Interaction of Polymorphisms in the CARD15 and CD14 Genes in Patients with Crohn Disease

Background: Associations of variations in the CARD15 gene (Arg702Trp, Gly908Arg and Leu1007fsinsC) and Crohn disease (CD) have been shown recently. These variations are neither necessary nor sufficient for the genetic predisposition of CD. Further genetic and environmental factors play a crucial role in the pathogenesis of CD. Methods: To evaluate putative interactions between the CARD15 and CD14 genes in CD, a functionally relevant polymorphism in the promoter region (T/C at position &#109 159) has been genotyped for 650 healthy controls and 253 patients with CD by RFLP analyses. CD patients were genotyped for the variations of the CARD15 gene. Results: T allele and TT genotype frequencies of the CD14 promoter were significantly increased only in CD patients with at least one variation in the CARD15 gene compared to controls ( P &#114 = &#114 0.02 and 0.0002, respectively). No significant association was found in CD patients without any of the variations. Conclusion: Interactions of the CARD15 and CD14 genes, both of which are involved in the recognition of lipopolysaccharides, increase the risk for developing CD.     

CARD15 frameshift mutation in patients with Crohn disease is associated with immune dysregulation

Background: Mutations in the caspase-activating recruitment domain 15 (CARD15) gene are associated with Crohn disease (CD). CARD15 is an intracellular receptor for bacterial lipopolysaccharides (LPS). LPS-induced activation of transfectants containing the frameshift mutation (1007fs) of CARD15 is impaired. The aim of this study was to investigate whether the presence of CARD15 1007fs affects activation of CD patients' own cells. Patients (4 homozygotes, 6 heterozygotes, and 6 wild-type) were matched according to clinical picture and medication. Methods: Immune inflammatory status was evaluated by measuring monocyte HLA-DR and CD11b densities and the proportion of CD14[Formula: See Text]CD16[Formula: See Text] monocytes, and was found to be comparable in the three groups. Blood mononuclear cells were cultured overnight in serum-free medium alone, or the medium supplemented with LPS (0.1-10.0?ng/mL), a combination of IFN-γ (100 IU/mL) and granulocyte-macrophage colony stimulating factor (GM-CSF) (5?ng/mL), or both. TNF and IL-10 levels in the culture supernatant were determined. Results: LPS 0.1 or 1.0?ng/mL alone did not increase TNF levels. IFN-γ/GM-CSF induced TNF release, and co-culture with LPS 1.0 or 10.0?ng/mL was strongly synergistic. CARD15 1007fs mutation was linked in a gene-dose-dependent manner to low TNF release induced by IFN-γ/GM-CSF (P value for linear trend?=?0.001). The degree of synergism in co-culture was normal or high, suggesting that 1007fs did not depress responses to LPS. IL-10 levels were not related to CARD15 1007fs. Conclusions: In CD patients, CARD15 1007fs is associated in a gene-dose-dependent manner to low mononuclear cell TNF release by IFN-γ/GM-CSF but does not impair TNF release by LPS. This type of immune dysregulation may influence susceptibility to and/or phenotype of CD.     

Editorial: The CARD15 gene mutation in Crohn disease

Background: The immunosuppressive effects of thiopurine drugs are mainly mediated through their intracellular metabolism into active 6-thioguanine nucleotide (6-TGN) metabolites, which are incorporated into DNA. Erythrocyte 6-TGN (E-6TGN) levels have been proposed as an instrument for monitoring treatment. The aim of the study was to use erythrocyte E-6TGN, methylated mercaptopurine (MeMP) metabolites, and thiopurine methyltransferase (TPMT) measurements in a clinical setting to determine the clinical outcome in relation to thiopurine metabolism. Methods: Fifty-five adult patients with inflammatory bowel disease were included in a prospective study and followed for 6 months. Metabolite levels were measured and correlated to outcome and AZA/6-MP dose. Results: The E-6TGN level was significantly related to the TPMT genotype (P?=?0.008). Patients in disease remission had higher E-6TGN levels than patients with disease activity both at baseline (P?&;lt;?0.05) and after 6 months (P?=?0.02). Active disease was more frequent among subjects with E-6TGN?≤??125?nmol/mmol Hb at baseline (P?=?0.04), but not at 6 months. AZA/6-MP drug dose was positively correlated to E-MeMP levels (r [Formula: See Text]?=?0.48; P?&;lt;?0.001) and E-MeMP/E-6TGN ratio (r [Formula: See Text]?=?0.41; P?=?0.002). Dose changes were positively correlated with the changes in E-MeMP levels (P?=?0.01) and E-MeMP/E-6TGN ratio (P?=?0.03). Conclusions: E-6TGN level was the only factor in this study related to disease activity, while there was no relationship between AZA/6-MP dose and E-6TGN levels. This finding illustrates the clinical usefulness of E-6TGN monitoring in the evaluation of treatment intensity.     

Prevalence of mutations of the NOD2/CARD15 gene and relation to phenotype in Spanish patients with Crohn disease

BACKGROUND: We assessed the prevalence of R702W, G908R, and L1007fs coding mutations in the NOD2/CARD15 gene and the genotype-phenotype relation in Spanish patients with Crohn disease. METHODS: A cohort of 204 unrelated patients with Crohn disease and 140 healthy controls were studied. The phenotype was established before commencement of genotyping. Genotyping of the R702W, G908R, and L1007fs gene polymorphisms of NOD2/CARD15 was performed by two independent laboratories using different techniques. In the case of discordant results, specific sequencing of DNA strands was performed. RESULTS: At least one mutation was present in 32.8% of patients compared to 10.7% in controls (OR = 4.08, 95% CI 2.21 to 7.50). In patients with Crohn disease, the frequency of R702W, G908R, and L1007fs carriers was 13.7%, 8.3%, and 14.2%, respectively. Compound heterozygotes and homozygotes occurred in 3.4% and 2.9% of patients and in none of the controls. The correlation of genotype-Vienna classification showed a significant association with ileal disease (RR = 1.61, 95% CI 1.21-2.15, P = 0.001) and an inverse association with colonic localization (RR = 0.29, 95% CI 0.11-0.80, P = 0.007). There was a significant association between G908R carriership and previous appendectomy, surgical interventions, and stricturing behavior. A gene-dosage effect on phenotypic characteristics was not observed. CONCLUSIONS: In a Spanish population from Madrid, mutations of the NOD2/CARD15 gene were a marker of susceptibility to Crohn disease and were associated with ileal disease. Carriers of the G908R mutation showed a stricturing disease behavior, history of appendectomy, and surgical interventions over the course of the disease.     

Prevalence of mutations of the NOD2/CARD15 gene and relation to phenotype in Spanish patients with Crohn disease

Background: We assessed the prevalence of R702W, G908R, and L1007fs coding mutations in the NOD2/CARD15 gene and the genotype–phenotype relation in Spanish patients with Crohn disease. Methods: A cohort of 204 unrelated patients with Crohn disease and 140 healthy controls were studied. The phenotype was established before commencement of genotyping. Genotyping of the R702W, G908R, and L1007fs gene polymorphisms of NOD2/CARD15 was performed by two independent laboratories using different techniques. In the case of discordant results, specific sequencing of DNA strands was performed. Results: At least one mutation was present in 32.8% of patients compared to 10.7% in controls (OR?=?4.08, 95% CI 2.21 to 7.50). In patients with Crohn disease, the frequency of R702W, G908R, and L1007fs carriers was 13.7%, 8.3%, and 14.2%, respectively. Compound heterozygotes and homozygotes occurred in 3.4% and 2.9% of patients and in none of the controls. The correlation of genotype–Vienna classification showed a significant association with ileal disease (RR?=?1.61, 95% CI 1.21–2.15, P?=?0.001) and an inverse association with colonic localization (RR?= 0.29, 95% CI 0.11–0.80, P?=?0.007). There was a significant association between G908R carriership and previous appendectomy, surgical interventions, and stricturing behavior. A gene‐dosage effect on phenotypic characteristics was not observed. Conclusions: In a Spanish population from Madrid, mutations of the NOD2/CARD15 gene were a marker of susceptibility to Crohn disease and were associated with ileal disease. Carriers of the G908R mutation showed a stricturing disease behavior, history of appendectomy, and surgical interventions over the course of the disease.     

Association between polymorphisms in the Toll-like receptor 4, CD14, and CARD15／NOD2 and inflammatory bowel disease in the Greek population

AIM: Crohn's disease (CD) and ulcerative colitis (DC) are multifactorial diseases with a significant genetic background. Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune response such as CD14 or Toll-like receptor 4 (TLR4), are involved in their pathogenesis. In further exploring the genetic background of these diseases, we investigated the variations in the CARD15/NOD2 gene (Arg702Trp, Gly908Arg and Leu1007fsinsC), and polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) as well as in the promoter of the CD14 gene (T/C at position -159) in Greek patients with CD and UC. METHODS: DNA was obtained from 120 patients with CD, 85 with UC and 100 healthy individuals. Genotyping was performed by allele specific PCR or by PCR-RFLP analysis. RESULTS: The 299Gly allele frequency of the TLR4 gene and the T allele and TT genotype frequencies of the CD14 promoter were significantly higher in CD patients only compared to healthy individuals (P= 0.026<0.05; P= 0.0048<0.01 and P= 0.047<0.05 respectively). Concerning the NOD2/CARD15 mutations the overall presence in CD patients was significantly higher than that: in UC patients or in controls. Additionally, 51.67% of the CD patients were carriers of a TLR4 and/or CD14 polymorphic allele and at least one variant of the NOD2/CARD15, compared to 27% of the UC patients. It should be pointed out that both frequencies significantly increased as compared with the 10% frequency of multiple carriers found in healthy controls. A possible interaction of the NOD2/CARD15 with TLR4 and especially CD14, increased the risk of developing inflammatory bowel disease (IBD). CONCLUSION: Our results indicate that co-existence of a mutation in either the TLR4 or CD14 gene, and in NOD2/CARD15 is associated with an increased susceptibility to developing CD compared to UC, and to developing either CD or UC compared to healthy individuals.     

A polymorphism in the CD14 gene is associated with Crohn disease

BACKGROUND: Inflammatory bowel diseases (IBD) are multifactorial disorders, characterized by failure to limit the inflammatory response to luminal antigens. Although genetic factors play an important role in the pathogenesis, little is known about the genes accountable. Immune response to intestinal bacteria seems to be crucial in the pathogenesis of IBD. METHODS: To evaluate the role of the CD14 gene in IBD, a functionally relevant polymorphism in the promoter region (T/C at position -159) has been genotyped in 219 patients with Crohn disease (CD), 142 patients with ulcerative colitis (UC) and 410 healthy controls by RFLP analysis. RESULTS: T allele and TT genotype frequencies were found increased in CD patients compared to controls (Pc=0.044 and 0.005, respectively). CONCLUSION: An altered immune response to LPS seems to play a role in the genetic predisposition to CD but not to UC.     

CARD15 gene polymorphisms in patients with spondyloarthropathies identify a specific phenotype previously related to Crohn's disease

BACKGROUND: The association between spondyloarthropathy and Crohn's disease is well known. A risk for evolution to Crohn's disease has already been shown in the subgroup of patients with spondyloarthropathy associated with chronic gut inflammation. OBJECTIVE: To investigate whether the reported polymorphisms in the CARD15 gene, a susceptibility gene for Crohn's disease, are associated with the presence of preclinical intestinal inflammation observed in spondyloarthropathies. METHODS: 104 patients with spondyloarthropathies were studied. All underwent ileocolonoscopy with biopsies between 1983 and 2004. The prevalence of three single nucleotide polymorphisms in the CARD15 gene (R702W, G908R, and 1007fs) was assessed using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR); the patients were compared with an ethnically matched Crohn's disease population and a control population. RESULTS: The carrier frequency of R702W, G908R, or 1007fs variants in the spondyloarthropathy populations (20%) was similar to the control population (17%), but increased to 38% in the spondyloarthropathy subgroup with chronic gut inflammation. This frequency was significantly higher than in the other spondyloarthropathy subgroups (p = 0.001) or the control group (p = 0.006), but not different from the Crohn's disease group (49%) (NS). This indicates that CARD15 polymorphisms are associated with a higher risk for development of chronic gut inflammation. CONCLUSIONS: CARD15 gene polymorphisms clearly identify a subgroup of patients with spondyloarthropathies associated with chronic intestinal inflammation.     

Role of CARD15, DLG5 and OCTN genes polymorphisms in children with inflammatory bowel diseases

AIM: To investigate the contribution of variants of CARD15, OCTN1/2 and DLG5 genes in disease predispo- sition and phenotypes in a large Italian cohort of pediatric patients with inflammatory bowel diseases (IBD). METHODS: Two hundred patients with Crohn’s disease (CD), 186 ulcerative colitis (UC) patients, 434 par- ents (217 trios), and 347 healthy controls (HC) were studied. Polymorphisms of the three major variants of CARD15, 1672C/T and -207G/C SNPs for OCTN genes, IGR2096a_1 and IGR2198a_1 SNPs for the IBD5 locus, and 113G/A variant of the DLG5 gene were evaluated. Potential correlations with clinical sub-phenotypes were investigated. RESULTS: Polymorphisms of CARD15 were significantly associated with CD, and at least one variant was found in 38% of patients (15% in HC, OR = 2.7, P < 0.001). Homozygosis for both OCTN1/2 variants was more com- mon in CD patients (1672TT 24%, -207CC 29%) than in HC (16% and 21%, respectively; P = 0.03), with an in- creased frequency of the TC haplotype (44.8% vs 38.3% in HC, P = 0.04). No association with the DLG5 variant was found. CD carriers of OCTN1/2 and DLG5 variants more frequently had penetrating disease (P = 0.04 and P = 0.01), while carriers of CARD15 more frequently had ileal localization (P = 0.03). No gene-gene interaction was found. In UC patients, the TC haplotype was morefrequent (45.4%, P = 0.03), but no genotype/phenotype correlation was observed. CONCLUSION: Polymorphisms of CARD15 and OCTN genes, but not DLG5 are associated with pediatric on- set of CD. Polymorphisms of CARD15, OCTN, and DLG5 genes exert a weak influence on CD phenotype.     

Association of chronic non-bacterial osteomyelitis with Crohn’s disease but not with CARD15 gene variants

Chronic non-bacterial osteomyelitis (CNO) is an inflammatory, non-infectious disorder of the skeletal system with unknown etiology. Besides bone-inflammation, patients may present with inflammatory involvement of other tissues. Chronic recurrent multifocal osteomyelitis (CRMO) is the most severe form of CNO. We describe the occurrence of Crohn’s disease (CD) in four patients, previously diagnosed with CRMO. Mutations in CARD15, encoding the NOD2 protein, have recently been found in patients with CD. Based on the occurence of CNO and CD in these four and several reported patients, we hypothesized that CD and CRMO might share a common autoinflammatory process. Thus, we searched for CD associated CARD15 gene variants R702W, G908R and 1007fs in 29 CNO patients, 4 of them additionally diagnosed with CD. In the latter one out of the four showed compound heterozygosity for the gene variants R702W and 1007fs. The allele frequency in the 25 patients diagnosed with CNO but not CD was not different from that already reported in healthy people (R702W 4.0%, G908R 2.0%, 1007fs 2.0%). The occurrence of non-bacterial bone inflammation and granulomatous intestinal inflammation seems to represent an extended phenotype of CD, which partly might be explained by potential disease causing mutations in CARD15. However, CNO without intestinal inflammation is not associated with common CARD15 gene variants. Therefore, other variants of genes coding for proteins involved in innate immunity and inflammation might predispose for the occurrence of CNO.     

NOD2/CARD15, NOD1/CARD4, and ICAM-1 gene polymorphisms in Turkish patients with inflammatory bowel disease

Purpose The genetic susceptibility of people with certain NOD2/CARD15, NOD1/CARD4, and ICAM-1 gene variants to inflammatory bowel disease is still under investigation. The aim of this study was to investigate polymorphisms in the NOD2/CARD15 (R702W, G908R, and 3020insC), NOD1/CARD4 (E266K, D372N), and ICAM-1 (G241R, K469E) genes, which are known to be associated with inflammation, in Turkish patients with inflammatory bowel disease and healthy control groups. Methods The genotypes of 70 patients with endoscopically and histopathologically diagnosed Crohn's disease (38 men, 32 women; mean age, 38.8 ± 1.3), 120 patients with ulcerative colitis (67 men, 53 women; mean age, 41.7 ± 1.3) and 106 healthy control subjects (37 men, 69 women; mean age, 35.7 ± 1.4), who stated that they had never had any prior bowel disease history, were compared. A polymerase chain reaction-restriction fragment length polymorphism analysis was performed for two variants of the ICAM-1 gene, the three main variants of the NOD2/CARD15 gene, and the E266K variant of the NOD1/CARD4 gene, and DNA sequencing was used for the D372N polymorphism of the NOD1/CARD4 gene. Results In this study, the three previously described Crohn's disease-predisposing variants of the NOD2/CARD15 gene and the polymorphisms examined in the NOD1/CARD4 and ICAM-1 genes were not found to be associated with ulcerative colitis or Crohn's disease. Conclusions These findings suggest that the polymorphisms observed in the NOD2/CARD15, NOD1/CARD4, and ICAM-1 genes are not genetic susceptibility factors for Crohn's disease or ulcerative colitis in Turkey.     

Role of the CARD15 gene in the pathogenesis of Crohn disease: phenotypic classification and prognostic implications

Annese V, Bassotti G, Napolitano G, Usai P, Andriulli A, Vantrappen G. Gastrointestinal motility disorders in patients with inactive Crohn's disease. Scand J Gastroenterol 1997; 32:1107–1117.

Background: Although some symptoms of Crohn's disease may be related to gastrointestinal motility disorders, studies on gastrointestinal motility in inactive Crohn's disease are lacking. Methods: Fasting and postprandial motor activity (1 h) was recorded in the gastric antrum and upper small intestine of 35 patients with inactive Crohn's disease and 18 controls, using conventional manometry. Results: Motor disorders were observed in 26 of 35 patients. The number of phase-II contractions was reduced (1.3 ±0.7/min versus 1.8±.6/min in controls; P< 0.02) (mean ± standard deviation), whereas the incidence of propagated single (2.2 ± 3.2/h versus 0.5 ± 0.6/h; P< 0.03) and clustered contractions (3.8 ± 7/h versus 1.1 ±1.4, P < 0.04) was markedly increased. Motor abnormalities were more frequent and severe in patients with Crohn's ileitis than in controls, and in patients with gastrointestinal symptoms than in asymptomatic patients. Conclusion: Most patients with inactive, uncomplicated Crohn's disease show marked gastrointestinal motor disorders, characterized either by reduced incidence of small-bowel contractions and increased incidence of single or clustered propagated contractions.     

Radiological sacroiliitis, a hallmark of spondylitis, is linked with CARD15 gene polymorphisms in patients with Crohn's disease

BACKGROUND: Sacroiliitis is a common extraintestinal manifestation of Crohn's disease but its association with the HLA-B27 phenotype is less evident. Polymorphisms in the CARD15 gene have been linked to higher susceptibility for Crohn's disease. In particular, associations have been found with ileal and fibrostenosing disease, young age at onset of disease, and familial cases. OBJECTIVES: To investigate whether the presence of sacroiliitis in patients with Crohn's disease is linked to the carriage of CARD15 polymorphisms. METHODS: 102 consecutive patients with Crohn's disease were clinically evaluated by a rheumatologist. Radiographs of the sacroiliac joints were taken and assessed blindly by two investigators. The RFLP-PCR technique was used to genotype all patients for three single nucleotide polymorphisms (SNP) in the CARD15 gene. Every SNP was verified by direct sequencing. The HLA-B27 phenotype was determined. RESULTS: Radiological evidence of sacroiliitis with or without ankylosing spondylitis was found in 23 patients (23%), of whom only three were HLA-B27 positive. In contrast, 78% of patients with sacroiliitis carried a CARD15 variant v 48% of those without sacroiliitis (p = 0.01; odds ratio 3.8 (95% confidence interval, 1.3 to 11.5)). Multivariate analysis (logistic regression) showed that the association between sacroiliitis and CARD15 polymorphisms was independent of other CARD15 related phenotypes (ileal and fibrostenosing disease, young age at onset of disease, familial Crohn's disease) (p = 0.039). CONCLUSIONS: CARD15 variants were identified as genetic predictors of Crohn's disease related sacroiliitis. An association was demonstrated between these polymorphisms and an extraintestinal manifestation of Crohn's disease.     

Development of rheumatoid arthritis is not associated with two polymorphisms in the Crohn's disease gene CARD15

INTRODUCTION: It has been proposed that genetic susceptibility loci for rheumatoid arthritis (RA) may be shared with other autoimmune/inflammatory diseases. Recently, common variation in the CARD15 (NOD2) gene on chromosome 16q12 has been associated with Crohn's disease (CD) in several independent populations. CARD15 is an excellent functional and positional candidate gene for RA. METHODS: Genomic DNA was obtained from 392 RA cases and 471 ethnically matched healthy controls. All samples were genotyped for two polymorphisms in CARD15, 1007fs and R702W, using 5' nuclease reporter assays. Allele frequencies were compared between cases and controls using the chi(2) test. Estimated haplotype frequencies across the two mutations were determined using the EH program. RESULTS: The allele frequency of the 1007fs variant in RA cases was 1.8% compared with 1.6% in normal controls (not significant). The frequency of the R702W variant was 4.0% in both cases and controls. Haplotypes carrying either of the two mutations accounted for 5.6% of possible haplotypes. A haplotype carrying both mutations was rare, with estimated frequency <0.01%. This study provided high power to detect an association of similar magnitude to that in Crohn's disease. These data therefore exclude the possibility that the contribution of these mutations to RA is comparable to that seen in CD. CONCLUSION: Within defined statistical parameters, we excluded a role for the CARD15 1007fs and R702W variants in RA susceptibility. These data do not preclude a role for other polymorphisms in the CARD15 gene in RA susceptibility. Results from other autoimmune and inflammatory diseases will reveal whether the CARD15 gene is in fact a common autoimmune susceptibility locus.     

Association of polymorphisms in the interleukin-18 gene in patients with Crohn's disease depending on the CARD15/NOD2 genotype

An increased expression of interleukin-18 (IL-18), a proinflammatory cytokine inducing interferon-gamma, has been found in Crohn's disease (CD). In the IL-18 gene, several partly functional relevant polymorphisms are known. This study sought to investigate associations of IL-18 polymorphisms in inflammatory bowel disease and CD according to CARD15/NOD2 mutation status and clinical phenotypes. METHODS: The IL-18 polymorphisms -607, -137, and the third position of codon 35 (c35/3) were genotyped in 210 patients with CD, 140 patients with ulcerative colitis, and 265 healthy controls using polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS: Frequencies of alleles and genotypes of the 3 polymorphisms and of the respective haplotypes and diplotypes displayed no significant differences between the whole groups of patients with CD and ulcerative colitis, respectively, compared with the controls. After stratification of patients with CD for CARD15/NOD2 status, significant associations of genotypes -137 CC (P = 0.018) and c35/3 CC (P = 0.010) and of the diplotype 2-2 (P = 0.018) were found in cases carrying CARD15/NOD2 mutations. Associations of genotypes -137 GG (P = 0.015) and c35/3 AA (P = 0.030) with colonic disease only in cases positive for CARD15/NOD2 mutations and of the genotype -607 AA (P = 0.007) with fistulas in cases negative for CARD15/NOD2 mutations were observed. CONCLUSIONS: In this study, significant differences of several genotypes and diplotypes within the IL-18 gene in CD depending on CARD15/NOD2 status have been found. In context with an increased expression of IL-18 in CD, it remains to be shown whether the expression of IL-18 is influenced by CARD15/NOD2 mutation status.