Is there an association between commonly employed biomarkers of liver fibrosis and liver stiffness in the general population?

Value of Mac-2 Binding Protein Glycosylation Isomer (M2BPGi) in Assessing Liver Fibrosis in Metabolic Dysfunction-Associated Liver Disease: A Comprehensive Review of its Serum Biomarker Role

Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) is a broad condition characterized by lipid accumulation in the liver tissue, which can progress to fibrosis and cirrhosis if left untreated. Traditionally, liver biopsy is the gold standard for evaluating fibrosis. However, non-invasive biomarkers of liver fibrosis are developed to assess the fibrosis without the risk of biopsy complications. Novel serum biomarkers have emerged as a promising tool for non-invasive assessment of liver fibrosis in MAFLD patients. Several studies have shown that elevated levels of Mac-2 binding protein glycosylation isomer (M2BPGi) are associated with increased liver fibrosis severity in MAFLD patients. This suggests that M2BPGi could serve as a reliable marker for identifying individuals at higher risk of disease progression. Furthermore, the use of M2BPGi offers a non-invasive alternative to liver biopsy, which is invasive and prone to sampling errors. Overall, the usage of M2BPGi in assessing liver fibrosis in MAFLD holds great promise for improving risk stratification and monitoring disease progression in affected individuals. Further research is needed to validate its utility in clinical practice and establish standardized protocols for its implementation.

Nonalcoholic fatty liver disease: an update

PURPOSE OF REVIEW

We discuss two recent controversial issues in the research field of fatty liver: the proposal to replace nonalcoholic fatty liver disease (NAFLD) with metabolically associated fatty liver disease (MAFLD) and the suggestion to extend to primary care the noninvasive testing for liver fibrosis that was developed for secondary care.

RECENT FINDINGS

There is preliminary evidence that MAFLD-only patients are at greater risk of fibrosis than NAFLD-only patients. There are a large number of false positives associated with the downshift of noninvasive testing for liver fibrosis from secondary to primary care.

SUMMARY

More studies are needed to compare the MAFLD and NAFLD operational definitions. Noninvasive testing of liver fibrosis also needs further evaluation before it can be used in primary care or in the general population.

Performance of American Gastroenterological Association Clinical Care Pathway for the risk stratification of patients with nonalcoholic fatty liver disease in the US population

BACKGROUND AND AIMS

The American Gastroenterological Association (AGA) recently launched the Clinical Care Pathway for the Risk Stratification and Management of Patients with NAFLD to identify adults with significant fibrosis. We aimed to examine this pathway's performance in the US population.

APPROACH AND RESULTS

Using the 2017-2018 National Health and Nutrition Examination Survey data, we identified participants aged ≥18 with available Fibrosis-4 (FIB-4) score and liver stiffness measurement (LSM) in the absence of other liver diseases. Based on the AGA clinical pathway, FIB-4 < 1.3 and LSM < 8 kilopascals (kPa) by vibration-controlled transient elastography (VCTE) are associated with low risk of significant fibrosis. Using these cutoffs, we examined the pathway performance using negative predictive value (NPV) and positive predictive value (PPV) and explored alternative risk-stratification strategies. There were 2322 participants with available data (projected to 94.2 million US adults). The NPV of LSM ≥ 8 kPa among those with FIB-4 < 1.3 was 90%, whereas the PPV among those with FIB-4 1.3-2.67 was 13%. As diabetes was a strong predictor of fibrosis, we propose a simple, alternative strategy to eliminate the indeterminate FIB-4 range and perform VCTE in those with FIB-4 ≥ 1.3 and diabetes. This strategy would decrease the number of VCTEs from 14.5 to 4.9 million and increase PPV from 13% to 33% without compromising the NPV among those who did not undergo VCTE.

CONCLUSION

The implementation of the current AGA clinical pathway would lead to overutilization of VCTE. An alternative strategy using FIB-4 ≥ 1.3 and diabetes to select adults undergoing second-line testing will improve this pathway's performance and minimize unnecessary VCTEs.

Low Accuracy of FIB-4 and NAFLD Fibrosis Scores for Screening for Liver Fibrosis in the Population

BACKGROUND & AIMS

Fibrosis-4 (FIB-4) and the nonalcoholic fatty liver disease fibrosis score (NFS) are the 2 most popular noninvasive blood-based serum tests proposed for widespread fibrosis screening. We therefore aimed to describe the accuracy of FIB-4 and NFS to detect elevated liver stiffness as an indicator of hepatic fibrosis in low-prevalence populations.

METHODS

This study included a total of 5129 patients with concomitant measurement of FIB-4, NFS, and liver stiffness measurement (LSM) by Fibroscan (Echosens, France) from 5 independent population-based cohorts from Spain, Hong Kong, Denmark, England, and France; 3979 participants from the general population and 1150 from at-risk cohorts due to alcohol, diabetes, or obesity. We correlated LSM with FIB-4 and NFS, and calculated pre- and post-test predictive values of FIB-4 and NFS to detect elevated LSM at 8 kPa and 12 kPa cutoffs. The mean age was 53 ± 12 years, the mean body mass index was 27 ± 5 kg/m², and 2439 (57%) were women. One in 10 patients (552; 11%) had liver stiffness ≥8 kPa, but 239 of those (43%) had a normal FIB-4, and 171 (31%) had normal NFS. The proportion of false-negatives was higher in at-risk patients than the general population. FIB-4 was false-negative in 11% of diabetic subjects, compared with 2.5% false-negatives with NFS. Waist circumference outperformed FIB-4 and NFS for detecting LSM ≥8 kPa in the general population. Almost one-third (28%-29%) of elevated FIB-4/NFS were false-positive in both the general population and at-risk cohorts.

CONCLUSIONS

FIB-4 and NFS are suboptimal for screening purposes due to a high risk of overdiagnosis and a non-negligible percentage of false-negatives, especially in patients with risk factors for chronic liver disease. Waist circumference emerged as a potential first step to identify patients at risk for liver fibrosis in the general population.

Accuracy of FIB-4 to Detect Elevated Liver Stiffness Measurements in Patients with Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study in Referral Centers

The identification of advanced fibrosis by applying noninvasive tests is still a key component of the diagnostic algorithm of NAFLD. The aim of this study is to assess the concordance between the FIB-4 and liver stiffness measurement (LSM) in patients referred to two liver centers for the ultrasound-based diagnosis of NAFLD. Fibrosis 4 Index for Liver Fibrosis (FIB-4) and LSM were assessed in 1338 patients. A total of 428 (32%) had an LSM ≥ 8 kPa, whereas 699 (52%) and 113 (9%) patients had an FIB-4 < 1.3 and >3.25, respectively. Among 699 patients with an FIB-4 < 1.3, 118 (17%) had an LSM ≥ 8 kPa (false-negative FIB-4). This proportion was higher in patients ≥60 years, with diabetes mellitus (DM), arterial hypertension or a body mass index (BMI) ≥ 27 kg/m2. In multiple adjusted models, age ≥ 60 years (odds ratio (OR) = 1.96, 95% confidence interval (CI) 1.19−3.23)), DM (OR = 2.59, 95% CI 1.63−4.13), body mass index (BMI) ≥ 27 kg/m2 (OR = 2.17, 95% CI 1.33−3.56) and gamma-glutamyltransferase ≥ 25 UI/L (OR = 2.68, 95% CI 1.49−4.84) were associated with false-negative FIB-4. The proportion of false-negative FIB-4 was 6% in patients with none or one of these risk factors and increased to 16, 31 and 46% among those with two, three and four concomitant risk factors, respectively. FIB-4 is suboptimal to identify patients to refer to liver centers, because about one-fifth may be false negative at FIB-4, having instead an LSM ≥ 8 KPa.

Predictors of Hepatocellular Carcinoma Early Recurrence in Patients Treated with Surgical Resection or Ablation Treatment: A Single-Center Experience

Introduction: Hepatocellular carcinoma (HCC) is the sixth most diagnosed malignancy and the fourth leading cause of cancer-related death worldwide, with poor overall survival despite available curative treatments. One of the most crucial factors influencing survival in HCC is recurrence. The current study aims to determine factors associated with early recurrence of HCC in patients with BCLC Stage 0 or Stage A treated with surgical resection or local ablation. Materials and Methods: We retrospectively enrolled 58 consecutive patients diagnosed with HCC within BCLC Stage 0 or Stage A and treated either by surgical resection or local ablation with maximum nodule diameter < 50 mm. In the first year of follow-up after treatment, imaging was performed regularly one month after treatment and then every three months. Each case was discussed collectively by the Liver Multidisciplinary Group to decide diagnosis, treatment, follow-up, and disease recurrence. Variables resulting in statistically significant difference were then studied by Cox regression analysis; univariately and then multivariately based on forward stepwise Cox regression. Results are represented in hazard ratio (H.R.) with 95% confidence interval (C.I.). Results: There was no statistically significant difference in recurrence rates (34.8 vs. 45.7%, log-rank test, p = 0.274) between patients undergoing surgical resection and local ablation, respectively. Early recurrence was associated with male gender (HR 2.5, 95% C.I. 1.9−3.1), nodule diameter > 20 mm (HR 4.5, 95% C.I. 3.9−5.1), platelet count < 125 × 103 cell/mm3 (HR 1.6, 95% C.I. 1.2−1.9), platelet-lymphocyte ratio < 95 (HR 2.1, 95% C.I. 1.7−2.6), lymphocyte-monocyte ratio < 2.5 (HR 1.9, 95% C.I. 1.4−2.5), and neutrophil-lymphocyte ratio > 2 (HR 2.7, 95% C.I. 2.2−3.3). Discussion and Conclusions: Our results are in line with the current literature. Male gender and tumor nodule dimension are the main risk factors associated with early HCC recurrence. Platelet count and other combined scores can be used as predictive tools for early HCC recurrence, although more studies are needed to define cut-offs.

Two-dimensional shear wave elastography for assessing liver fibrosis in patients with chronic liver disease: a prospective cohort study

BACKGROUND/AIMS

The objective of this study was to determine whether the newly developed two-dimensional shear wave elastography (2D-SWE, RS85, Samsung-shearwave imaging) was more valid and reliable than transient elastography (TE) for predicting the stage of liver fibrosis.

METHODS

The study prospectively enrolled a total of 116 patients with chronic liver disease who underwent 2D-SWE, TE, laboratory testing, and liver biopsy on the same day from two tertiary care hospitals. One patient with unreliable measurement was excluded. The measurement of 2D-SWE was considered acceptable when a homogenous color pattern in a region of interest of at least 10 mm was detected at 10 different sites. Diagnostic performance was calculated using area under the receiver operating characteristic curve (AUROC).

RESULTS

Liver fibrosis stages included F0 (18%), F1 (19%), F2 (24%), F3 (22%), and F4 (17%). Interclass correlation coefficient for inter-observer agreement in 2D-SWE was 0.994 (95% confidence interval [CI], 0.988 to 0.997). Overall, the results of 2D-SWE and stages of histological fibrosis were significantly correlated (r = 0.601, p < 0.001). For The 2D-SWE showed good diagnostic ability (AUROC, 0.851; 95% CI, 0.773 to 0.911) comparable to TE (AUROC, 0.859; 95% CI, 0.781 to 0.916) for the diagnosis of significant fibrosis (≥ F2), and the cut-off value was 5.8 kPa. AUROC and optimal cut-off of 2D-SWE for the diagnosis of liver cirrhosis were 0.889 (95% CI, 0.817 to 0.940) and 9.6 kPa, respectively. TE showed similar diagnostic performance in distinguishing cirrhosis (AUROC, 0.938; 95% CI, 0.877 to 0.974; p = 0.08).

CONCLUSION

2D-SWE is comparable to TE in diagnosing significant fibrosis and liver cirrhosis with high reliability.

Liver Injury and Elevated FIB-4 Define a High-Risk Group in Patients with COVID-19

Liver involvement in Coronavirus Disease 2019 (COVID-19) has been widely documented. However, data regarding liver-related prognosis are scarce and heterogeneous. The current study aims to evaluate the role of abnormal liver tests and incidental elevations of non-invasive fibrosis estimators on the prognosis of hospitalized COVID-19 patients. We conducted a retrospective cohort study to investigate the impact of elevated liver tests, non-invasive fibrosis estimators (the Fibrosis-4 (FIB-4), Forns, APRI scores, and aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio), and the presence of computed tomography (CT)-documented liver steatosis on mortality in patients with moderate and severe COVID-19, with no prior liver disease history. A total of 370 consecutive patients were included, of which 289 patients (72.9%) had abnormal liver biochemistry on admission. Non-survivors had significantly higher FIB-4, Forns, APRI scores, and a higher AST/ALT ratio. On multivariate analysis, severe FIB-4 (exceeding 3.25) and elevated AST were independently associated with mortality. Severe FIB-4 had an area under the receiver operating characteristic (AUROC) of 0.73 for predicting survival. The presence of steatosis was not associated with a worse outcome. Patients with abnormal liver biochemistry on arrival might be susceptible to a worse disease outcome. An FIB-4 score above the threshold of 3.25, suggestive of the presence of fibrosis, is associated with higher mortality in hospitalized COVID-19 patients.

Liver stiffness assessed by shear-wave elastography declines in parallel with immunoregulatory proteins in patients with chronic HCV infection during DAA therapy

BACKGROUND

A rapid decline of liver stiffness (LS) was detected by non-invasive methods in patients with chronic hepatitis C (HCV) infection during treatment with direct-acting antivirals (DAA).

OBJECTIVE

To investigate the influence of inflammation on LS.

METHODS

We prospectively examined LS by sonographic shear-wave elastography in 217 patients during DAA therapy from treatment initiation (BL) to 12 weeks after end of therapy (SVR12). Demographic data, laboratory findings and serum levels of cytokines were determined.

RESULTS

Values of LS decreased from 1.86 m/s to 1.68 m/s (p = 0.01) which was most pronounced in patients who had F4 fibrosis at BL (3.27 m/s to 2.37 m/s; p <  0.001). Initially elevated values of aminotransferases, ferritin, IgG (p <  0.001 each) and international normalized ratio (p <  0.003) declined, thrombocyte count (p = 0.007) increased. Correlations of these laboratory parameters with BL levels of LS measurement (LSM) were most apparent in patients with F1-F3 fibrosis. Tumor necrosis factor (TNF)-α (p = 0.031), interleukin (IL)-10 (p = 0.005) and interferon y inducible protein (IP)-10 (p <  0.001) decreased in parallel with LSM under DAA therapy and corelated with BL values.

CONCLUSION

Decrease of systemic inflammatory parameters correlated with LSM under DAA therapy. We conclude that regression of LSM is attributable to the decline of inflammation rather than reflecting fibrosis.

Molecular Crosstalk between the Hepatitis C Virus and the Extracellular Matrix in Liver Fibrogenesis and Early Carcinogenesis

Simple Summary

In the era of direct-acting antivirals against the hepatitis C virus (HCV), curing chronic hepatitis C has become a reality. However, while replicating chronically, HCV creates a peculiar state of inflammation and oxidative stress in the infected liver, which fuels DNA damage at the onset of HCV-induced hepatocellular carcinoma (HCC). This cancer, the second leading cause of death by cancer, remains of bad prognosis when diagnosed. This review aims to decipher how HCV durably alters elements of the extracellular matrix that compose the liver microenvironment, directly through its viral proteins or indirectly through the induction of cytokine secretion, thereby leading to liver fibrosis, cirrhosis, and, ultimately, HCC.

Abstract

Chronic infection by the hepatitis C virus (HCV) is a major cause of liver diseases, predisposing to fibrosis and hepatocellular carcinoma. Liver fibrosis is characterized by an overly abundant accumulation of components of the hepatic extracellular matrix, such as collagen and elastin, with consequences on the properties of this microenvironment and cancer initiation and growth. This review will provide an update on mechanistic concepts of HCV-related liver fibrosis/cirrhosis and early stages of carcinogenesis, with a dissection of the molecular details of the crosstalk during disease progression between hepatocytes, the extracellular matrix, and hepatic stellate cells.

Metformin Actions on the Liver: Protection Mechanisms Emerging in Hepatocytes and Immune Cells against NASH-Related HCC

Nonalcoholic fatty liver disease (NAFLD) is strongly linked to the global epidemic of obesity and type 2 diabetes mellitus (T2DM). Notably, NAFLD can progress from the mildest form of simple steatosis to nonalcoholic steatohepatitis (NASH) that increases the risk for hepatocellular carcinoma (HCC), which is a malignancy with a dismal prognosis and rising incidence in the United States and other developed counties, possibly due to the epidemic of NAFLD. Metformin, the first-line drug for T2DM, has been suggested to reduce risks for several types of cancers including HCC and protect against NASH-related HCC, as revealed by epidemical studies on humans and preclinical studies on animal models. This review focuses on the pathogenesis of NASH-related HCC and the mechanisms by which metformin inhibits the initiation and progression of NASH-related HCC. Since the functional role of immune cells in liver homeostasis and pathogenesis is increasingly appreciated in developing anti-cancer therapies on liver malignancies, we discuss both the traditional targets of metformin in hepatocytes and the recently defined effects of metformin on immune cells.

The Effect of Genetic Polymorphism in Response to Body Weight Reduction in Japanese Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND

weight loss as a result of lifestyle intervention is effective when treating non-alcoholic fatty liver disease (NAFLD). We estimated the effects of PNPLA3 rs738409 and HSD17B13 rs6834314 variants in response to diet therapy in Japanese patients with NAFLD.

METHODS

we analyzed the correlation between the change in liver stiffness and change in body weight in 140 patients administered diet therapy for 1-year, according to PNPLA3 and HSD17B13 genotypes.

RESULTS

the bodyweight (BW) reduction rate was greater in patients with the PNPLA3 genotype CC than CG and GG (p = 0.035). Change in liver stiffness measurement (LSM) was significantly associated with a change in BW in PNPLA3 CG/GG (r = 0.279/0.381), but not in PNPLA3 CC (p = 0.187). Change in LSM was correlated with change in BW only in patients with HSD17B13 AG/GG (r = 0.425), but not the AA genotype (p = 0.069). A multivariate analysis identified that a change in LSM was correlated with a change in BW in carriers of HSD17B13 AG/GG (B = 3.043, p = 0.032), but not HSD17B13 AA. The change in LSM of patients with a BW reduction of more than 7% (0.50) was significantly greater than that of patients with a BW reduction of less than 7% (0.83) (p = 0.038).

CONCLUSIONS

in Japanese patients with NAFLD, HSD17B13 rs6834314 polymorphism is associated with the change in LSM by lifestyle intervention. The approach, including genetic assessments, may contribute to the establishment of appropriate therapeutic strategies to treat NAFLD.

External Validation of Surrogate Indices of Fatty Liver in the General Population: the Bagnacavallo Study

We externally validated the fatty liver index (FLI), the lipid accumulation product (LAP), the hepatic steatosis index (HSI), and the Zhejiang University index (ZJU) for the diagnosis of fatty liver (FL) and non-alcoholic fatty liver disease (NAFLD) in the general population. The validation was performed on 2159 citizens of the town of Bagnacavallo (Ravenna, Italy). Calibration was evaluated by calculating the calibration slope and intercept and by inspecting calibration plots; discrimination was evaluated using the c-statistic. The average calibration slope was 1 and the average intercept was 0 for all combinations of outcomes and indices. For the diagnosis of FL, the c-statistic was 0.85 for FLI, 0.83 for ZJU, 0.82 for HSI, and 0.80 for LAP; for the diagnosis of NAFLD, the c-statistic was 0.77 for FLI, 0.76 for ZJU, 0.75 for HSI, and 0.74 for LAP. All indices were strongly correlated with each other. In conclusion, FLI, LAP, HSI, and ZJU perform similarly well to diagnose FL and NAFLD in the Bagnacavallo population, even if FLI has a small advantage as discrimination is concerned.

The role of elastography in alcoholic liver disease: fibrosis staging and confounding factors, a review of the current literature

INTRODUCTION

Alcohol-related liver disease (ALD) was estimated to have a prevalence of 2% among the USA population. Since severe fibrosis in compensated patients is the main predictor of long-term survival, it is of utmost importance to early detect patients with severe fibrosis before decompensation occurs. Liver elastography has been used to stage liver fibrosis. However, there is a widespread lack in guidelines for the correct use of liver stiffness (LS) in ALD.

EVIDENCE ACQUISITION

A structured search was carried out on MEDLINE/PubMed database. From the original 225 research articles identified, only 12 studies met the inclusion criteria, with 10 studies being eventually included.

EVIDENCE SYNTHESIS

According to reported data, patients with aspartate aminotransferase (AST)>100 IU/L and 50 IU/L showed significantly higher values of LS if compared to patients with the same fibrosis stage. Also, excessive alcohol consumption greatly influences elastography, leading to false fibrosis staging. When LS values >5-6 kPa are detected, several aspects should be taken into account. First of all, the patient should be asked about the current alcohol consumption (i.e. active vs. abstinence, determination of abstinence period, and quantification of alcohol intake), and if the patient is an active drinker, liver elastography can be repeated after a complete abstinence period of at least two weeks. and if the patient is an active drinker, liver elastography can be repeated after a complete abstinence period of at least two weeks. Secondly, clinicians should check liver transaminases level, and if AST are above 100 IU/L, they should be aware of a possible overestimation of fibrosis. However, whether transaminases-adapted cut-off values should be used for ad-hoc decisions in patients with no time or option to withdraw from alcohol consumption is still a matter of debate.

CONCLUSIONS

We hope that our review article may serve as a reference point in the prospect of futures guidelines.

Chemerin Is a Valuable Biomarker in Patients with HCV Infection and Correlates with Liver Injury

Hepatitis C virus (HCV)-induced inflammation contributes to progressive liver disease. The chemoattractant protein chemerin is associated with systemic inflammation. We hypothesized that chemerin is a biomarker that predicts the severity of liver disease in HCV patients. Furthermore, we investigated whether serum chemerin levels change during the course of HCV treatment using direct-acting antivirals (DAAs). Therefore, we measured serum concentration of chemerin in a cohort of 82 HCV-infected patients undergoing DAA treatment. Serum chemerin was positively associated with leukocyte count and negatively with markers of hepatic function and the model of end-stage liver disease (MELD) score. Low circulating chemerin levels significantly correlated with advanced liver fibrosis and cirrhosis as measured by the fibrosis-4 (FIB-4) score, the aminotransferase/platelet (AST/PLT) ratio index (APRI) score and the non-alcoholic fatty liver disease (NAFLD) score. Chemerin did not correlate with viral load or viral genotype. Treatment with DAAs did not improve MELD score and leukocyte count within the observation period, up to three months after the end of DAA treatment. Accordingly, chemerin levels remained unchanged during the treatment period. We conclude that low circulating chemerin is a noninvasive biomarker for hepatic dysfunction and advanced liver fibrosis and cirrhosis in HCV infection.

The Appropriate Opportunity for Evaluating Liver Fibrosis by Using the FIB-4 Index in Patients with Nonalcoholic Fatty Liver Disease in Japan

In patients with nonalcoholic fatty liver disease (NAFLD), liver fibrosis is the predictive factor for liver-related events and prognosis. This retrospective study aimed to evaluate longitudinal changes in the FIB-4 index and to determine a strategy for diagnosing and following patients with NAFLD using this index. We analyzed the FIB-4 index at baseline and after 1 and 5 years in 272 consecutive patients with biopsy-proven NAFLD. Of these, 52 patients underwent serial biopsies. The change in the FIB-4 index was correlated with changes in the fibrosis stage among these patients (p = 0.048). The median FIB-4 index was 1.64 at baseline, 1.45 at 1 year, and 1.74 at 5 years. The negative predictive value for advanced fibrosis at a low cutoff point was 90.4/90.1 at baseline/1 year. Its specificity at a high cutoff point increased from 65.0% at baseline to 82.3% at 1 year. Multivariate analysis identified the FIB-4 index at 1 year as a predictive factor for a FIB-4 index > 2.67 at 5 years. A FIB-4 index < 1.30 was acceptable for excluding advanced fibrosis at baseline. In contrast, to evaluate and predict advanced liver fibrosis with the FIB-4 index at a high cutoff point, we should use the index at 1 year after appropriate therapy.

Optimization of Point-Shear Wave Elastography by Skin-to-Liver Distance to Assess Liver Fibrosis in Patients Undergoing Bariatric Surgery

BACKGROUND

Obesity is a primary limiting factor in liver stiffness measurement (LSM). The impact of obesity has always been evaluated in terms of body mass index (BMI), without studying the effects of skin-to-liver distance (SLD) on LSM. We studied the impact of SLD on LSM in a cohort of obese patients undergoing bariatric surgery and intra-operatory liver biopsy.

MATERIALS AND METHODS

299 patients underwent LSM by point-shear wave elastography (ElastPQ protocol), with two different ultrasound machines. SLD was measured as the distance between the skin and the liver capsule, perpendicular to where the region of interest (ROI) was positioned. We used the following arbitrary cut-offs: <5.7 kPa, F0-1; 5.7-7.99 kPa, F2; ≥8 kPa, F3-4.

RESULTS

We developed two logistic regression models using elastography-histology agreement (EHA) as the dependent variable and SLD as the independent variable. The model based on the second machine showed strongly more performant discriminative and calibration metrics (AIC 38.5, BIC 44.2, Nagelkerke Pseudo-R2 0.894, AUROC 0.90). The SLD cut-off value of 34.5 mm allowed a correct EHA with a sensitivity of 100%, a specificity of 93%, negative predictive value of 100%, positive predictive value of 87%, an accuracy of 96%, and positive likelihood ratio of 3.56.

CONCLUSION

The impact of SLD is machine-dependent and should be taken into consideration when interpreting LSM. We believe that our findings may serve as a reference point for appropriate fibrosis stratification by liver elastography in obese patients.