-obese than obese NAFLD patients (78.4% vs. 59.8%; P=0.001). Obesity, high hemoglobin A1c, insulin resistance, hyperferritinemia, and the PNPLA3 G allele were independent factors associated with NAFLD in non-obese subjects. Even among non-obese subjects with normoglycemia, those with NAFLD were more insulin resistant (mean homeostasis model assessment of insulin resistance: 2.0±1.0 vs. 1.1±1.1; P<0.001). CONCLUSIONS: One-fifth of the general non-obese Chinese population has NAFLD. Non-obese patients with NAFLD do not have a higher risk of steatohepatitis or advanced fibrosis. Patients with risk factors of advanced fibrosis such as metabolic syndrome and PNPLA3 G allele carriage should be assessed for severe NAFLD.