Diagnosis and Staging of Pediatric Non-Alcoholic Fatty Liver Disease: Is Classical Ultrasound the Answer?

Efficacy of Ultrasound for the Detection of Possible Fatty Liver Disease in Children

Pediatric MASLD (previously referred to as NAFLD) incidence has continued to rise along with the obesity pandemic. Pediatric MASLD increases the risk of liver fibrosis and cirrhosis in adulthood. Early detection and intervention can prevent and reduce complications. Liver biopsy remains the gold standard for diagnosis, although imaging modalities are increasingly being used. We performed a retrospective study of 202 children seen in a pediatric gastroenterology clinic with a complaint of abdominal pain, elevated liver enzymes or MASLD, or a combination of the three to evaluate screening methods for MASLD. A total of 134 of the 202 patients included in the study underwent laboratory testing and abdominal ultrasound. Ultrasound images were reviewed with attention to liver size and echotexture by a fellowship-trained pediatric radiologist for liver size and echotexture. Overall, 76.2% of the initial radiology reports correctly identified hepatomegaly based on age and 75.4% of the initial radiology reports correctly described hepatic echogenicity that was consistent with increased hepatic fat deposition. Use of screening ultrasound in concert with other clinical evaluations can be helpful to identify children at risk of MASLD. Utilizing ranges for liver span according to age can help to diagnose hepatomegaly, and understanding how to identify hepatic echogenicity is important for identifying possible hepatic steatosis.

Ultrasound screening of paediatric non-alcoholic fatty liver disease (NAFLD): A critical literature review

INTRODUCTION

Paediatric NAFLD is an increasing global health concern, which can be effectively managed with early detection. Screening, using accurate, affordable, and accessible tests is recommended, however, there is currently no consensus on the most appropriate tests. Although ultrasound techniques are widely used, their performance against reference tests have not been fully assessed.

METHODS

A literature search of related databases for peer-reviewed original articles published from January 2010-March 2024 was conducted. Appropriate tools were used to systematise and document the search results and selected studies were quality assessed and critically appraised. Extracted data was subjected to thematic analysis and narrative synthesis.

RESULTS

Eighteen articles met the inclusion criteria. B-mode and Quantitative ultrasound techniques were compared against MR spectroscopy, MRI-PDFF and Liver biopsy.

CONCLUSION

Liver echogenicity and Steato-scores were the B-mode methods used. The former was less effective, with a maximum reported sensitivity of 70%. The latter reached up to 100% sensitivity, and >80% specificity. Ultrasound performed better with moderate-severe steatosis. There was not enough evidence to support steatosis grading, possibly due to small sample sizes and lack of established cut-off values. QUS (Quantitative Ultrasound)) methods including Continuous Attenuation Parameter (CAP), Attenuation Coefficient (AC), Ultrasound derived fat fraction (UDFF), Tissue Scatter Imaging (TSI) Hepato-Renal Index (HRI), Heterogeneity Index (HIA), Computer Assisted Ultrasound (CAUS) and Picture Archiving and Communication System (PACS-based Image analysis performed better than B-mode methods. Although QUS demonstrated excellent performance, with sensitivity and specificity of up to 100%, this will require further verification before implementation in practice.

PRACTICE IMPLICATIONS

Ultrasound techniques can effectively be used for paediatric NAFLD screening, especially in higher-risk subjects. The steato-scores method is currently recommendable for this, with excellent potential for the use of QUS, after cut-off values and validation requirements have been addressed.

Associations of Ultrasound Findings with Serum Iron and Ferritin Levels in Children with Obesity

The nutritional status of children is always a concern for medical professionals. Increasingly, obesogenic factors have created a new global epidemic. Obesity is characterized by persistent inflammation, which can have detrimental effects on the growth and development of children. Iron and ferritin are both important factors to consider when evaluating these children due to their role in the pathophysiology of chronic inflammation. Recently, ultrasonographic evaluation seems to be an increasingly used method in pediatric clinical practice. In this study, we included 98 children aged 6-14 years, 72 of whom were obese and 26 had normal weight. The data obtained indicated that there was an association between low iron and increased ferritin levels, aspects of non-alcoholic fatty liver visualized by ultrasonography, and the degree of fibrosis assessed elastographically. Ultrasonography can help us identify liver damage, but the possibility of identifying an association with other paraclinical investigations such as iron and ferritin levels can be cumulative. In this way, the assessment can be more complex, as the child benefits from comprehensive evaluation and management. The results drew attention to non-invasive, easy-to-perform, and low-cost methods of assessing obese children in terms of iron metabolism and structural liver changes.

Correlation of hepatic transient elastography measurements and abdominal adiposity in children: A cross-sectional study

BACKGROUND

Transient elastography is a non-invasive assessment of steatosis (measured as the controlled attenuation parameter, [CAP]) and fibrosis (measured as liver stiffness measurement, [LSM]) in patients with pediatric non-alcoholic fatty liver disease (NAFLD). Abdominal adiposity is considered the most important factor for metabolic dysregulation including NAFLD. However, there is lack of a correlation between transient elastography measurements and abdominal adiposity. Accordingly, this study aimed to assess the correlation between transient elastography measurements and abdominal adiposity in children.

METHODS

This cross-sectional study included 137 children who visited the Taipei Veterans General Hospital. Hepatic steatosis (CAP) and fibrosis (LSM), were assessed by transient elastography. Abdominal adiposity including subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and preperitoneal adipose tissue (PPT) was assessed using abdominal sonography. The correlation between transient elastography measurements and abdominal adiposity was assessed using multiple linear regression.

RESULTS

In total, 137 children were included in this study. SAT and VAT were significantly associated with CAP, whereas SAT was significantly associated with LSM. An increment of 1 mm in SAT increased CAP and LSM by 5.56 dB/m and 0.06 kPa, respectively.

CONCLUSION

Certain abdominal adiposities, especially SAT, are significantly associated with CAP and LSM, as determined by transient elastography. Simple abdominal adiposity measured using sonography may be useful for the early detection of pediatric NAFLD.

Role of microRNA in non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH): a comprehensive review

Non-alcoholic fatty liver disease (NAFLD) is a prevalent liver condition that affects people who do not overconsume alcohol. Uncertainties exist over how microRNAs (miRNAs) in the blood and liver relate to NAFLD. The aim of this narrative review was to investigate the role of miRNAs in the onset and progression of non-alcoholic steatohepatitis (NASH) from NAFLD, and explore their potential as diagnostic tools and treatment targets for NAFLD patients. Liver miRNA-34a levels were found to accurately represent the degree of liver damage, with lower levels suggesting more damage. In patients with NAFLD and severe liver fibrosis, higher levels of miRNA-193a-5p and miRNA-378d were found. Moreover, miRNA-34a, miRNA-122, and miRNA-192 levels might aid in differentiating NASH from NAFLD. Similar to this, miRNA-21 and miRNA-27 levels in rats were able to distinguish between steatosis and steatohepatitis. High-fat diets enhanced the expression of 15 distinct miRNAs in rats, and there were substantial differences in the miRNA expression patterns between obese and lean people. The results from the present review imply that miRNA microarrays and sequencing may be helpful diagnostic tools, and miRNAs may be a possible treatment target for patients with NAFLD.

Diagnostic Performance of Biomarker-Based Scores as Predictors of Metabolic Dysfunction-Associated Fatty Liver Disease Risk in Healthy Children

INTRODUCTION

Metabolic dysfunction-associated fatty liver disease (MAFLD)-a new definition for non-alcoholic fatty liver disease-reflects the impact of metabolic abnormalities on liver function. We assessed the diagnostic accuracy of biomarker-based scores for prediction of MAFLD in apparently healthy children.

METHODS

This study included 144 children aged 9-11. MAFLD was recognized in 14 girls and 29 boys. Anthropometric indices, glycemia, insulin resistance, lipid profile, enzymes (ALT, AST, GGT, ALP), CRP, N-terminal propeptide of type I procollagen (P1NP) and collagen type I C-telopeptide (CTX-1) levels were measured. Fatty liver and hepatic steatosis index (FLI, HSI) and potential indicators of liver fibrogenesis: P1NP/ALP, P1NP/ALPxALT, P1NP/ALPxCRP were calculated.

RESULTS

P1NP/ALPxALT and P1NP/ALPxCRP were significantly higher in subjects with MAFLD. FLI was a good, significant predictor of MAFLD occurrence, regardless of sex. In boys, P1NP/ALPxCRP was a comparable predictor as CRP (OR 1.14 vs. 1.17; p < 0.001). P1NP/ALPxCRP had better discrimination capability in boys (AUC = 0.79; p < 0.001). However, the use of this algorithm did not improve discriminatory power in comparison to CRP (AUC = 0.81; p < 0.001), but gave a better sensitivity for MAFLD prediction (86% vs. 59%).

CONCLUSIONS

We suggest that P1NP/ALPXCRP is a reliable tool for MAFLD prediction in routine pediatric practice.

Clinical and diagnostic characteristics of non-alcoholic fatty liver disease among Egyptian children and adolescents with type1 diabetes

BACKGROUND

Type 1 diabetes mellitus (T1DM) patients are at an increased risk for non-alcoholic fatty liver disease (NAFLD). This study aimed to evaluate the clinical criteria associated with the diagnosis of Non-Alcoholic Fatty Liver Disease (NAFLD) among T1DM Egyptian children and adolescents.

METHODS

74 T1DM patients aged 8-18 year were enrolled in this cross sectional study. Assessments of Clinical status, anthropometric measures, lipid profile, glycated haemoglobin (HbA1c) and liver enzymes were done. Abdominal Ultrasound evaluation of hepatic steatosis was done. Accordingly, patients were divided into two groups (NAFLD and normal liver group) and compared together. Assessment of liver fibrosis using acoustic radiation force impulse elastography (ARFI) was done. Statistical analysis included; independent t-test, Chi square and Fisher's Exact, Pearson and Spearman tests and Logistic regression models for factors associated with fatty liver were used when appropriate.

RESULTS

In this study; 74 patients were enrolled; 37 males (50%) and 37 females with mean age 14.3 ± 3.0 year. The mean insulin dose was 1.1 ± 0.4 U/kg and mean disease duration was 6.3 ± 3.0 year. NAFLD was detected in 46 cases while 28 cases had normal liver as diagnosed by abdominal ultrasound. Cases with NAFLD had statistically significant higher BMI-Z scores, waist/hip, waist/height and sum of skin fold thicknesses compared to those with normal liver (P < 0.05). The mean value of HbA1c % was significantly higher in NAFLD group (P = 0.003). Total cholesterol, triglycerides and LDL serum levels were significantly elevated (p < 0.05), while the HDL level was significantly lower in NAFLD cases (p = 0.001). Although, serum levels of liver enzymes; ALT and AST were significantly higher among cases with NAFLD than in normal liver group (p < 0.05), their means were within normal. Using the ARFI elastography; NAFLD cases exhibited significant fibrosis (F2, 3 and 4). BMI, patient age and female gender were among risk factors for NAFLD.

CONCLUSIONS

NAFLD represents a serious consequence in type 1 diabetic children and adolescents that deserves attention especially with poor glycemic control. NAFLD has the potential to evolve to fibrosis. This study demonstrated a very high prevalence of NAFLD in T1D children and adolescents using US which was (62.2%) with the percent of liver fibrosis among the NAFLD cases (F2-F4) using ARFI elastography was 26%. BMI, age of patients and female gender were detected as risk factors for NAFLD.

Current Research on the Pathogenesis of NAFLD/NASH and the Gut-Liver Axis: Gut Microbiota, Dysbiosis, and Leaky-Gut Syndrome

Global lifestyle changes have led to an increased incidence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH), requiring further in-depth research to understand the mechanisms and develop new therapeutic strategies. In particular, high-fat and high-fructose diets have been shown to increase intestinal permeability, which can expose the liver to endotoxins. Indeed, accumulating evidence points to a link between these liver diseases and the intestinal axis, including dysbiosis of the gut microbiome and leaky-gut syndrome. Here, we review the mechanisms contributing to these links between the liver and small intestine in the pathogenesis of NAFLD/NASH, focusing on the roles of intestinal microbiota and their metabolites to influence enzymes essential for proper liver metabolism and function. Advances in next-generation sequencing technology have facilitated analyses of the metagenome, providing new insights into the roles of the intestinal microbiota and their functions in physiological and pathological mechanisms. This review summarizes recent research linking the gut microbiome to liver diseases, offering new research directions to elucidate the detailed mechanisms and novel targets for treatment and prevention.

Attenuation Coefficient Measurement Using a High-Frequency (2-9 MHz) Convex Transducer for Children Including Fatty Liver

We evaluated the measurement feasibility and diagnostic ability of an ultrasound-guided attenuation parameter (UGAP) using a high-frequency convex transducer in children. This retrospective study included all consecutive children who underwent abdomen ultrasonography from July to December 2020. Attenuation coefficients (ACs) of the liver were measured using both 1- to 6-MHz (AC1-6) and 2- to 9-MHz (AC2-9) probes of the LOGIQ E10 system (GE Healthcare). t-Tests and Pearson's or partial correlation analyses were performed, and AC cutoff values for diagnosing fatty liver were obtained from receiver operating characteristic curve analyses. Finally, 118 patients (M:F = 83:35, mean age: 10.2 ± 4.1 y) were evaluated, and the measurement success rate was 98.3% (116/118) for AC2-9. AC1-6 was available in children with a liver depth greater than 9 cm. The ratio of interquartile range to median of the AC2-9 was lower than that of the AC1-6 (4.3 vs. 8.5, p < 0.001). In the normal group (n = 41), the AC2-9 values were not associated with age, sex or body mass index. For the evaluation of steatosis, the AC2-9 values exhibited a positive correlation with the MR fat fraction (coefficient = 0.498, p < 0.001). The cutoff value of 0.699 dB/cm/MHz had 90.2% sensitivity and 100% specificity for diagnosing fatty liver. In conclusion, measurements of ACs using a high-frequency convex transducer are feasible even in small children, with lower measurement variability. The AC2-9 values also had good diagnostic performance for pediatric fatty liver.