Prominent role of gut dysbiosis in the pathogenesis of cystic fibrosis-related liver disease in mice.

BACKGROUND & AIMS: Cystic fibrosis-related liver disease (CFLD) is a chronic cholangiopathy that increases morbidity and mortality in patients with CF. Current treatments are unsatisfactory, and incomplete understanding of CFLD pathogenesis hampers therapeutic development. We have previously shown that mouse CF cholangiocytes respond to lipopolysaccharide with excessive inflammation. Thus, we investigated the role of the gut-liver axis in the pathogenesis of CFLD. METHODS: Wild-type (WT), whole-body Cftr knockout (CFTR-KO) and gut-corrected (CFTR-KO-GC) mice were studied. Liver changes were assessed by immunohistochemistry and single-cell transcriptomics (single-cell RNA sequencing), inflammatory mediators were analysed by proteome array, faecal microbiota by 16S ribosomal RNA sequencing and gut permeability by FITC-dextran assay. RESULTS: The livers of CFTR-KO mice showed ductular proliferation and periportal inflammation, whereas livers of CFTR-KO-GC mice had no evident pathology. Single-cell RNA sequencing analysis of periportal cells showed increased presence of neutrophils, macrophages and T cells, and activation of pro-inflammatory and pathogen-mediated immune pathways in CFTR-KO livers, consistent with a response to gut-derived stimuli. CFTR-KO mice exhibited gut dysbiosis with enrichment of Enterobacteriaceae and Enterococcus spp., which was associated with increased intestinal permeability and mucosal inflammation, whereas gut dysbiosis and inflammation were absent in CFTR-KO-GC mice. Treatment with nonabsorbable antibiotics ameliorated intestinal permeability and liver inflammation in CFTR-KO mice. Faecal microbiota transfer from CFTR-KO to germ-free WT mice did not result in dysbiosis nor liver pathology, indicating that defective intestinal CFTR is required to maintain dysbiosis. CONCLUSION: Defective CFTR in the gut sustains a pathogenic microbiota, creates an inflammatory milieu, and alters intestinal permeability. These changes are necessary for the development of cholangiopathy. Restoring CFTR in the intestine or modulating the microbiota could be a promising strategy to prevent or attenuate liver disease. IMPACT AND IMPLICATIONS: Severe cystic fibrosis-related liver disease (CFLD) affects 10% of patients with cystic fibrosis (CF) and contributes to increased morbidity and mortality. Treatment options remain limited due to a lack of understanding of disease pathophysiology. The cystic fibrosis transmembrane conductance regulator (CFTR) mediates Cl- and HCO3- secretion in the biliary epithelium and its defective function is thought to cause cholestasis and excessive inflammatory responses in CF. However, our study in Cftr-knockout mice demonstrates that microbial dysbiosis, combined with increased intestinal permeability caused by defective CFTR in the intestinal mucosa, acts as a necessary co-factor for the development of CFLD-like liver pathology in mice. These findings uncover a major role for the gut microbiota in CFLD pathogenesis and call for further investigation and clinical validation to develop targeted therapeutic strategies acting on the gut-liver axis in CF.

Cystic fibrosis liver disease in the new era of cystic fibrosis transmembrane conductance regulator (CFTR) modulators.

Cystic fibrosis liver disease (CFLD) is characterised by a wide heterogenity of manifestations and severity. It represents a major cause of morbidity in people with cystic fibrosis (PwCF), which will be of increasing relevance as survival increases in the new era of cystic fibrosis care. No medical therapy currently available has evidence to treat or prevent progression of liver disease. Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulators may be transformative on pulmonary, nutritional and quality of life, but direct effect on long term liver disease outcomes is not yet established. Drug-associated hepatic adverse effects may be common, and clinician familiarity with drug-monitoring recommendations is essential. Longitudinal studies are required to understand the effect of CFTR modulators on the incidence and natural history of CFLD, including with early treatment initiation, in established advanced liver disease, and post liver transplantation.

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.

Cystic fibrosis-related liver disease: Clinical presentations, diagnostic and monitoring approaches in the era of CFTR modulator therapies.

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population. Cystic fibrosis-related liver disease (CFLD) is defined as the pathogenesis related to the underlying CFTR defect in biliary epithelial cells. CFLD needs to be distinguished from other liver manifestations that may not have any pathological significance. The clinical/histological presentation and severity of CFLD vary. The main histological presentation of CFLD is focal biliary fibrosis, which is usually asymptomatic. Portal hypertension develops in a minority of cases (about 10%) and may require specific management including liver transplantation for end-stage liver disease. Portal hypertension is usually the result of the progression of focal biliary fibrosis to multilobular cirrhosis during childhood. Nevertheless, non-cirrhotic portal hypertension as a result of porto-sinusoidal vascular disease is now identified increasingly more frequently, mainly in young adults. To evaluate the effect of new CFTR modulator therapies on the liver, the spectrum of hepatobiliary involvement must first be precisely classified. This paper discusses the phenotypic features of CFLD, its underlying physiopathology and relevant diagnostic and follow-up approaches, with a special focus on imaging.

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

BACKGROUND: Complications from liver cirrhosis are a leading cause of death in children with cystic fibrosis. Identifying children at risk for developing liver cirrhosis and halting its progression are critical to reducing liver-associated mortality. OBJECTIVE: Quantitative US imaging, such as shear-wave elastography (SWE), might improve the detection of liver fibrosis in children with cystic fibrosis (CF) over gray-scale US alone. We incorporated SWE in our pediatric CF liver disease screening program and evaluated its performance using magnetic resonance (MR) elastography. MATERIALS AND METHODS: Ninety-four children and adolescents with CF underwent 178 SWE exams, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and platelet measurements. Of these, 27 children underwent 34 MR elastography exams. We evaluated SWE performance using 6-MHz and 9-MHZ point SWE, and 9-MHz two-dimensional (2-D) SWE. RESULTS: The 6-MHz point SWE was the only method that correlated with MR elastography (r=0.52; 95% confidence interval [CI] 0.20-0.74; P=0.003). SWE of 1.45 m/s distinguished normal from abnormal MR elastography (79% sensitivity, 100% specificity, 100% positive predictive value [PPV], 55% negative predictive value [NPV], area under the receiver operating characteristic [AUROC] curve 0.94). SWE of 1.84 m/s separated mild-moderate (3.00-4.77 kPa) from severe (>4.77 kPa) MR elastography (88% sensitivity, 86% specificity, 78% PPV, 93% NPV, AUROC 0.79). Elevations of AST, ALT, GGT and thrombocytopenia were associated with higher SWE. AST-to-platelet ratio index of 0.42, fibrosis-4 of 0.29, and GGT-to-platelet ratio of 1.43 all had >95% NPV for SWE >1.84 m/s. CONCLUSION: Given its correlation with MR elastography, SWE might be a clinically useful predictor of liver fibrosis. We identified imaging criteria delineating the use of SWE to identify increased liver stiffness in children with CF. With multicenter validation, these data might be used to improve the detection and monitoring of liver fibrosis in children with CF.

Heterogeneous Liver on Research Ultrasound Identifies Children with Cystic Fibrosis at High Risk of Advanced Liver Disease: Interim Results of a Prospective Observational Case-Controlled Study.

OBJECTIVE: To assess if a heterogeneous pattern on research liver ultrasound examination can identify children at risk for advanced cystic fibrosis (CF) liver disease. STUDY DESIGN: Planned 4-year interim analysis of a 9-year multicenter, case-controlled cohort study (Prospective Study of Ultrasound to Predict Hepatic Cirrhosis in CF). Children with pancreatic insufficient CF aged 3-12 years without known cirrhosis, Burkholderia species infection, or short bowel syndrome underwent a screening research ultrasound examination. Participants with a heterogeneous liver ultrasound pattern were matched (by age, Pseudomonas infection status, and center) 1:2 with participants with a normal pattern. Clinical status and laboratory data were obtained annually and research ultrasound examinations biannually. The primary end point was the development of a nodular research ultrasound pattern, a surrogate for advanced CF liver disease. RESULTS: There were 722 participants who underwent screening research ultrasound examination, of which 65 were heterogeneous liver ultrasound pattern and 592 normal liver ultrasound pattern. The final cohort included 55 participants with a heterogeneous liver ultrasound pattern and 116 participants with a normal liver ultrasound pattern. All participants with at least 1 follow-up research ultrasound were included. There were no differences in age or sex between groups at entry. Alanine aminotransferase (42 ± 22 U/L vs 32 ± 19 U/L; P = .0033), gamma glutamyl transpeptidase (36 ± 34 U/L vs 15 ± 8 U/L; P < .001), and aspartate aminotransferase to platelet ratio index (0.7 ± 0.5 vs 0.4 ± 0.2; P < .0001) were higher in participants with a heterogeneous liver ultrasound pattern compared with participants with a normal liver ultrasound pattern. Participants with a heterogeneous liver ultrasound pattern had a 9.1-fold increased incidence (95% CI, 2.7-30.8; P = .0004) of nodular pattern vs a normal liver ultrasound pattern (23% in heterogeneous liver ultrasound pattern vs 2.6% in normal liver ultrasound pattern). CONCLUSIONS: Research liver ultrasound examinations can identify children with CF at increased risk for developing advanced CF liver disease.

Assessment of liver disease in cystic fibrosis.

Liver disease in cystic fibrosis has many causes, with biliary fibrosis due to abnormal CFTR protein predominating. Assessment requires aetiology to be defined. Biliary fibrosis may progress to cirrhosis and portal hypertension, which although initially asymptomatic, may cause varices and splenomegaly. Monitoring progression includes clinical and ultrasound assessment with endoscopic assessment of varices for those at risk. Extrapolated primarily from longitudinal assessment of viral hepatitis in adults, non-invasive elastography has a potential role. Evidence is lacking to support intervention strategies, but ursodeoxycholic acid and ligation of varices are widely applied. Indication and timing of liver transplantation are not clearly defined. Multidisciplinary approach is needed to tailor assessment and guide management.

Serum Phospholipid Fatty Acid Composition in Cystic Fibrosis Patients with and without Liver Cirrhosis.

BACKGROUND/AIMS: Cystic fibrosis (CF) liver disease is the third most frequent cause of death in CF patients. Although it alters fatty acid (FA) metabolism, data concerning the profile of FA in CF patients with liver cirrhosis is lacking. This study aimed to assess the FA composition of serum phospholipids in CF patients with and without liver cirrhosis. METHODS: The study comprised 25 CF patients with liver cirrhosis and 25 without it. We assessed Z-scores for body height and weight, lung function, exocrine pancreatic sufficiency and colonization with Pseudomonas aeruginosa. FAs' profile of serum glycerophospholipids was quantified by gas chromatography mass spectrometry. RESULTS: In CF patients with liver cirrhosis, the levels of C16:0 were higher and the amounts of C20:2n-6, C20:3n-6, C20:4n-6, and all the n-3 polyunsaturated FAs (PUFAs) (C18:3n-3, C20:5n-3, C22:5n-3, C22:6n-3) were lower than those in CF subjects without liver cirrhosis. The n-6/n-3, C20:4n-6/C18:2n-6, total n-6/C18:2n-6, C20:5n-3/C18:3n-3 and total n-3/C18:3n-3 ratios did not differ between the 2 groups. CONCLUSIONS: Liver cirrhosis may associate with profound abnormalities in the composition of serum glycerophospholipids FAs in CF patients. None of the analyzed clinical factors could explain the greater prevalence of low levels of PUFAs in this CF subgroup.

Multisystemic Effects of Elexacaftor-Tezacaftor-Ivacaftor in Adults with Cystic Fibrosis and Advanced Lung Disease.

Rationale: Limited data exist on the safety and effectiveness of elexacaftor-tezacaftor-ivacaftor (ETI) in people with cystic fibrosis (pwCF) and advanced lung disease. Objectives: To evaluate the effects of ETI in an unselected population of pwCF and advanced lung disease. Methods: A prospective observational study, including all adults aged 18 years and older with percentage predicted forced expiratory volume in 1 second (ppFEV1) ⩽ 40 who initiated ETI from December 2019 to June 2021 in France, was conducted. PwCF were followed until August 8, 2022. Results: ETI was initiated in 434 pwCF with a median ppFEV1 of 30 (interquartile range, 25-35), including 27 with severe cystic fibrosis liver disease and 183 with diabetes. PwCF were followed for a median of 587 (interquartile range, 396-728) days after ETI initiation. Discontinuation of ETI occurred in 12 (2.8%) pwCF and was due mostly to lung transplantation (n = 5) or death (n = 4). Absolute increase in ppFEV1 by a mean of +14.2% (95% confidence interval, 13.1-15.4%) occurred at 1 month and persisted throughout the study. Increase in ppFEV1 in the youngest age quartile was almost twice that of the oldest quartile (P < 0.001); body mass index < 18.5 kg/m2 was found in 38.6% at initiation versus 11.3% at 12 months (P = 0.0001). Increases in serum concentrations of vitamins A and E, but not 25-hydroxy vitamin D3, were observed. Significant reductions in the percentages of pwCF using oxygen therapy, noninvasive ventilation, nutritional support, and inhaled and systemic therapies (including antibiotics) were observed; insulin was discontinued in 12% of patients with diabetes. Conclusions: ETI is safe in pwCF and advanced lung disease, with multisystem pulmonary and extrapulmonary benefits.

Alterations in the fecal microbiota in patients with advanced cystic fibrosis liver disease after 6 months of elexacaftor/tezacaftor/ivacaftor.

BACKGROUND: Cystic fibrosis associated liver disease (CFLD) carries a significant disease burden with no effective preventive therapies. According to the gut-liver axis hypothesis for CFLD pathogenesis, dysbiosis and increased intestinal inflammation and permeability permit pathogenic bacterial translocation into the portal circulation, leading to hepatic inflammation and fibrosis. Evaluating the effect of CFTR (cystic fibrosis transmembrane conductance regulator) modulation with elexacaftor/tezacaftor/ivacaftor (ETI) may help determine the role of CFTR in CFLD and increase understanding of CFLD pathogenesis, which is critical for developing therapies. We aimed to characterize the fecal microbiota in participants with CF with and without advanced CFLD (aCFLD) before and after ETI. METHODS: This is an ancillary analysis of stool samples from participants ages ≥12 y/o enrolled in PROMISE (NCT04038047). Included participants had aCFLD (cirrhosis with or without portal hypertension, or non-cirrhotic portal hypertension) or CF without liver disease (CFnoLD). Fecal microbiota were defined by shotgun metagenomic sequencing at baseline and 1 and 6 months post-ETI. RESULTS: We analyzed 93 samples from 34 participants (11 aCFLD and 23 CFnoLD). Compared to CFnoLD, aCFLD had significantly higher baseline relative abundances of potential pathogens Streptococcus salivarius and Veillonella parvula. Four of 11 aCFLD participants had an initially abnormal fecal calprotectin that normalized 6 months post-ETI, correlating with a significant decrease in S. salivarius and a trend towards decreasing V. parvula. CONCLUSIONS: These results support an association between dysbiosis and intestinal inflammation in CFLD with improvements in both post-ETI, lending further support to the gut-liver axis in aCFLD.

Clinical and genetic risk factors for cystic fibrosis-related liver disease in Egyptian CF children: A single-center experience.

BACKGROUND: Cystic fibrosis (CF) is an autosomal recessive disease. It affects multiple organ systems, including the liver, leading to CF-related liver disease (CFLD). It was noted that CFLD in Egyptian children with CF is more common than in non-Egyptian people with CF (pwCF). This study aimed to determine the incidence of CFLD and the potential risk factors for developing CFLD in Egyptian children. The correlation between CFLD and the various genotypes prevalent in Egyptian CF children will be discussed. In addition, comparison of CFLD in Egyptian and non-Egyptian CF patients will be presented. METHODS: This cross-sectional study included 50 pwCF from Ain Sham University's Pediatric Pulmonology Clinic in Children's Hospital, Cairo, Egypt. The sweat chloride test and genetic studies were done at the time of diagnosis. Additionally, all subjects underwent detailed history taking, laboratory investigations, clinical assessment, and pelvic abdominal ultrasound for evaluation of hepatic involvement. RESULTS: One-third of the Egyptian children with CF were found to have liver disease. The following independent risk factors for developing CFLD were identified as: male sex, severe genetic mutation (class I and II), long duration of CF disease, early onset of the CF, pancreatic insufficiency, as well as history of meconium ileus. In addition, diabetes mellitus and severe lung disease were proven to significantly increase the risk of developing CFLD. CONCLUSION: CFLD is common in Egyptian pwCF. CFLD's risk factors are similar to other reported research from other countries in the region.

Heterogeneous liver on research ultrasound identifies children with cystic fibrosis at high risk of advanced liver disease.

BACKGROUND: This study examines whether heterogeneous (HTG) pattern on liver ultrasound (US) identifies children at risk for advanced cystic fibrosis liver disease (aCFLD). METHODS: Prospective 6-year multicenter case-controlled cohort study. Children with pancreatic insufficient cystic fibrosis (CF) aged 3-12 years without known cirrhosis underwent screening US. Participants with HTG were matched (by age, Pseudomonas infection status and center) 1:2 with participants with normal (NL) US pattern. Clinical status and laboratory data were obtained annually and US bi-annually for 6 years. Primary endpoint was development of nodular (NOD) US pattern consistent with aCFLD. RESULTS: 722 participants underwent screening US, with 65 HTG and 592 NL. Final cohort included 55 HTG and 116 NL with ≥ 1 follow-up US. ALT, AST, GGTP, FIB-4, GPR and APRI were higher, and platelets were lower in HTG compared to NL. HTG had a 9.5-fold increased incidence (95% confidence interval [CI]:3.4, 26.7, p<0.0001, 32.7% vs 3.4%) of NOD versus NL. HTG had a sensitivity of 82% and specificity of 75% for subsequent NOD. Negative predictive value of a NL US for subsequent NOD was 96%. Multivariate logistic prediction model that included baseline US, age, and log(GPR) improved the C-index to 0.90 compared to only baseline US (C-index 0.78). Based on survival analysis, 50% of HTG develop NOD after 8 years. CONCLUSIONS: Research US finding of HTG identifies children with CF with a 30-50% risk for aCFLD. A score based on US pattern, age and GPR may refine the identification of individuals at high risk for aCFLD. CLINICAL TRIAL REGISTRATION: Prospective Study of Ultrasound to Predict Hepatic Cirrhosis in CF: NCT 01,144,507 (observational study, no consort checklist).

The natural history of cystic fibrosis liver disease a prospective cohort study.

BACKGROUND: Our understanding of the natural history of cystic fibrosis liver disease (CFLD) is limited, leading to uncertainty for patients their families and clinicians when liver abnormalities are identified. AIM: to determine the incidence of CFLD, identify risk factors and document the natural history of liver abnormalities in cystic fibrosis (CF). METHODS: The Irish longitudinal study of CFLD (ILSCFLD) prospectively enrolled 95% of children with CF in 2007. Their liver disease status was classified as (i) advanced liver disease with portal hypertension (CFLD). (ii) nonspecific cystic fibrosis liver disease (NSCFLD) (iii) no liver disease (NoLD) RESULTS: 480/522 (91.9%) children were followed for a median 8.53 years IQR 1.28, of whom 35 (7.29%) had CFLD, 110 (22.9%) NSCFLD and 335 (69.79%) had NoLD. At follow-up 28/445 (6.29%) participants without CFLD at baseline, progressed to CFLD (Incidence 7.51/1000 person years (Pyrs) (95%CI 4.99-10.86). Of these 25/28(89.28%) were <10 years. No participant >10 years of age without clinical or radiological evidence of liver disease at baseline progressed to CFLD. During follow-up 18/35(51.43%) participants with CFLD died or received a transplant, MTx rate 7.75/100 Pyrs (95%CI 4.59-12.25) compared to NSCFLD 2.33/100 Pyrs (95%CI 1.44-3.56) and NoLD 1.13/100 Pyrs (95%CI 0.77-1.59). CFLD was an independent risk factor for mortality in CF. Children with CFLD also had a shorter life expectancy. CONCLUSION: The incidence of CFLD was highest in children under10 years. Children over10 years, with normal hepatic function did not develop CFLD. Research to identify the cause and improve outcome should focus on young children.

Effects of elexacaftor/tezacaftor/ivacaftor on liver fibrosis markers in adults with cystic fibrosis.

BACKGROUND: There are limited studies to date on the effects of elexacaftor/tezacaftor/ivacaftor (E/T/I) on markers of liver fibrosis in adults with cystic fibrosis (CF). This study aims to analyse changes in makers of liver fibrosis before and after initiation of E/T/I in CF adults. METHODS: Outcome measures of liver fibrosis, including liver stiffness measurement (LSM) using FibroScan, AST-to-platelet-ratio index (APRI) and gamma-GT-to-platelet-ratio (GPR) were available in 74 CF adults following initiation of E/T/I. This was compared to historical data collected in 2018 prior to UK availability of E/T/I. RESULTS: The median duration of E/T/I therapy at the time liver fibrosis markers were repeated was 21 (IQR: 17-25) months. There was an increase in APRI from historical measurement to follow-up but no change in LSM or GPR. There were no differences in change in fibrosis markers according to CF liver disease (CFLD) status, although those with a raised LSM at baseline (>6.8 kPa) (n = 14) had a significant reduction in LSM from historical measurement to follow-up versus those with a normal historical value (-3.3 kPa vs 0.25 kPa, p < 0.01). CONCLUSIONS: Apart from APRI, we found no changes in liver fibrosis outcomes after initiation of E/T/I in adults with CF. Those with a historical diagnosis of CFLD had no significant worsening or improvement of liver fibrosis markers. We did observe a reduction in LSM in those with liver nodularity, with an initial highest result suggesting a potential positive treatment effect of E/T/I in this category of those with severe CFLD.

Future Comorbidities in an Aging Cystic Fibrosis Population.

Cystic fibrosis (CF) is an autosomal recessive disease due to mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. With the advent of highly effective modulator therapy targeting the abnormal CFTR protein, people with CF (PwCF) are living more than 40 years longer than the pre-modulator therapy era. As a result, PwCF are facing new challenges of managing similar comorbidities affecting the average aging population. While CF is notoriously identified as a chronic respiratory disease, the multisystem presence of the CFTR gene can contribute to other organ-related complications acutely, but also heighten the likelihood of chronic conditions not routinely encountered in this cohort. In this overview, we will focus on risk factors and epidemiology for PwCF as they relate to cardiovascular disease, dyslipidemia, CF-related diabetes, pulmonary hypertension, obstructive sleep apnea, CF-liver disease, bone health and malignancy. With increased awareness of diseases affecting a newly aging CF population, a focus on primary and secondary prevention will be imperative to implementing a comprehensive care plan to improve long-term morbidity and mortality.

Long-term follow-up and liver outcomes in children with cystic fibrosis and nodular liver on ultrasound in a multi-center study.

BACKGROUND: Nodular liver (NOD) in cystic fibrosis (CF) suggests advanced CF liver disease (aCFLD); little is known about progression of liver disease (LD) after detection of sonographic NOD. METHODS: Clinical, laboratory, and ultrasound (US) data from Prediction by Ultrasound of the Risk of Hepatic Cirrhosis in CFLD Study participants with NOD at screening or follow-up were compared with normal (NL). Linear mixed effects models were used for risk factors for LD progression and Kaplan-Meier estimator for time-to-event. RESULTS: 54 children with NOD (22 screening, 32 follow-up) and 112 NL were evaluated. Baseline (BL) and trajectory of forced expiratory volume, forced vital capacity, height/BMI z-scores were similar in NOD vs NL. Platelets were lower in NOD at BL (250 vs 331×103/microL; p < 0.001) and decreased by 8600/year vs 2500 in NL. Mean AST to Platelet Ratio Index (1.1 vs 0.4; p < 0.001), Fibrosis-4 Index (0.4 vs 0.2, p < 0.001), and spleen size z-score (SSZ) [1.5 vs 0.02; p < 0.001] were higher in NOD at BL; SSZ increased by 0.5 unit/year in NOD vs 0.1 unit/year in NL. Median liver stiffness (LSM) by transient elastography was higher in NOD (8.2 kPa, IQR 6-11.8) vs NL (5.3, 4.2-7, p < 0.0001). Over 6.3 years follow-up (1.3-10.3), 6 NOD had esophageal varices (cumulative incidence in 10 years: 20%; 95% CI: 0.0%, 40.0%), 2 had variceal bleeding, and 2 underwent liver transplantation; none had ascites or hepatic encephalopathy. No NL experienced liver-related events. CONCLUSIONS: NOD developed clinically evident portal hypertension faster than NL without worse growth or lung disease.

Lumacaftor-ivacaftor effects on cystic fibrosis-related liver involvement in adolescents with homozygous F508 del-CFTR.

BACKGROUND: The effects of lumacaftor-ivacaftor on cystic fibrosis transmembrane conductance regulator (CFTR)-associated liver disease remain unclear. The objective of the study was to describe the effect of this treatment on features of liver involvement in a cystic fibrosis (CF) adolescent population homozygous for F508del. METHODS: Clinical characteristics, liver blood tests, abdominal ultrasonography (US), and pancreas and liver proton density fat fraction (PDFF) by magnetic resonance imaging, were obtained at treatment initiation and at 12 months for all patients. Biomarkers of CFTR activity (sweat chloride test, nasal potential difference, and intestinal current measurement) were assessed at initiation and at 6 months therapy. RESULTS: Of the 37 patients who started ivacaftor/lumacaftor treatment, 28 were eligible for analysis. In this group, before treatment initiation, 4 patients were diagnosed with multinodular liver and portal hypertension, 19 with other forms of CF liver involvement, and 5 with no signs of liver involvement. During treatment, no hepatic adverse reactions were documented, and no patient developed liver failure. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gammaglutamyl transferase (GGT) decreased significantly following initiation of lumacaftor-ivacaftor, and remained so after 12 months treatment. This was not correlated with changes in clinical status, liver and pancreas US and PDFF, fecal elastase, or lumacaftor-ivacaftor serum levels. The most "responsive" patients demonstrated a significant increase in biomarkers of CFTR activity. CONCLUSIONS: These results may suggest a potential beneficial effect of CFTR modulators on CF liver disease and warrant further investigation in larger, prospective studies.

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.

The impact of liver disease on mortality in cystic fibrosis-A systematic review.

BACKGROUND: There is conflicting evidence on the impact of liver disease (CFLD) on life expectancy in CF. Therefore the aim of this systematic review was to evaluate the impact of liver disease (CFLD) on mortality in CF. METHODS: The protocol was published at (https://hrbopenresearch.org/articles/3-44/v3) using PRISPMA-P guidelines and registered in Prospero 2020 (CRD42020182885). Three databases were searched for publications (1938-2020) where the outcome was all-cause mortality (defined as death and transplantation) or CF-specific mortality in participants with CFLD. Studies with and without a comparator group were included. Studies were divided into 2 groups based on the definition of CFLD: Group 1 used 2 categories of liver disease (i) liver disease with portal hypertension (PH) (ii) non-specific abnormalities which did not meet the criteria for PH, Group 2 studies only included participants with PH. RESULTS: All 14 eligible studies were observational, with a moderate-high risk of bias, Six of the 14 studies directly compared mortality between those with CFLD and those with no liver disease, and 5/6 demonstrated that those with CFLD had at least 3 time the risk of death compared to those with no liver disease. Pulmonary complications were the primary cause of death. CONCLUSION: This SR demonstrates that liver disease shortens life expectancy in CF, and that pulmonary complications are the primary cause of death in those with CFLD. There has been no improvement in survival for persons with CFLD despite significant improvements in life expectancy for persons with CF who have no evidence of liver disease.

Serum bile acids in cystic fibrosis patients - glycodeoxycholic acid as a potential marker of liver disease.

BACKGROUND: Cystic fibrosis (CF) and CF-related liver disease can lead to disturbances in bile acid metabolism. AIM: This study determined serum bile acid concentrations in CF to define their usefulness in liver disease assessment. METHODS: Primary, secondary and conjugated bile acid levels were measured in three CF groups (25 patients each) exhibiting: liver cirrhosis, other liver disease, no liver disease, and in 25 healthy subjects (HS). RESULTS: Bile acid levels were higher in CF patients than in HS, except for glycodeoxycholic acid (GDCA). However, bile acid concentrations did not differ between patients with cirrhosis and other liver involvement. GDCA and deoxycholic acid (DCA) differentiated CF patients with non-cirrhotic liver disease from those without liver disease (GDCA-AUC: 0.924, 95%CI 0.822-1.000, p<0.001; DCA-AUC: 0.867, 95%CI: 0.731-1.000, p<0.001). Principal component analysis revealed that in CF liver disease was related to GDCA, GGTP activity, severe genotype and pancreatic insufficiency. CONCLUSIONS: A CF-specific bile acid profile was defined and shown to relate to liver disease. GDCA differentiates patients with non-cirrhotic liver involvement from those with no detectable liver disease. Hence, GDCA is a candidate for validation as a biomarker of non-cirrhotic progression of liver disease in CF.