Impact of CFTR Modulation on Intestinal pH, Motility, and Clinical Outcomes in Patients With Cystic Fibrosis and the G551D Mutation. Clin Transl Gastroenterol. 2017;8:e81. [PMID: 28300821 PMCID: PMC5387753 DOI: 10.1038/ctg.2017.10]

Extracellular pH and lung infections in cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive disease caused by CFTR mutations. It is characterized by high NaCl concentration in sweat and the production of a thick and sticky mucus, occluding secretory ducts, intestine and airways, accompanied by chronic inflammation and infections of the lungs. This causes a progressive and lethal decline in lung function. Therefore, finding the mechanisms driving the high susceptibility to lung infections has been a key issue. For decades the prevalent hypothesis was that a reduced airway surface liquid (ASL) volume and composition, and the consequent increased mucus concentration (dehydration), create an environment favoring infections. However, a few years ago, in a pig model of CF, the Na⁺/K⁺ concentrations and the ASL volume were found intact. Immediately a different hypothesis arose, postulating a reduced ASL pH as the cause for the increased susceptibility to infections, due to a diminished bicarbonate secretion through CFTR. Noteworthy, a recent report found normal ASL pH values in CF children and in cultured primary airway cells, challenging the ASL pH hypothesis. On the other hand, recent evidences revitalized the hypothesis of a reduced ASL secretion. Thus, the role of the ASL pH in the CF is still a controversial matter. In this review we discuss the basis that sustain the role of CFTR in modulating the extracellular pH, and the recent results sustaining the different points of view. Finding the mechanisms of CFTR signaling that determine the susceptibility to infections is crucial to understand the pathophysiology of CF and related lung diseases.

Cystic fibrosis transmembrane conductance regulator-emerging regulator of cancer

Mutations of cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis, the most common life-limiting recessive genetic disease among Caucasians. CFTR mutations have also been linked to increased risk of various cancers but remained controversial for a long time. Recent studies have begun to reveal that CFTR is not merely an ion channel but also an important regulator of cancer development and progression with multiple signaling pathways identified. In this review, we will first present clinical findings showing the correlation of genetic mutations or aberrant expression of CFTR with cancer incidence in multiple cancers. We will then focus on the roles of CFTR in fundamental cellular processes including transformation, survival, proliferation, migration, invasion and epithelial-mesenchymal transition in cancer cells, highlighting the signaling pathways involved. Finally, the association of CFTR expression levels with patient prognosis, and the potential of CFTR as a cancer prognosis indicator in human malignancies will be discussed.

EPC/HPSG evidence-based guidelines for the management of pediatric pancreatitis

BACKGROUND

Pediatric pancreatitis is an underdiagnosed disease with variable etiology. In the past 10-15 years the incidence of pediatric pancreatitis has increased, it is now 3.6-13.3 cases per 100,000 children. Up-to-date evidence based management guidelines are lacking for the pediatric pancreatitis. The European Pancreatic Club, in collaboration with the Hungarian Pancreatic Study Group organized a consensus guideline meeting on the diagnosis and management of pancreatitis in the pediatric population.

METHODS

Pediatric Pancreatitis was divided into three main clinical categories: acute pancreatitis, acute recurrent pancreatitis and chronic pancreatitis. Fifteen relevant topics (acute pancreatitis: diagnosis; etiology; prognosis; imaging; complications; therapy; biliary tract management; acute recurrent pancreatitis: diagnosis; chronic pancreatitis: diagnosis, etiology, treatment, imaging, intervention, pain, complications; enzyme replacement) were defined. Ten experts from the USA and Europe reviewed and summarized the available literature. Evidence was classified according to the GRADE classification system.

RESULTS

Within fifteen topics, forty-seven relevant clinical questions were defined. The draft of the updated guideline was presented and discussed at the consensus meeting held during the 49th Meeting of European Pancreatic Club, in Budapest, on July 1, 2017.

CONCLUSIONS

These evidence-based guidelines provides the current state of the art of the diagnosis and management of pediatric pancreatitis.

Reduction of Recurrence Risk of Pancreatitis in Cystic Fibrosis With Ivacaftor: Case Series

The effect of ivacaftor in patients with cystic fibrosis (CF) with recurrent pancreatitis is unknown. We conducted a multicenter retrospective study of patients with CF taking ivacaftor who had a history of recurrent pancreatitis. During the first 3 months of therapy, only 1 of the 6 patients had an episode of pancreatitis, which was managed on an outpatient basis. Between 3 and 12 months on ivacaftor therapy, none of the patients had recurrence of pancreatitis or required hospitalization. The use of ivacaftor was associated with a reduced frequency and recurrence rate of pancreatitis in patients with CF.

Germline genetic variants with implications for disease risk and therapeutic outcomes

Genetic testing has multiple clinical applications including disease risk assessment, diagnosis, and pharmacogenomics. Pharmacogenomics can be utilized to predict whether a pharmacologic therapy will be effective or to identify patients at risk for treatment-related toxicity. Although genetic tests are typically ordered for a distinct clinical purpose, the genetic variants that are found may have additional implications for either disease or pharmacology. This review will address multiple examples of germline genetic variants that are informative for both disease and pharmacogenomics. The discussed relationships are diverse. Some of the agents are targeted for the disease-causing genetic variant, while others, although not targeted therapies, have implications for the disease they are used to treat. It is also possible that the disease implications of a genetic variant are unrelated to the pharmacogenomic implications. Some of these examples are considered clinically actionable pharmacogenes, with evidence-based, pharmacologic treatment recommendations, while others are still investigative as areas for additional research. It is important that clinicians are aware of both the disease and pharmacogenomic associations of these germline genetic variants to ensure patients are receiving comprehensive personalized care.