Prevalence of elevated liver enzymes in children with cystic fibrosis diagnosed by newborn screen

Porcine-derived pancreatic enzyme replacement therapy may be linked to chronic hepatitis E virus infection in cystic fibrosis lung transplant recipients

OBJECTIVES

In high-income countries hepatitis E virus (HEV) is an uncommonly diagnosed porcine-derived zoonoses. After identifying disproportionate chronic HEV infections in persons with cystic fibrosis (pwCF) postlung transplant, we sought to understand its epidemiology and potential drivers.

DESIGN

All pwCF post-transplant attending our regional CF centre were screened for HEV. HEV prevalence was compared against non-transplanted pwCF and with all persons screened for suspected HEV infection from 2016 to 2022 in Alberta, Canada. Those with chronic HEV infection underwent genomic sequencing and phylogenetic analysis. Owing to their swine derivation, independently sourced pancreatic enzyme replacement therapy (PERT) capsules were screened for HEV.

RESULTS

HEV seropositivity was similar between transplanted and non-transplanted pwCF (6/29 (21%) vs 16/83 (19%); p=0.89). Relative to all other Albertans investigated for HEV as a cause of hepatitis (n=115/1079, 10.7%), pwCF had a twofold higher seropositivity relative risk and this was four times higher than the Canadian average. Only three chronic HEV infection cases were identified in all of Alberta, all in CF lung transplant recipients (n=3/29, 10.3%). Phylogenetics confirmed cases were unrelated porcine-derived HEV genotype 3a. Ninety-one per cent of pwCF were taking PERT (median 8760 capsules/person/year). HEV RNA was detected by RT-qPCR in 44% (47/107) of PERT capsules, and sequences clustered with chronic HEV cases.

CONCLUSION

PwCF had disproportionate rates of HEV seropositivity, regardless of transplant status. Chronic HEV infection was evident only in CF transplant recipients. HEV may represent a significant risk for pwCF, particularly post-transplant. Studies to assess HEV incidence and prevalence in pwCF, and potential role of PERT are required.

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.

Advanced cystic fibrosis liver disease: Endovascular, endoscopic, radiologic, and surgical considerations

Up to 90% of people with CF (pwCF) will have some form of hepatobiliary involvement. This manuscript aims to explore the different endovascular, endoscopic, radiological and surgical procedures available to diagnose and manage the most severe form of CF hepatobiliary involvement (CFHBI) known as advanced cystic fibrosis liver disease (aCFLD), seen in 10% of pwCF. These procedures and interventions include liver biopsy, hepatic venous pressure gradient measurement, gastrostomy tube placement to optimize nutrition, paracentesis, endoscopic variceal control of bleeding and portosystemic shunting before liver transplantation. By utilizing advanced diagnostic or surgical techniques, healthcare professionals of pwCF can more effectively manage patients with CFHBI and aCFLD and potentially improve patient outcomes.

Pathophysiology of Cystic Fibrosis Liver Disease

Hepatobiliary complications of Cystic Fibrosis (CF) constitute a significant burden for persons with CF of all ages, with advanced CF liver disease in particular representing a leading cause of mortality. The causes of the heterogeneity of clinical manifestations, ranging from steatosis to focal biliary cholestasis and biliary strictures, are poorly understood and likely reflect a variety of environmental and disease-modifying factors in the setting of underlying CFTR mutations. This review summarizes the current understanding of the pathophysiology of hepatobiliary manifestations of CF, and discusses emerging disease models and therapeutic approaches that hold promise to impact this important yet incompletely addressed aspect of CF care.

Cystic fibrosis hepatobiliary involvement: an update on imaging in diagnosis and monitoring

Analysis of the liver using imaging for persons with cystic fibrosis (CF) continues to evolve as new medical therapies are developed improving and extending life. In the 2010s, therapies targeted at modulating protein folding became available to those with CF. Therapeutic options have continued to expand, now providing both correction of protein folding and stabilization for most gene mutations that code for the CF transmembrane receptor protein (CFTR). Today, approximately 80% of persons with CF are eligible for highly effective modulator therapy. With these advancements, the impact of CF on the liver has become more complex, adding metabolism of CFTR modulators to intrinsic CF hepatobiliary involvement (CFHBI) and adding not previously appreciated vascular changes within the liver due to increased longevity in persons with CF. A combination of serum biomarkers and imaging is needed to add clarity to the diagnosis and monitoring of the severity of liver disease. A substantial portion of persons with CF will develop at least CFHBI and a subset will develop advanced cystic fibrosis-associated liver disease (aCFLD); therefore, diagnosis and monitoring need to begin in childhood. In this review, we cover the use of and need for imaging, including elastography, ultrasound, and magnetic resonance imaging (MRI), in diagnosing and monitoring CFHBI and its associated complications.

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.

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.

Diagnosis, Management, and Prognosis of Cystic Fibrosis-Related Liver Disease in Children

Cystic fibrosis (CF) is a multifaceted disorder predominantly investigated for its pulmonary manifestations, yet patients with CF also exhibit a spectrum of extrapulmonary manifestations, notably those involving the hepatobiliary system. The latter constitutes the third leading cause of morbidity and mortality in individuals with CF. Cystic fibrosis-related liver disease (CFLD), with an escalating prevalence, manifests diverse clinical presentations ranging from hepatomegaly to cirrhosis and hepatopulmonary syndrome. Consequently, early detection and appropriate management are imperative for sustaining the health and influencing the quality of life of CF patients afflicted with CFLD. This review aims to consolidate existing knowledge by providing a comprehensive overview of hepatobiliary manifestations associated with CF. It delineates the clinical hepatobiliary manifestations, diagnostic methodologies, incorporating minimally invasive markers, and therapeutic approaches, encompassing the impact of novel CFTR modulators on CFLD. Given the exigency of early diagnosis and the intricate management of CFLD, a multidisciplinary team approach is essential to optimize care and enhance the quality of life for this subset of patients. In conclusion, recognizing CF as more than solely a pulmonary ailment, the authors underscore the imperative for further clinical investigations to establish a more robust evidence base for CFLD management within the continuum of this chronic disease.

Liver magnetic resonance elastography and fat fraction in pediatric patients with cystic fibrosis versus healthy children

BACKGROUND

Liver involvement is an important cause of morbidity and mortality in patients with cystic fibrosis (CF). While liver biopsy is the gold standard for demonstrating involvement, its invasiveness prompts a search for noninvasive alternatives.

OBJECTIVE

To evaluate liver involvement in pediatric patients with CF (versus healthy controls) using magnetic resonance (MR) elastography/spectroscopy and to correlate the imaging findings with clinical/laboratory characteristics.

MATERIALS AND METHODS

This was a single-center, prospective cross-sectional study conducted between April 2020 and March 2022 in patients with CF versus healthy controls. Patients with CF were divided into two subgroups: those with CF-related liver disease and those without. MR images were acquired on a 1.5-tesla machine. Kilopascal (kPa) values were derived from processing MR elastography images. MR spectroscopy was used to measure liver fat fraction, as an indication of hepatosteatosis. Groups were compared using either the Student's t test or the Mann‒Whitney U test. The chi-square test or Fisher's exact test were used to compare qualitative variables.

RESULTS

Fifty-one patients with CF (12 ± 3.3 years, 32 boys) and 24 healthy volunteers (11.1 ± 2.4 years, 15 boys) were included in the study. Median liver stiffness (P=0.003) and fat fraction (P=0.03) were higher in the CF patients than in the controls. Median liver stiffness values were higher in CF patients with CF-related liver disease than in those without CF-related liver disease (P=0.002). Liver stiffness values of CF patients with high alanine aminotransferase (ALT), high gamma-glutamyl transferase, and thrombocytopenia were found to be higher than those without (P=0.004, P<0.001, P<0.001, respectively). Only the high ALT group showed a high fat fraction (P=0.002).

CONCLUSIONS

Patients with CF had higher liver stiffness than the control group, and patients with CF-related liver disease had higher liver stiffness than both the CF patients without CF-related liver disease and the control group. Patients with CF had a higher fat fraction than the control group. Noninvasive assessment of liver involvement using MR elastography/spectroscopy can support the diagnosis of CF-related liver disease and the follow-up of patients with CF.

Intrahepatic Cholangiolitis in Cystic Fibrosis (ICCF): An Under-Appreciated Cause of Persistent Cholestasis in Infancy

Liver histology in infants with cystic fibrosis (CF) and persistent cholestasis is seldom reported in detail. We extend previous observation of a distinctive intrahepatic cholangiopathy (ICCF) to 3 additional infants homozygous for CFTR pathological variants and a fourth infant with a heterozygous CFTR variant, summarizing our experience in 10 infants with CFTR variants and persistent cholestasis. Cholangiograms demonstrate abnormal extrahepatic ducts in 2 infants with CF, 1 with uniform dilatation interpreted as a choledochal cyst and the other with narrow patent ducts. Liver histology in 3 CF homozygotes had prominent ductular reaction with a focally destructive cholangiolitis (inflammation of small bile ducts). The CFTR heterozygote had generalized portal edema with ductular reaction and paucity but no cholangitis. Cholestasis slowly subsided in all infants. ICCF is characterized by severe ductular reaction, prominent cholangiocyte injury, and multifocal necrotizing cholangiolitis. Local aggregates of portal ceroid might suggest previous bile leakage from damaged ducts. ICCF in liver biopsies from infants with cystic fibrosis and persistent cholestasis is unrelated to the specific CFTR genotype. Liver biopsy findings and intraoperative cholangiogram help rule out biliary atresia. ICCF is an early manifestation of CF, a likely prototype for pathogenesis of cystic fibrosis liver disease later in life.

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.

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).

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.

Cystic fibrosis related liver disease and endocrine considerations

Cystic fibrosis-liver disease (CFLD) is one of the most common non-pulmonary complications in the CF population, is associated with significant morbidity and represents the third leading cause of mortality in those with CF. CFLD encompasses a broad spectrum of hepatobiliary manifestations ranging from mild transaminitis, biliary disease, hepatic steatosis, focal biliary cirrhosis and multilobular biliary cirrhosis. The diagnosis of CFLD and prediction of disease progression remains a clinical challenge. The identification of novel CFLD biomarkers as well as the role of newer imaging techniques such as elastography to allow for early detection and intervention are active areas of research focus. Biliary cirrhosis with portal hypertension represents the most severe spectrum of CFLD, almost exclusively develops in the pediatric population, and is associated with a decline in pulmonary function, poor nutritional status, and greater risk of hospitalization. Furthermore, those with CFLD are at increased risk for vitamin deficiencies and endocrinopathies including CF-related diabetes, CF-related bone disease and hypogonadism, which can have further implications on disease outcomes and management. Effective treatment for CFLD remains limited and current interventions focus on optimization of nutritional status, identification and treatment of comorbid conditions, as well as early detection and management of CFLD specific sequelae such as portal hypertension or variceal bleeding. The extent to which highly effective modulator therapies may prevent the development or modify the progression of CFLD remains an active area of research. In this review, we discuss the challenges with defining and evaluating CFLD and the endocrine considerations and current management of CFLD.

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.

Recent advances in the early treatment of cystic fibrosis: Bridging the gap to highly effective modulator therapy

Highly effective modulator therapy (HEMT) for cystic fibrosis (CF) has been touted as one of the greatest advances to date in CF care. As these therapies are now available for many older children and adults with CF, marked improvement of their nutritional status, pulmonary and gastrointestinal symptoms has been observed. However, most infants and younger children are not current candidates for HEMT due to age and/or cystic fibrosis transmembrane conductance regulator (CFTR) mutation. For these young children, it is essential to provide rigorous monitoring and care to avoid potential disease sequelae while awaiting HEMT availability. The following article highlights recent advances in the care of infants and young children with CF with regard to surveillance and treatment of nutritional, pulmonary, and gastrointestinal disorders. Recent clinical trials in this population are also reviewed.

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.

Early intrahepatic duct defects in a cystic fibrosis porcine model

Hepatobiliary disease causes significant morbidity and mortality in people with cystic fibrosis (CF), yet this problem remains understudied. Previous studies in the newborn CF pig demonstrated decreased bile flow into the small intestine and a microgallbladder with increased luminal mucus and fluid secretion defects. In this study, we examined the intrahepatic bile ducts of the newborn CF pig. We assessed whether our findings from the gallbladder are present elsewhere in the porcine biliary tract and if CF pig cholangiocytes have fluid secretion defects. Immunohistochemistry demonstrated apical CFTR expression in non-CF pig intrahepatic bile ducts of a variety of sizes; CF pig intrahepatic bile ducts lacked CFTR expression. Assessment of serum markers did not reveal significant signs of hepatobiliary disease except for an elevation in direct bilirubin. Quantitative histology demonstrated that CF pigs had smaller bile ducts that more frequently contained luminal mucus. CF intrahepatic cholangiocyte organoids were smaller and lacked cAMP-mediated fluid secretion. Together these data suggest that cholangiocyte fluid secretion is decreased in the CF pig, contributing to structural changes in bile ducts and decreased biliary flow.

Pancreas transplantation for cystic fibrosis: A frequently missed opportunity

Cystic fibrosis (CF) is an inherited autosomal recessive disorder. Despite optimized therapy, the majority of affected individuals ultimately die of respiratory failure. As patients with CF are living longer, extra-pulmonary manifestations may develop including pancreatic failure, which manifests as exocrine insufficiency, and CF-related diabetes (CFRD). Both of these can be managed through pancreas transplantation. Pancreas transplantation is usually performed in combination with another organ, most often with a kidney transplant for end-stage diabetic nephropathy. In the CF patient population, the two settings where inclusion of a pancreas transplant should be considered would be in combination with a lung transplant for CF pulmonary disease, or in combination with a liver for CF-related liver disease with cirrhosis. This report will discuss this topic in detail, including a review of the literature regarding combinations of lung/pancreas and liver/pancreas transplant.

Long-term safety of lumacaftor-ivacaftor in children aged 2-5 years with cystic fibrosis homozygous for the F508del-CFTR mutation: a multicentre, phase 3, open-label, extension study

BACKGROUND

A previous phase 3 study showed that lumacaftor-ivacaftor was generally safe and well tolerated over 24 weeks of treatment in children aged 2-5 years with cystic fibrosis homozygous for the F508del-CFTR mutation. In this study, we aimed to assess the long-term safety of lumacaftor-ivacaftor in a rollover study of children who participated in this previous phase 3 study.

METHODS

In this multicentre, phase 3, open-label, extension study (study 116; VX16-809-116), we assessed safety of lumacaftor-ivacaftor in children included in a previous multicentre, phase 3, open-label study (study 115; VX15-809-115). The study was done at 20 cystic fibrosis care centres in the USA and Canada. Children aged 2-5 years with cystic fibrosis homozygous for the F508del-CFTR mutation who completed 24 weeks of lumacaftor-ivacaftor treatment in study 115 received weight-based and age-based doses of oral lumacaftor-ivacaftor: children weighing less than 14 kg and aged younger than 6 years at study 116 screening received lumacaftor 100 mg-ivacaftor 125 mg every 12 h; children weighing 14 kg or more and aged younger than 6 years at screening received lumacaftor 150 mg-ivacaftor 188 mg every 12 h; and children aged 6 years or older received lumacaftor 200 mg-ivacaftor 250 mg every 12 h. Children received treatment for up to 96 weeks, equivalent to up to 120 weeks of treatment in total from the start of study 115 to completion of study 116. The primary endpoint was the safety and tolerability of the study drug in all participants who had received lumacaftor-ivacaftor for 24 weeks in study 115 and had received at least one dose in study 116. Secondary endpoints included change from baseline in study 115 at week 96 of study 116 in sweat chloride concentration, growth parameters, markers of pancreatic function, and lung clearance index (LCI) parameters in all children who received at least one dose of lumacaftor-ivacaftor in study 116. This study is registered with ClinicalTrials.gov, NCT03125395.

FINDINGS

This extension study ran from May 12, 2017, to July 17, 2019. Of 60 participants enrolled and who received lumacaftor-ivacaftor in study 115, 57 (95%) were included in study 116 and continued to receive the study drug. A total of 47 (82%) of 57 participants completed 96 weeks of treatment. Most participants (56 [98%] of 57) had at least one adverse event during study 116, most of which were mild (19 [33%] participants) or moderate (29 [51%] participants) in severity. The most common adverse events were cough (47 [82%] participants), nasal congestion (25 [44%] participants), pyrexia (23 [40%] participants), rhinorrhoea (18 [32%] participants), and vomiting (17 [30%] participants). A total of 15 (26%) participants had at least one serious adverse event; most were consistent with underlying cystic fibrosis or common childhood illnesses. Respiratory adverse events occurred in five (9%) participants, none of which were serious or led to treatment discontinuation. Elevated aminotransferase concentrations, most of which were mild or moderate in severity, occurred in ten (18%) participants. Three (5%) participants discontinued treatment due to adverse events (two due to increased aminotransferase concentrations [one of whom had concurrent pancreatitis], considered as possibly related to study drug; and one due to gastritis and metabolic acidosis, considered unlikely to be related to study drug). No clinically significant abnormalities or changes were seen in electrocardiograms, vital signs, pulse oximetry, ophthalmological examinations, or spirometry assessments. Improvements in secondary endpoints observed in study 115 were generally maintained up to week 96 of study 116, including improvements in sweat chloride concentration (mean absolute change from study 115 baseline at week 96 of study 116 -29·6 mmol/L [95% CI -33·7 to -25·5]), an increase in growth parameters and pancreatic function, and stable lung function relative to baseline, as measured by the LCI.

INTERPRETATION

Lumacaftor-ivacaftor was generally safe and well tolerated, and treatment effects were generally maintained for the duration of the extension study. These findings support the use of lumacaftor-ivacaftor for up to 120 weeks in young children with cystic fibrosis aged 2 years and older homozygous for the F508del-CFTR mutation.

FUNDING

Vertex Pharmaceuticals Incorporated.

Gastrointestinal, Pancreatic, and Hepatic Manifestations of Cystic Fibrosis in the Newborn

Gastrointestinal, pancreatic, and hepatic signs and symptoms represent the most common presentation of early disease among patients with cystic fibrosis and may be the initial indication of disease. Regardless of whether cystic fibrosis is diagnosed early by newborn screening or later by clinical course, the impact of gastrointestinal, pancreatic, and hepatic manifestations on early life is nearly ubiquitous. Conditions strongly linked with cystic fibrosis, such as meconium ileus and pancreatic insufficiency, must be recognized and treated early to optimize both short- and long-term care. Similarly, less specific conditions such as reflux, poor weight gain, and cholestasis are frequently encountered in infants with cystic fibrosis. In this population, these conditions may present unique challenges in which early interventions may have significant influence on both short- and long-term morbidity and mortality outcomes.

Clinical features and accompanying findings of Pseudo-Bartter Syndrome in cystic fibrosis

BACKGROUND

Pseudo-Bartter syndrome (PBS) is a rare complication of cystic fibrosis (CF) and there are limited data in the literature about it. We aimed to compare clinical features and accompanying findings of patients with PBS in a large patient population.

METHODS

The data were collected from the Cystic Fibrosis Registry of Turkey where 1170 CF patients were recorded in 2017. Clinical features, diagnostic test results, colonization status, complications, and genetic test results were compared in patients with and without PBS.

RESULTS

Totally 1170 patients were recorded into the registry in 2017 and 120 (10%) of them had PBS. The mean age of diagnosis and current age of patients were significantly younger and newborn screening positivity was lower in patients with PBS (P < .001). There were no differences between the groups in terms of colonization status, mean z-scores of weight, height, BMI, and mean FEV₁ percentage. Types of genetic mutations did not differ between the two groups. Accompanying complications were more frequent in patients without PBS.

CONCLUSION

PBS was detected as the most common complication in the registry. It could be due to warm weather conditions of our country. It is usually seen in younger ages regardless of mutation phenotype and it could be a clue for early diagnosis of CF.

A longitudinal assessment of non-invasive biomarkers to diagnose and predict cystic fibrosis-associated liver disease

BACKGROUND & AIMS

A practical, inexpensive, and non-invasive biomarker of liver fibrosis is needed as a reliable screening test for cystic fibrosis-associated liver disease (CFLD). Studies have shown the utility of AST to Platelet Ratio Index (APRI), fibrosis index based on 4 factors (FIB-4), and gamma-glutamyl transferase (GGT) as good biomarkers for identifying CFLD. The goal of the study was to evaluate the effectiveness of APRI, FIB-4, AST/ALT ratio, platelet count, GGT, and GGT platelet ratio (GPR) in predicting CFLD development.

METHODS

Data was collected from CF Foundation Patient Registry for patients aged 3-21 years at Johns Hopkins from January 1, 2002 to December 31, 2014. Collected data included demographic characteristics, presence of splenomegaly, hepatomegaly, ascites, and variceal bleeding, AST, ALT, GGT, platelet count, and FEV₁. The sensitivity and specificity of each biomarker were analyzed and reported by the area under receiver operating characteristic (AUROC) curve.

RESULTS

By the end of the study, 144 "healthy" CF, 12 CFLD, 19 CF-associated pulmonary disease (CFPD), and 4 CFLD with CFPD cases were identified. APRI scores were higher in CFLD, 0.85 versus 0.28 in "healthy" CF and 0.23 in CFPD groups (p<0.001). GPR had the highest AUROC curve at 0.91.

CONCLUSIONS

GPR, GGT, APRI score, and platelet count were potentially useful biomarkers while FIB-4 did not predict CFLD development. Cost-effectiveness studies are needed to analyze the utility of these biomarkers in clinical practice.

Hepatic manifestations of cystic fibrosis

PURPOSE OF REVIEW

Liver disease in cystic fibrosis (CF) usually develops before puberty, is often asymptomatic and slowly progressive. Multilobular cirrhosis develops in approximately 5-10% of patients by the age of 18, and is a significant contributor to the morbidity and mortality. No therapy, including ursodeoxycholic acid and cystic fibrosis transmembrane conductance regulator correctors or potentiators, has proven effective to prevent or halt the progression of liver disease towards cirrhosis and portal hypertension. This review provides the current knowledge in the epidemiology of CF liver disease and development of noninvasive tools to assess liver disease severity and progression overtime in order to optimize clinical management and therapeutic options.

RECENT FINDINGS

Liver disease not only develops during childhood but also later in the lifetime of patients with CF; the incidence of cirrhosis with portal hypertension increases progressively reaching 10% by age 30. Several noninvasive tools to measure liver stiffness as an indirect measure of fibrosis are being investigated, and show promising results for the assessment of early stages of liver fibrosis and disease progression.

SUMMARY

Identifying noninvasive biomarkers is fundamental to improving early diagnosis, monitoring disease evolution and measuring treatment effects. A prerequisite is the use of consistent definitions for CF- liver disease (LD) in clinical trials.

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.

Liver Ultrasound Patterns in Children With Cystic Fibrosis Correlate With Noninvasive Tests of Liver Disease

OBJECTIVES

Early identification of children with cystic fibrosis (CF) at risk for severe liver disease (CFLD) would enable targeted study of preventative therapies. There is no gold standard test for CFLD. Ultrasonography (US) is used to identify CFLD, but with concerns for its diagnostic accuracy. We aim to determine if differences in standard blood tests, imaging variables and noninvasive liver fibrosis indices correlate with liver US patterns, and thus provide supportive evidence that a heterogeneous US liver pattern reflects clinically relevant liver disease.

METHODS

We studied baseline research abdominal US and bloodwork from 244 children with pancreatic insufficient CF, ages 3 to 12 years, enrolled in a prospective study of the ability of US to predict CF cirrhosis (PUSH study). Children with a heterogeneous (HTG) liver pattern on US (n = 62) were matched 1 : 2 in design with children with normal US (NL, n = 122). Analyses included children with nodular (NOD, n = 22) and homogeneous hyperechoic (HMG, n = 38) livers.

RESULTS

Univariate analysis showed significant differences between US groups for standard blood tests, spleen size, and noninvasive liver fibrosis indices. Multivariable models discriminated NOD versus NL with excellent accuracy (AUROC 0.96). Models also distinguish HTG versus NL (AUROC 0.76), NOD versus HTG (0.78), and HMG versus NL (0.79).

CONCLUSIONS

Liver US patterns in children with CF correlate with platelet count, spleen size and indices of liver fibrosis. Multivariable models of these biomarkers have excellent discriminating ability for NL versus NOD, and good ability to distinguish other US patterns, suggesting that US patterns correlate with clinically relevant liver disease.

Cystic fibrosis liver disease: A condition in need of structured transition and continuity of care

Liver disease affects one-third of patients with cystic fibrosis (CF) and it is one of the major causes of morbidity and mortality in these patients. Historically considered a disease of childhood, its impact is now seen more often in adulthood. The heterogeneous pattern of CF liver disease and its rapid progression to cirrhosis remain a diagnostic challenge and new questions pertaining to the nature of liver involvement have recently been raised. Non-invasive measures to stratify the severity of liver involvement are increasingly used to predict clinical outcomes. A single treatment, ursodeoxycholic acid, has been used to slow progression of liver disease while recent advances in the field of CF treatments are promising. Management of portal hypertension remains challenging but outcomes after liver transplantation are encouraging. While many questions remain unanswered, a growing number of CF patients reach adulthood and will require care for CF liver disease.

Hepatic Manifestations of Cystic Fibrosis

Cystic fibrosis liver disease (CFLD) remains the third leading cause of death in patients with cystic fibrosis. Although most patients with CFLD present in childhood, recent studies suggest a second wave of liver disease in adulthood. There are no clear guidelines for diagnosing CFLD. Treatment options for CFLD remain limited, and while UDCA is widely used, its long-term benefit is unclear. Those who develop hepatic decompensation or uncontrolled variceal bleeding may benefit from liver transplant, either alone, or in combination with lung transplant.

An open-label extension study of ivacaftor in children with CF and a CFTR gating mutation initiating treatment at age 2-5 years (KLIMB)

BACKGROUND

KIWI (NCT01705145) was a 24-week, single-arm, pharmacokinetics, safety, and efficacy study of ivacaftor in children aged 2 to 5 years with cystic fibrosis (CF) and a CFTR gating mutation. Here, we report the results of KLIMB (NCT01946412), an 84-week, open-label extension of KIWI.

METHODS

Children received age- and weight-based ivacaftor dosages for 84 weeks. The primary outcome was safety. Other outcomes included sweat chloride, growth parameters, and measures of pancreatic function.

RESULTS

All 33 children who completed KIWI enrolled in KLIMB; 28 completed 84 weeks of treatment. Most adverse events were consistent with those reported during KIWI. Ten (30%) children had transaminase elevations >3 × upper limit of normal (ULN), leading to 1 discontinuation in a child with alanine aminotransferase >8 × ULN. Improvements in sweat chloride, weight, and body mass index z scores and fecal elastase-1 observed during KIWI were maintained during KLIMB; there was no further improvement in these parameters.

CONCLUSIONS

Ivacaftor was generally well tolerated for up to 108 weeks in children aged 2 to 5 years with CF and a gating mutation, with safety consistent with the KIWI study. Improvements in sweat chloride and growth parameters during the initial 24 weeks of treatment were maintained for up to an additional 84 weeks of treatment. Prevalence of raised transaminases remained stable and did not increase with duration of exposure during the open-label extension.

Ivacaftor treatment of cystic fibrosis in children aged 12 to <24 months and with a CFTR gating mutation (ARRIVAL): a phase 3 single-arm study

BACKGROUND

Ivacaftor is generally safe and effective in patients aged 2 years and older who have cystic fibrosis and specific CFTR mutations. We assessed its use in children aged 12 to <24 months.

METHODS

The ARRIVAL study is a phase 3, single-arm, two-part, multicentre study. Eligible children were aged 12 to <24 months at enrolment and had a confirmed diagnosis of cystic fibrosis and a CFTR gating mutation on at least one allele and could participate in one or both parts of the study. Children received 50 mg (bodyweight 7 to <14 kg) or 75 mg (bodyweight ≥14 to <25 kg) ivacaftor orally every 12 h. In study part A, children received ivacaftor for 3 days plus one morning. In study part B, children received 24 weeks of treatment. Children were enrolled into part A at seven sites in Australia (one site), the UK (one), and the USA (five) and into part B at 13 sites in Australia (two sites), Canada (one), the UK (three), and the USA (seven). Primary endpoints were pharmacokinetics (part A) and safety (parts A and B) in children who received at least one dose of ivacaftor. Secondary endpoints in part B were pharmacokinetics in children who received at least one dose of ivacaftor and absolute change from baseline in sweat chloride concentration. We also explored changes in growth parameters and markers of pancreatic function. This study is registered with ClinicalTrials.gov, number NCT02725567.

FINDINGS

Children aged 12 to <24 months were enrolled between Aug 25, 2016, and Nov 1, 2017. Seven children were enrolled in part A, of whom five received 50 mg and two received 75 mg ivacaftor. All completed treatment. Of 19 children enrolled in part B, including one from part A, all received 50 mg ivacaftor and 18 completed treatment (one withdrew because of difficulty with blood draws). All children received at least one dose of ivacaftor. Pharmacokinetics indicated exposure was similar to that in children aged 2 to <6 years and adults. No children discontinued because of adverse events or safety findings. In part A, three (43%) of seven children had treatment-emergent adverse events, all of which were mild and deemed not to be or unlikely to be related to ivacaftor. By 24 weeks in part B, treatment-emergent adverse events had been reported in 18 (95%) of 19 children, of which most were mild or moderate and the most frequent was cough (14 [74%] children). Two children in part B had four serious adverse events: one had constipation (possibly related to ivacaftor), distal intestinal obstruction syndrome, and eczema herpeticum, and one had persistent cough, all needing hospital admission. In five (28%) of 18 children aspartate or alanine aminotransferase concentrations rose to more than three times the upper limit of normal (to more than eight times in two children with concurrent infections). At week 24, the mean absolute change from baseline in sweat chloride concentration was -73·5 (SD 17·5) mmol/L. Growth parameters for age were normal at baseline and at week 24. At week 24, concentrations of faecal elastase-1 had increased and concentrations of immunoreactive trypsinogen had decreased from baseline. Mean serum lipase and amylase were raised at baseline and rapidly decreased after treatment was started.

INTERPRETATION

Ivacaftor was generally safe and well tolerated in children aged 12 to <24 months for up to 24 weeks and was associated with rapid and sustained reductions in sweat chloride concentrations. Improvements in biomarkers of pancreatic function suggest that ivacaftor preserves exocrine pancreatic function if started early. The study is continuing in infants younger than 12 months.

FUNDING

Vertex Pharmaceuticals Incorporated.

Liver disease in patients with cystic fibrosis

PURPOSE OF REVIEW

The aim of this study was to provide an overview of the current understanding of the pathophysiology, diagnosis and management of cystic fibrosis-liver disease (CFLD).

RECENT FINDINGS

CFLD has a variety of manifestations. Previously, it was thought that patients progressed from mild cholestatic disease to cirrhosis to decompensated cirrhosis with portal hypertension. Newer evidence suggests that some patients may develop cirrhosis while others develop noncirrhotic portal hypertension. Advances in our understanding of the pathophysiology of disease necessitate modifications to the current diagnostic criteria. Both fibroscan and noninvasive biomarkers can be used to identify patients with cirrhosis and portal hypertension. Ursodeoxycholic acid remains the mainstay of therapy despite a paucity of rigorous studies supporting its use. Novel therapeutic agents such as CF transmembrane conductance regulator (CFTR) modulators and potentiators are encouraging but need to be evaluated specifically in CFLD.

SUMMARY

A better understanding of the pathophysiology of disease is critical to developing more disease-specific diagnostics and therapeutics.

Diagnosis, follow-up and treatment of cystic fibrosis-related liver disease

PURPOSE OF REVIEW

To provide an insight and overview of the challenges in the diagnosis, follow-up and treatment of cystic fibrosis-related liver disease (CFLD).

RECENT FINDINGS

The variable pathophysiology of CFLD complicates its diagnosis and treatment. A 'gold standard' for CFLD diagnosis is lacking. Over the past years, new techniques to diagnose features of CFLD, such as transient elastography, have been investigated. Although most of these tests confirm cystic fibrosis-related liver involvement (CFLI), they are, however, not suitable to distinguish various phenotypical presentations or predict progression to clinically relevant cirrhosis or portal hypertension. A combined initiative from the European and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition has been started, aimed to obtain consensus on CFLD criteria and definitions. Currently, only ursodeoxycholic acid is used in CFLD treatment, although it has not been convincingly demonstrated to change the natural course of the disease. Drugs that directly target cystic fibrosis transmembrane conductance regulator protein dysfunction show promising results; however, more long-term follow-up and validation studies are needed.

SUMMARY

CFLD is an umbrella term referring to a wide variety of liver manifestations with variable clinical needs and consequences. CFLD with portal hypertension is the most severe form of CFLD due to its significant implications on morbidity and mortality. The clinical relevance of other CFLI is uncertain. Consensus on CFLD definitions is essential to validate new diagnostic tools and therapeutic outcome measures.