Frank Bodewes

Persistent fat malabsorption in cystic fibrosis; lessons from patients and mice

Fat malabsorption in pancreatic insufficient cystic fibrosis (CF) patients is classically treated with pancreatic enzyme replacement therapy (PERT). Despite PERT, intestinal fat absorption remains insufficient in most CF patients. Several factors have been suggested to contribute to the persistent fat malabsorption in CF (CFPFM). We reviewed the current insights concerning the proposed causes of CFPFM and the corresponding intervention studies. Most data are obtained from studies in CF patients and CF mice. Based on the reviewed literature, we conclude that alterations in intestinal pH and intestinal mucosal abnormalities are most likely to contribute to CFPFM. The presently available data indicate that acid suppressive drugs and broad spectrum antibiotics could be helpful in individual CF patients for optimizing fat absorption and/or nutritional status.

Treatment of Infants and Toddlers With Cystic Fibrosis-related Pancreatic Insufficiency and Fat Malabsorption With Pancrelipase MT

Background: Pancreatic enzyme replacement therapy (PERT) improves nutritional status and growth in patients with cystic fibrosis (CF) with pancreatic insufficiency (PI). The current recommendation for infants and young children, who are not able to swallow the whole capsule, is to open the capsule and mix the beads in a spoon with some applesauce; however, the efficacy and safety data of this approach are currently lacking. The aim of this study was to assess the efficacy, palatability (ease of swallowing), and safety of 4 dose levels of pancrelipase microtablets (Pancrease MT) in infants and young children with CF-related PI. Patients and Methods: This study was a phase II randomized, investigator-blinded, parallel-group pilot study in DNA-proven infants with CF and PI. The study design included a run-in period (days 1–5) and an experimental period (days 6–11). Pancrelipase microtablets (2-mm, enteric coated) were provided orally. Sixteen subjects, 6 to 30 months of age, were provided 500 U lipase/kg/meal for 5 days (baseline period). Subsequently, subjects were randomly assigned to 1 of 4 treatment groups (each n = 4), receiving 500, 1000, 1500, or 2000 U (Ph. EUR) of lipase/kg/meal, respectively, for 5 days (experimental period). The primary endpoint was medication efficacy assessed by the 72-hour fecal fat excretion, expressed as coefficient of fecal fat absorption (CFA), and 13C mixed triglyceride breath test. Secondary endpoints were safety and palatability. Results: Overall compliance, defined as used study medication, was 89% to 99% for the entire study. None of the 4 dose regimens significantly influenced the CFA, relative to the baseline period (median range 83%–93%). During the run-in period the median cumulative % 13C was 11 (range −8 to 59). After randomization the median cumulative % 13C was 18 (range 14–23) in the 500-U, 14 (range −1 to 17) in the 1000-U, 10 (range 10–27) in the 1500-U, and 3 (range 1–49) in the 2000-U groups. Palatability was scored fair to good by the parents in each of the treatment groups. Gastrointestinal symptoms were reported in some patients, including common adverse events reported in clinical trials involving pancreatic enzyme therapy. No serious or other adverse events were reported. Conclusion: Treatment with Pancrease MT at a dosage of 500 U lipase/kg/meal resulted in a CFA of approximately 89% in pediatric subjects ages 6 to 30 months with PI resulting from CF. Pancrease MT doses were well tolerated and mean palatability was scored as fair to good. Present results do not indicate that a dosage higher than 500 U (Ph. EUR) lipase/kg/meal increases the coefficient of fat absorption in a cohort of infants 6 to 30 months of age.

Cystic fibrosis and the role of gastrointestinal outcome measures in the new era of therapeutic CFTR modulation

With the development of new drugs that directly affect CFTR protein function, clinical trials are being designed or initiated for a growing number of patients with cystic fibrosis. The currently available and accepted clinical endpoints, FEV1 and BMI, have limitations. The aim of this report is to draw attention to the need and the ample possibilities for the development and validation of relevant gastrointestinal clinical endpoints for scientific evaluation of CFTR modulation treatment, particularly in young children and infants. The gastrointestinal tract offers very good opportunities to measure CFTR protein function and systematically evaluate CF related clinical outcomes based on the principal clinical gastrointestinal manifestations of CF: intestinal pH, intestinal transit time, intestinal bile salt malabsorption, intestinal inflammation, exocrine pancreatic function and intestinal fat malabsorption. We present a descriptive analysis of a variety of gastrointestinal outcome measures for clinical relevance, reliability, validity, responsiveness to interventions, feasibility in particular in young children and the availability of reference values.

Pediatric Achalasia in the Netherlands: Incidence, Clinical Course, and Quality of Life.

OBJECTIVE To assess incidence and clinical course of Dutch patients with achalasia diagnosed before 18 years of age as well as their current symptoms and quality of life (QoL). STUDY DESIGN Retrospective medical chart review and a cross-sectional study assessing current clinical status using the Eckardt score and reflux disease questionnaire. General QoL was measured using Kidscreen-52 for patients <18 years of age or to 36-Item Short Form Health Survey for patients ≥18 years of age. RESULTS Between 1990 and 2013, 87 children (mean age 11.4 ± 3.4 years, 60% male) diagnosed with achalasia in the Netherlands were included. Mean incidence was 0.1/100,000/y (range 0.03-0.21). Initial treatment was pneumodilation (PD) in 68 (79%) patients and Heller myotomy (HM) in 18 (21%) patients. Retreatment was required more often after initial PD compared with initial HM (88% vs 22%; P < .0001). More complications of initial treatment occurred after HM compared with PD (55.6% vs 1.5%; P < .0001). Three esophageal perforations were seen after HM (16.7%), 1 after PD (1.5%). Sixty-three of 87 (72%) patients were prospectively contacted. Median Eckardt score was 3 (IQR 2-5), with 32 patients (44.5%) having positive scores suggesting active disease. Reflux disease questionnaire scores were higher after initial HM vs PD (1.71 [0.96-2.90] vs 0.58 [0-1.56]; P = .005). The 36-Item Short Form Health Survey (n = 52) was lower compared with healthy population norms for 7/8 domains. Kidscreen-52 (n = 20) was similar to population norms. CONCLUSIONS Pediatric achalasia is rare and relapse rates are high after initial treatment, especially after pneumodilation, but with more complications after HM. Symptoms often persist into adulthood, without any clinical follow-up. QoL in adulthood was decreased.

Persistent Fat Malabsorption in Cystic Fibrosis

Despite pancreas enzyme replacement therapy, intestinal fat absorption remains insufficient in most cystic fibrosis (CF) patients. We reviewed the potential causes of CF-related persistent intestinal fat malabsorption. Data are obtained from studies in patients and in CF experimental animal models. Based on the physiology of intestinal fat absorption, we discuss the pathology in CF conditions. The chapter covers CF-related alterations of intestinal pH and bicarbonate secretion, bile salt metabolism, and enterohepatic circulation and intestinal mucosal abnormalities.

Altered intestinal bile salt biotransformation in a cystic fibrosis (Cftr(-/-)) mouse model with hepato-biliary pathology

BACKGROUND Cftr(-/-tm1Unc) mice develop progressive hepato-biliary pathology. We hypothesize that this liver pathology is related to alterations in biliary bile hydrophobicity and bile salt metabolism in Cftr(-/-tm1Unc) mice. METHODS We determined bile production, biliary and fecal bile salt- and lipid compositions and fecal bacterial composition of C57BL/6J Cftr(-/-tm1Unc) and control mice. RESULTS We found no differences between the total biliary bile salt or lipid concentrations of Cftr(-/-) and controls. Compared to controls, Cftr(-/-) mice had a ~30% higher bile production and a low bile hydrophobicity, related to a ~7 fold higher concentration of the choleretic and hydrophilic bile salt ursocholate. These findings coexisted with a significantly smaller quantity of fecal Bacteroides bacteria. CONCLUSIONS Liver pathology in Cftr(-/-tm1Unc) is not related to increased bile hydrophobicity. Cftr(-/-) mice do however display a biliary phenotype characterized by increased bile production and decreased biliary hydrophobicity. Our findings suggest Cftr dependent, alterations in intestinal bacterial biotransformation of bile salts.

Ursodeoxycholate modulates bile flow and bile salt pool independently from the cystic fibrosis transmembrane regulator (Cftr) in mice

Cystic fibrosis liver disease (CFLD) is treated with ursodeoxycholate (UDCA). Our aim was to evaluate, in cystic fibrosis transmembrane regulator knockout (Cftr(-/-)) mice and wild-type controls, whether the supposed therapeutic action of UDCA is mediated via choleretic activity or effects on bile salt metabolism. Cftr(-/-) mice and controls, under general anesthesia, were intravenously infused with tauroursodeoxycholate (TUDCA) in increasing dosage or were fed either standard or UDCA-enriched chow (0.5% wt/wt) for 3 wk. Bile flow and bile composition were characterized. In chow-fed mice, we analyzed bile salt synthesis and pool size of cholate (CA). In both Cftr(-/-) and controls intravenous TUDCA stimulated bile flow by ∼250% and dietary UDCA by ∼500%, compared with untreated animals (P < 0.05). In non-UDCA-treated Cftr(-/-) mice, the proportion of CA in bile was higher compared with that in controls (61 ± 4 vs. 46 ± 4%; P < 0.05), accompanied by an increased CA synthesis [16 ± 1 vs. 10 ± 2 μmol·h(-1)·100 g body wt (BW)(-1); P < 0.05] and CA pool size (28 ± 3 vs. 19 ± 1 μmol/100 g BW; P < 0.05). In both Cftr(-/-) and controls, UDCA treatment drastically reduced the proportion of CA in bile below 5% and diminished CA synthesis (2.3 ± 0.3 vs. 2.2 ± 0.4 μmol·day(-1)·100 g BW(-1); nonsignificant) and CA pool size (3.6 ± 0.6 vs. 1.5 ± 0.3 μmol/100 g BW; P < 0.05). Acute TUDCA infusion and chronic UDCA treatment both stimulate bile flow in cystic fibrosis conditions independently from Cftr function. Chronic UDCA treatment reduces the hydrophobicity of the bile salt pool in Cftr(-/-) mice. These results support a potential beneficial effect of UDCA on bile flow and bile salt metabolism in cystic fibrosis conditions.

Cystic Fibrosis–related Liver Disease: Research Challenges and Future Perspectives

Objectives: Hepatobiliary complications are a leading cause of morbidity and mortality in cystic fibrosis (CF) patients. Knowledge of the underlying pathological aspects and optimal clinical management is, however, sorely lacking. Methods: We provide a summary of the lectures given by international speakers at the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) monothematic conference on cystic fibrosis–related liver disease (CFLD) held in Paris in January 2016, to discuss the status of our current knowledge of liver disease in CF patients, to define the critical areas that need to be addressed, and to resolve actions to elucidate relevant mechanisms of disease to optimise future therapeutic options. Conclusions: The need for a universal consensus on the definition of CFLD to clarify disease stage and to identify relevant biomarkers to assess disease severity was highlighted. A deeper understanding of the pathophysiology and prognostic factors for the long-term evolution of CFLD is fundamental to move forward and has a strong bearing on identifying potential treatments. Novel experimental models and new treatment options under investigation are discussed and offer hope for the near future of CFLD.

Gastroenterological endpoints in drug trials for cystic fibrosis

The phenotype of cystic fibrosis includes a wide variety of clinical and biochemical gastrointestinal presentations. These gastrointestinal characteristics of the disease have come under renewed interest as potential outcome measures and clinical endpoints for therapeutic trials in cystic fibrosis. Established gastrointestinal clinical endpoints, like e.g. fecal elastase‐1, are already used in trials. Other potential gastrointestinal outcome measures gather more scientific interest for evaluation in future trials. Gastrointestinal outcome measures look particularly relevant and promising for trials in CF patients with normal lung function or therapeutic studies in young children and infants.

Increase of Serum gamma-Glutamyltransferase Associated With Development of Cirrhotic Cystic Fibrosis Liver Disease

Background: Identification of patients at risk for developing cirrhotic cystic fibrosis liver disease (CCFLD) is essential for targeting potentially preventive treatment. We studied the evolution of serum liver enzymes and thrombocyte counts as predictors of CCFLD development. Methods: For this study, we defined the diagnosis of CCFLD as the combination of splenomegaly (on either physical examination or ultrasound scan) and macronodularity of the liver on ultrasound scan. We reviewed the medical records of 277 pediatric patients with CF for the diagnosis of CCFLD. In each patient with CCFLD, we reviewed serum liver enzymes and thrombocyte counts in the 2-year period preceding the diagnosis of CCFLD. We compared these results with a non-CCFLD control group (patients with CF older than 15 years with no reported signs or symptoms of CCFLD). Results: In the 2 years preceding the diagnosis, the &ggr;-glutamyltranspeptidase (GGT) levels of patients with CCFLD were significantly higher compared to non-CCFLD controls (42 ± 5 vs 17 ± 2 U/L, respectively; P < 0.001). Corresponding aspartate aminotransferase and alanine aminotransferase levels did not significantly differ between patients with CCFLD and controls. The thrombocyte counts in patients with CCFLD were significantly lower than those in controls (252 ± 108 vs 320 ± 94 × 109 /L, respectively; P < 0.05). The predictive value for CCFLD of a single GGT measurement was low; however, for patients with CF with a mean GGT > 35 U/L, based on repeated measurements, the odds ratio for developing CCFLD was 39 (95% confidence interval 9–175, specificity was 95%, sensitivity was 64%, positive predictive value was 50%). For the thrombocytes, however, no reliable cutoff value could be identified. Conclusions: In pediatric patients with CF, a persistently high-normal GGT is strongly associated with the diagnosis of CCFLD within 2 years. The prognostic value of a single GGT measurement is limited, but repeated GGT measurements may allow the identification of groups of patients at increased risk for CCFLD.