Gastrointestinal, Pancreatic, and Hepatobiliary Manifestations of Cystic Fibrosis

Venous Thromboembolism Occurrence and Association with Gastrointestinal Disorders in Children with Cystic Fibrosis: An Analysis from the TriNetX Research Network Global Multicenter Real-World Dataset

The purpose of this study is to (1) estimate and compare the prevalence of venous thromboembolism (VTE) in children (age 0 to ≤21) with versus without cystic fibrosis (CF); (2) investigate putative associations between specific gastrointestinal (GI) manifestations and the development of VTE among children with CF. This was a multicenter case-control analysis among patients aged 0 to ≤ 21 years between 2010 and 2020, using the TriNetX Research Network. Data queries included ICD-9/10 (International Classification of Diseases-9th/10th Revision) diagnosis codes. Bivariate associations with VTE among CF patients were compared using Chi-square testing for categorical variables and Student's t-test for continuous variables. We used multivariable logistic regression to test for independent associations of GI manifestations with VTE among children with CF, with adjustment for other salient covariates. There was a total of 7,689 children with and 22,327,660 without CF. The frequency of occurrence of VTE was increased nearly 20-fold among those with, as compared with without CF (130 vs. 7 per 10,000 patients). Acute pancreatitis (adjusted odd ratio [aOR] = 3.80, [95% confidence interval, CI: 2.00-7.22]), biliary disease (aOR = 2.17 [95% CI: 1.17-4.03]), gastrostomy status (aOR = 2.01 [95% CI: 1.27-3.18]), and malabsorption/malnutrition (aOR = 2.41 [95% CI: 1.52-3.82]) were each associated with a higher likelihood of VTE among children with CF. In conclusion, we found a significantly increased frequency of VTE occurrence and association of specific GI diseases as independent risk factors for VTE among children with CF compared with those without.

Constipation and DIOS: Diagnosis, differential diagnosis, and management

Cystic Fibrosis (CF) is a complex disorder that requires multidisciplinary expertise for effective management. The GALAXY study estimated the prevalence of constipation to be about 25% among People with Cystic Fibrosis (PwCF), identifying it as one of the common gastrointestinal (GI) symptoms within this patient population. Quality of Life (QoL) assessments uncovered high patient dissatisfaction, highlighting the imperative need for enhanced treatment strategies. Similarly, Distal Intestinal Obstruction Syndrome (DIOS) is a unique condition exclusive to PwCF that, if left undiagnosed, can lead to considerable morbidity and mortality. Given the broad spectrum of differential diagnoses for abdominal pain, including constipation and DIOS, it is paramount for healthcare providers to possess a clear understanding of these conditions. This paper aims to delineate various differentials for abdominal pain while elucidating the pathogenesis, diagnostic criteria, and treatment options for managing constipation and DIOS in PwCF.

Reduction in abdominal symptoms (CFAbd-Score), faecal M2-pyruvate-kinase and Calprotectin over one year of treatment with Elexacaftor-Tezacaftor-Ivacaftor in people with CF aged ≥12 years - The RECOVER study

BACKGROUND

RECOVER is a multicentre post-approval study of Elexacaftor/Tezacaftor/Ivacaftor (ETI) in pwCF in Ireland and the UK. The CFAbd-Score is the first validated CF-specific patient reported outcome measure (PROM) focusing on gastrointestinal symptoms; it comprises 28 items in 5 domains. In a preliminary study, we previously reported reductions in abdominal symptoms (AS) in pwCF after 26 weeks of ETI-therapy using the CFAbd-Score.

AIM

to assess changes in AS in a second, large cohort and explore novel GI-biomarkers of gut inflammation and cell-proliferation in pwCF over one year of ETI-therapy.

METHODS

Participants were recruited as part of the RECOVER study at 8 sites (Ireland&UK). The CFAbd-Score was administered prior to ETI-initiation, and subsequently at 1,2,6 and 12 months on treatment. Faecal M2-pyruvate kinase (M2-PK) and calprotectin (FC) were quantified in samples collected at baseline, 1 and 6 months.

RESULTS

108 CFAbd-Scores and 73 stool samples were collected at baseline. After 12 months of ETI-therapy, total CFAbd-Scores had significantly declined (15.0±1.4→9.8±1.2pts/p<0.001), and so had all its five domains of "pain" (16.9±2.0pts→9.9±1.8pts/p<0.01), "GERD" (14.4±1.8→9.9±1.6/p<0.05), "disorders of bowel movements" (19.2±1.4→14.1±1.5/p<0.01), "appetite" (7.0±1.1→4.6±1.2/p<0.01) and "impaired-QoL" (13.3±1.9→7.5±1.5/p<0.001). Levels of M2-PK and FC significantly decreased during ETI-therapy.

DISCUSSION

In-depth analysis of AS with the CFAbd-Score reveals a statistically significant, clinically relevant and sustained improvement with ETI. We attribute this to high sensitivity of the implemented CF-specific PROM, developed and validated following FDA-guidelines. Furthermore, for the first time during ETI-therapy a significant decline in faecal M2-PK, a marker of inflammation and cell-proliferation, was found, in parallel to FC.

A Gastroenterologist's Guide to Care Transitions in Cystic Fibrosis from Pediatrics to Adult Care

Cystic Fibrosis is a chronic disease affecting multiple systems, including the GI tract. Clinical manifestation in patients can start as early as infancy and vary across different age groups. With the advent of new, highly effective modulators, the life expectancy of PwCF has improved significantly. Various GI aspects of CF care, such as nutrition, are linked to an overall improvement in morbidity, lung function and the quality of life of PwCF. The variable clinical presentations and management of GI diseases in pediatrics and adults with CF should be recognized. Therefore, it is necessary to ensure efficient transfer of information between pediatric and adult providers for proper continuity of management and coordination of care at the time of transition. The transition of care is a challenging process for both patients and providers and currently there are no specific tools for GI providers to help ensure a smooth transition. In this review, we aim to highlight the crucial features of GI care at the time of transition and provide a checklist that can assist in ensuring an effective transition and ease the challenges associated with it.

Web-Based Survey Piloting Process as a Model for Developing and Testing Past Contraceptive Use and Pregnancy History: Cystic Fibrosis Case Study

BACKGROUND

Individuals with complex, chronic diseases are now living longer, making reproductive health an important topic to address in the health care setting. Self-respondent surveys are a feasible way to collect past contraceptive use and pregnancy history to assess contraceptive safety and effectiveness. Because sensitive topics, such as contraception and pregnancy outcomes, can vary across social groups or cultures, piloting questions and evaluating survey administration procedures in the target population are necessary for precise and reliable responses before wide distribution.

OBJECTIVE

This study aimed to develop a precise and reliable survey instrument and related procedures among individuals with cystic fibrosis regarding contraceptive use and obstetrical history.

METHODS

We piloted and tested web-based questions related to contraceptive use and pregnancy history among 50 participants with and those without cystic fibrosis aged 18 to 45 years using a 3-tier process. Findings from each tier informed changes to the questionnaire before testing in the subsequent tier. Tier 1 used cognitive pretesting to assess question understanding and the need for memory prompts. In tier 2, we used test-retest self- and interviewer-administered approaches to assess question reliability, evaluate response missingness, and determine confidence between 2 types of survey administration approaches. In tier 3, we tested the questionnaire for clarity, time to complete, and whether additional prompts were necessary.

RESULTS

In tier 1, respondents suggested improvements to the web-based survey questions and to the written and visual prompts for better recall regarding past contraceptive use. In tier 2, the test-retest reliability between self- and interviewer-administrative procedures of "ever use" contraceptive method questions was similar, with percent absolute agreement ranging between 84% and 100%. When the survey was self-administered, the percentage of missing responses was higher and respondent confidence about month and year when contraceptive methods were used was lower. Most respondents reported that they preferred the self-administered survey because it was more convenient and faster to complete.

CONCLUSIONS

Our 3-tier process to pilot web-based survey questions related to contraceptive and obstetrical history in our complex disease population helped us tailor content and format questions before wide dissemination to our target population. Results from this pilot study informed the subsequent larger study design to include a 10% respondent test-retest self- and interviewer-administered quality control component to better inform imputation procedures of missing data.

D-Lactate: Implications for Gastrointestinal Diseases

D-lactate is produced in very low amounts in human tissues. However, certain bacteria in the human intestine produce D-lactate. In some gastrointestinal diseases, increased bacterial D-lactate production and uptake from the gut into the bloodstream take place. In its extreme, excessive accumulation of D-lactate in humans can lead to potentially life-threatening D-lactic acidosis. This metabolic phenomenon is well described in pediatric patients with short bowel syndrome. Less is known about a subclinical rise in D-lactate. We discuss in this review the pathophysiology of D-lactate in the human body. We cover D-lactic acidosis in patients with short bowel syndrome as well as subclinical elevations of D-lactate in other diseases affecting the gastrointestinal tract. Furthermore, we argue for the potential of D-lactate as a marker of intestinal barrier integrity in the context of dysbiosis. Subsequently, we conclude that there is a research need to establish D-lactate as a minimally invasive biomarker in gastrointestinal diseases.

Epidemiology of Eosinophilic Esophagitis in Patients with Cystic Fibrosis: A Population-Based 5-Year Study

PURPOSE

The prevalence of eosinophilic esophagitis (EoE) has been on the rise since it was first described in the 1990s. Several diseases and exogenous factors have been associated with EoE. Our aim was to investigate the epidemiology of EoE in cystic fibrosis (CF) patients.

METHODS

We identified individuals with CF from September 2014 to September 2019 within a database (IBM Explorys Solutions, Inc.). The prevalence of EoE in patients with CF was compared to the general population.

RESULTS

The database included 36,111,860 patients during the 5-year study period: 12,950 with CF (0.036%) and 28,090 with EoE (0.078%). EoE prevalence was higher in CF patients than the general population (46 in 10,000 vs. 7.8 in 10,000, p<0.001). Patients with CF and EoE were more likely to be male (50% vs. 33.5%, p<0.008), children (33.3% vs. 16.5%, p<0.001), and non-Hispanic (100% vs. 88.7%, p<0.001) than CF patients without EoE. CF with EoE patients were more likely to be children than EoE only (33.3% vs. 10.5%, p<0.001). Allergic conditions were generally more prevalent in CF with EoE than CF only (83.3% vs. 68.3%, p=0.01) and EoE only (83.3% vs. 69.3%, p=0.014).

CONCLUSION

EoE is nearly 6-times more prevalent in CF patients. Those patients had higher incidence of other atopic conditions. EoE must be considered in the differential diagnosis of patients with CF presenting with dysphagia, refractory gastroesophageal reflux, vomiting, and other esophagus-related symptoms.

Pancreatic, hepatobiliary, and gastrointestinal manifestations of children with cystic fibrosis: A 10-year experience from a tertiary care center in southern India

OBJECTIVES

To describe the demography and spectrum of pancreatic, hepatobiliary, and gastrointestinal (GI) manifestations in children with cystic fibrosis (CF) from the Indian subcontinent.

METHODS

In this retrospective study, relevant information from the database of all children with CF below 18 years of age was collected and analyzed.

RESULTS

Among the total 109 children, 58 (53%) were from the southern states of India. The most common manifestation was pancreatic insufficiency (PI) in 85 (83%) children. Those with PI presented at an earlier age (1.8 vs. 6.9 years). Cirrhosis with portal hypertension was documented in only one patient and meconium ileus in three (2.8%). There was significant malnutrition in the PI cohort with a mean weight-for-age Z-score of - 3.17 ± 1.79 at diagnosis. Twenty-one (19%) patients had died during the follow-up and 18 (90%) of them had PI. There was no difference in the prevalence of selected pulmonary manifestations in the PI and pancreatic sufficient (PS) groups. Among children with PI, 78 were screened for ΔF508 mutation, 16 (21%) were homozygous, and 17 (22%) were heterozygous. In the PS group, only 2 (14%) were heterozygous for ΔF508 mutation. The median duration of follow-up of the patients was 1.8 (1.5) years.

CONCLUSION

PI is the most common GI manifestation of children with CF and is associated with severe malnutrition and poor outcome. Timely identification and management of the comorbidities involving the digestive system are essential for better growth and quality of life in these children.

Coming Full Circle: Reflections and Inspirations from a Cystic Fibrosis Patient Scientist Panel

Care for many progressive chronic diseases continues to improve, allowing patients to survive and thrive for longer periods of time¹. People living with such conditions may now find themselves able to achieve long-term goals in education and career development². Many people now occupy the dual roles of scientist and patient³. This commentary article synthesizes experiences of scientists and advocates with the progressive genetic disease cystic fibrosis (CF) who collaborated on a career development session for the Cystic Fibrosis Foundation’s inaugural ResearchCon event in 2019. It explores how such collaborations affirm and transform individual perspectives on patient science and its importance in broader scientific research agenda setting. We first share our own individual insights about the experience and impact of the ResearchCon panel session before progressing to discussion and future directions centering the shared insights from one another’s reflections.

Non-invasive Diagnostic Tests in Cystic Fibrosis-Related Liver Disease: A Diagnostic Test Accuracy Network Meta-Analysis

Background and Aims: Cystic fibrosis-related liver disease (CFLD) is one of the leading causes of morbidity and mortality in cystic fibrosis (CF). Several non-invasive diagnostic methods have been proposed as screening tools for CFLD. Our aim was to rank all available non-invasive modalities for diagnostic performance. Methods: A systematic search was performed in five medical databases to find studies which reported on any single or composite non-invasive diagnostic test (as an index test) compared to the Debray, the EuroCare or the Colombo criteria (as a reference standard). Ranking was carried out with a Bayesian diagnostic test accuracy network meta-analysis based on superiority indices, calculated for pooled sensitivity (Se) and specificity (Sp) with a 95% confidence interval (CI). The study was registered under CRD42020155846 in PROSPERO. Results: Fifteen studies with 15 index tests and a combination of them were included. The New criteria proposed by Koh et al. - which represent a composite diagnostic definition for CFLD including liver biochemistry, ultrasonography, transient elastography and fibrosis markers-had the best performance for detecting CFLD (Se:94%[CI:58-100], Sp:72%[CI:52-84]); while transient elastography (Se:65%[CI:56-74], Sp:88%[CI:84-91]) and a combination of it with a tissue inhibitor of metalloproteinase-4 measurement (Se:78%[CI:30-100], Sp:64%[CI:18-95%]) proved to be the second and third best options, respectively. In the imaging techniques subgroup, transient elastography (Se:66%[CI:57-72], Sp:88%[CI:85-91%]), acoustic radiation force impulse in the right lobe (Se:54%[CI:33-74], Sp:88%[CI:66-96]) and that in the left lobe (Se:55%[CI:23-81], Sp:82%[CI:50-95]) were ranked the highest. Comparing biochemical markers/fibrosis indices, the measurement of the Forns index (Se:72%[CI:25-99], Sp:63%[CI:16-94]), the aspartate aminotransferase-to-platelet ratio (Se:55%[CI:41-68], Sp:83%[CI:66-89]) and alkaline phosphatase (Se:63%[CI:18-93], Sp:64%[CI:19-95]) were ranked the highest. Conclusion: The New criteria show the best diagnostic performance. In clinical practice, transient elastography seems to be a simple, cheap and non-invasive tool, outperforming imaging, biochemical and fibrosis tests for detecting CFLD. Further studies are needed to validate our findings.

Use of proton pump inhibitors is associated with lower hemoglobin levels in people with cystic fibrosis

BACKGROUND

Proton pump inhibitors (PPIs) and histamine H2-receptor antagonists (H2RAs) are commonly prescribed to people with cystic fibrosis (PwCF) to treat gastroesophageal reflux disease (GERD) and/or protect pancreatic enzymes from degradation in the stomach. Acid suppressive medications (ASMs) could theoretically reduce hemoglobin (Hgb) levels by restricting enteral iron absorption, but evidence of an association between use of ASMs and lower Hgb levels is lacking in PwCF.

METHODS

We used unadjusted and covariate-adjusted generalized linear mixed models (GLMMs) to estimate the fixed effects of using versus never using ASMs on annual Hgb levels of PwCF in the U.S. Cystic Fibrosis Foundation Patient Registry (CFFPR) from 2011 to 2017.

RESULTS

There were 9850 users and 9007 never-users of ASMs from 2011 to 2017 who met inclusion criteria. Not adjusting for covariates, Hgb estimates were lower for male and female H2RA and/or PPI users versus never-users. Adjusting for covariates, mean Hgb was 0.1 g/dl (95% CI: 0.03, 0.17) lower for males that exclusively used PPIs than it was for male never-users of ASMs (p = .008). Adjusting for covariates, mean Hgb levels were 0.11 g/dl (95% CI: 0.04, 0.18) lower for females that exclusively used PPIs and 0.16 g/dl (95% CI: 0.05, 0.27) lower for females that used PPIs and H2RAs concurrently than it was for female never-users of ASMs (p = .005 and p = .002 for respective comparisons).

CONCLUSIONS

Males and females with cystic fibrosis (CF) who used PPIs and females with CF who concurrently used PPIs and H2RAs had lower Hgb levels than never-users of ASMs of the same sex in the CFFPR from 2011 to 2017.

Prevalence of constipation in cystic fibrosis patients: a systematic review of observational studies

OBJECTIVE

To systematically revise the literature in search of data about the prevalence of constipation in patients with cystic fibrosis according to the publications in this field, which partly refer to guidelines defined in 2010 by the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition.

SOURCES

Systematic review selecting articles based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, including Cystic Fibrosis patients of all ages. Sources of information were selected to identify the articles without period limitation: CADTH - Canadian Agency for Drugs and Technologies in Health, CINAHL Complete, Clinical Trials US NIH, Cochrane Library, Embase, MEDLINE via Ovid, Scopus, Web Of Science, PubMed, SciELO, MEDLINE and LILACS , Health Systems Evidence, PDQ Evidence, CRD Canadian Agency for Drugs and Technologies in Health, INAHTA - International Network of Agencies for Health Technology Assessment, and PEDro.

FINDINGS

The prevalence of constipation was reported in eight observational studies. Only two studies assessed the frequency of constipation as a primary objective; in the others, constipation was quoted along with the prevalence of the spectrum of gastrointestinal manifestations. Altogether, the publications included 2,018 patients, the reported prevalence varied from 10% to 57%. Only two of the six articles published after 2010 followed the definition recommended by the European Society.

CONCLUSIONS

Constipation is a frequent but still insufficiently assessed complaint of Cystic Fibrosis patients. The use of diverse diagnostic criteria restricts comparison and epidemiological conclusions, future studies should compulsorily apply the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition definition.

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.

CFTR dysregulation drives active selection of the gut microbiome

Patients with cystic fibrosis (CF) have altered fecal microbiomes compared to those of healthy controls. The magnitude of this dysbiosis correlates with measures of CF gastrointestinal (GI) disease, including GI inflammation and nutrient malabsorption. However, whether this dysbiosis is caused by mutations in the CFTR gene, the underlying defect in CF, or whether CF-associated dysbiosis augments GI disease was not clear. To test the relationships between CFTR dysfunction, microbes, and intestinal health, we established a germ-free (GF) CF mouse model and demonstrated that CFTR gene mutations are sufficient to alter the GI microbiome. Furthermore, flow cytometric analysis demonstrated that colonized CF mice have increased mesenteric lymph node and spleen TH17+ cells compared with non-CF mice, suggesting that CFTR defects alter adaptive immune responses. Our findings demonstrate that CFTR mutations modulate both the host adaptive immune response and the intestinal microbiome.

It has been difficult to establish causal relationships between host genetics and the selection of the vast multitude of micro-organisms that live in and on us (i.e. the microbiota). Cystic fibrosis has been shown to be associated with changes in the fecal microbiome (the genetic constitution of the microbiota) although it was not evident whether mutation of CFTR, the gene mutated in CF, could drive this selection or whether the frequent use of antibiotics in this population was at fault. Here, by using a germfree (i.e. sterile, lacking all microbiota) mouse model of CF we clearly demonstrate that mutated CFTR alone can alter the microbiome. We also show an increase in an adaptive immune cell type (TH17 cells) in the mesenteric lymph nodes and spleens of CF mice compared to control mice. Our study provides new insights into the dominant role that CFTR plays in microbiome determination and suggests that therapies restoring CFTR function could also correct the microbial dysbiosis observed in CF.

Review of Cystic Fibrosis

Cystic fibrosis (CF) is an autosomal recessive disease characterized by pancreatic insufficiency and chronic endobronchial airway infection. This latter feature results in progressive bronchiectasis and ultimately respiratory failure, which is the leading cause of death in patients with CF. Other complications include sinusitis, diabetes mellitus, bowel obstruction, hepatobiliary disease, hyponatremic dehydration, and infertility. Diagnosis of CF is confirmed by demonstration of elevated sweat chloride. Most cases of CF are identified through newborn screening (NBS). There are also infants with positive NBS but inconclusive diagnostic testing; a small proportion of these infants may go on to develop CF. CF is a lifelong, life-limiting disease, but an organized care center network with multidisciplinary approach, quality improvement initiatives, and research has led to markedly increased survival and development of adult CF care programs. In the past few years, medications that directly target the underlying CF defect have been developed, which should result in even greater survival benefits. [Pediatr Ann. 2019;48(4):e154-e161.].

Cystic Fibrosis: Clinical Phenotypes in Children and Adolescents

PURPOSE

The objective of this study was to describe the clinical phenotypes of children and adolescents with cystic fibrosis (CF); and to assess the role of pancreatic insufficiency and neonatal screening in diagnosis.

METHODS

A cross-sectional study was conducted, which included 77 patients attending a reference center of CF between 2014 and 2016. Epidemiological data, anthropometric measurements, and the presence of pulmonary, pancreatic, gastrointestinal and hepatobiliary manifestations were evaluated based on clinical data and complementary examinations.

RESULTS

Of the 77 patients, 51.9% were male, with a median age of 147 months (7.0-297.0 months), and the majority showed adequate nutritional status. The most common phenotype was pulmonary (92.2%), followed by pancreatic (87.0%), with pancreatic insufficiency in most cases. Gastrointestinal manifestation occurred in 46.8%, with constipation being the more common factor. Hepatobiliary disease occurred in 62.3% of patients. The group with pancreatic insufficiency was diagnosed earlier (5.0 months) when compared to the group with sufficiency (84.0 months) (p=0.01). The age of diagnosis was reduced following implementation of neonatal screening protocols for CF (6.0 months before vs. 3.0 months after, p=0.02).

CONCLUSION

The pulmonary phenotype was the most common, although extrapulmonary manifestations were frequent and clinically relevant, and should mandate early detection and treatment. Neonatal screening for CF led to earlier diagnosis in patients with pancreatic failure, and therefore, should be adopted universally.

Hepatobiliary disease in children and adolescents with cystic fibrosis

OBJECTIVES

The aims of the study were to determine the frequency of hepatobiliary disease in patients with cystic fibrosis and to describe the sociodemographic, clinical, and laboratory profile of these patients.

METHODS

This was a retrospective, descriptive, and analytical study of 55 patients diagnosed with cystic fibrosis, aged between 3 months and 21 years, followed-up from January 2008 to June 2016 in a referral center. Medical records were consulted and sociodemographic, clinical and laboratory data, including hepatobiliary alterations, imaging studies, genetic studies, liver biopsies, and upper digestive endoscopies were registered.

RESULTS

Hepatobiliary disease was diagnosed in 16.4% of the patients and occurred as an initial manifestation of cystic fibrosis in 55.6% of these cases. The diagnosis of hepatopathy occurred before or concomitantly with the diagnosis of cystic fibrosis in 88.9% of the children. All patients with hepatobiliary disease were considered non-white, with a predominance of females (77.8%) and median (IQR) of 54 (27-91) months. Compared with the group without hepatobiliary disease, children with liver disease had a higher frequency of severe mutations identified in the CFTR gene (77.8% vs. 39.6%, p=0.033) and severe pancreatic insufficiency (88.9% vs. 31.6%, p=0.007).

CONCLUSION

The frequency of hepatobiliary disease was high, with a very early diagnosis of the disease and its complications in the studied series. A statistical association was observed between the occurrence of hepatobiliary disease and the presence of pancreatic insufficiency and severe mutations in the CFTR gene. It is emphasized that cystic fibrosis is an important differential diagnosis of liver diseases in childhood.

Cystic Fibrosis Disease Modifiers: Complex Genetics Defines the Phenotypic Diversity in a Monogenic Disease

In many respects, genetic studies in cystic fibrosis (CF) serve as a paradigm for a human Mendelian genetic success story. From recognition of the condition as a heritable pathological entity to implementation of personalized treatments based on genetic findings, this multistep pathway of progress has focused on the genetic underpinnings of CF clinical disease. Along this path was the recognition that not all CFTR gene mutations produce the same disease and the recognition of the complex, multifactorial nature of CF genotype–phenotype relationships. The non- CFTR genetic components (gene modifiers) that contribute to variation in phenotype are the focus of this review. A multifaceted approach involving candidate gene studies, genome-wide association studies, and gene expression studies has revealed significant gene modifiers for multiple CF phenotypes. The bold challenges for the future are to integrate the findings into our understanding of CF pathogenesis and to use the knowledge to develop novel therapies.

Serum Level of D-Lactate in Patients with Cystic Fibrosis: Preliminary Data

D-Lactate is produced by the intestinal biota and later absorbed into circulation. Some patients with cystic fibrosis (CF) develop exocrine pancreatic insufficiency that may disturb the gut microbiome and enhance the production of D-lactate. However, this concept has not been studied yet. The aim of the study was to assess D-lactate concentration in relation to the occurrence of clinical features, activity of CF, and diet composition in paediatric patients. Patients and Method. Serum concentrations of D-lactate were measured in 38 CF patients (19 girls and 19 boys) from 6 months to 18 years of age. The analysis included age, sex, clinical symptoms, diet (the variety and calorie needs), the laboratory tests for pancreatic efficiency (serum levels of albumin and glucose, faecal elastase activity, and faecal fat index) and faecal calprotectin (the marker of intestinal inflammation), and parameters of liver damage and of cholestasis (the activity of aminotransferases, γ-glutamyltransferase, level of bilirubin, and international normalized ratio). Results. The median level of D-lactate was 0.86 μg/ml (1Q-3Q: 0.48-2.03) and correlated with the CF severity in the Schwachman-Kulczycki score, parameters of pancreatic insufficiency, and the presence of intestinal inflammation. An increased level of D-lactate was observed in the subgroup with pancreas insufficiency (1.05 versus 0.73; p < 0.05), parallel with an elevated level of calprotectin (0.948 versus 0.755; p = 0.08). There was no relationship between energy consumption and diet composition and serum D-lactates. Conclusion. Serum D-lactate concentration in CF patients is a promising new marker of exocrine pancreatic insufficiency probably related to intestinal flora dysbiosis/overgrowth.

An update on new and emerging therapies for cystic fibrosis

INTRODUCTION

Cystic fibrosis (CF) is a genetic disorder that results in a multi-organ disease with progressive respiratory decline that ultimately leads to premature death. CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which codes for the CFTR anion channel. Established CF treatments target downstream manifestations of the primary genetic defect, including pulmonary and nutritional interventions. Areas covered: CFTR modulators are novel therapies that improve the function of CFTR, and have been approved in the past five years to mitigate the effects of several CF-disease causing mutations. This review summarizes currently approved CFTR modulators and discusses emerging modulator therapies in phase II and III clinical trials described on clinical trials.gov as of April, 2017. Results of relevant trials reported in peer-reviewed journals in Pubmed, scientific conference abstracts and sponsor press releases available as of November, 2017 are included. Expert opinion: The current scope of CF therapeutic development is robust and CFTR modulators have demonstrated significant benefit to patients with specific CFTR mutations. We anticipate that in the future healthcare providers will be faced with a different treatment paradigm, initiating CFTR-directed therapies well before the onset of progressive lung disease.

Personalized or Precision Medicine? The Example of Cystic Fibrosis

The advent of the knowledge on human genetics, by the identification of disease-associated variants, culminated in the understanding of human variability. With the genetic knowledge, the specificity of the clinical phenotype and the drug response of each individual were understood. Using the cystic fibrosis (CF) as an example, the new terms that emerged such as personalized medicine and precision medicine can be characterized. The genetic knowledge in CF is broad and the presence of a monogenic disease caused by mutations in the CFTR gene enables the phenotype–genotype association studies (including the response to drugs), considering the wide clinical and laboratory spectrum dependent on the mutual action of genotype, environment, and lifestyle. Regarding the CF disease, personalized medicine is the treatment directed at the symptoms, and this treatment is adjusted depending on the patient’s phenotype. However, more recently, the term precision medicine began to be widely used, although its correct application and understanding are still vague and poorly characterized. In precision medicine, we understand the individual as a response to the interrelation between environment, lifestyle, and genetic factors, which enabled the advent of new therapeutic models, such as conventional drugs adjustment by individual patient dosage and drug type and response, development of new drugs (read through, broker, enhancer, stabilizer, and amplifier compounds), genome editing by homologous recombination, zinc finger nucleases, TALEN (transcription activator-like effector nuclease), CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR-associated endonuclease 9), and gene therapy. Thus, we introduced the terms personalized medicine and precision medicine based on the CF.

Recurrent Pneumonia in Children: A Reasoned Diagnostic Approach and a Single Centre Experience

Recurrent pneumonia (RP), i.e., at least two episodes of pneumonia in one year or three episodes ever with intercritical radiographic clearing of densities, occurs in 7.7%–9% of children with community-acquired pneumonia. In RP, the challenge is to discriminate between children with self-limiting or minor problems, that do not require a diagnostic work-up, and those with an underlying disease. The aim of the current review is to discuss a reasoned diagnostic approach to RP in childhood. Particular emphasis has been placed on which children should undergo a diagnostic work-up and which tests should be performed. A pediatric case series is also presented, in order to document a single centre experience of RP. A management algorithm for the approach to children with RP, based on the evidence from a literature review, is proposed. Like all algorithms, it is not meant to replace clinical judgment, but it should drive physicians to adopt a systematic approach to pediatric RP and provide a useful guide to the clinician.