Liver transplantation in cystic fibrosis: a report from Baylor College of Medicine and the Texas Children's Hospital

Clinical outcomes after liver transplant in people with cystic fibrosis: A systematic review and meta-analysis

BACKGROUND

Data on the impact of liver transplantation (LT) in cystic fibrosis (CF) on lung function and exacerbations are limited. The objective of this study was to summarize the literature on lung function, nutritional status, survival, and complications following LT in people with CF.

METHODS

Three databases were searched until September 2023, to identify the impact of LT in CF. Lung transplant prior to LT and simultaneous liver-lung transplant were excluded. Pooled hazard ratios were calculated using random-effects models.

RESULTS

Thirty studies were included in this review, with 3 and 9 studies included in meta-analyses for nutritional status and lung function, respectively. Eighty-three percent of the studies used data that was more than a decade old. There was a significant increase in percent-predicted forced expiratory volume with mean change of 7.16 % (2.13, 12.19; p = 0.005) one year post-LT. Pulmonary exacerbations decreased in the short-term, however there was no significant change in body mass index (BMI). One-year survival post-LT ranged between 75 and 100 %, while five-year survival was lower at 64-89 %.

CONCLUSION

Existing data suggest that LT improves lung function in the short term and does not increase the likelihood of pulmonary exacerbations, despite ongoing immunosuppression in the setting of chronic lung infection.

Liver transplant in children and adults with cystic fibrosis: Impact of growth failure and nutritional status

Nutritional status is known to strongly predict health outcomes in people with cystic fibrosis (CF), but the prevalence of and consequences for CF children with growth failure and underweight CF adults on the liver transplant (LT) waitlist has not been delineated. We utilized UNOS registry data from 2003 to 2017 to investigate the impact of growth failure and underweight on outcomes in liver transplant candidates with CF. Almost 1 in 3 children and adults with CF had growth failure or were underweight, respectively, at listing. Body mass index under-estimated growth failure compared to height and weight z-scores for children. In multivariate analysis of children, growth failure (HR 2.1, 95% CI 1.7-2.6), and CF (HR 2.7, 95% CI 1.6-4.6, vs. Non-CF) were independent risk factors for waitlist death among children; having both increased death risk almost fourfold (SHR 3.88, 95% CI 1.42-10.58). However, among children who did receive a LT, CF was not associated with death within 1-year post-LT. Underweight adult CF candidates were less likely to receive LT, again suggesting the importance of nutritional evaluation and early intervention in this at-risk cohort.

Cystic Fibrosis Liver Disease: Know More

Cystic fibrosis (CF) is a multisystem disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CFTR is expressed in the apical surface of cholangiocytes. Homozygous CFTR gene mutation results in viscous and acidic bile secretions secondary to deficient surface fluid and bicarbonate efflux. Viscous, inspissated bile causes ductular obstruction and hepatotoxicity from retained bile components, leading to fibrosis and ultimately cirrhosis, known as CF liver disease (CFLD). CFLD is the third leading cause of death in CF patients. CFLD manifestations can take many forms. They range from asymptomatic elevation of transaminases to cirrhosis and end-stage liver disease. CFLD is diagnosed after excluding other causes of chronic liver disease. To date, there is no effective therapy to prevent or treat CFLD. Management of CFLD emphasizes on optimizing nutritional status. Ursodeoxycholic acid is the only available treatment that may prevent progression of CFLD at present. All CF patients with CFLD need annual investigations and follow-up for early detection of the disease. Liver transplantation should be considered in patients with decompensated cirrhosis and portal hypertension, with acceptable long-term outcomes. Novel therapies of CFLD are promising. This review article aims to summarize the published literature on CFLD, its pathophysiology, clinical features and complications, and management including new therapeutic options.

Vascular Remodeling of Visceral Arteries Following Interruption of the Splenic Artery During Liver Transplantation

Splenic artery (SA) ligation can be performed during liver transplantation (LT) to avoid portal hyperperfusion, which is involved in the pathogenesis of both small-for-size and SA syndrome. The SA can also be used as an inflow for arterial reconstruction. Exceptionally, SA interruption or agenesis has been associated with positive remodeling of collateral arteries supplying the spleen via the left gastric artery (LGA), short gastric vessels, and the gastroepiploic arcade (GEA), with subsequent severe upper gastrointestinal (GI) bleeding. To determine incidence, magnitude, predictors, and clinical implications of vascular remodeling after SA interruption during LT, we identified 465 patients transplanted in the period 2007-2017 who had the SA ligated or interrupted at LT. Among them, 88 had a computed tomography angiography suitable for evaluation of vascular remodeling after LT. The presence of prominent gastric arterial collaterals and the increase in LGA and GEA diameter were evaluated on 2-dimensional axial images and multiplanar reconstructions. Of the 88 patients, 28 (31.8%), 32 (36.4%), and 22 (25.0%) developed gastric collateralization graded as mild, moderate, or severe. Of the patients for whom comparison with pre-LT imaging was possible (n = 54), 51 (94.4%) presented a median 37% and 55% increase in LGA and GEA diameter, respectively. Severe gastric collateralization was associated with lower body mass index (odds ratio, 0.84; 95% confidence interval [CI], 0.71-0.98; P = 0.03), whereas a GEA caliper measurement increase was positively correlated with Model for End-Stage Liver Disease score (r² = 0.12; 95% CI, 0.65-4.15; P = 0.008). Out of 465 patients, 2 (0.43%) had severe episodes of arterial upper GI bleeding, possibly exacerbated by vascular remodeling. In conclusion, vascular remodeling after SA interruption during LT is frequent and can aggravate GI bleeding during follow-up.

A Multidisciplinary Approach to Pretransplant and Posttransplant Management of Cystic Fibrosis-Associated Liver Disease

Approximately 5%-10% of patients with cystic fibrosis (CF) will develop advanced liver disease with portal hypertension, representing the third leading cause of death among patients with CF. Cystic fibrosis with advanced liver disease and portal hypertension (CFLD) represents the most significant risk to patient mortality, second only to pulmonary or lung transplant complications in patients with CF. Currently, there is no medical therapy to treat or reverse CFLD. Liver transplantation (LT) in patients with CFLD with portal hypertension confers a significant survival advantage over those who do not receive LT, although the timing in which to optimize this benefit is unclear. Despite the value and efficacy of LT in selected patients with CFLD, established clinical criteria outlining indications and timing for LT as well as disease-specific transplant considerations are notably absent. The goal of this comprehensive and multidisciplinary report is to present recommendations on the unique CF-specific pre- and post-LT management issues clinicians should consider and will face.

The Efficacy of MRI in the diagnostic workup of cystic fibrosis-associated liver disease: A clinical observational cohort study

PURPOSE

To identify independent imaging features and establish a diagnostic algorithm for diagnosis of cystic fibrosis (CF)-associated liver disease (CFLD) in CF patients compared to controls using gadoxetic acid-enhanced MRI.

METHODS

A total of 90 adult patients were enrolled: 50 with CF, 40 controls. The CF group was composed of two subgroups: a retrospective test subgroup (n = 33) and a prospective validation subgroup (n = 17). Controls (patients with normal liver enzymes and only benign focal liver lesions) were divided accordingly (27:13). MRI variables, including quantitative and qualitative parameters, were used to distinguish CFLD from controls using clinical symptoms, laboratory tests and Debray criteria. Disease severity was classified according to Child-Pugh and Albumin-Bilirubin (ALBI) scores. Fifteen qualitative single-lesion CF descriptors were defined. Two readers independently evaluated the images. Univariate statistical analysis was performed to obtain significant imaging features that differentiate CF patients from controls. Through multivariate analysis using chi-squared automatic interaction detector (CHAID) methodology the most important descriptors were identified. Diagnostic performance was assessed by receiver-operating characteristic (ROC) analysis.

RESULTS

Three independent imaging descriptors distinguished CFLD from controls: (1) presence of altered gallbladder morphology; (2) periportal tracking; and (3) periportal fat deposition. Prospective validation of the classification algorithm demonstrated a sensitivity of 94.1% and specificity of 84.6% for discriminating CFLD from controls. Disease severity was well associated with the imaging features.

CONCLUSIONS

A short unenhanced MRI protocol can identify the three cardinal imaging features of CFLD. The hepatobiliary phase of gadoxetic acid-enhanced MRI can define CFLD progression.

KEY POINTS

• Using a multivariate classification analysis, we identified three independent imaging features, altered gallbladder morphology (GBAM), periportal tracking (PPT) and periportal fat deposition (PPFD), that could diagnose CFLD with high sensitivity, 94.1 % (95% CI: 71.3-99.9) and moderate specificity, 84.6 % (95% CI: 54.6-98.1). • Based upon the results of this study, gadoxetic acid-enhanced MRI with DWI is able to diagnose early-stage CFLD, as well as its progression.

Transplantation

Despite improvement in median life expectancy and overall health, some children with cystic fibrosis (CF) progress to end-stage lung or liver disease and become candidates for transplant. Transplants for children with CF hold the promise to extend and improve the quality of life, but barriers to successful long-term outcomes include shortage of suitable donor organs; potential complications from the surgical procedure and immunosuppressants; risk of rejection and infection; and the need for lifelong, strict adherence to a complex medical regimen. This article reviews the indications and complications of lung and liver transplantation in children with CF.

Cystic Fibrosis Associated with Worse Survival After Liver Transplantation

BACKGROUND

Survival in cystic fibrosis patients after liver transplantation and liver-lung transplantation is not well studied.

AIMS

To discern survival rates after liver transplantation and liver-lung transplantation in patients with and without cystic fibrosis.

METHODS

The United Network for Organ Sharing database was queried from 1987 to 2013. Univariate Cox proportional hazards, multivariate Cox models, and propensity score matching were performed.

RESULTS

Liver transplant and liver-lung transplant were performed in 212 and 53 patients with cystic fibrosis, respectively. Univariate Cox proportional hazards regression identified lower survival in cystic fibrosis after liver transplant compared to a reference non-cystic fibrosis liver transplant cohort (HR 1.248; 95 % CI 1.012, 1.541; p = 0.039). Supplementary analysis found graft survival was similar across the 3 recipient categories (log-rank test: χ(2) 2.68; p = 0.262). Multivariate Cox models identified increased mortality hazard among cystic fibrosis patients undergoing liver transplantation (HR 2.439; 95 % CI 1.709, 3.482; p < 0.001) and liver-lung transplantation (HR 2.753; 95 % CI 1.560, 4.861; p < 0.001). Propensity score matching of cystic fibrosis patients undergoing liver transplantation to non-cystic fibrosis controls identified a greater mortality hazard in the cystic fibrosis cohort using a Cox proportional hazards model stratified on matched pairs (HR 3.167; 95 % CI 1.265, 7.929, p = 0.014).

CONCLUSIONS

Liver transplantation in cystic fibrosis is associated with poorer long-term patient survival compared to non-cystic fibrosis patients, although the difference is not due to graft survival.

Lung transplantation for cystic fibrosis: results, indications, complications, and controversies

Survival in patients with cystic fibrosis (CF) has improved dramatically over the past 30 to 40 years, with mean survival now approximately 40 years. Nonetheless, progressive respiratory insufficiency remains the major cause of mortality in CF patients, and lung transplantation (LT) is eventually required. Timing of listing for LT is critical, because up to 25 to 41% of CF patients have died while awaiting LT. Globally, approximately 16.4% of lung transplants are performed in adults with CF. Survival rates for LT recipients with CF are superior to other indications, yet LT is associated with substantial morbidity and mortality (∼50% at 5-year survival rates). Myriad complications of LT include allograft failure (acute or chronic), opportunistic infections, and complications of chronic immunosuppressive medications (including malignancy). Determining which patients are candidates for LT is difficult, and survival benefit remains uncertain. In this review, we discuss when LT should be considered, criteria for identifying candidates, contraindications to LT, results post-LT, and specific complications that may be associated with LT. Infectious complications that may complicate CF (particularly Burkholderia cepacia spp., opportunistic fungi, and nontuberculous mycobacteria) are discussed.

Cystic fibrosis related liver disease--another black box in hepatology

Due to improved medical care, life expectancy in patients with cystic fibrosis (CF) has veritably improved over the last decades. Importantly, cystic fibrosis related liver disease (CFLD) has become one of the leading causes of morbidity and mortality in CF patients. However, CFLD might be largely underdiagnosed and diagnostic criteria need to be refined. The underlying pathomechanisms are largely unknown, and treatment strategies with proven efficacy are lacking. This review focuses on current invasive and non-invasive diagnostic standards, the current knowledge on the pathophysiology of CFLD, treatment strategies, and possible future developments.

Intestinal complications of cystic fibrosis

PURPOSE OF REVIEW

The article reviews advances in gastrointestinal aspects of cystic fibrosis (CF) published in the literature over the past year, and highlights new and interesting research.

RECENT FINDINGS

Animal models can be used to understand the pathophysiology of gastrointestinal complications in CF. The CF mouse is useful for studying distal intestinal obstruction, dysmotility and dysbiosis, and the CF pig model has helped us better understand meconium ileus and pancreatic and hepatobiliary secretory problems. Studies in humans help elucidate the evolution of pancreatic insufficiency, how reflux may lead to lung disease, problems with intestinal dysmotility, mechanisms leading to pancreatitis and the increased prevalence of gastrointestinal cancer. Biomarkers are shedding light on CF-related liver disease. Rectal biopsies can help in diagnosis and in studying new drugs for CF.

SUMMARY

Gastrointestinal complications of CF are likely to be seen with increasing frequency as patients with CF lead longer lives. CF animal models and modern research techniques are providing new insights into extrapulmonary complications. CF clinicians should be familiar with diagnosis and management of common gastrointestinal complications and should build bridges with specialists so that referrals can be made when needed.