Rare and common variant discovery in complex disease: the IBD case study.

Complex diseases such as inflammatory bowel disease (IBD), which consists of ulcerative colitis and Crohn's disease, are a significant medical burden-70 000 new cases of IBD are diagnosed in the United States annually. In this review, we examine the history of genetic variant discovery in complex disease with a focus on IBD. We cover methods that have been applied to microsatellite, common variant, targeted resequencing and whole-exome and -genome data, specifically focusing on the progression of technologies towards rare-variant discovery. The inception of these methods combined with better availability of population level variation data has led to rapid discovery of IBD-causative and/or -associated variants at over 200 loci; over time, these methods have grown exponentially in both power and ascertainment to detect rare variation. We highlight rare-variant discoveries critical to the elucidation of the pathogenesis of IBD, including those in NOD2, IL23R, CARD9, RNF186 and ADCY7. We additionally identify the major areas of rare-variant discovery that will evolve in the coming years. A better understanding of the genetic basis of IBD and other complex diseases will lead to improved diagnosis, prognosis, treatment and surveillance.

Past and Future Burden of Inflammatory Bowel Diseases Based on Modeling of Population-Based Data.

BACKGROUND & AIMS: Inflammatory bowel diseases (IBDs) exist worldwide, with high prevalence in North America. IBD is complex and costly, and its increasing prevalence places a greater stress on health care systems. We aimed to determine the past current, and future prevalences of IBD in Canada. METHODS: We performed a retrospective cohort study using population-based health administrative data from Alberta (2002-2015), British Columbia (1997-2014), Manitoba (1990-2013), Nova Scotia (1996-2009), Ontario (1999-2014), Quebec (2001-2008), and Saskatchewan (1998-2016). Autoregressive integrated moving average regression was applied, and prevalence, with 95% prediction intervals (PIs), was forecasted to 2030. Average annual percentage change, with 95% confidence intervals, was assessed with log binomial regression. RESULTS: In 2018, the prevalence of IBD in Canada was estimated at 725 per 100,000 (95% PI 716-735) and annual average percent change was estimated at 2.86% (95% confidence interval 2.80%-2.92%). The prevalence in 2030 was forecasted to be 981 per 100,000 (95% PI 963-999): 159 per 100,000 (95% PI 133-185) in children, 1118 per 100,000 (95% PI 1069-1168) in adults, and 1370 per 100,000 (95% PI 1312-1429) in the elderly. In 2018, 267,983 Canadians (95% PI 264,579-271,387) were estimated to be living with IBD, which was forecasted to increase to 402,853 (95% PI 395,466-410,240) by 2030. CONCLUSION: Forecasting prevalence will allow health policy makers to develop policy that is necessary to address the challenges faced by health systems in providing high-quality and cost-effective care.

[A medical biography of Ludwig van Beethoven]. / Ludwig van Beethoven, el genio de Bonn atormentado por sus enfermedades: su historia médica.

Much emphasis has been given to the deafness of Ludwig van Beethoven and its potential causes. However, when analyzing several symptoms reported by himself throughout his life in many letters and his final illness, a common etiology emerges. This article reports the medical history of this artist, based on authoritative scientific sources.

[Advances in diagnosis and therapy of inflammatory bowel diseases]. / Pokroky v diagnostice a lécbe nespecifických strevních zánetu

The inflammatory bowel diseases have been an interesting topic not only for gastroenterologists, but also for other medical professionals, since the beginning of the last century, when this group of inflammatory autoimmune diseases was revealed. Logically, the doyen of Czech gastroenterology, Professor MUDr. Zdenek Maratka, DrSc., who dedicated a substantial part of his life to research into inflammatory bowel disease, particularly ulcerative colitis, was no exception. The current century is characterized by a very rapid development of scientific research and almost immediate introduction of scientific knowledge into clinical practice. In the area of inflammatory bowel diseases, the biggest advances have been made in diagnosis and therapy. The examination of the small bowel and large bowel by magnetic resonance belongs at the very pinnacle in the non-invasive diagnosis of the lower part of the gastrointestinal tract. The administration of biological therapy to patients with the most severe forms of inflammatory bowel diseases should be considered a breakthrough since the introduction of corticosteroids into the therapy of inflammatory bowel diseases in the 1950s.

[History of surgical treatment of non-specific inflammatory bowel diseases]. / Historie chirurgické lécby nespecifických zánetu strevních.

Treatment of non-specific inflammatory bowel diseases was from the start accompanied by forced operations. In the 19th and early 20th century operations were burdened with high mortality, but most were more successful than the limited possibilities of conservative treatment. Gradually developed principles for the treatment of Crohns disease, a length of bowel sparing surgery are still valid today. Surgical treatment of ulcerative colitis passed the time of colonic irrigation, bypass surgery, limited resection to todays gold standard - proctocolectomy with ileo-pouch-anal anastomosis.

The history and philosophy of inflammatory bowel disease.

Many interesting statements about inflammatory bowel diseases (IBD) and also Crohn's disease have been made in recent years in journals and scientific meetings. They have influenced our thinking and the perception of the diseases. Among these statements is the notion that IBDs are 'relatively new diseases', that 'IBD is rather a syndrome than a disease' or that with the new insights into pathophysiology, 'we will be able to discriminate many different Crohn's diseases based on genetic risk factors'. A look into history and philosophy may help to clarify misconceptions and prove that many of these statements are either wrong or misleading. People suffered from symptoms that are suggestive of Crohn's disease centuries before the disease concept evolved in the early 19th century and before Burrill B. Crohn could describe a complex of symptoms he suggested to be a so far non-identified disease. Early concepts on the pathophysiology of CD were not so different to present-time theories as it may be assumed. 'Pre-ideas' and basic concepts were leading the search for a cause of Crohn's disease and IBD. With respect to pathophysiology, we have to accept that most likely we will never come up with one unifying concept ('the cause of IBD') as different scientific schools and think-collectives exist. Therefore, the 'classical adaptive immunologists' and the 'innate immunologist' as well as scientists focused on barrier function or the microbiome will never completely understand each other and each other's concepts. As for many other diseases, several different pathophysiological concepts existed in parallel and will do so in the future as it is impossible to prove the exclusive 'truth' of one of the concepts for reasons that will be further discussed below. This means on the other hand that none of the concepts on pathophysiology of IBD we have at present will ever unequivocally be proven to be wrong.

[Inflammatory bowel disease - the past 50 years]. / Chronisch entzündliche Darmerkrankungen - die letzten 50 Jahre.

Since ancient times chronic inflammatory bowel diseases have been known as non-contagious colitis and remain as an unsolved enigma of internal medicine. In the past 50 years it became clear that the incidence is increasing, the cause is multifactorial genetics as well as environment and the intestinal immune reaction is directed against the intestinal microbiota and not tissue antigens. Based on groundbreaking genetic studies the focus has moved from adaptive to innate immunity and thus from autoimmunity to a barrier defect. This paradigm shift will have a major impact on therapies which are traditionally immunosuppressive and will be developed to improve the antibacterial mucosal barrier in the future.

Evolving primary and secondary endpoints in randomized controlled trials leading to approval of biologics and small molecules in IBD: an historical perspective.

Introduction: Therapeutic goals in inflammatory bowel diseases (IBD) have evolved, over the last decades, from clinical response to complete remission (clinical and endoscopic remission).Areas covered: Development of biologics and small molecules has been associated with the development of new endpoints in IBD trials that could not have been achieved in the pre-biologics era. Herein, we focus on evolving endpoints for approved biologics and small molecules. We searched for relevant publications using Medline/PubMed, Embase and the Cochrane Library from their inception to 1 July 2019.Expert opinion: Endpoints differ between induction (clinical and endoscopic response) and maintenance trials (clinical and endoscopic remission) because the goal is to evaluate the anti-inflammatory effect of a given drug during induction, whereas full disease control is the ultimate goal during the maintenance phase in order to change patients' life and disease course. Histological healing has recently emerged as a new co-primary endpoint in ulcerative colitis, and is now part of the definition of mucosal healing in these trials. Whether new endpoints such as transmural and radiologic healing could become an endpoint and replace endoscopy in Crohn's disease trials in the near future requires further investigation.

Can we modulate the clinical course of inflammatory bowel diseases by our current treatment strategies?

Ulcerative colitis and Crohn's disease are chronic disabling lifelong diseases which may be disturbed by severe flares and anatomical complications requiring surgery. Until the very last years there was no clear indication that treatment was able to modify the long-term natural history of the disease. In particular, there are no data demonstrating a clear improvement through the period 1950-2003 in disease activity, occurrence of complications and need for surgery, in spite of an increased use of immunosuppressants since the 1990s. However, in inflammatory bowel disease, both thiopurines and methotrexate are very efficient in about one half of the patients, and in responders, may heal the mucosa and decrease the need for surgery. The early use of immunosuppressants in selected patients may have an impact on occurrence of severe flares and complications, and need for surgery. Moreover, anti-TNF now used for 10 years in Crohn's disease and for 5 years in ulcerative colitis demonstrated in two thirds of the patients a remarkable anatomic effect, healing the mucosa, closing fistulae and preventing strictures. Infliximab does prevent endoscopic recurrence following ileal resection for Crohn's disease. Actually, because irreversible anatomical damage may develop during the first years of disease, there is a need to classify early in the course of the disease patients who will benefit from anti-TNF and classical immunosuppressants, respectively. There is the need in the next few years to better define these subgroups and to compare different strategies within each group through randomized interventional studies.

Overview of inflammatory bowel disease in Australia in the last 50 years.

Inflammatory diseases of the intestine, including Crohn's disease, ulcerative colitis, and celiac disease are now very common in Australia and remain major challenges for clinicians. Australian (and New Zealand) clinicians and scientists have made considerable contributions to our current understanding of these diseases over the last 50 years, including pathogenesis (such as the 'butyrate hypothesis', 'endoplasmic reticulum (ER) stress', and the identification of the peptide sequences that incite celiac disease), true population epidemiology (albeit in New Zealand), precise clinical observation, new investigative tools, innovative new potential therapies, influential clinical drug trials (such as triple antibiotics for Crohn's disease), and a dietary approach with efficacy for functional gut symptoms (the low FODMAP diet). Underpinning the success has been clinical excellence and adaptation of clinicians to the changing landscape of disease severity and therapeutic options. The future is indeed bright if such trends continue.

Fifty years of Australian pediatric gastroenterology.

When the Gastroenterological Society of Australia (GESA) began 50 years ago there were very few pediatric gastroenterologists in the world. The 'Mother' of Paediatric Gastroenterology was Australian Charlotte ('Charlo') Anderson who established one of the world's first pediatric gastroenterology units in Melbourne in the early 1960s. Her earlier work in Birmingham had identified gluten as the component of wheat responsible for celiac disease and helped separate maldigestion (cystic fibrosis) and mucosal malabsorption. The first comprehensive textbook of Paediatric Gastroenterology was edited by Charlotte Anderson and Valerie Burke in 1975. Rudge Townley succeeded Charlotte Anderson in Melbourne and went on to further develop small bowel biopsy techniques making it a safe, simple, and quick procedure that led to much greater understanding of small bowel disease and ultimately the discovery of Rotavirus by Ruth Bishop et al. and subsequently to Rotavirus immunization. Australian Paediatric Gastroenterology subsequently developed rapidly with units being established in all mainland capital cities by the end of the 1970s. The Australian Society of Paediatric Gastroenterology Hepatology and Nutrition (AuSPGHAN) was established in the 1980s. Australians have contributed significantly in many areas of gastroenterology in infants, children, and adolescents including celiac disease, cystic fibrosis, liver disease, transplantation, gastrointestinal infection, allergy, indigenous health, inflammatory bowel disease, gastrointestinal motility, and the development of novel tests of gastrointestinal function and basic science. There have also been major contributions to nutrition in cystic fibrosis, end-stage liver disease, and intestinal failure. The future of Australian Paediatric Gastroenterology is in good hands.