Relationship between site of disease and familial occurrence in Crohn's disease

Episodic, severe abdominal pain due to isolated jejunal Crohn's disease

Small bowel Crohn's disease can present with episodic, relapsing, and remitting symptoms and delays in the diagnosis are common. We present a case of a young woman with three years of intermittent abdominal pain and nausea with negative previous evaluations. On presentation, inflammatory markers were elevated, and repeat imaging showed jejunal inflammation, with histopathological examination showing non-caseating granulomas of the small bowel consistent with Crohn's disease. This case highlights the importance of gastroenterologist recognizing the alarm signs in a patient with unexplained symptoms and adds to the literature on the clinical presentation of a rare diagnosis of isolated jejunal Crohn's disease.

Recent advances in clinical practice: a systematic review of isolated colonic Crohn's disease: the third IBD?

The genetics of isolated colonic Crohn's disease place it approximately midway between Crohn's disease with small intestinal involvement and UC, making a case for considering it as a separate condition. We have therefore systematically reviewed its epidemiology, pathophysiology and treatment. Key findings include a higher incidence in females (65%) and older average age at presentation than Crohn's disease at other sites, a mucosa-associated microbiota between that found in ileal Crohn's disease and UC, no response to mesalazine, but possibly better response to antitumour necrosis factor than Crohn's disease at other sites. Diagnostic distinction from UC is often difficult and also needs to exclude other conditions including ischaemic colitis, segmental colitis associated with diverticular disease and tuberculosis. Future studies, particularly clinical trials, but also historical cohorts, should assess isolated colonic Crohn's disease separately.

Are there any differences in phenotype or disease course between familial and sporadic cases of inflammatory bowel disease? Results of a population-based follow-up study

BACKGROUND

The influence of familial IBD on phenotype and course of disease in patients with CD and UC has not been studied in population-based cohorts.

AIM

To compare phenotype and course of disease between IBD patients with a first-degree relative with IBD and sporadic cases in a population-based cohort followed prospectively for 5 yr.

METHODS

Family history of IBD was registered at diagnosis and after 1 and 5 yr. Phenotype and course of disease were compared between sporadic and familial cases.

RESULTS

Data for 200 patients with CD and 454 with UC were sufficient for analysis. A first-degree relative with IBD was registered in 14.5% of CD patients and 10.1% of UC patients. The concordance for type of disease was 82% and 70% for CD and UC, respectively. No differences between familial and sporadic cases as regards localization and behavior of disease in CD patients or disease extent in UC patients were observed. In CD patients with colonic involvement, those in the familial group were significantly younger at diagnosis than the sporadic cases. No difference in disease severity in CD patients was observed between the familial and sporadic groups. In UC patients relapse was more frequent in familial cases, but no difference was observed in the need for surgery or medical treatment.

CONCLUSIONS

A family history of IBD does not seem to influence phenotype or to be an important prognostic factor for disease course in IBD patients.

Crohn's disease: a comparative prospective study of transabdominal ultrasonography, small intestine contrast ultrasonography, and small bowel enema

BACKGROUND

Small intestine contrast ultrasonography (SICUS), when performed after distention of the small bowel lumen with an iso-osmolar polyethylene glycol electrolyte-balanced solution, shows high sensitivity (100%) and specificity (97%) in detecting small bowel abnormalities in patients who have not received a diagnosis but in whom there is a suspicion of intestinal diseases. The diagnostic yield of SICUS remains to be established in detecting small bowel lesions in patients with proven Crohn's disease (CD) in comparison with transabdominal ultrasonography (TUS), and in relationship to the experience of the operator, using small bowel enema (SBE) as the "gold standard."

AIM

The aim of this study was to evaluate the diagnostic value of SICUS, when performed by a sonologist with 1 year of experience, and TUS, when performed by a sonologist with 10 years of experience, compared to SBE in the assessment of the site, extension, and stenosis of small intestinal lesions in CD patients.

PATIENTS AND METHODS

A total of 28 consecutive patients (men, 16; women, 12; age range, 21 to 60 yr) with a diagnosis of CD underwent TUS and SICUS, which were performed by 2 sonologists who were unaware of the radiologic findings, on the same day. SICUS was performed after the ingestion of 375 mL of a polyethylene glycol contrast solution. A standard SBE was performed on a different day by an expert radiologist who was unaware of the sonographic findings.

RESULTS

Sensitivities in the detection of small bowel lesions were 96% for TUS and 100% for SICUS. Compared with SBE, SICUS detected the presence of 4 lesions in the jejunum that had been missed by TUS. The mean (+/-SD) extent of the ileal disease was 22 +/- 12.5 cm when measured during SBE, 14.5 +/- 8.6 cm when measured during TUS, and 19.5 +/- 12.5 cm when measured during SICUS [P = 0.05 (SICUS versus SBE)]. The correlation of the extension of the lesions between SICUS and SBE (r = 0.88) was better than that between TUS and SBE (r = 0.64). The sensitivities of TUS and SICUS in the detection of at least 1 stricture were 76% and 94%, respectively. Sensitivity and specificity in assessing prestenotic dilatation were 50% and 100%, respectively, at TUS, and 100% and 90%, respectively, at SICUS.

CONCLUSION

In inexperienced hands, SICUS is a more accurate technique for assessing CD lesions, and the accuracy is better than that of TUS performed by an expert sonologist. The use of SICUS, instead of SBE, could be indicated for the follow-up of patients with CD.

Clinical characteristics of familial versus sporadic Crohn's disease using the Vienna Classification

BACKGROUND

The etiology of Crohn's disease, an illness protean in its manifestations, may be better resolved through studies involving more homogenous subgroups of patients. Because a strong genetic influence exists, family history of inflammatory bowel disease may be a useful variable for patient classification if patients with familial and sporadic Crohn's disease are clinically different. Our study attempted to define any possible differences.

METHODS

The medical records of 552 patients were reviewed, and patients were classified according to guidelines of the Vienna Classification. Patients were then divided based on family history of inflammatory bowel disease, and the familial and sporadic groups were compared.

RESULTS

Overall, 422 (78.9%) patients were diagnosed before age 40 years (A1) and 114 (21.1%) at age 40 years or older (A2). There were 141 (26.3%) patients with disease involving the terminal ileum only (L1), 211 (39.4%) in the colon only (L2), 117 (21.9%) in the terminal ileum and colon (L3), and 66 (12.3%) in the upper gastrointestinal tract (L4). Disease behavior, as determined at the time of last visit or telephone contact, was nonstricturing, nonpenetrating (B1) in 149 (27.9%) patients, stricturing (B2) in 50 (9.3%) patients, and penetrating (B3) in 336 (62.8%) patients. Comparisons among the groups of 53 patients with first-degree relatives only, the 96 patients with either first-, second-, or third-degree relatives (familial CD group), and the 439 patients with sporadic disease demonstrated no differences in sex, age at diagnosis, or disease location. There was a difference in disease behavior between the familial and sporadic groups (p = 0.048) that failed to exist when nonstricturing, nonpenetrating cases were excluded. No such difference was observed between the first-degree relatives only group and the sporadic group (p > 0.10).

CONCLUSIONS

Using the Vienna Classification, familial and sporadic Crohn's disease differed only in disease behavior. However, this difference failed to exist after patients with nonstricturing, nonpenetrating disease were excluded. Therefore, familial and sporadic groups appear to be quite similar clinically, and family history does not appear to be a variable useful for disease subclassification.

CARD15 and HLA DRB1 alleles influence susceptibility and disease localization in Crohn's disease

OBJECTIVES

Crohn's disease (CD) is a chronic inflammatory disease of the gut associated with allelic variants of CARD15 and HLA-DRB1 genes. We investigated the prevalence and effects of these variants in a Canadian CD cohort.

METHODS

507 unrelated CD patients were genotyped for the three major CD-associated variants (Arg702Trp, Gly908Arg, and Leu1007fsinsC) and for thirteen HLA-DRB1 alleles.

RESULTS

At least one CARD15 variant was present in 32.5% of the CD patients compared with 20% of controls. The prevalence of CARD15 mutation was similar in both sporadic and familial and Jewish and non-Jewish CD patients. The Gly908Arg variant was significantly higher and the Arg702Trp variant significantly lower in Jewish compared to non-Jewish patients. A positive association between the HLA-DRB1*0103 allele and CD was detected in non-Jewish, familial cases (p = 0.0002), with risk for CD increased by 6.7 fold by the presence of an HLA-DRB1*0103 allele as compared to 1.9 fold and 19 fold by a single or two CARD15 variant alleles, respectively. We show a significant association of ileal involvement with CARD15 variants (OR = 1.8; p = 0.02), HLA-DRB1*0701 (OR = 1.9; p = 0.006) and DRB1*04 (OR = 1.7; p = 0.02) alleles and demonstrate the capacity of combined CARD15 and HLA-DRB1 genotyping to predict ileal disease in CD patients. By contrast, the HLA-DRB1*0103 allele was associated with later age of diagnosis (p = 0.02) and pure colonic disease (p = 0.000013).

CONCLUSIONS

These observations confirm the influence of CARD15 and HLA-DRB1 alleles on both CD susceptibility and site of disease and identify genotyping of these variants as a potential tool for improved diagnosis and risk prediction in CD.

Genotype-based phenotyping heralds a new taxonomy for inflammatory bowel disease

Inflammatory bowel disease (IBD) has traditionally been categorized as either ulcerative colitis or Crohn disease on the basis of clinical, radiologic, and histologic criteria. Within these diseases, however, significant heterogeneity is observed, suggesting the existence of phenotypic subtypes, based on features such as location and behavior of disease. Evidence for a possible genetic basis of these subgroups first emerged in the 1990s from epidemiologic studies in multiply affected families. Recent advances in our understanding of the genetics of IBD, in particular the identification of NOD2/CARD15, have provided the opportunity to explore the genetic basis for this heterogeneity. This article reviews recent studies investigating the contribution of genetics to IBD phenotype. Although many of the genes remain unidentified, the emerging data suggests that IBD comprises a heterogeneous family of oligogenic inflammatory disorders in which the specific clinical manifestations of disease in any individual are determined by the interaction of genetic and environmental factors. These data have validated the approach of classifying patients into accurately defined clinical subgroups, and they raise the possibility that a genetic basis for the observed disease heterogeneity may account for the discrepant findings from earlier genetic studies. A future molecular classification will provide the framework to understanding the different biologic mechanisms that underlie the clinical subgroups of IBD and, by patient stratification, permit the unraveling of the complex interaction between the genetic and environmental causes of disease.

The relationship between heritability and smoking habits in Crohn's disease. Italian Cooperative Study Group

OBJECTIVE

In Crohn's disease (CD), the relationship between genetic predisposition and smoking has not been well defined. The aim of this study was to compare the smoking habits at the time of the diagnosis of CD patients having familial occurrence of inflammatory bowel disease (IBD) with those of some control groups.

METHODS

In a multicenter study, 136 CD patients with a relative with IBD, 272 healthy controls matched for sex and age, 500 CD patients without familial occurrence of IBD, and 84 ulcerative colitis patients (UC) with familial occurrence of IBD were personally interviewed about their smoking habits. In addition, data for 35 healthy siblings of patients with familial CD were collected by interviewing the patients' relatives.

RESULTS

The prevalence of smokers was found significantly higher in CD patients with a family history for IBD than in healthy controls and in familial UC patients (OR 2.28 CI 1.5-3.48 and OR 5.81 CI 3.15-10.75, respectively). No significant difference was found either in the percentage of smokers or in the number of cigarettes smoked per day between familial and sporadic CD patients. Among all siblings of CD patients, 72% of affected siblings and 34% of healthy siblings were smokers, concordant with their relatives.

CONCLUSIONS

In CD patients with familial occurrence of IBD, the percentage of smokers is elevated. It is possible that in a genetically predisposed population, smoking could be an important environmental factor in determining CD or expressing this disease instead of UC.

Familial and sporadic inflammatory bowel disease: different entities?

The strongest risk factor for developing inflammatory bowel disease (IBD) is having a relative with the disease. Familial IBD may be one homogeneous subgroup, phenotypically different from sporadic IBD. Several observations support a role for familiarity in disease site and behavior, particularly in Crohn's disease (CD), but published findings do not all concur. Early disease onset is often found in children with IBD who have a parent with the disease. Genetic anticipation may explain this finding but other explanations and/or observational biasis are more likely. Location and type may differ between familial and sporadic CD cases: family studies report many cases involving both small bowel and colon, and few cases of colonic disease alone, although such features may be secondary to early age at onset. Most studies found no effect of positive family history on severity and course of CD. In ulcerative colitis (UC), phenotypic differences between familial and sporadic cases appear to be limited, but little data are available for analysis. No difference has been found between familial and sporadic IBD as far as disease markers such as pANCA, ASCA, or intestinal permeability are concerned. In conclusion, the only message available for clinical practice is that the relative risk of IBD in first-degree relatives is increased by a factor of 10-15 compared with the general population. Families should not receive genetic counseling/information about age at onset and disease severity.

Isolated jejunal Crohn's disease in a young adult presenting as fever of unknown origin

A 27-yr-old man was referred for fever, weight loss, fatigue, and occasional mild epimesogastric pain without diarrhea or vomiting. Laboratory tests were suggestive of an active inflammatory disease but serological, bacteriological, viral searches, markers of autoimmunity, and neoplasia were all negative. The following were also negative: ultrasonography; conventional x-rays; CT scans; esophagogastroduodenoscopy, pancolonoscopy with ileoscopy; cytohistology including duodenum and ileocolon. Empiric antibiotic regimens failed to control the temperature. Small bowel enema disclosed multiple proximal jejunal strictures. Jejunoscopy revealed erythema, friability, linear ulcerations, stenosis, and dilation in the proximal jejunum. Multiple directed biopsies showed inflammatory changes devoid of any specific features. The patient received steroid treatment and his temperature normalized. Six months later, he was readmitted on account of intestinal subocclusion that was managed conservatively. A few days later urgent laparotomy was performed with peritoneal lavage, repair of double perforated proximal jejunal ulcers, and stricturoplasty. Surgical jejunal biopsy confirmed the results of enteroscopic biopsies. The patient is presently without fever, in the absence of steroid treatment. There have been no reports of cryptogenic fever due to isolated jejunal Crohn's disease in the recent literature. Our patient's clinical picture resembled disease as seen in older children and adolescents, in whom it is a difficult diagnosis owing to the absence of diarrhea. In adults with Crohn's disease isolated jejunal involvement represents approximately 1% of cases. A thorough small bowel investigation is warranted in young adults with cryptogenic fever and low serum protein levels, even in the absence of major gastrointestinal complaints.