Enno Gentz

DLG5 Variants in Inflammatory Bowel Disease

OBJECTIVES:Genetic variants within DLG5 were recently reported to be associated with inflammatory bowel disease (IBD). The aim of our study was to test for allelic and haplotype associations of six DLG5 variants in 668 IBD patients from two European populations. Furthermore, we evaluated whether DLG5 variants alter gastrointestinal permeability in Crohns disease (CD).METHODS:Six DLG5 variants (p.R30Q, p.P1371Q, p.G1066G, rs2289308, DLG_e26, p.D1507D) were genotyped in two study populations: (1) German IBD patients (CD n = 250; ulcerative colitis (UC) n = 150) and German healthy controls (n = 422); (2) Hungarian IBD patients (CD n = 144; UC n = 124) and Hungarian healthy controls (n = 205). Subtyping analysis was performed in respect of CARD15 mutations and clinical characteristics. We also tested for differences within DLG5 genotypes in German CD patients with respect to gastroduodenal and intestinal permeability measured by triple-sugar-test.RESULTS:Allele as well as genotype frequencies of DLG5 variants did not differ between IBD patients and controls in either study population. Indeed, the p.R30Q polymorphism was found more frequently in controls than in patients. The distribution of DLG5 genotypes in German and Hungarian CD patients with CARD15 mutations was not different from patients without mutated CARD15. We did also not observe any association between DLG5 variants and clinical parameters. Importantly, DLG5 variants were not associated with gastroduodenal or intestinal permeability.CONCLUSIONS:We could not replicate that DLG5 is a relevant disease susceptibility gene for IBD in German or Hungarian subjects. In addition, we have no evidence that DLG5 variants are involved in altered gastrointestinal permeability in CD.

Molecular and Clinical Evidence for an ARMC5 Tumor Syndrome: Concurrent Inactivating Germline and Somatic Mutations Are Associated With Both Primary Macronodular Adrenal Hyperplasia and Meningioma

CONTEXT Primary macronodular adrenal hyperplasia (PMAH) is a rare cause of Cushings syndrome, which may present in the context of different familial multitumor syndromes. Heterozygous inactivating germline mutations of armadillo repeat containing 5 (ARMC5) have very recently been described as cause for sporadic PMAH. Whether this genetic condition also causes familial PMAH in association with other neoplasias is unclear. OBJECTIVE The aim of the present study was to delineate the molecular cause in a large family with PMAH and other neoplasias. PATIENTS AND METHODS Whole-genome sequencing and comprehensive clinical and biochemical phenotyping was performed in members of a PMAH affected family. Nodules derived from adrenal surgery and pancreatic and meningeal tumor tissue were analyzed for accompanying somatic mutations in the identified target genes. RESULTS PMAH presenting either as overt or subclinical Cushings syndrome was accompanied by a heterozygous germline mutation in ARMC5 (p.A110fs*9) located on chromosome 16. Analysis of tumor tissue showed different somatic ARMC5 mutations in adrenal nodules supporting a second hit hypothesis with inactivation of a tumor suppressor gene. A damaging somatic ARMC5 mutation was also found in a concomitant meningioma (p.R502fs) but not in a pancreatic tumor, suggesting biallelic inactivation of ARMC5 as causal also for the intracranial meningioma. CONCLUSIONS Our analysis further confirms inherited inactivating ARMC5 mutations as a cause of familial PMAH and suggests an additional role for the development of concomitant intracranial meningiomas.

Possible role of MDR1 two-locus genotypes for young-age onset ulcerative colitis but not Crohn's disease

BackgroundThe role of the single nucleotide polymorphisms (SNPs) on positions 2677G>T/A and 3435C>T of the multi-drug-resistance gene 1 (MDR1) in inflammatory bowel disease (IBD) remains unclear.AimsTo further elucidate the potential impact of MDR1 two-locus genotypes on susceptibility to IBD and disease behaviour.Patients and methodsThree hundred eighty-eight German IBD patients [244 with Crohn’s disease (CD), 144 with ulcerative colitis (UC)] and 1,005 German healthy controls were genotyped for the two MDR1 SNPs on positions 2677G>T/A and 3435C>T. Genotype–phenotype analysis was performed with respect to disease susceptibility stratified by age at diagnosis as well as disease localisation and behaviour.ResultsGenotype distribution did not differ between all UC or CD patients and controls. Between UC and CD patients, however, we observed a trend of different distribution of the combined genotypes derived from SNPs 2677 and 3435 (χ2 = 15.997, df = 8, p = 0.054). In subgroup analysis, genotype frequencies between UC patients with early onset of disease and controls showed significant difference for combined positions 2677 and 3435 (χ2 = 16.054, df = 8, p = 0.034 for age at diagnosis ≥25, lower quartile). Herein the rare genotype 2677GG/3435TT was more frequently observed (odds ratio = 7.0, 95% confidence interval 2.5 – 19.7). In this group severe course of disease behaviour depended on the combined MDR1 SNPs (χ2 = 16.101, df = 6, p = 0.017 for age at diagnosis ≥25). No association of MDR1 genotypes with disease subgroups in CD was observed.ConclusionsWhile overall genotype distribution did not differ, combined MDR1 genotypes derived from positions 2677 and 3435 are possibly associated with young age onset of UC and severe course of disease in this patient group.

The c.1-260C>T promoter variant of CD14 but not the c.896A>G (p.D299G) variant of toll-like receptor 4 (TLR4) genes is associated with inflammatory bowel disease.

Background: Inflammatory bowel disease (IBD) results from an aberrant immune response to the indigenous intestinal flora in genetically susceptible hosts. Therefore, the study of candidate genes involved in host pathogen interactions is of key interest. Methods: In this two-center, retrospective German and Hungarian cohort study, patients with Crohn’s disease (CD) (n = 379; German n = 235, Hungarian n = 144) and ulcerative colitis (UC) (n = 263; German n = 145, Hungarian n = 118) and healthy controls (n = 605; German n = 403, Hungarian n = 202) were genotyped for the presence of the CD14 c.1-260C>T promoter variant and the TLR4 c.896A>G (p.D299G) variant by melting curve analysis using fluorescence resonance energy transfer probes. Data were stratified according to the presence of NOD2 (CARD15) mutations and a detailed genotype-phenotype analysis was performed. Results: In the German cohort the CD14 single-nucleotide polymorphism was associated with UC, but not CD (UC p = 0.016 vs. CD p = 0.190), while the opposite was found in the Hungarian cohort (UC p = 0.083 vs. CD p = 0.019). No association of IBD with the TLR4 single-nucleotide polymorphism was found in either cohort (UC p = 0.430, CD p = 0.783 vs. UC p = 0.745, CD p = 0.383). Conclusion: IBD appears to be associated with the CD14 c.1-260C>T promoter variant in Germans and Hungarians, but not with the TLR4 c.896A>G (p.D299G) variant.

No association of the CARD8 (TUCAN) c.30T>A (p.C10X) variant with Crohn's disease: a study in 3 independent European cohorts.

Background: A recent study reported that the c.30T>A (p.Cys10Ter; rs2043211) variant, in the CARD8 (TUCAN) gene, is associated with Crohns disease (CD). The aim of this study was to analyze the frequency of p.C10X in 3 independent European (IBD) cohorts from Germany, Hungary, and the Netherlands. Methods: We included a European IBD cohort of 921 patients and compared the p.C10X genotype frequency to 832 healthy controls. The 3 study populations analyzed were: (1) Germany [CD, n = 317; ulcerative colitis (UC), n = 180], (2) Hungary (CD, n = 149; UC, n = 119), and (3) the Netherlands (CD, n = 156). Subtyping analysis was performed in respect to NOD2 variants (p.Arg702Trp, p.Gly908Arg, c.3020insC) and to clinical characteristics. Ethnically matched controls were included (German, n = 413; Hungarian, n = 202; Dutch, n = 217). Results: We observed no significant difference in p.C10X genotype frequency in either patients with CD or patients with UC compared with controls in all 3 cohorts. Conversely to the initial association study, we found a trend toward lower frequencies of the suggestive risk wild type in CD from the Netherlands compared with controls (P = 0.14). We found neither evidence for genetic interactions between p.C10X and NOD2 nor the C10X variant to be associated with a CD or UC phenotype. Conclusions: Analyzing 3 independent European IBD cohorts, we found no evidence that the C10X variant in CARD8 confers susceptibility for CD.

A study in three European IBD cohorts confirms that the ATG16L1 c.898A > G (p.Thr300Ala) variant is a susceptibility factor for Crohn’s disease

BACKGROUND AND AIMS A recent study reported that a nonsynonymous SNP rs2241880 (c.898A>G, p.Thr300Ala) within ATG16L1 confers susceptibility to Crohns disease (CD). We analyzed ATG16L1 c.898A>G in three independent European inflammatory bowel disease (IBD) cohorts from Germany, Hungary and the Netherlands. METHODS In total, we included 910 European IBD patients and compared the ATG16L1 c.898A>G genotype frequency with 707 ethnically matched healthy controls. We included patients from 3 populations originating from Germany (CD n=310; ulcerative colitis [UC] n=179), Hungary (CD n=147; UC n=117), and the Netherlands (CD n=157). Subtyping analysis was performed in respect to CARD15 alterations and clinical characteristics. RESULTS We found a highly significant association of c.898A>G to CD. The association was significant (p=0.0005) for the total CD cohort but also for the individual populations from Germany (p=0.02) and Netherlands (p=0.02) whereas in the Hungarian CD patients a clear trend was observed (p=0.19; OR 1.227, 95% CI 0.910; 1.654). No association was found between c.898A>G and UC. No statistical interactions were observed between ATG16L1 c.898A>G and CARD15 variants. Furthermore no association to a CD subphenotype was detected. CONCLUSIONS We confirm that ATG16L1 variant c898A>G confers a risk variant for CD but is not associated with a distinct CD phenotype.

Visceral Adipose Tissue in Patients with Crohn's Disease Correlates with Disease Activity, Inflammatory Markers, and Outcome

Background:Visceral adipose tissue (VAT) could affect Crohns disease (CD); however, no prospective clinical studies have explored the issue. Methods:We measured VAT with magnetic resonance imaging and total fat mass (FM) with air-displacement plethysmography in 31 women with CD in remission and 19 matched control women. We assessed the VAT/FM ratio as index of VAT accumulation, measured cytokines, and monitored clinical features (duration of remission, disease behavior, and outcome) in patients with CD retrospectively and prospectively. We also tested whether ultrasound could provide a surrogate marker of VAT in patients with CD. Results:Patients with CD had higher percentage of FM (37 ± 10% versus 31 ± 10%, P = 0.03), VAT (1885 ± 1403 mL versus 941 ± 988 mL, P = 0.02), and VAT/FM ratio (65 ± 24 mL/kg versus 37 ± 25 mL/kg, P = 0.004) than control women. In patients with CD, VAT/FM ratio was associated with leptin (P = 0.009) and interleukin 6 (P = 0.032) concentrations, and higher in short-term than in long-term remission (72.6 ± 27.1 mL/kg versus 54.8 ± 16.1 mL/kg, P = 0.079). Patients with CD with stricturing/fistulizing disease had a higher VAT/FM ratio than patients with nonstricturing/nonfistulizing behavior (79 ± 0.15 mL/kg versus 63 ± 28 mL/kg, P = 0.067). A higher baseline VAT/FM ratio was associated with an increased disease activity at follow-up (P = 0.029). The ultrasound-determined thickness between the abdominal wall and the aorta was strongly associated with VAT as measured by magnetic resonance imaging (P < 0.001). Conclusions:VAT accumulation could be a prospective risk factor for increased disease activity in CD.

Multifrequency Time-Harmonic Elastography for the Measurement of Liver Viscoelasticity in Large Tissue Windows

Elastography of the liver for the non-invasive diagnosis of hepatic fibrosis is an established method. However, investigations of obese patients or patients with ascites are often limited by small and superficial elastographic windows. Therefore, multifrequency time-harmonic elastography (THE) based on time-resolved A-line ultrasound has recently been developed for measuring liver viscoelasticity in wide soft tissue windows and at greater depths. In this study, THE was integrated into a clinical B-mode scanner connected to a dedicated actuator bed driven by superimposed vibrations of 30- to 60-Hz frequencies. The resulting shear waves in the liver were captured along multiple profiles 7 to 14 cm in width and automatically processed for reconstruction of mean efficient shear wave speed and shear wave dispersion slope. This new modality was tested in healthy volunteers and 22 patients with clinically proven cirrhosis. Patients could be separated from controls by higher shear wave speeds (3.11 ± 0.64 m/s, 2.14-4.81 m/s, vs. 1.74 ± 0.10 m/s, 1.60-1.91 m/s) without significant degradation of data by high body mass index or ascites. Furthermore, the wave speed dispersion slope was significantly (p = 0.0025) lower in controls (5.2 ± 1.8 m/s/kHz) than in patients (39.1 ± 32.2 m/s/kHz). In conclusion, THE is useful for the diagnosis of cirrhosis in large tissue windows.

Use of Intestinal Ultrasound to Monitor Crohn’s Disease Activity

BACKGROUND & AIMS We performed a multicenter study to determine whether transabdominal bowel wall ultrasonography, a noninvasive procedure that does not require radiation, can be used to monitor progression of Crohn’s disease (CD). METHODS We performed a 12‐month prospective, noninterventional study at 47 sites in Germany, from December 2010 through September 2014. Our study included 234 adult patients with CD who experienced a flare, defined as Harvey‐Bradshaw index score of ≥7. All patients received treatment intensification, most with tumor necrosis factor antagonists. Ultrasound parameters and clinical data were assessed at baseline and then after 3, 6, and 12 months. The primary endpoint was the change in ultrasound parameters within 12 months of study enrollment. RESULTS All patients included had bowel wall alterations either within the terminal ileum and/or segments of the colon. After 3 and 12 months, ultrasonographic examination showed significant improvements of nearly all ultrasound parameters, including reductions in bowel wall thickening or stratification, decreased fibrofatty proliferation, and increased signals in color Doppler ultrasound (P < .01 for all parameters at months 3 and 12). Median Harvey‐Bradshaw index scores decreased from 10 at baseline to 2 after 12 months. Improvement in bowel wall thickness correlated with reduced levels of C‐reactive protein after 3 months (P ≤ .001). CONCLUSIONS In a multicenter prospective study, we found that ultrasonographic examination can be used to monitor disease activity in patients with active CD. Bowel ultrasonography seems to be an ideal follow‐up method to evaluate early transmural changes in disease activity, in response to medical treatment. German Clinical Trials Register: drks.de/DRKS00010805.

Contents Vol. 76, 2007

C. Beglinger, Basel (Switzerland) B. Göke, Munich (Germany) International Journal of Gastroenterology Founded as ‘Archiv für Verdauungskrankheiten’ 1895 by I. Boas Continued as ‘Gastroenterologia’ 1939–1967 Former Editors: P. Morawitz (1934–1936), R. Staehelin (1937–1943), A. Hurst (1940–1945), W. Löffl er (1943–1961), T.C. Hunt (1947–1967), N. Henning (1953–1962), B. Ihre (1953–1967), H. Bartelheimer (1963–1967), M. Demole (1963–1971), H. Kapp (1968–1970), R. Lambert (1972–1978), W. Creutzfeldt (1979–1992), R. Arnold (1993–2003)