Gender-stratified analysis of DLG5 R30Q in 4707 patients with Crohn disease and 4973 controls from 12 Caucasian cohorts.

BACKGROUND: DLG5 p.R30Q has been reported to be associated with Crohn disease (CD), but this association has not been replicated in most studies. A recent analysis of gender-stratified data from two case-control studies and two population cohorts found an association of DLG5 30Q with increased risk of CD in men but not in women and found differences between 30Q population frequencies for males and females. Male-female differences in population allele frequencies and male-specific risk could explain the difficulty in replicating the association with CD. METHODS: DLG5 R30Q genotype data were collected for patients with CD and controls from 11 studies that did not include gender-stratified allele counts in their published reports and tested for male-female frequency differences in controls and for case-control frequency differences in men and in women. RESULTS: The data showed no male-female allele frequency differences in controls. An exact conditional test gave marginal evidence that 30Q is associated with decreased risk of CD in women (p = 0.049, OR = 0.87, 95% CI 0.77 to 1.00). There was also a trend towards reduced 30Q frequencies in male patients with CD compared with male controls, but this was not significant at the 0.05 level (p = 0.058, OR = 0.87, 95% CI 0.74 to 1.01). When data from this study were combined with previously published, gender-stratified data, the 30Q allele was found to be associated with decreased risk of CD in women (p = 0.010, OR = 0.86, 95% CI 0.76 to 0.97), but not in men. CONCLUSION: DLG5 30Q is associated with a small reduction in risk of CD in women.

The role of the selenoprotein S (SELS) gene -105G>A promoter polymorphism in inflammatory bowel disease and regulation of SELS gene expression in intestinal inflammation.

Recently, a -105G>A promoter polymorphism coding for selenoprotein S (SELS) has been shown to increase proinflammatory cytokine expression. We, therefore, analyzed SELS expression and potential phenotypic consequences of the -105G>A polymorphism in patients with inflammatory bowel disease (IBD). SELS mRNA was measured by quantitative polymerase chain reaction (PCR) in intestinal epithelial cells (IEC) after stimulation with proinflammatory cytokines and in human colonic biopsies of IBD patients as well as in murine models of ileitis and murine cytomegalovirus (MCMV) colitis. Genomic DNA from 563 individuals (Crohn's disease: n = 205; ulcerative colitis: n = 154; controls: n = 204) was analyzed for the presence of the SELS-105G>A polymorphism and the three nucleotide-binding oligomerization domain-containing protein 2 (NOD2)/caspase recruitment domain-containing protein 15 (CARD15) variants p.Arg702Trp, p.Gly908Arg and p.Leu1007fsX1008. SELS mRNA expression was increased in IEC after stimulation with proinflammatory cytokines, while its expression was not significantly altered in murine ileitis and MCMV colitis and in inflamed ileal and colonic lesions in IBD patients compared with normal controls. The SELS-105G>A polymorphism was observed with similar frequencies in IBD patients and controls and was not associated with a certain disease phenotype or serum tumor necrosis factor alpha (TNF-alpha) levels in these patients. Medium serum TNF-alpha was 1.27 pg/ml in IBD patients, while none of the controls had TNF-alpha concentrations above the detection threshold (P < 0.0001). SELS mRNA expression is upregulated by proinflammatory cytokines in IECs but the SELS-105G>A polymorphism is not associated with IBD susceptibility and does not contribute to a certain disease phenotype or increased TNF-alpha levels in IBD patients.

A645G (Lys216Glu) polymorphism of the bactericidal/permeability-increasing protein gene in periodontal disease.

Bactericidal/permeability-increasing protein (BPI) is a member of the pattern recognition receptors of the innate immune system and recognizes lipopolysaccharides (LPS), a bacterial component belonging to the pathogen-associated molecular patterns (PAMPs). BPI mediates the neutralization of LPS and increases the phagocytosis and cytotoxicity against bacteria. Recently, the functionally effective polymorphism A645G resulting in the amino acid alteration Lys216Glu has been described. The aim of the study was to investigate the association of the A645G polymorphism with chronic periodontal disease. The study population comprised 123 patients with periodontal disease (36 with mild, 52 with moderate and 35 with severe periodontitis) and 122 healthy, unrelated control individuals. Genotyping of the BPI gene polymorphism A645G (Lys216Glu) was performed by polymerase chain reaction and restriction fragment length polymorphism analysis. Statistical analysis was carried out employing the chi(2) test with Yates correction. Genotype and allele frequencies of the polymorphism tested herein showed no significant differences between periodontal disease as compared to the control group. The frequencies of the G allele were 52.4% in patients with periodontal disease and 49.2% in the control individuals (P = 0.528). Moreover, no significant associations could be detected after stratification for disease severity and according to gender. The present study does not give evidence for the contribution of the BPI gene to the genetic background of chronic periodontal disease.

The leukocyte count predicts the efficacy of treatment with azathioprine in inflammatory bowel disease.

INTRODUCTION: Azathioprine has variable efficacy in inflammatory bowel disease. Previous studies suggested that either neutropenia, an increase in the mean corpuscular volume, the assessment of thiopurine methyl-transferase activity or erythrocyte 6-thioguanine values might predict the treatment response. However, due to the conflicting results of the preceding studies there are yet no established laboratory values which allow an estimation of the clinical response. PATIENTS AND METHODS: 45 patients with Crohn's disease and 39 patients with ulcerative colitis were enrolled in this retrospective evaluation. After a minimum of six months therapy with azathioprine patients in remission were compared with those who did not achieve a stable remission with respect to the number of leucocytes, lymphocytes, neutrophil granulocytes and the mean corpuscular volume. RESULTS: Patients who went into remission during treatment with azathioprine displayed significantly lower leukocyte counts if compared to patients who were not in remission (p = 0.004 in Crohn's disease and 0.003 in ulcerative colitis). A similar tendency was also observed with respect to the granulocyte count (p = 0.007 in Crohn's disease and 0.004 in ulcerative colitis). The mean corpuscular volume did not correlate with the response to purine analogues. DISCUSSION: The absolute leukocyte count and the percentage of granulocytes seem to predict the response to purine analogues in inflammatory bowel disease and possibly offers a feasible and cost effective diagnostic tool for the assessment of therapeutic efficacy. Subsequent preferably prospective studies should aim to define the optimal cut-off value for the leukocyte count.

Serum antibodies in first-degree relatives of patients with IBD: a marker of disease susceptibility? A follow-up pilot-study after 7 years.

INTRODUCTION: Various disease-specific serum antibodies were described in patients with inflammatory bowel disease and their yet healthy first-degree relatives. In the latter, serum antibodies are commonly regarded as potential markers of disease susceptibility. The present long-term follow-up study evaluated the fate of antibody-positive first-degree relatives. PATIENTS AND METHODS: 25 patients with Crohn's disease, 19 patients with ulcerative colitis and 102 first-degree relatives in whom presence of ASCA, pANCA, pancreatic- and goblet-cell antibodies had been assessed were enrolled. The number of incident cases with inflammatory bowel disease was compared between antibody-positive and antibody-negative first-degree relatives 7 years after storage of serum samples. RESULTS: 34 of 102 (33%) first-degree relatives were positive for at least one of the studied serum antibodies. In the group of first-degree relatives, one case of Crohn's disease and one case of ulcerative colitis were diagnosed during the follow-up period. However, both relatives did not display any of the investigated serum antibodies (p=1). DISCUSSION: The findings of our pilot study argue against a role of serum antibodies as a marker of disease susceptibility in first-degree relatives of patients with inflammatory bowel disease. However, these data have to await confirmation in larger ideally prospective multicenter studies before definite conclusions can be drawn.

Prevalence of the -295 T-to-C promoter polymorphism of the interleukin (IL)-16 gene in periodontitis.

Interleukin (IL)-16 is involved in the regulation of the expression of several proinflammatory cytokines, i.e. tumour necrosis factor (TNF)alpha and interleukin (IL)-1beta. The present study aimed to determine the prevalence of the -295 promoter polymorphism of the interleukin (IL)-16 gene in periodontal disease. A total of 123 patients with periodontal disease and 122 healthy controls were genotyped for the -295 IL-16 promoter polymorphism. Genotyping has been performed by PCR and restriction fragment length polymorphism (RFLP) analysis. The frequencies of alleles and genotypes as well of haplotypes within both study groups were compared using the Pearson chi(2) test at a level of significance of 5% (P < 0.05). The distribution of genotypes for the -295 IL-16 gene polymorphism showed no significant difference between periodontitis patients and healthy control subjects (P = 0.886). Also stratification analysis according to the disease severity revealed no significant difference regarding the genotype distribution among both study groups. Herein the IL-16 -295 gene polymorphism was not associated with chronic periodontitis.

Polymorphisms in the DLG5 and OCTN cation transporter genes in Crohn's disease.

BACKGROUND AND AIMS: Recent data suggest identification of causal genetic variants for inflammatory bowel disease in the DLG5 gene and in the organic cation transporter (OCTN) cluster, both situated in previously described linkage regions. PATIENTS AND METHODS: The polymorphisms in DLG5 (113 G-->A, 4136 C-->A, and DLG5_e26), SLC22A4 (1672 C-->T), and SLC22A5 (-207 G-->C) were assessed in 625 patients with Crohn's disease (CD), 363 patients with ulcerative colitis (UC), and 1012 healthy controls. Association with disease susceptibility, clinical phenotypes, and possible genetic interactions of these polymorphisms with disease associated CARD15/NOD2 mutations was analysed. RESULTS: No significant association of DLG5 polymorphisms with CD or UC was observed. Homozygosity for the OCTN-TC haplotype was associated with an increased CD risk (OR = 1.65), which was even greater in the presence of CARD15 mutations. Genotype-phenotype analysis revealed that this association was particularly strong in patients with colonic disease. The TC haplotype was associated with non-fistulising non-fibrostenotic disease, an earlier age of disease onset, and reduced need for surgery. CONCLUSION: Our observations argue against a role of DLG5 polymorphisms in the susceptibility for inflammatory bowel disease, whereas the OCTN polymorphisms are associated with CD. However, due to the comparable weak association observed herein, extended linkage disequilibrium analyses of these variants with the IBD5 haplotype tagged single nucleotide polymorphims might be advisable before definitive conclusions about their causative role in CD can be drawn.

Pancreatic autoantibodies in Crohn's disease: a feasible diagnostic tool?

Potential implications of antibody markers in Crohn's disease: Diagnostic markers, alone or in conjunction with other antibodies? Delineation of clinical phenotypes? Markers of disease behaviour? Markers of (genetic) susceptibility? Identification of genetically homogenous subgroups? Bridge between basic science and clinic? The exact role of serum antibodies in inflammatory bowel disease remains a matter of ongoing debate. Although a direct implication in the disease pathogenesis is unlikely, their diagnostic potential in cases of an undetermined colitis or in defining clinical phenotypes in Crohn's disease has been shown in several studies. Serum antibodies might also be helpful in predicting the disease behaviour and are thus valuable tools in the choice of medical or surgical therapy.

Inflammatory bowel disease-specific autoantibodies in HLA-B27-associated spondyloarthropathies: increased prevalence of ASCA and pANCA.

AIMS: An association between inflammatory bowel disease (IBD) and spondyloarthropathies (SpA) has repeatedly been reported. The aim of the present study was to investigate whether serologic markers of IBD, e.g. antibodies against Saccharomyces cerevisiae (ASCA), antibodies against exocrine pancreas (PAB) and perinuclear antineutrophil cytoplasmic antibodies (pANCA) are present in HLA-B27-associated SpA. METHODS: 87 patients with HLA-B27-positive SpA and 145 controls were tested for ASCA, PAB and pANCA employing ELISA or indirect immunofluorescence, respectively. Antibody-positive patients were interviewed regarding IBD-related symptoms using a standardized questionnaire. RESULTS/CONCLUSION: When compared to the controls, ASCA IgA but not ASCA IgG levels were significantly increased in patients with SpA, in particular in ankylosing spondylitis (AS) and undifferentiated SpA (uSpA). pANCA were found in increased frequency in patients with SpA whereas PAB were not detected. The existence of autoantibodies was not associated with gastrointestinal symptoms but sustains the presence of a pathophysiological link between bowel inflammation and SpA.

No significant association between mutations in exons 6 and 8 of the autoimmune regulator (AIRE) gene and inflammatory bowel disease.

Various autoantibodies have been described in patients with inflammatory bowel disease. The autoimmune regulator (AIRE) functions as a transcription factor in cells responsible for the induction and maintenance of immunological tolerance. In contrast to classic autoimmune disorders, polymorphisms of the AIRE gene are not associated with inflammatory bowel disease, despite the presence of disease-specific autoantibodies.

Toll-like receptor (TLR) 2 and 4 mutations in periodontal disease.

Toll-like receptors (TLR) are signal molecules essential for the cellular response to bacterial cell wall components. Different functional effective polymorphisms for the TLR 4 gene (Asp299Gly; Thr399Ile) and for the TLR 2 gene (Arg677Trp, Arg753Gln) have recently been described that are associated with impaired lipopolysaccharide signal transduction. A total of 122 patients with chronic periodontal disease and 122 healthy unrelated controls were genotyped for the Asp299Gly and Thr399Ile polymorphism of the TLR 4 gene and the Arg677Trp and Arg753Gln mutation of the TLR 2 gene. The mutations were identified with polymerase chain reaction followed by restriction fragment length polymorphism (RFLP) analysis. The prevalence of the Asp299Gly and the Thr399Ile mutant allele was 4.1% (10/244) and 4.5% (11/244) among periodontitis patients. For the healthy controls the prevalence was 3.3% (8/244) for the Asp299Gly (P = 0.810) and 3.7% (9/244) for the Thr399Ile mutant allele (P = 0.819). The Arg753Gln mutant allele was found in 2.9% (7/244) of the periodontitis subjects as compared to 4.1% (10/244) in the control group (P = 0.622). The Arg677Trp mutant allele was not found in any of the study subjects. Unlike in ulcerative colitis there was not observed an association between chronic periodontitis and the various mutations of the TLR 2 and 4 gene.

Comparison of inflammatory bowel disease at younger and older age.

OBJECTIVE: In a substantial number of patients inflammatory bowel disease develops past the age of 40 years. However, data about the clinical presentation and disease behaviour in this age group are scarce. METHODS: The following parameters were evaluated retrospectively in 191 consecutive patients with inflammatory bowel disease: Gender, age at diagnosis, leading symptoms, disease localization and behaviour (e. g. fistulizing, fibrostenotic or inflammatory), extraintestinal manifestations, medication, smoking habits, dysplasia, cancer and mortality. RESULTS: In 16 % of patients inflammatory bowel disease had been diagnosed past the age of 40 years. In elderly patients with ulcerative colitis male gender was predominant. Diarrhea, abdominal pain and anaemia were observed more frequently in younger patients, whereas the remainder of parameters showed an equal distribution in both age groups. CONCLUSIONS: Younger patients are frequently afflicted by symptoms which potentially impair the quality of life. However, in this retrospective single center evaluation the disease localization and behaviour of inflammatory bowel disease in elderly patients was comparable to young adults. Due to a potential referral bias, these data await confirmation in larger prospective multicenter trials.

The Delta 32 mutation of the chemokine-receptor 5 gene neither is correlated with chronic hepatitis C nor does it predict response to therapy with interferon-alpha and ribavirin.

Unlike in HIV, homozygosity for a 32-bp deletion (Delta 32) of the chemokine receptor 5 (CCR5) gene was recently described in increased frequency in patients with chronic hepatitis C (HCV). Thus, it was speculated that this mutation might be relevant for disease susceptibility and influence the response to antiviral therapy. The present study sought to confirm the association between HCV and the Delta 32 mutation of the CCR5 gene and to correlate it with the response to therapy with interferon-alpha-2a and ribavirin. Sixty-two patients with HCV and 119 healthy unrelated controls were genotyped for the Delta 32 mutation. For the correlation between the Delta 32 mutation and response to therapy, only patients (n = 59) who completed 6 months of combination therapy as part of a prospective study were evaluated. The Delta 32 mutation was not observed in increased frequency in HCV. Furthermore, a significant difference of the HCV load or aminotransferase concentrations was not observed in carriers versus noncarriers of the Delta 32 mutation. After stratification for potentially confounding factors such as gender or HCV genotype, a significant difference was also not detected with respect to treatment outcome. These observations argue strongly against a role of CCR5 for susceptibility to HCV infection or response to combination therapy.

The -295T-to-C promoter polymorphism of the IL-16 gene is associated with Crohn's disease.

Recently, a T-to-C polymorphism at position -295 in the promoter region of the human interleukin-16 (IL-16) gene was reported. The expression of IL-16 is increased in inflammatory bowel disease, in particular in Crohn's disease. However, data concerning the IL-16 promoter polymorphism in inflammatory bowel disease are lacking. Thus, the current study aimed at the assessment of this polymorphism in Crohn's disease and ulcerative colitis. One hundred three patients with Crohn's disease, 100 patients with ulcerative colitis, and 120 healthy unrelated controls were genotyped for the promoter polymorphism. Furthermore, patients with Crohn's disease were stratified according to disease localization and the respective clinical phenotype (fistulizing, fibrostenotic, or inflammatory). The frequencies of the T allele (P < 0.01) and the TT genotype (P < 0.01) were significantly increased in patients with Crohn's disease compared to the controls, regardless of the disease phenotype or the site of intestinal involvement. An association with ulcerative colitis was not observed. Herein a new association between a promoter polymorphism of the IL-16 gene and Crohn's disease was observed and correlates with the previously described increased mucosal expression of IL-16 in inflammatory bowel disease.

Anti-saccharomyces cerevisiae antibodies in patients with inflammatory bowel disease and their first-degree relatives: potential clinical value.

Anti-Saccharomyces cerevisiae antibodies (ASCA) have been described as specific markers in Crohn's disease and their healthy first-degree relatives. 171 patients with Crohn's disease, their 105 first-degree relatives, 145 patients with ulcerative colitis and 101 first-degree relatives of patients with ulcerative colitis, 50 patients with infectious enterocolitis and 100 healthy controls were tested for ASCA employing the ELISA technique. When compared with the healthy controls (p < 0.0001) and patients with infectious enterocolitis (p < 0.0001) the prevalence of ASCA was significantly increased in patients with Crohn's disease and their first-degree relatives (p < 0.01). Further significant differences concerning the frequency of ASCA within the different groups of our study population were not observed. In particular, ASCA were not found in increased prevalence in infectious enterocolitis. These observations are compatible with a role of ASCA as a marker of genetic predisposition to Crohn's disease.