Concordance of familial characteristics in Crohn's disease and ulcerative colitis

Concordance regarding disease type and phenotypic characteristics among patients with familial inflammatory bowel disease

BACKGROUND AND AIMS

The phenotypic concordance among familial cases of inflammatory bowel disease (IBD) has been rarely reported. Thus, the present study aimed to evaluate the concordance regarding disease type and phenotypic features in a large cohort of Korean patients with IBD.

METHODS

A total of 6647 patients with IBD who visited the Asan Medical Center between June 1989 and September 2016 were enrolled in the study. When at least two familial cases existed in our cohort, they were included in the concordance analysis (κ index). The concordance between younger and older members for IBD type [Crohn's disease (CD) and ulcerative colitis (UC)] and phenotypic characteristics such as disease extent and location, disease behavior, the use of medication, and need for surgery were evaluated.

RESULTS

A positive family history of IBD was noted in 216 patients with CD (7.0%) and in 238 patients with UC (6.7%). Of all patients, 167 consanguineous pairs in 146 families were identified. The crude concordance rate for IBD type was 82.6% with a κ index of 0.656 [95% confidence interval (CI): 0.545-0.768, good concordance]. There was mild concordance for disease location in CD (κ = 0.256; 95% CI: 0.007-0.505) and for the use of antitumor necrosis factor agents in UC (κ = 0.354; 95% CI: -0.049-0.757). The concordance for IBD type and several phenotypes in first-degree relative pairs was better than that in the entire pairs.

CONCLUSIONS

Disease type and phenotypic characteristics of patients with familial IBD may be anticipated.

Phenotypic concordance in familial inflammatory bowel disease (IBD). Results of a nationwide IBD Spanish database

BACKGROUND & AIMS

Disease outcome has been found to be poorer in familial inflammatory bowel disease (IBD) than in sporadic forms, but assessment of phenotypic concordance in familial IBD provided controversial results. We assessed the concordance for disease type and phenotypic features in IBD families.

METHODS

Patients with familial IBD were identified from the IBD Spanish database ENEIDA. Families in whom at least two members were in the database were selected for concordance analysis (κ index). Concordance for type of IBD [Crohn's disease (CD) vs. ulcerative colitis (UC)], as well as for disease extent, localization and behaviour, perianal disease, extraintestinal manifestations, and indicators of severe disease (i.e., need for immunosuppressors, biological agents, and surgery) for those pairs concordant for IBD type, were analyzed.

RESULTS

798 out of 11,905 IBD patients (7%) in ENEIDA had familial history of IBD. Complete data of 107 families (231 patients and 144 consanguineous pairs) were available for concordance analyses. The youngest members of the pairs were diagnosed with IBD at a significantly younger age (p<0.001) than the oldest ones. Seventy-six percent of pairs matched up for the IBD type (κ=0.58; 95%CI: 0.42-0.73, moderate concordance). There was no relevant concordance for any of the phenotypic items assessed in both diseases.

CONCLUSIONS

Familial IBD is associated with diagnostic anticipation in younger individuals. Familial history does not allow predicting any phenotypic feature other than IBD type.

Environmental risk factors and Crohn's disease: a population-based, case-control study in Spain

BACKGROUND

The pathogenesis of inflammatory bowel disease probably involves an interaction between genetic and environmental factors: cigarette smoking, appendectomy and oral contraceptives have been the factors most frequently linked to its aetiology

AIM

To analyse the association between known environmental risk factors and development of Crohn's disease in the community of Aragón, Spain.

PATIENTS AND METHODS

A case-control, population-based study has been carried out. All patients diagnosed with Crohn's disease in the community of Aragón from 1st February 1992 to 31st January 1995 were prospectively included. The Lennard Jones criteria were used to define the cases and selected controls among the healthy population matched with patients for age, sex and rural/urban habitat. Statistical analysis included multivariate analysis using conditional logistic regression, testing 38 different models.

RESULTS

A total of 103 patients were diagnosed with Crohn's disease in Aragón from 1st February, 1992 to 31st January, 1995. Of these 62 patients (60.2%) with Crohn's disease were smokers, compared with 42 (40.8%) controls (p<0.001). Cigarette smoking is considered a risk factor for Crohn's disease with an odds ratio of 3.09 (95% confidence interval, 1.58-6.05). After multivariate analysis, the positive association is maintained. A dose-dependent relation could not be demonstrated. No statistical differences (p=0.50) were detected in the analysis of previous appendectomy. Use of oral contraceptive acts as a risk factor with a p=0.048; odds ratio 2, 8, 95% confidence interval: 1.009-7.774; but this association disappears in the multivariate analysis. Eight patients had a family history (3 first degree and 5 second degree relatives) versus none of the controls (p=0.002). Of the variables studied for childhood hygiene none appeared significant.

CONCLUSION

Smoking, family history, and oral contraceptive use, appear as risk factors for developing Crohn's disease in univariate analysis, but only smoking remains significant in all models of multivariate analysis.

Clinical features in familial cases of Crohn's disease and ulcerative colitis in Italy: a GISC study. Italian Study Group for the Disease of Colon and Rectum

OBJECTIVE

Previous studies have reported genetic anticipation, genomic imprinting, and phenotypic concordance of some clinical features in familial cases of Crohn's disease (CD) and ulcerative colitis (UC). The aim of our study was to investigate the phenotypic features of affected members in a large sample of CD and UC Italian families.

METHODS

In a multicenter study, CD and UC families were recruited. Affected members were questioned about date of birth, gender, age at onset of symptoms and at diagnosis, location and extension of disease, occurrence of extraintestinal manifestations, use of steroids and/or of immunosuppressive drugs, need for resective surgery, and number of relapses per year (< 1 yr or > or = 1 yr). Statistical analysis was performed with chi2, Fisher's, Mann-Whitney U, and binomial probability tests, when appropriate.

RESULTS

A total of 128 families with 270 affected members were studied: 35 were CD, 64 UC, and 29 mixed families (when UC and CD affected different members). In 99 of 128 families (77%), the diagnosis was concordant. In CD families, a high concordance for localization (46%), extraintestinal manifestations (67%), need for steroids (77%), need for immunosuppressive drugs (100%), need for surgery (29%), and relapse rate (36%) was found. In UC families, a high concordance for disease extension (33%), need for steroids (47%), and relapse rate (34%) was disclosed. A higher than expected concordance for ileal localization (p < 0.4) in CD families and extensive colitis (p < 0.05) in UC families was demonstrated. A generation difference of 15-20 yr in mean ages at onset of symptoms and at diagnosis was recorded. No features of more aggressive disease in subsequent generations and no differences in gender of transmitting parents and relatives were found.

CONCLUSIONS

Our study shows a high rate of concordance for diagnosis and clinical features in UC and, especially, CD families. The disease occurred 15-20 yr earlier than in previous generations without features of increased severity.

Genotype-phenotype relationship in inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) are chronic diseases of unknown etiology. Much effort has been made in the last years to clarify the pathogenesis of inflammatory bowel disease (IBD). Data are not conclusive at the moment, but the most important known risk factor for developing IBD is a positive familial history. Genetic analyses have shown a linkage between loci on several chromosomes and IBD (IBD1 gene on chromosome 16 for CD and on chromosome 12 for UC). The association of genotype to specific phenotypes of disease could be hypothesized by the concordance of clinical characteristics in familial IBD, by the association of specific HLA haplotypes to clinically different groups of patients, and by different responses to treatment related to different polymorphisms of other chromosome 6 genes. The clinical heterogeneity of IBD has led to classifications of patients with Crohn's disease based upon clinical features (e.g. Rome and Vienna classifications) that allow the identification of subgroups of patients with similar clinical behavior. The possible drawbacks of these classifications are the lack of validation of intra-interobserver concordance, the absence of prospective evaluations, and stratification into too many subgroups. Furthermore, in our experience, clinical presentation (surgical or medical) seems to have a good correlation with prognosis, is easy identifiable, and can be applied at the time of diagnosis. In UC, extension of disease and clinical behavior correlate with prognosis. For these reasons, studies correlating genotype to phenotype should be performed to improve our knowledge of the diseases and possibly to stratify patients into different subgroups for more personalized treatments, in clinical trials and for research purposes.