Intensive treatment and dietary fats in adolescents with nonalcoholic fatty liver disease

The development of the pediatric NAFLD fibrosis score (PNFS) to predict the presence of advanced fibrosis in children with nonalcoholic fatty liver disease

BACKGROUND

Noninvasive hepatic fibrosis scores that predict the presence of advanced fibrosis have been developed and validated in adult patients with NAFLD. The aims of our study were to assess the utility of commonly used adult fibrosis scores in pediatric NAFLD and to develop a pediatric specific fibrosis score that can predict advanced fibrosis.

METHODS

Consecutive children with biopsy-proven NAFLD were included. Fibrosis was determined by an experienced pathologist (F0-4). Advanced fibrosis was defined as fibrosis stage ≥ 3. The following adult fibrosis scores were calculated for each child: AST/ALT ratio, AST/platelet ratio index (APRI), NAFLD fibrosis score (NFS), and FIB-4 Index. Multivariable logistic regression analysis was performed to build a new pediatric model for predicting advanced fibrosis.

RESULTS

Our cohort consisted of 242 children with a mean age of 12.4 ± 3.1 years and 63% were female. 36 (15%) subjects had advanced fibrosis. APRI and FIB-4 were higher in patients with advanced fibrosis compared to those with fibrosis stage 0-2; however, AST/ALT ratio and NFS were not different between the two groups. We used our data to develop a new model to predict advanced fibrosis which included: ALT, alkaline phosphatase, platelet counts and GGT. The multivariable logistic regression model (z) was defined as follows: z = 1.1+(0.34*sqrt(ALT))+(0.002*alkaline phosphatase) - (1.1*log(platelets) - (0.02*GGT). This value was then converted into a probability distribution (p) with a value between 0 to 100 by the following formula: p = 100 × exp(z)/[1+exp(z)]. The AUCROC for this model was 0.74 (95% CI: 0.66, 0.82). This was found to be significantly better than APRI, NAFLD Fibrosis Score and FIB-4 Index.

CONCLUSION

Noninvasive hepatic fibrosis scores developed in adults had poor performance in diagnosing advanced fibrosis in children with NAFLD. We developed a new pediatric NAFLD fibrosis score with improved performance characteristics.

Ultrasonographic quantitative estimation of hepatic steatosis in children With NAFLD

BACKGROUND AND AIMS

The diagnostic accuracy of hepatic ultrasonography (US) for detection and grading of hepatic steatosis in children with suspected nonalcoholic fatty liver disease (NAFLD) remains poorly characterized. The aim of this study was to prospectively evaluate the clinical utility of ultrasonographic quantification of hepatic steatosis.

PATIENTS AND METHODS

Our cohort consisted of 208 consecutive pediatric patients with biopsy-proven NAFLD. Hepatic US was performed within 1 month of the liver biopsy procedure. Steatosis identified by US was scored using a 0 to 3 scale based on echogenicity and visualization of vasculature, parenchyma, and diaphragm, and compared to histological features based on Brunt's classification.

RESULTS

The median age at time of first visit was 10.8 years and 64% were boys. Sixty-nine percent had moderate to severe steatosis on histology. Ultrasonographic steatosis score (USS) had an excellent correlation with histological grade of steatosis (with a Spearman's coefficient of 0.80). The area under the receiver operating characteristic curve for ultrasonographic detection of moderate-to-severe steatosis was 0.87. The USS did not correlate significantly with inflammatory activity or fibrosis stage; however, there was significant correlation with the NAFLD activity score (NAS), albeit this was in large part the result of the strong correlation with the steatosis component of NAS. Serum alanine transaminase and aspartate transaminase were not associated with histological grade of steatosis and showed no correlation with USS.

CONCLUSIONS

Our results, which represent the largest prospective pediatric study evaluating the role of hepatic US in children with biopsy-proven NAFLD, demonstrate the utility of this technique for noninvasive diagnosis and estimation of hepatic steatosis in children.

A combination of the pediatric NAFLD fibrosis index and enhanced liver fibrosis test identifies children with fibrosis

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) encompasses diseases from simple steatosis, to steatohepatitis, to fibrosis, and cirrhosis. The pediatric NAFLD fibrosis index (PNFI) and the enhanced liver fibrosis (ELF) test are potential noninvasive markers for fibrosis. We prospectively evaluated the performance of PNFI and ELF in assessing fibrosis in children with biopsy-proven NAFLD.

METHODS

We analyzed 111 consecutive children with NAFLD. The stage of fibrosis was scored according to the Nonalcoholic Steatohepatitis Clinical Research Network. PNFI was calculated based on age, waist circumference, and levels of triglycerides. The ELF test was used to determine levels of hyaluronic acid, the amino-terminal propeptide of type III collagen, and tissue inhibitor of metalloproteinase-1.

RESULTS

Some degree of fibrosis was detected in 68.5% of patients (62 had stage 1, 5 had stage 2, and 9 had stage 3). PNFI and ELF test values was higher among patients with fibrosis (P < .001). The area under the receiver operating characteristic (ROC) curve for predicting fibrosis using the PNFI and ELF test was 0.761 and 0.924, respectively. The best performance was obtained by combining PNFI and ELF test with (area under the receiver operating characteristic curve = 0.944). The combined results from the PNFI and ELF test predicted the presence or absence of fibrosis in 86.4% of children with NAFLD.

CONCLUSIONS

In children with NAFLD, the combined results from the PNFI and ELF test can accurately assess the presence of liver fibrosis and identify patients that should be evaluated by liver biopsy.