Clinical use of shear-wave elastography for detecting liver fibrosis in children and adolescents with cystic fibrosis

The effect of elexacaftor-tezacaftor-ivacaftor on liver stiffness in children with cystic fibrosis

OBJECTIVES

Cystic fibrosis hepato-biliary involvement (CFHBI) is a common comorbidity in patients with CF and is associated with increased morbidity and mortality. The effect of the new and highly potent CF transmembrane conductance regulator modulator therapy, elexacaftor-tezacaftor-ivacaftor (ETI), on CFHBI, is still unclear. This study aimed to investigate the impact of ETI on liver stiffness in children with CF, as measured using two-dimensional (2D) shear wave elastography (SWE).

METHODS

Twenty-one children with CF were included in this retrospective study at the CF centre, Skåne University Hospital, Lund, Sweden. Twelve children of our cohort had CFHBI; none had advanced CF liver disease. 2D SWE data from annual assessments, clinical data and liver enzymes were analysed.

RESULTS

We found a significant reduction in liver stiffness after starting treatment with ETI in the total cohort. This reduction in liver stiffness could even be seen in children with CFHBI. Liver enzymes were within the normal range in both pre- and post-ETI therapy in the total cohort. In children with CFHBI, a decline in aspartate aminotransferase activity was observed after ETI was initiated. Lung function and lung clearance index improved significantly after ETI treatment commenced.

CONCLUSION

ETI treatment could positively affect CFHBI in children with CF, as demonstrated by reduced liver stiffness during treatment.

Early detection of hepatobiliary involvement in cystic fibrosis: Biomarkers, radiologic methods, and genetic influences

Cystic fibrosis-related hepatobiliary involvement (CFHBI) is a term used to describe a spectrum of hepatobiliary involvement ranging from a transient elevation of transaminase levels to advanced cystic fibrosis-associated liver disease (aCFLD). While CFHBI is common among people with cystic fibrosis (PwCF), aCFLD is rare impacting only approximately 5%-10% of the CF population. After respiratory/cardiorespiratory issues and transplant-related complications, aCFLD is now the 4th leading cause of mortality among PwCF. Additionally, aCFLD is an independent predictor of all-cause mortality and is associated with significant morbidity. Despite this recognition, our ability to predict those patients at greatest risk for aCFLD, identify early aCFLD, and monitor the incremental progression of CFHBI is lacking. Here, we review the strengths and weaknesses of the common biomarkers and imaging modalities used in the evaluation and monitoring of CFHBI, as well as the current understanding of genetic modifiers related to aCFLD.

WFUMB Guideline/Guidance on Liver Multiparametric Ultrasound: Part 1. Update to 2018 Guidelines on Liver Ultrasound Elastography

The World Federation for Ultrasound in Medicine and Biology (WFUMB) endorsed the development of this document on multiparametric ultrasound. Part 1 is an update to the WFUMB Liver Elastography Guidelines Update released in 2018 and provides new evidence on the role of ultrasound elastography in chronic liver disease. The recommendations in this update were made and graded using the Oxford classification, including level of evidence (LoE), grade of recommendation (GoR) and proportion of agreement (Oxford Centre for Evidence-Based Medicine [OCEBM] 2009). The guidelines are clinically oriented, and the role of shear wave elastography in both fibrosis staging and prognostication in different etiologies of liver disease is discussed, highlighting advantages and limitations. A comprehensive section is devoted to the assessment of portal hypertension, with specific recommendations for the interpretation of liver and spleen stiffness measurements in this setting.

Cystic fibrosis screening, evaluation, and management of hepatobiliary disease consensus recommendations

Cystic fibrosis (CF) may cause a spectrum of hepatobiliary complications, including portal hypertension, multilobular cirrhosis, and liver failure. Current guidelines on the detection and monitoring of hepatobiliary complications in CF were published in 1999. The CF Foundation assembled a committee to evaluate research advances and formulate revised guidelines for CF-associated liver disease. A committee of hepatologists, gastroenterologists, pulmonologists, pharmacists, nurses, dietitians, individuals with CF, and the parents of a child with CF devised "population, intervention, comparison, and outcome" questions regarding hepatobiliary disease in CF. PubMed literature searches were performed for each population, intervention, comparison, and outcome question. Recommendations were voted on with 80% agreement required to approve a recommendation. Public comment on initial recommendations was solicited prior to the formulation of final recommendations. Thirty-one population, intervention, comparison, and outcome questions were assembled, 6401 manuscripts were title screened for relevance, with 1053 manuscripts undergoing detailed full-text review. Seven recommendations were approved for screening, 13 for monitoring of existing disease, and 14 for treatment of CF-associated hepatobiliary involvement or advanced liver disease. One recommendation on liver biopsy did not meet the 80% threshold. One recommendation on screening ultrasound was revised and re-voted on. Through a multidisciplinary committee and public engagement, we have assembled updated recommendations and guidance on screening, monitoring, and treatment of CF-associated hepatobiliary involvement and advanced liver disease. While research gaps remain, we anticipate that these recommendations will lead to improvements in CF outcomes through earlier detection and increased evidence-based approaches to monitoring and treatment.

Prospective study of quantitative liver MRI in cystic fibrosis: feasibility and comparison to PUSH cohort ultrasound

BACKGROUND

Pediatric radiologists can identify a liver ultrasound (US) pattern predictive of progression to advanced liver disease. However, reliably discriminating these US patterns remains difficult. Quantitative magnetic resonance imaging (MRI) may provide an objective measure of liver disease in cystic fibrosis (CF).

OBJECTIVE

The purpose of this study was to determine if quantitative MRI, including MR elastography, is feasible in children with CF and to determine how quantitative MRI-derived metrics compared to a research US.

MATERIALS AND METHODS

A prospective, multi-institutional trial was performed evaluating CF participants who underwent a standardized MRI. At central review, liver stiffness, fat fraction, liver volume, and spleen volume were obtained. Participants whose MRI was performed within 1 year of US were classified by US pattern as normal, homogeneous hyperechoic, heterogeneous, or nodular. Each MRI measure was compared among US grade groups using the Kruskal-Wallis test.

RESULTS

Ninety-three participants (51 females [54.8%]; mean 15.6 years [range 8.1-21.7 years]) underwent MRI. MR elastography was feasible in 87 participants (93.5%). Fifty-eight participants had an US within 1 year of MRI. In these participants, a nodular liver had significantly higher stiffness (P<0.01) than normal or homogeneous hyperechoic livers. Participants with a homogeneous hyperechoic liver had a higher fat fraction (P<0.005) than others.

CONCLUSION

MR elastography is feasible in children with CF. Participants with a nodular pattern had higher liver stiffness supporting the US determination of advanced liver disease. Participants with a homogeneous hyperechoic pattern had higher fat fractions supporting the diagnosis of steatosis.

Ultrasound Elastography in Children

Ultrasound elastography is a novel ultrasound technique, being extensively researched in children in the last decade. It measures tissue elasticity with the observation of tissue response after an external stimulus. From research to clinical practice, ultrasound elastography has evolved significantly in liver fibrosis evaluation in children; however, several other applications of the technique are available in both clinical practice and research environments. Practically, in children any organ can be assessed, including the brain in early ages, along with muscle and connective tissue elasticity evaluation, spleen, kidney, skin, lymphatic tissue, etc. The elastography method, age, body mass index and technical points should be considered when performing ultrasound elastography. This review highlights its vast potential as a diagnostic tool in the pediatric population, where ultrasound is a dominant imaging tool; however, the indications and exam protocol for its clinical use in several fields in pediatrics have yet to be elucidated.

Effects of CFTR modulators on serum biomarkers of liver fibrosis in children with cystic fibrosis

The cystic fibrosis (CF) transmembrane conductance regulator corrector/potentiator combinations lumacaftor/ivacaftor and elexacaftor/tezacaftor/ivacaftor improve sweat chloride, pulmonary function, and nutrition. Yet it is unclear whether they may also impact the progression of liver fibrosis, which is a substantial source of morbidity and mortality for patients with CF. We conducted a retrospective, single-center analysis of children and adolescents with CF treated with lumacaftor/ivacaftor and/or elexacaftor/tezacaftor/ivacaftor therapy, focusing on alterations in liver function tests and fibrosis indices using previously-established thresholds that corresponded with increased liver elastography. In pairwise comparisons of before and during treatment timepoints, we found that those with CF-associated liver involvement experienced significant decreases in gamma-glutamyl transferase, aspartate aminotransferase-to-platelet index, and gamma-glutamyl transferase-to-platelet ratio while on lumacaftor/ivacaftor. These differences were not observed in patients treated with elexacaftor/tezacaftor/ivacaftor, nor were they observed in patients without underlying CF-associated liver disease. These results provide the first evidence that lumacaftor/ivacaftor may improve liver fibrosis in children and adolescents with CF and suggest it may be beneficial in the treatment of CF-associated liver disease.

A novel prediction tool based on shear wave elastography, gallbladder ultrasound, and serum biomarkers for the early diagnosis of biliary atresia in infants younger than 60 days old

Background

Early Kasai surgery before 60 days of life results in better clinical outcomes in patients with biliary atresia (BA). We aimed to develop and validate a prediction tool for the early diagnosis of BA in infants younger than 60 days old.

Methods

This prospective study recruited consecutive infants younger than 60 days old with conjugated hyperbilirubinemia who were evaluated with an ultrasound (US) scan, including B-mode US with color Doppler flow imaging (CDFI) features and liver two-dimensional shear wave elastography (2D SWE), from March 2017 to July 2021. The reference standard for diagnosis was intraoperative cholangiography, liver biopsy, or the resolution of jaundice. Area under the receiver operating characteristic curve (AUC) analysis, logistic regression analysis, and establishment of a nomogram were performed.

Results

A total of 174 patients (mean age, 46 days), including 87 infants with BA and 87 non-BA cholestatic infants, were included in the study. The established nomogram based on gallbladder (GB) abnormality, liver 2D SWE, and serum γ-glutamyl transferase (GGT) and alanine aminotransferase (ALT) had an AUC of 0.99 [95% confidence interval (CI): 0.94-1.00], a sensitivity of 92%, and a specificity of 100%. The nomogram in the validation cohort also had good diagnostic performance in the diagnosis of BA, with an AUC of 0.98 (95% CI: 0.95-1.00).

Conclusions

The new prediction tool had a good diagnostic performance in the early prediction of BA in infants younger than 60 days old and will facilitate timely Kasai surgery.

The Usefulness of Combining Noninvasive Methods for Early Identification and Potential Prevention of Cystic Fibrosis-Associated Liver Disease

Cystic fibrosis-associated liver disease is the third leading cause of morbidity and mortality in patients with cystic fibrosis (CF). Liver damage in the course of CF ranges from biochemical abnormalities to full-blown cirrhosis and may involve complicated processes like inflammation, fibrogenesis, remodeling, apoptosis, and cholestasis. Despite robust research in the field of CF, its complex pathogenesis is not fully understood. Because of the unknown pathogenesis, it is difficult to develop a highly sensitive and specific test or technology that is standardized, acceptable, and available at most pediatric institutions. The Cystic Fibrosis Foundation (CFF) recommends annual blood tests to screen for liver pathology, which often fails to identify early-onset liver disease. In this review article, we present the use of different liver indices and imaging modalities that can help identify liver disease at the onset and may help in its prevention. Although the disease is commonly diagnosed in the pediatric population, due to increased life expectancy, there is increasing evidence of liver disease in adults too. We believe that the tools we present in this review will help in the prevention of liver disease and thereby reduce the associated morbidity and mortality.

Ultrasound elastography in children - nice to have for scientific studies or arrived in clinical routine?

Ultrasound elastography (USE) is a modality that in addition to fundamental B-mode, Doppler, and contrast-enhanced sonography is suitable to make qualitative and quantitative statements about the stiffness of tissues. Introduced more than 20 years ago in adults, USE becomes now a diagnostic tool also in children. The aim of this paper is to describe current available techniques for USE in children. The significance for routine use in children is shown, and further interesting applications are reported.

Comparison of Quantitative Liver US and MRI in Patients with Liver Disease

Background Quantitative US techniques can be used to identify changes of liver disease, but data regarding their diagnostic performance and relationship to MRI measures are sparse. Purpose To define associations between quantitative US and MRI measures of the liver in children, adolescents, and young adults with liver disease and to define the predictive ability of quantitative US measures to detect abnormal liver stiffening and steatosis defined with MRI. Materials and Methods In this prospective study, consecutive patients aged 8-21 years and known to have or suspected of having liver disease and body mass index less than 35 kg/m² underwent 1.5-T MRI and quantitative liver US during the same visit at a pediatric academic medical center between April 2018 and December 2020. Acquired US parameters included shear-wave speed (SWS) and attenuation coefficient, among others. US parameters were compared with liver MR elastography and liver MRI proton density fat fraction (PDFF). Pearson correlation, multiple logistic regression, and receiver operating characteristic curve analyses were performed to assess associations and determine the performance of US relative to that of MRI. Results A total of 44 study participants (mean age, 16 years ± 4 [SD]; age range, 8-21 years; 23 male participants) were evaluated. There was a positive correlation between US SWS and MR elastography stiffness (r = 0.73, P < .001). US attenuation was positively correlated with MRI PDFF (r = 0.45, P = .001). For the prediction of abnormal (>2.8 kPa) liver shear stiffness, SWS (1.56 m/sec [7.3 kPa] cutoff) had an area under the receiver operating characteristic curve (AUC) of 0.95 with 91% sensitivity (95% CI: 71, 99) (20 of 22 participants) and 95% specificity (95% CI: 76, 99) (20 of 21 participants). For the prediction of abnormal (>5%) liver PDFF, US attenuation (0.55 dB/cm/MHz cutoff) had an AUC of 0.75 with a sensitivity of 73% (95% CI: 39, 94) (eight of 11 participants) and a specificity of 73% (95% CI: 55, 86) (24 of 33 participants). Conclusion In children, adolescents, and young adults with known or suspected liver disease, there was moderate to high correlation between US shear-wave speed (SWS) and MR elastography-derived stiffness. US SWS predicted an abnormal liver shear stiffness with high performance. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Khanna and Alazraki in this issue.

Hepatic manifestations of systemic disease: an imaging-based review

The liver is responsible for many processes that maintain human metabolic homeostasis and can be affected by several pediatric systemic diseases. In this manuscript, we explore key pathological findings and imaging features across multiple modalities of a spectrum of congenital, metabolic and autoimmune disorders. Strengthening the radiologists' knowledge regarding potential hepatic manifestations of these systemic diseases will ultimately lead to improved care for pediatric patients.

Comparison of Transient Elastography, ShearWave Elastography, Magnetic Resonance Elastography and FibroTest as routine diagnostic markers for assessing liver fibrosis in children with Cystic Fibrosis

BACKGROUND AND OBJECTIVE

Reliable markers are needed for early diagnosis and follow-up of liver disease in Cystic Fibrosis (CF). The objective was to evaluate the diagnostic performance of Transient Elastography (TE), Real-Time ShearWave Ultrasound Elastography (SWE), Magnetic Resonance Elastography (MRE) and the FibroTest as markers of Cystic Fibrosis Liver Disease (CFLD).

METHODS

A monocentric prospective cross-modality comparison study was proposed to all children (6 to 18 years of age) attending the CF center. Based on liver ultrasound findings, participants were classified into 3 groups: multinodular liver or portal hypertension (Nodular US/PH, advanced CFLD), heterogeneous increased echogenicity (Heterogeneous US, CFLD) or neither (Normal/Homogeneous US, no CFLD). The 4 tests were performed on the same day. The primary outcome was the FibroTest value and liver stiffness measurements (LSM).

RESULTS

55 participants (mean age 12.6 ± 3.3 years; 25 girls) were included between 2015 and 2018: 23 in group Nodular US/PH, 8 in group Heterogeneous US and 24 in group Normal/Homogeneous US (including 4 with steatosis). LSM on TE, SWE and MRE were higher in participants with CFLD (groups Nodular US/PH and Heterogeneous US) compared to others (group Normal/Homogeneous US) (p<0.01), while FibroTest values did not differ (p = 0.09). The optimal cut-off values for predicting CFLD on TE, SWE and MRE were 8.7 (AUC=0.83, Se=0.71, Sp=0.96), 7.8 (AUC=0.85, Se=0.73, Sp=0.96) and 4.15 kPa (AUC=0.68, Se=0.73, Sp=0.64), respectively. LSM predicted the occurrence of major liver-related events at 3 years. TE and SWE were highly correlated (Spearman's ρ=0.9) and concordant in identifying advanced CFLD (Cohen's κ=0.84) while MRE was moderately correlated and concordant with TE (ρ=0.41; κ=36) and SWE (ρ=0.5; κ=0.50).

CONCLUSION

This study demonstrated excellent diagnostic performance of TE, SWE and MRE for the diagnosis of CFLD.

Emerging clinical perspectives in cystic fibrosis liver disease

PURPOSE OF REVIEW

Liver disease (CFLD) as a complication of cystic fibrosis is recognized as a more severe disease phenotype in both children and adults. We review recent advances in understanding the disease mechanism and consider the implications of new strategies for the diagnosis and management of cystic fibrosis in those with evidence of clinically significant liver disease.

RECENT FINDINGS

Evidence suggests that the prevalence of CFLD has not declined with the introduction of newborn screening. Furthermore, children with CFLD, who have been diagnosed with cystic fibrosis following newborn screening continue to have a much higher mortality rate compared with those with no liver disease. There is further data suggesting noncirrhotic obliterative portal venopathy as the predominant pathological mechanism in the majority of children and young adults receiving a liver transplantation. Little progress has been made in developing an accurate noninvasive test for early diagnosis or monitoring disease progression in CFLD. The benefit of new modulator therapies is not well understood in those with established CFLD, whereas the risk of hepatotoxicity as a complication of treatment must be carefully monitored.

SUMMARY

Better understanding of the pathophysiology of CFLD would allow a standardized approach to diagnosis, with the potential to improve outcomes for those with CFLD.

Non-invasive tools for detection of liver disease in children and adolescents with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a multi-organ genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene which encodes the CFTR protein. CF-associated liver disease (CFLD) is a common complication; diagnosis is based on clinical, laboratory findings and abdominal imaging. However, non-invasive diagnostic approaches are needed to early detect CFLD, its progression and severity. Recent studies demonstrate a possible role of point shear wave elastography (p-SWE) with liver stiffness measurement (LSM) as a tool for CFLD diagnosis also in children. This non-invasive technique measures liver stiffness to assess liver fibrosis and is suggested to be less operator-dependent compared to ultrasonography. Aim of our prospective observational study is to investigate the role of p-SWE with LSM for CFLD diagnosis in children and adolescents with CF and to compare this finding with aspartate aminotransferase to platelet ratio index (APRI), fibrosis index based on four factors (FIB-4) and gamma-glutamyl-transpeptidase to platelet ratio (GPR) indices.

METHODS

Fifty-nine children with CF, who had routinely undergone abdominal imaging, were consecutively enrolled. Laboratory findings and clinical data were recorded, as abdominal ultrasound and shear wave elastography at baseline. The cases were divided into two groups based on collected data and classified as CFLD and CFnoLD (without liver disease) according to Debray criteria. APRI, FIB-4 and GPR fibrosis indices were also evaluated.

RESULTS

Twenty-four/59 (40.7%) were defined as CFLD. LSM test is superior to the APRI (P<0.001), the FIB-4 test (P=0.001) and the GPR test for early detection of liver fibrosis. LSM had an area under receiver operating characteristic (ROC) curve =0.818 (95% CI: 0.702-0.934) compared with APRI (0.571, 95% CI: 0.421-0.722), FIB-4 (0.656, 95% CI: 0.511-0.801) and GPR (0.632, 95% CI: 0.485-0.779). At a cut-off of ≥6.2 LSM show a sensitivity of 75.0% and a specificity of 88.6%.

CONCLUSIONS

LSM by transient p-SWE is a non-invasive, highly accessible, reliable, and reproducible test that can be used to assess early detection of liver fibrosis and its severity in children and adolescents with CF, limiting the use of liver biopsy. These preliminary observations point to the need of larger study population to confirm our data.