Noninvasive assessment of liver fibrosis in pediatric intestinal failure patients using liver stiffness measurement by Vibration-Controlled Transient Elastography

Use of a combined transient elastography and biochemical strategy to determine liver fibrosis in pediatric intestinal failure

BACKGROUND & AIMS

Non-invasive monitoring of intestinal failure (IF) associated liver disease is an ongoing challenge in children with IF. Our objective was to develop a combined algorithm of clinical, transient elastography (TE) and biochemical parameters to identify liver fibrosis in this population.

METHODS

A retrospective cohort study of IF patients followed by our intestinal rehabilitation program between November 2015 to October 2019. Patients with a liver biopsy and TE were included. Demographic and liver function tests were collected. Fibrosis on liver biopsies was graded using the modified Scheuer score. Decision tree based algorithms classified low (F0-F1) versus high (F2-F4) fibrosis scores based on a combination of TE, biochemical and demographic parameters, using 6-fold classification error, sensitivity and specificity cross-validation (CV) scores.

RESULTS

42 patients (74% male, median age 7.6 (4.6; 42.7) months) were evaluated. Median length of PN therapy was 182 (121; 556) days. High fibrosis was present in 40.5% with a median TE of 12.1 (6.7; 12.9) kPa in high fibrosis children. An algorithm, based on cut-off values for TE of 11.3 kPa and AST of 40 U/L, and grouping of the underlying etiology resulted in a correct classification of 88.1% of the pathology scores; with sensitivity 0.82 (95% CI 0.57; 0.96), specificity 0.92 (95% CI 0.74; 0.99), positive predictive value 0.88 (95% CI 0.64; 0.96) and negative predictive value 0.88 (95% CI 0.73; 0.96). The CV classification error was 28.6%, CV sensitivity 72.2% and CV specificity 75.5%.

CONCLUSIONS

This algorithm shows promising results that could simplify non-invasive monitoring of liver fibrosis in children with IF. Validation in additional IF cohorts is needed.

Current short bowel syndrome management: An era of improved outcomes and continued challenges

Prior to the late 1960s, pediatric short bowel syndrome was a frequently fatal disease. Currently, pediatric interdisciplinary bowel rehabilitation centers report very high survival rates. The mortality trends, up-to-date definitions, incidence, causes, and clinical manifestations of short bowel syndrome are reviewed. Emphasis is placed upon the nutritional, medical, and surgical advances that have contributed to the dramatic improvement in outcomes for pediatric short bowel syndrome patients. Recent findings and remaining challenges are highlighted.

IFALD in children: What's new? A narrative review

Intestinal failure-associated liver disease (IFALD) is a progressive liver disease complicating intestinal failure (IF). It is a preventable and reversible condition, but at the same time, a potential cause of liver cirrhosis and an indication to combined or non-combined liver and small bowel transplantation. The diagnostic criteria are not yet standardized, so that its prevalence varies widely in the literature. Pathophysiology seems to be multifactorial, related to different aspects of intestinal failure and not only to the long-term parenteral nutrition treatment. The survival rates of children with IF have increased, so that the main problems today are preventing complications and ensuring a good quality of life. IFALD is one of the most important factors that limit long-term survival of patients with IF. For this reason, more and more interest is developing around it and the number of published articles is increasing rapidly. The purpose of this narrative review was to focus on the main aspects of the etiology, pathophysiology, management, prevention, and treatment of IFALD, based on what has been published mainly in the last 10 years. Controversies and current research gaps will be highlighted with the aim to pave the way for new project and high-quality clinical trials.

Long-term assessment of bilirubin and transaminase trends in pediatric intestinal failure patients during the era of hepatoprotective parenteral nutrition

PURPOSE

This study aimed to characterize the relationship between hepatoprotective parenteral nutrition (PN) dependence and long-term serum liver tests in children with intestinal failure (IF).

METHODS

A retrospective review was performed of children with severe IF (> 90 consecutive days of PN) who were followed from 2012 to 2019 at a multidisciplinary intestinal rehabilitation program. Patients were stratified into three groups based on level of PN dependence at most recent follow up: EN (achieved enteral autonomy), mixed (parenteral and enteral nutrition), and PN (> 75% of caloric intake from PN). PN at any point for this cohort was hepatoprotective, defined as soy-based lipids < 1.5 g/kg/day, combination (soy, medium chain fatty acid, olive and fish oil) lipid emulsion, or fish oil-based lipid emulsion. Kaplan-Meier analysis and a generalized estimating equation (GEE) model were utilized to estimate time to normalization and trends, respectively, of two serum markers of liver health: direct bilirubin (DB) and alanine aminotransferase (ALT).

RESULTS

The study included 123 patients (67 EN, 32 mixed, 24 PN). Median follow up time was 4 years. Based on the Kaplan Meier curve, 100% of EN and mixed group patients achieved normal DB levels by 3 years, while 32% of the PN group had elevated DB levels (Fig. 1). At 5 years, 16% of EN patients had elevated ALT levels compared to 73% of PN patients (p < 0.001, Fig. 2). The PN group's ALT levels were 1.76-fold above normal at 3 years (95%CI 1.48-2.03) and 1.65-fold above normal at 5 years (95%CI 1.33-1.97, Fig. 3).

CONCLUSIONS

While serum bilirubin levels tend to normalize, long-term PN dependence in the era of hepatoprotective PN is associated with a persistent transaminase elevation in an overwhelming majority of patients. These data support continued vigilant monitoring of liver health in children with intestinal failure.

LEVEL OF EVIDENCE

III.

ASPEN definitions in pediatric intestinal failure

Pediatric intestinal failure (PIF) is a relatively rare disease entity which requires focused interdisciplinary care and specialized nutrition management. There has long been a lack of consensus in the definition of key terms related to PIF due to its rarity and plethora of small studies rather than large trials. As such, the American Society for Parenteral and Enteral Nutrition (ASPEN) Pediatric Intestinal Failure Section, composed of clinicians from a variety of disciplines caring for children with intestinal failure, is uniquely poised to provide insight into this definition void. This document is the product of an effort by the Section to create evidence-based consensus definitions, with the goal of allowing for appropriate comparisons between clinical studies and measurement of longterm patient outcomes. This manuscript was approved by the ASPEN Board of Directors. This article is protected by copyright. All rights reserved.

Evaluation of the fibrosis-4 index for detection of advanced fibrosis among individuals at risk for intestinal failure-associated liver disease

BACKGROUND

Intestinal failure-associated liver disease (IFALD) refers to the spectrum of liver injury secondary to IF and parenteral nutrition use. Our aim was to evaluate the use of noninvasive indices of liver fibrosis to detect advanced fibrosis among individuals at risk for IFALD.

METHODS

We performed a secondary analysis of a retrospective study, including all liver biopsies performed on individuals undergoing intestinal transplantation (ITx) between January 2000 and May 2014. To determine the clinical utility of detecting advanced fibrosis, receiver operating characteristic curves were developed. Comparison between the area under the curves was performed by DeLong test.

RESULTS

Fifty-three patients had a liver biopsy performed at the time of ITx; 13 of 53 (24.5%) patients had advanced fibrosis. The fibrosis-4 (FIB-4) index positively correlated to the stage of fibrosis on liver biopsy (r = 0.426, P = .002). When compared against the FIB-4 index, the aspartate aminotransferase to platelet ratio index had a significantly decreased ability to correctly identify the presence of advanced fibrosis (P = .019). When determining the cutoff value with 90% specificity for the detection of advanced fibrosis, a FIB-4 index of ≥4.4 had a sensitivity of 0.462 and a positive predictive value of 0.6.

CONCLUSION

In this retrospective cohort study, we found a positive correlation between the FIB-4 index and the liver fibrosis stage as characterized by the Brunt classification. This evaluation of the FIB-4 index against liver biopsies supports the use of the FIB-4 index in the detection of liver fibrosis in IF.

New insights into the indications for intestinal transplantation

PURPOSE OF REVIEW

To discuss the new guidelines on the indications for intestinal transplantation (ITx) devised in 2019 by the Intestinal Rehabilitation and Transplant Association.

RECENT FINDINGS

Early referral of patients with intestinal failure to expert intestinal rehabilitation/transplant centre is strongly recommended. Listing for a life-saving transplantation is recommended for intestinal failure-associated liver disease (IFALD) evolving to liver failure, invasive intra-abdominal desmoids, acute diffuse intestinal infarction with hepatic failure, re-transplant, and children with loss of at least three of the four upper central venous access sites or with high morbidity intestinal failure. Developments in ITx made the probability of posttransplant survival equal to that on home parenteral nutrition (HPN) and the QoL after successful ITx better than on HPN. However, for patients who have not an actual increased risk of death on HPN, the matter of preemptive listing for ITx is still controversial. For these patients, a careful case-by-case decision is recommended.

SUMMARY

The new guidelines on ITx confirm the straight referral for ITx only for patients at actual risk of death on HPN. Improvements in ITx practice and results, advances in the severity classification of intestinal failure, monitoring of the evolution of IFALD, and measuring patients' QoL are required for an immediate progression in the treatment of intestinal failure.

The prevalence of liver fibrosis according to non-invasive tools in a pediatric home parenteral nutrition cohort

BACKGROUND & AIMS

Liver biopsy is no viable tool to routinely screen for liver fibrosis in children suffering from chronic intestinal failure (IF). We aim to assess the prevalence of liver fibrosis in a cohort of children with chronic IF by non-invasive tests: transient elastography (TE), aspartate-aminotransferase-to-platelet-ratio-index (APRI) and enhanced liver fibrosis (ELF) score.

METHODS

Cross sectional study where patients with chronic IF, receiving parenteral nutrition (PN) for at least 3 months, were enrolled. TE, APRI and ELF score were measured. Using Spearman's rank correlation coefficient and Kruskal-Wallis H test, the correlation between TE, APRI, ELF score and known risk factors for development of intestinal failure-associated liver disease (IFALD) were calculated.

RESULTS

32 patients were included (50% female), median age was 8 years and 4 months, median PN duration was 45 months. Six patients (21%) had TE ≥6.5 kPa, indicating significant fibrosis. Twelve patients (38%) had APRI ≥.5, indicating fibrosis. ELF score indicated moderate fibrosis in 17 patients (63%) and significant fibrosis in 10 patients (37%). TE and APRI correlated significantly with known risk factors for IFALD, but ELF showed poor correlation with known risk factors for IFALD.

CONCLUSION

In a cohort of pediatric patients suffering from chronic IF, TE measurement, APRI and ELF test show a varying, but substantial proportion of subjects with fibrosis. The diagnostic value of these tests and their role in the management of pediatric IF must be determined in larger cohorts with liver biopsy as reference standard.

TRIAL REGISTRATION

Academic Medical Center medical ethics committee number: METC 2017_185.