Review Articles in 2015

Bariatric surgery is efficient in achieving weight loss in severe obesity, but associated anatomical or mechanical alterations might also affect oesophageal function. Each type of surgery has its own risks and benefits when it comes to pre-existing or the potential development of postoperative oesophageal disorders. Here, the three most common types of bariatric surgery and their respective influences on oesophageal function are discussed.

IBD is a chronic inflammatory disorder of the gut and major progress has been made in understanding the underlying mechanisms that mediate the disease. Here, the authors provide a comprehensive overview of the immunopathogenesis of IBD, discussing known and emerging pathogenic factors that include immune and nonimmune events.

Oropharyngeal dysphagia is a common swallowing disorder. In this Review, Rommel and Hamdy describe the most frequent manifestations of oropharyngeal dysphagia, including potential causes and complications. They also provide a comprehensive overview of the techniques available to diagnose this condition.

Pre-operative diagnosis of biliary strictures often presents as a challenge to clinicians. Strictures have a range of benign causes, but can also be a result of cancer and so an ability to diagnose them accurately is very important. In this Review the authors discuss the existing modalities of assessing strictures and argue that a multimodal and multidisciplinary approach is likely to be best. New biomarkers and emerging techniques are hoped to improve diagnostic capabilities in future.

Hepatocellular carcinoma (HCC) is an antigenic lesion infiltrated by T cells, but factors within the tumour and its microenvironment dampen the immune response and prevent effective antitumour immunity. The stepwise elucidation of the various immunosuppressive mechanisms at play in HCC has exposed new therapeutic options. This Review gives a comprehensive overview of the different immunotherapeutic modalities applicable in HCC, including vaccines, adoptive T-cell therapy, cytokines, gene therapy and immune checkpoint inhibitors.

Traditionally, the diagnosis of hepatorenal syndrome has been based on stringent criteria that are not ideal for patients with cirrhosis and kidney injury, leading to underdiagnosis. Acute kidney injury is now proposed to characterize renal disease in patients with cirrhosis. Florence Wong describes the evolution of these criteria that have addressed this issue and improved care for these patients.

The concept that the nervous system can adapt to gastrointestinal disorders is a new concept. In this Review the authors discuss neural plasticity in pancreatic diseases such as pancreatitis and cancer. Given the translational importance of neuropathic changes in pancreatic disorders the authors look at the available mouse models we have to study the phenomenon and highlight areas of research that still need investigation.

Liver transplantation outcomes have improved substantially over the years, but patients still have to deal with a number of consequences and risks that might follow the procedure. Optimal screening and management of recurrent disease or associated pathologies, such as metabolic, renal, cardiac disease and cancer, are essential to provide the best possible care for transplant recipients.

The gastrointestinal hormones ghrelin and motilin are released during hunger to stimulate appetite and interdigestive movement of the stomach, respectively. Ghrelin and motilin receptor agonists also increase gastric emptying of meals and emerging data shows previously unknown effects on nausea and constipation. In this Review, Sanger and Furness describe the complex interactions of ghrelin and motilin with their receptors and the pathways influencing gastrointestinal functions. Finally, they describe the potential of receptor agonists to treat various gastrointestinal disorders.

A gluten-free diet is the mainstay of treatment for patients with coeliac disease, and is still the only treatment available. In this Review, the authors provide practical insights into implementation of a gluten-free diet as a guide for clinicians, including challenges for patients, considerations for special populations, adherence and follow-up.

Leaks are the most common post-operative complication of bariatric surgery; a procedure which is on the rise owing to the increased prevalence of obesity. Pierre Eisendrath and Jacques Deviere discuss the use of endoscopy as a therapeutic approach to resolving these complications, showing that it is a valid alternative to avoid additional surgical procedures.

A small subset of patients with coeliac disease do not respond to therapy with a gluten-free diet. These individuals are considered to have refractory coeliac disease (RCD), of which there are two known subtypes. In this Review, the authors provide an overview of RCD discussing the pathogenesis, diagnosis and management of this condition.

With a growing population of children developing NAFLD, our understanding of the similarities and differences between paediatric, adolescent and adult NAFLD is getting ever more important. In this Review, Mencin, Loomba and Lavine outline the clinically relevant differences in epidemiology, pathology, pathophysiology and treatment of paediatric NAFLD and discuss the transition of care into adulthood.

Many autoimmune diseases are known to occur alongside coeliac disease and, in some instances, patients see improvements in both if coeliac disease is diagnosed and treated. Shared genetic traits have been identified between coeliac disease and many of these forms of autoimmunity. In this Review, an overview is presented of the genetic and immunological features of coeliac disease, its overlap with other autoimmune diseases and implications for screening strategies.

IBS is the most common brain–gut disorder and a major cause of chronic abdominal pain. Here, Mayer and colleagues describe the key components of the gut–brain–microbiota axis in IBS and present a systems-based view of how these components interact to integrate the central, peripheral and behavioural IBS-related alterations.

The landscape of treatment for IBD changed dramatically with the introduction of biologic agents, of which several are now in use for this condition. Here, the authors provide practical insights into the use of biologic agents in IBD, discussing issues such as comparative effectiveness, safety, immunogenicity, cost and patient preference.

Coeliac disease is common, but remains under-diagnosed, partly because it can present with extraintestinal symptoms that do not immediately enable an accurate diagnosis of the underlying disease. In this Review, Leffler and colleagues discuss the most common extraintestinal manifestations, including dermatitis herpetiformis, gluten ataxia, anaemia, osteoporosis and others, to raise additional awareness among clinicians.

Disease risk and treatment response is determined by an individual's complex history of genetic and environmental interactions. Personalized health care therefore requires an in-depth understanding of patient biology that can now be measured using '-omics' technologies. In this Review, different metabolic profiling methods and applications are described that might introduce a new dimension in personalized patient care in gastroenterology and hepatology.

Striking placebo responses seen in randomized clinical trials have generated an interest in investigating this phenomenon in gastroenterology. Sigrid Elsenbruch and Paul Enck discuss general aspects of the placebo response relating to gastroenterology and aspects that are unique to gastrointestinal disease. This Review provides a fascinating insight into placebo research and how this phenomenon could be exploited in the future for better patient care.

Diverticular disease is a common condition and can have acute or chronic as well as uncomplicated or complicated disease courses. Here, an overview of the management of the condition is provided, describing classification, pathogenesis, prevention and treatment for all disease types. How to manage chronic complications and diverticular bleeding is also discussed.