Vibeke Binder

Association of NOD2 leucine-rich repeat variants with susceptibility to Crohn's disease

Crohns disease and ulcerative colitis, the two main types of chronic inflammatory bowel disease, are multifactorial conditions of unknown aetiology. A susceptibility locus for Crohns disease has been mapped to chromosome 16. Here we have used a positional-cloning strategy, based on linkage analysis followed by linkage disequilibrium mapping, to identify three independent associations for Crohns disease: a frameshift variant and two missense variants of NOD2, encoding a member of the Apaf-1/Ced-4 superfamily of apoptosis regulators that is expressed in monocytes. These NOD2 variants alter the structure of either the leucine-rich repeat domain of the protein or the adjacent region. NOD2 activates nuclear factor NF-kB; this activating function is regulated by the carboxy-terminal leucine-rich repeat domain, which has an inhibitory role and also acts as an intracellular receptor for components of microbial pathogens. These observations suggest that the NOD2 gene product confers susceptibility to Crohns disease by altering the recognition of these components and/or by over-activating NF-kB in monocytes, thus documenting a molecular model for the pathogenic mechanism of Crohns disease that can now be further investigated.

CARD15/NOD2 Mutational Analysis and Genotype-Phenotype Correlation in 612 Patients with Inflammatory Bowel Disease

CARD15/NOD2 encodes a protein involved in bacterial recognition by monocytes. Mutations in CARD15 have recently been found in patients with Crohn disease (CD), a chronic inflammatory condition of the digestive tract. Here, we report the mutational analyses of CARD15 in 453 patients with CD, including 166 sporadic and 287 familial cases, 159 patients with ulcerative colitis (UC), and 103 healthy control subjects. Of 67 sequence variations identified, 9 had an allele frequency >5% in patients with CD. Six of them were considered to be polymorphisms, and three (R702W, G908R, and 1007fs) were confirmed to be independently associated with susceptibility to CD. Also considered as potential disease-causing mutations (DCMs) were 27 rare additional mutations. The three main variants (R702W, G908R, and 1007fs) represented 32%, 18%, and 31%, respectively, of the total CD mutations, whereas the total of the 27 rare mutations represented 19% of DCMs. Altogether, 93% of the mutations were located in the distal third of the gene. No mutations were found to be associated with UC. In contrast, 50% of patients with CD carried at least one DCM, including 17% who had a double mutation. This observation confirmed the gene-dosage effect in CD. The patients with double-dose mutations were characterized by a younger age at onset (16.9 years vs. 19.8 years; P=.01), a more frequent stricturing phenotype (53% vs. 28%; P=.00003; odds ratio 2.92), and a less frequent colonic involvement (43% vs. 62%; P=.003; odds ratio 0.44) than were seen in those patients who had no mutation. The severity of the disease and extraintestinal manifestations were not different for any of the CARD15 genotypes. The proportion of familial and sporadic cases and the proportion of patients with smoking habits were similar in the groups of patients with CD with or without mutation. These findings provide tools for a DNA-based test of susceptibility and for genetic counseling in inflammatory bowel disease.

Frequency of glucocorticoid resistance and dependency in Crohn's disease.

The outcome of the first steroid treatment course was prospectively studied in a regional cohort of 196 patients with Crohns disease diagnosed 1979-1987. The immediate outcome after 30 days, and the prolonged outcome 30 days after treatment had stopped, are described. In all 109 patients treatment was analysed. Complete remission was obtained in 48%, partial remission in 32%, and no response in 20% within 30 days of treatment. Among primary responders (complete and partial remission), 55% remained in prolonged response after treatment had finished, while 45% relapsed or could not be withdrawn from treatment within one year. Localisation of disease, age, sex or clinical symptoms did not significantly correlate with outcome, which can be summarised as prolonged steroid response in 44%, steroid dependency in 36%, and steroid resistant in 20% of the patients.

Familial Occurrence of Inflammatory Bowel Disease

BACKGROUND AND METHODS We assessed the familial occurrence of inflammatory bowel disease in Copenhagen County, where there has been a long-term interest in the epidemiology of such disorders. In 1987 we interviewed 662 patients in whom inflammatory bowel disease had been diagnosed before 1979, asking whether their first- and second-degree relatives had this disorder. Ninety-six percent of the patients (504 with ulcerative colitis and 133 with Crohns disease) provided adequate information. RESULTS As compared with the general population, the first-degree relatives of the 637 patients with ulcerative colitis or Crohns disease had a 10-fold increase in the risk of having the same disease as the patients, after standardization for age and sex. The risk of having the other of the two diseases was also increased, but less so, and the increase in the risk of having Crohns disease was not significant in the relatives of patients with ulcerative colitis. The risk of ulcerative colitis in first-degree relatives of patients with ulcerative colitis appeared to be virtually independent of the generation to which the first-degree relative belonged and of the sex of the patient and the relative. The risk of ulcerative colitis in first-degree relatives tended to be higher if the disease had been diagnosed in the patient before the age of 50, but the risk seemed to be independent of the current age of the relatives. The prevalence of the same disease as that of the patient (either ulcerative colitis or Crohns disease) among second-degree relatives was increased; the prevalence of the other disease was not increased. CONCLUSIONS The 10-fold increase in the familial risk of ulcerative colitis and Crohns disease strongly suggests that these disorders have a genetic cause.

Colorectal cancer risk and mortality in patients with ulcerative colitis

A regional inception cohort of 1161 ulcerative colitis (UC) patients was followed up from diagnosis to the end of 1987. The follow-up rate for death and occurrence of cancer was 99.9% (median observation time, 11.7 years; range, 0-26 years). One hundred forty-one deaths were observed, 26 caused by UC or complications thereof. No significant excess mortality was found after the first year, but in the year of diagnosis the relative risk of death was 2.4 (P < 0.001). The cumulative colectomy rate 25 years after diagnosis was 32.4%. The initial extent of disease significantly influenced the colectomy probability, being 35% in total colitis, 19% in substantial colitis, and 9% in distal colitis within the first 5 years after diagnosis. Six patients developed colorectal cancer within the observation period. Compared with the expected number of 6.6, the relative risk for patients with UC was 0.9. The calculated cumulative cancer incidence was 3.1% after 25 years (95% confidence limits, 0.0-6.8). The calculated lifetime risk (0-74 years) for development of colorectal cancer was 3.5% for UC patients compared with 3.7% for the Danish population. It is concluded that with an active approach to medical and surgical treatment, as practiced here, patients whose colons are left intact bear no significantly increased risk of colorectal malignancy.

Intestinal cancer risk and mortality in patients with Crohn's disease

BACKGROUND It is important to know about mortality, risk of intestinal cancer, and surgical intervention as well as possible predictive factors for patients with Crohns disease. These prognostic parameters were estimated by regular follow-up of a complete, regional incidence cohort of 373 patients. METHODS Annual assessments of clinical conditions were the basis for statistical evaluation with life table analysis, calculations of relative risk, and lifetime cancer risk. RESULTS Survival curves for the total group of patients with Crohns disease and the background population did not differ. However, a subgroup of patients aged 20-29 years at diagnosis (P = 0.04) and a subgroup of patients with extensive small bowel disease (P = 0.03) showed slightly increased mortality within the first 5 years. Cancer in small and/or large bowel occurred in 3 patients vs. an expected 1.8(P = NS). Small bowel cancer was found in 2 patients vs. the 0.04 expected (P = 0.001). Lifetime risk of intestinal cancer was 4.1% compared with 3.8% for the Danish population in general (P = NS). Probability of surgical resection within 15 years after diagnosis was 70%. The initial extent of disease significantly influenced the probability for resection, which was 78% in ileocecal enteritis and 44% in all other localizations within 5 years after diagnosis. CONCLUSIONS The overall mortality and life-time risk of cancer in patients with Crohns disease was not found increased, although the risk of rare small bowel cancer was significantly increased.

A Placebo-Controlled, Double-Blind, Randomized Trial of Cyclosporine Therapy in Active Chronic Crohn's Disease

We randomly assigned 71 patients with active chronic Crohns disease who were resistant to or intolerant of corticosteroids to treatment with oral cyclosporine (5 to 7.5 mg per kilogram of body weight per day) or placebo for three months. Disease activity was assessed on a clinical grading scale without knowledge of the treatment given. At the end of the treatment period, 22 of the 37 cyclosporine-treated patients (59 percent) had improvement, as compared with 11 of the 34 placebo-treated patients (32 percent) (P = 0.032). During cyclosporine treatment, there was significant improvement in plasma orosomucoid levels (P = 0.0025) and the Crohns Disease Activity Index (P = 0.00012). The effect of treatment became evident after two weeks. In the subsequent three months, during which the patients were gradually withdrawn from treatment, the improvement continued in 14 of the 37 patients (38 percent) in the cyclosporine group and in 5 of the 34 (15 percent) in the placebo group (P = 0.034). No serious adverse events were observed. We conclude that cyclosporine has a beneficial therapeutic effect in patients with active chronic Crohns disease and resistance to or intolerance of corticosteroids.

Changes in clinical characteristics, course, and prognosis of inflammatory bowel disease during the last 5 decades: A population‐based study from Copenhagen, Denmark

Background: It remains uncertain whether the increasing incidence of inflammatory bowel disease (IBD) during the last decades has been accompanied by an alteration in the presentation, course, and prognosis of the disease. To answer this question, 3 consecutive population‐based IBD cohorts from Copenhagen, Denmark (1962–2005), were assessed and evaluated. Methods: Phenotype, initial disease course, use of medications, cumulative surgery rate, standardized incidence ratio of colorectal cancer (CRC), and standardized mortality ratio (SMR) were compared in the 3 cohorts, which had a total of 641 patients with Crohns disease (CD) and 1575 patients with ulcerative colitis (UC). Results: From 1962 to 2005, the proportion of IBD patients suffering from CD increased (P < 0.001), time from onset of symptoms to diagnosis of CD decreased (P = 0.001), and median age at diagnosis of UC increased (P < 0.01). The prevalence of upper gastrointestinal involvement and pure colonic CD varied significantly between cohorts. UC patients diagnosed in the 1990s had a higher prevalence of proctitis, received more medications, and had a milder initial disease course than did previous patients. The surgery rate decreased significantly in CD but not in UC. The risk of CRC in IBD was close to expected over the entire period, whereas the mortality of patients with CD increased (overall SMR, 1.31; 95% CI, 1.07–1.60). Conclusions: Despite variations in the presentation and initial course of IBD during the last 5 decades, its long‐term prognosis remained fairly stable. Treatment of IBD changed recently, and future studies should address the effect of these changes on long‐term prognosis.

Incidence and Prevalence of Crohn's Disease in the County of Copenhagen, 1962-87: A Sixfold Increase in Incidence

The incidence of Crohns disease increased sixfold from 1962 to 1987 in the county of Copenhagen. The mean annual incidence for 1979-87 was 4.1 per 10(5) inhabitants. The increase was found equally in both sexes, with an approximately 40% higher incidence in women. The maximal incidence was found in the 15- to 24-year age group, being 12.8 per 10(5) per year for women and 6.0 per 10(5) per year for men, as mean of the period 1979-87. The prevalence at the end of the study was 54 per 10(5) inhabitants, 46 per 10(5) in men and 63 per 10(5) in women. The clinical appearance of the disease at the time of diagnosis was remarkably similar during the study period with regard to both the localization of disease and the clinical symptoms and signs. A slightly higher percentage of the patients, however, were in high disease activity at diagnosis in the later years of the study.

Incidence and Prevalence of Ulcerative Colitis and Crohn's Disease in the County of Copenhagen, 1962 to 1978

The incidence of ulcerative colitis and of Crohns disease in the County of Copenhagen was estimated during the years 1962 to 1978. A total of 909 patients were diagnosed in this area with approximately 500,000 inhabitants. The mean incidence of ulcerative colitis was 8.1 per 10(5) inhabitants. This incidence was constant during the period for women but rose significantly around 1970 for men. The rise in male incidence is due to a rise in the incidence late in life. The prevalence of ulcerative colitis as of December 31, 1978 was 117 per 10(5) inhabitants. The incidence of Crohns disease was increasing during the period for both sexes with a mean value for the period 1970 to 1978 to 2.7 per 10(5) inhabitants. The prevalence of Crohns disease as of December 31, 1978 was 34 per 10(5) inhabitants.