Worse impact of second wave COVID-19 pandemic in adults but not in children with inflammatory bowel disease: an Italian single tertiary center experience.

OBJECTIVE: From September 2020, a second wave of COVID-19 pandemic started. We aimed at exploring the impact of SARS-CoV-2 infection in IBD patients during the two waves. PATIENTS AND METHODS: All IBD patients with a confirmed diagnosis of SARS-CoV-2 infection were enrolled. They were sorted into two groups (those infected before September 2020, and those from September 2020 to January 2021) and compared by demographic and clinical data. RESULTS: Twenty-five patients (out of about 600 with a follow-up visit) were infected with SARS-CoV-2 (4.1%). Sixteen were male and the mean age was 46.5 ± 14.3 years (range 24-74). Six were smokers and 11 had comorbidities; 2 were on steroids and 17 on immunosuppressants or biologics. Three patients (12%) needed hospitalization and other three patients were treated with azithromycin, steroids and LMWH, all of them during the second wave. No patient died or developed any sequelae. Two subjects were infected during the first wave (0.3 vs. 3.83, p<0.0001). Non-significant differences were found between the two groups. CONCLUSIONS: A higher number of IBD patients were infected during the second wave. No patient developed a severe form of pneumonia, even those treated with immunosuppressants or biologics. No risk factor for hospitalization was found.

Glucocorticoid resistance in Crohn's disease and ulcerative colitis: an association study investigating GR and FKBP5 gene polymorphisms.

The aim of this study is to investigate the role of single-nucleotide polymorphisms (SNPs) of the glucocorticoid receptor (GR) and of the related co-chaperone FKBP5 genes in the development of glucocorticoid (GC) resistance in Crohn's disease (CD) and ulcerative colitis (UC) patients. We have developed a high-resolution DNA melting method that allows simultaneous identification of GR (BclI, N363S and ER22/23EK) and FKBP5 (rs3800373, rs1360780 and rs4713916) polymorphisms. Genotype frequencies were determined in 100 consecutive CD and 100 UC patients under GCs therapy (50 responders and 50 resisters). The variation of FKBP5 polymorphism rs4713916 (G/A), in the putative promoter region of FKBP5, is significantly associated with resistance to GC treatment in CD (responder=17% versus resister=35%; P=0.0043). No significant differences were found in UC patients. If these preliminary findings will be confirmed, the combination of GR and FKBP5 mutational analyses could help to identify subgroups of CD patients with higher chances to benefit from GC treatment.

The -A2518G polymorphism of monocyte chemoattractant protein-1 is associated with Crohn's disease.

OBJECTIVES: The -A2518G variation in monocyte chemoattractant protein (MCP)-1 gene promoter has been associated with autoimmune diseases. Our aim was to investigate the gene polymorphism and MCP-1 plasma levels in patients with inflammatory bowel disease (IBD). METHODS: Family-based and case-control association analyses of the -A2518G polymorphism (rs1024611) were performed in 1,936 subjects (770 patients with Crohn's disease (CD), 316 patients with ulcerative colitis (UC), 302 healthy relatives (151 CD trios), and 548 healthy controls (HCs)). Extensive gene sequencing was also undertaken, and a further six single-nucleotide polymorphisms (SNPs) were genotyped in 435 CD patients and 189 HCs. MCP-1 protein plasma levels in 234 CD patients, 117 UC patients, and 108 HCs were assessed by an immunosorbent assay. RESULTS: Five SNPs in strong linkage disequilibrium (D'>0.85) were associated with CD, with the strongest signal found at the -A2518G SNP. The frequency of the G allele was significantly lower in CD patients (22.1%), compared with HCs (29.8%), both at case-control (P=6 x 10(-6)) and at transmission disequilibrium test analyses (T/U 41/88; P=4 x 10(-4)). No difference in alleles (26.1%) and genotype frequencies were found in UC patients. MCP-1 plasma levels in CD and UC patients were similar to those in HCs (P=0.38), irrespective of disease activity, or MCP-1 genotypes. However, 30 CD (13%) and 20 UC patients (17%) with extensive colonic involvement had plasma levels significantly higher than HCs (P=0.02). CONCLUSIONS: The -A2518G polymorphism seems to be associated with CD but does not influence MCP-1 plasma levels, which in contrast are increased in UC and CD with extensive colonic involvement.

Polymorphism of the IRGM gene might predispose to fistulizing behavior in Crohn's disease.

OBJECTIVES: Recently, genome-wide association analyses have identified single nucleotide polymorphisms in the IRGM gene (rs1000113 and rs4958847) as strong candidate susceptibility factors for Crohn's disease (CD). The aim of our study was to test whether these variants are associated with inflammatory bowel disease (IBD) in adult- and childhood-onset Italian patients. METHODS: Allele and genotype frequencies of rs1000113 and rs4958847 were determined in 823 CD (265 younger than 19 years at diagnosis), 353 ulcerative colitis (UC) (130 younger than 19 years at diagnosis), and 578 controls. Genotype distributions were examined both within IBD clinical sub-phenotypes and CARD15 genotypes. RESULTS: rs1000113 and rs4958847 were both associated with adult-onset (P=2 x 10(-4); P=2.5 x 10(-3), respectively) and childhood-onset (P=4 x 10(-4); P=8 x 10(-3), respectively) CD cohorts. Similarly, the genotype frequencies remained significantly different for both variants (adult rs1000113, P=1 x 10(-4); rs4958847, P=1 x 10(-3); pediatric rs1000113, P=2.3 x 10(-4); rs4958847, P=9.6 x 10(-3)). At logistic regression, the rs4958847 polymorphism was associated with fistulizing behavior (P=0.037, OR=1.54, CI=1.02-2.31) and perianal fistulas (P=0.045, OR=1.55, CI=1.01-2.38). Conversely, no association with UC and sub-phenotypes was shown. CONCLUSIONS: We replicated the previously reported associations between CD and rs1000113 and rs4958847, confirming that IRGM is a susceptibility locus only for CD, either adult- or early-onset in the Italian population; furthermore, we have also shown its influence on specific clinical features (fistulizing disease).

Gene-centric association mapping of chromosome 3p implicates MST1 in IBD pathogenesis.

Association mapping and candidate gene studies within inflammatory bowel diseases (IBD) linkage regions, as well as genome-wide association studies in Crohn's disease (CD) have led to the discovery of multiple risk genes, but these explain only a fraction of the genetic susceptibility observed in IBD. We have thus been pursuing a region on chromosome 3p21-22 showing linkage to CD and ulcerative colitis (UC) using a gene-centric association mapping approach. We identified 12 functional candidate genes by searching for literature cocitations with relevant keywords and for gene expression patterns consistent with immune/intestinal function. We then performed an association study composed of a screening phase, where tagging single nucleotide polymorphisms (SNPs) were evaluated in 1,020 IBD patients, and an independent replication phase in 745 IBD patients. These analyses identified and replicated significant association with IBD for four SNPs within a 1.2 Mb linkage disequilibrium region. We then identified a non-synonymous coding variant (rs3197999, R689C) in the macrophage-stimulating 1 (MST1) gene (P-value 3.62 x 10(-6)) that accounts for the association signal, and shows association with both CD and UC. MST1 encodes macrophage-stimulating protein (MSP), a protein regulating the innate immune responses to bacterial ligands. R689C is predicted to interfere with MSP binding to its receptor, suggesting a role for this gene in the pathogenesis of IBD.

MAST3: a novel IBD risk factor that modulates TLR4 signaling.

Inflammatory bowel disease (IBD) is a chronic disorder caused by multiple factors in a genetically susceptible host. Significant advances in the study of genetic susceptibility have highlighted the importance of the innate immune system in this disease. We previously completed a genome-wide linkage study and found a significant locus (IBD6) on chromosome 19p. We were interested in identifying the causal variant in IBD6. We performed a two-stage association mapping study. In stage 1, 1530 single-nucleotide polymorphisms (SNPs) were selected from the HapMap database and genotyped in 761 patients with IBD. Among the SNPs that passed the threshold for replication, 26 were successfully genotyped in 754 additional patients (stage 2). One intronic variant, rs273506, located in the microtubule-associated serine/threonine-protein kinase gene-3 (MAST3), was found to be associated in both stages (pooled P=1.8 x 10(-4)). We identified four MAST3 coding variants, including a non-synonymous SNP rs8108738, correlated to rs273506 and associated with IBD. To test whether MAST3 was expressed in cells of interest, we performed expression assays, which showed abundant expression of MAST3 in antigen-presenting cells and in lymphocytes. The knockdown of MAST3 specifically decreased Toll-like receptor-4-dependent NF-kappaB activity. Our findings are additional proofs of the pivotal role played by modulators of NF-kappaB activity in IBD pathogenesis.

The association of MYO9B gene in Italian patients with inflammatory bowel diseases.

BACKGROUND: Variants of myosin IXB (MYO9B) gene, encoding for a motor protein implicated in epithelial permeability, have been recently associated with inflammatory bowel disease. AIMS: To investigate the contribution of three polymorphisms of MYO9B gene for predisposition to Crohn's disease and ulcerative colitis, their association with clinical phenotypes, particularly intestinal permeability, and possible interaction with the CARD15 gene. METHODS: 549 Crohn's disease patients, 658 ulcerative colitis patients and 674 controls were genotyped for the rs962917, rs1545620 and rs2305764 single nucleotide polymorphisms. RESULTS: Highly significant genotypic association with Crohn's disease and ulcerative colitis was shown for all three single nucleotide polymorphisms, with odds ratio ranging from 1.5 to 1.7 (P-value: <0.01 to <0.002). A significant difference in allele frequencies was also observed in inflammatory bowel disease patients, with the single most significant association for rs1545620, detected in 47% of Crohn's disease, 47% of ulcerative colitis patients and 42% of controls (P < 0.005). No association with specific sub-phenotypes was found, with the exception of a trend towards an abnormal intestinal permeability (P = 0.043) in Crohn's disease carrying the rs1545620 risk allele. CONCLUSIONS: Our findings confirm the association between the MYO9B polymorphisms and susceptibility to both ulcerative colitis and Crohn's disease, with a weak influence on sub-phenotypic expression.

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.

Sequential evaluation of thiopurine methyltransferase, inosine triphosphate pyrophosphatase, and HPRT1 genes polymorphisms to explain thiopurines' toxicity and efficacy.

AIM: To evaluate the polymorphisms of several genes involved in the azathioprine and mercaptopurine metabolism, in an attempt to explain their toxicity and efficacy in Crohn's disease and ulcerative colitis. METHODS: In 422 consecutive patients (250 with Crohn's disease and 172 with ulcerative colitis) and 245 healthy controls, single nucleotide polymorphisms of thiopurine methyltransferase, inosine triphosphate pyrophosphatase and hypoxanthine phosphoribosyl transferase (HPRT1) genes were related to the occurrence of adverse drug reactions (ADRs) and efficacy of therapy. RESULTS: Seventy-three patients reported 81 episodes of ADRs; 45 patients did not respond to therapy. Frequency of thiopurine methyltransferase risk haplotypes was significantly increased in patients with leucopenia (26% vs. 5.7% in patients without ADRs, and 4% of controls) (P < 0.001); no correlation with other ADRs and efficacy of therapy was found. Conversely, the frequency of inosine triphosphate pyrophosphatase and HPRT1 risk genotypes was not significantly different in patients with ADRs (included leucopenia). Non-responders had an increased frequency of inosine triphosphate pyrophosphatase risk genotypes (P = 0.03). CONCLUSIONS: The majority of azathioprine/mercaptopurine-induced ADRs and efficacy of therapy are not explained by the investigated gene polymorphisms. The combined evaluation of all three genes enhanced the correlation with leucopenia (43.5% vs. 23% in controls) (P = 0.008), at the expense of a reduced accuracy (60%).

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 predisposition 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 parents (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 common in CD patients (1672TT 24%, -207CC 29%) than in HC (16% and 21%, respectively; P = 0.03), with an increased 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 more frequent (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 onset of CD. Polymorphisms of CARD15, OCTN, and DLG5 genes exert a weak influence on CD phenotype.

Regularized least squares classifiers may predict Crohn's disease from profiles of single nucleotide polymorphisms.

In this paper we focus on the prediction of Crohn's disease (CD) susceptibility by analyzing SNP profiles for a number of defined or suggested gene polymorphisms. We assess the correlation between genetic markers and the phenotype by using well-founded methods and procedures developed in the field of statistical learning theory. To this end, we use a sample generated by a case-control study composed of 178 CD patients and 127 healthy controls. The genetic profile of each subject is composed of 16 genetic variants distributed over 11 genes. We find that regularized least squares (RLS) classifiers predict Crohn's disease with a statistically significant accuracy of 62%(p= 0.018), significantly increasing the diagnostic accuracy by at least 10% compared to that obtained with the more largely confirmed gene involved in CD predisposition, namely CARD15. This also demonstrates that our sample size is adequate for accurate and significant prediction estimates. The strength of this methodology, in contrast to classical statistical methods, is that it accounts simultaneously for the effect of several genetics markers and their possible interactions. The findings of this study show that RLS methodology is able to increase the diagnostic accuracy of CD prediction by contemporary evaluation of a large number of gene polymorphisms. This approach may be particularly useful in large-scale population screening programs, and when evaluating large datasets of gene polymorphisms (i.e. chips, microarrays). Moreover, it could shed more light on possible candidate genes with a weak genetic contribution, and for evaluating gene-gene and gene-phenotype interactions by analyzing populations with a reasonably small sample size.

Multidrug resistance 1 gene in inflammatory bowel disease: a meta-analysis.

The MDR1 gene is an attractive candidate gene for the pathogenesis of inflammatory bowel disease (IBD) and perhaps response to therapy, with evidences at both functional and genetic levels. Its product, the P-glycoprotein (P-gp) functions as a transmembrane efflux pump thus influencing disposition and response of many drugs, some of whom (i.e. glucocorticoids) central to IBD therapy. In addition P-gp is highly expressed in many epithelial surfaces, included gastrointestinal tract (G-I) with a putative role in decreasing the absorption of endogenous or exogenous toxins, and perhaps host-bacteria interaction. Many genetic variations of MDR1 gene has been described and in some instances evidences for different P-gp expression as well drugs metabolism have been provided. However data are often conflicting due to genetic heterogeneity and different methodologies employed. Perhaps the greatest piece of evidence of the physiological importance of P-gp in the G-I tract has come from the description of the mdr1 knock-out mice model, which develops a spontaneous colitis in a specific pathogen-free environment. Studies investigating MDR1 gene polymorphism and predisposition to IBD have also shown conflicting results, owing to the known difficulties in complex diseases, especially when the supposed genetic contribution is weak. In this study we have undertaken a meta-analysis of the available findings obtained with two SNPs polymorphism (C3435T and G2677T/A) in IBD; a significant association of 3435T allele and 3435TT genotype has been found with UC (OR = 1.17, P = 0.003 and OR = 1.36, P = 0.017, respectively). In contrast no association with CD and the G2677T/A polymorphism could be demonstrated.

HLA and enteric antineuronal antibodies in patients with achalasia.

The aetiopathogenesis of primary achalasia is largely unknown, although an immunogenetic predisposition is suspected. To establish whether a correlation exists among possible aetiological factors, including class II human leucocyte antigen (HLA) alleles and autoantibodies to enteric neurones, and clinical features of patients with achalasia, a total of 60 patients and 200 healthy subjects were typed by high-resolution HLA-DQ and HLA-DR alleles. Circulating antineuronal antibodies were investigated by using indirect immunofluorescence on enteric neurones of rat ileum and colon and immunoblotting assay in a subset of achalasic patients and in all controls. The DQB1*0502 and DQB1*0601 alleles were significantly increased in patients with achalasia compared with controls (P < 0.03, P < 0.001, respectively). Moreover a negative correlation with the DQB1*0201 allele was found (P = 0.016). As a whole, 14 of 60 (23.3%) achalasia patients were carriers of HLA risk alleles, and 10 of 41 (24.4%) presented antineuronal antibodies. No significant correlation among HLA risk alleles, antineuronal antibodies and clinical features was found. In achalasia, no correlation exists among HLA alleles, antineuronal antibodies and clinical features. However, given the association between achalasia and HLA-DQ1, further research is needed to clarify the role of HLA antigens and antineuronal antibodies in this disease.

Increased intestinal permeability and NOD2 variants in familial and sporadic Crohn's disease.

BACKGROUND: Abnormal barrier function may be genetically determined in Crohn's disease. AIM: To examine the role of abnormal intestinal permeability in genetic predisposition in multiplex vs. sporadic Crohn's disease families. METHODS: Intestinal permeability was measured in patients, relatives and partners by means of lactulose/mannitol test. Healthy subjects from the hospital staff served as controls. CARD15 mutations were investigated in sporadic and familial Crohn's disease patients and in a group of blood donors. RESULTS: The median lactulose/mannitol ratio was increased significantly in Crohn's disease patients vs. their relatives [0.03 (0.01-0.24) vs. 0.01 (0.003-0.19), P=0.005]. The percentage of abnormal tests was significantly higher in familial vs. sporadic first-degree relatives of Crohn's disease patients (29% vs. 11%, P=0.0281). Abnormal permeability occurred significantly more frequent in patients with familial Crohn's disease carrying the frameshift mutation. The frameshift mutation 3020 insC was associated with increased permeability in 75% in the multiplex and in 61% of the sporadic CD patients. One partner had abnormal lactulose/mannitol ratio. Conclusion Intestinal permeability is raised in Crohn's disease patients and relatives, with higher rates in familial vs. sporadic healthy relatives. CARD15 mutations are associated with abnormal permeability in ileal Crohn's disease.

The polymorphism of multi-drug resistance 1 gene (MDR1) does not influence the pharmacokinetics of dexamethasone loaded into autologous erythrocytes of patients with inflammatory bowel disease.

BACKGROUND: We have recently demonstrated that low doses of Dexamethasone 21-P (Dex 21-P), loaded in autologous erythrocytes and administered at monthly intervals, have been able to maintain steroid-dependent patients with Crohn's disease (CD) and ulcerative colitis (UC) in clinical remission with a progressive and complete tapering of systemic steroids. AIM: Since multi-drug resistance 1 gene (MDR1) has a potential influence on Dexamethasone (Dex) bioavailability, we designed this study to investigate the correlation between MDR1 genotype and Dex pharmacokinetic after its delivery in patients with inflammatory bowel disease (IBD). MATERIALS AND METHODS: Seventeen steroid-dependent consecutive patients with IBD (10 UC mean age 36 +/- 12, and 7 Crohn's disease mean age 31 +/- 5) were consecutively recruited. The C3435T polymorphism of MDR1 gene was studied by Denaturing High Performance Liquid Chromatography (DHPLC). Serum level of Dex were determined at the end of the infusion and after 15 days by high performance liquid chromatography electrospray mass spectrometry. RESULTS: The mean dose of Dex 21-P administered was 9.9 mg +/- 4 (range 2.7-20.3), while the mean levels of Dex at the end of the infusion and after 15 days were 0.66 +/- 0.23 mM and 0.06 +/- 0.06 mM, respectively. Concerning the C3435T genotype, two patients were wild-type, eleven heterozygotes, and four homozygotes. No correlation between basal or 15-days plasma level of Dex and MDR1 genotype was found (r = 0.19 and r = 0.21, respectively). CONCLUSION: Our findings demonstrated that Dex plasma level, after infusion of autologous erythrocytes loaded with Dex 21-P are completely independent by the MDR 1 gene polymorphism. This could be another potential advantage of this modality of drug delivering.

NOD2/CARD15 in healthy relatives of IBD patients.

BACKGROUND: Crohn's disease (CD) and Ulcerative Colitis (UC) are related chronic inflammatory disorders of the intestine (IBD) caused by a combination of genetic and environmental factors. Three polymorphisms within the NOD2/CARD15 gene are highly associated with CD, increasing the risk from 2 up to 44-fold, depending on the presence of one or two risk alleles. Aim of this study was to investigate the presence of two risk alleles on healthy relatives of IBD patients and prospectively follow them for possible development of IBD. MATERIALS AND METHODS: Healthy relatives of familial IBD patients were recruited in our Institution and across Italy in a multicenter study of the IG-IBD. One hundred and twenty one IBD families were identified and blood samples were obtained from 415 first-degree healthy relatives. Single nucleotide polymorphisms (SNPs) R702W, G908R, and L1007finsC of the CARD15 gene were investigated by multiplex pyrosequencing technique. Data obtained in 205 healthy controls (HC) were compared by chi-square or Fisher's test. RESULTS: Ninety eight (28.7%) healthy relatives had one risk allele (HC 14.6%; p = 0.002, OR 2, C.I. 1-4), while 8 had two risk alleles (vs 0.5% of healthy controls; p = 0.01). All subjects were asymptomatic at the time of blood sample and record collections (between 1996 and 1999) and were further investigated with abdominal ultrasonography, blood chemistry and haemoccult test, after 5-8 years of follow-up. All were still asymptomatic with negative findings. CONCLUSIONS: Our study once again supports the importance of gene-gene and gene-environment interactions for the final development of the disease.

Variants of OCTN1-2 cation transporter genes are associated with both Crohn's disease and ulcerative colitis.

BACKGROUND: Two variants in the organic cation transporter gene cluster have been recently reported to confer susceptibility to Crohn's disease (CD). AIM: To investigate these variants in CD and ulcerative colitis (UC), and their interaction with CARD15 gene and correlation to clinical subphenotypes. METHODS: Case-control association analysis was performed in 899 patients (444 CD and 455 UC) and 611 controls. The organic cation transporter gene cluster single nucleotide polymorphisms G207G-->C and 1672C-->T, the IGR2198a_1 single nucleotide polymorphism in the IBD5 locus, and the R702W, G908R and L1007finsC variants of CARD15 gene were genotyped by ABI-7700, restriction fragment length polymorphic analysis and multiplex pyrosequencing, respectively. RESULTS: The 1672TT and -207CC genotype frequencies were increased in both CD (OR = 1.5, P = 0.011; OR = 1.6, P = 0.002), and UC (OR = 1.5, P = 0.017; OR = 1.4, P = 0.033), respectively. Compared with controls, the TC haplotype frequency was increased in both CD (36% vs. 44%, P < or = 0.01) and UC (36% vs. 45%, P < or = 0.01). The frequency of the TC haplotype was 43% in CARD15-positive and 44% in CARD15-negative CD, respectively. Similar results were found in UC. In CD a significant association of the TC haplotype was found with presence of perianal fistulae (P = 0.007) and steno-fistulizing behaviour (P = 0.037). In UC, the TC haplotype was more frequent in patients with more extensive disease (P = 0.015), and those on immunosuppressives (P = 0.004). CONCLUSIONS: Organic cation transporter gene cluster variants may confer susceptibility to both CD and UC, and the TC haplotype may influence some clinical features of IBD, but does not interact with CARD15 variants.

Multidrug resistance 1 gene polymorphisms are not associated with inflammatory bowel disease and response to therapy in Italian patients.

BACKGROUND: Host genetic factors may be important in determining not only disease susceptibility, but also disease behaviour and response to therapy in inflammatory bowel disease. Two polymorphisms (C3435T and G2677T/A) of the multidrug resistance 1 gene have been correlated with the altered P-glycoprotein expression and function in humans, and associated with predisposition to ulcerative colitis and Crohn's disease. AIM: To investigate the contribution of these polymorphisms to disease susceptibility and response to medical therapy. METHODS: A total of 946 inflammatory bowel disease patients (478 Crohn's disease, 272 males, mean age 43 +/- 14 years and 468 ulcerative colitis, 290 males, mean age 48 +/- 15 years) and 450 healthy controls were genotyped for the single nucleotide polymorphisms C3435T and G2677T/A. Patients were also classified on the basis of response to medical therapy (mesalazine, steroids, immunosuppressives and infliximab). RESULTS: Both single nucleotide polymorphisms were in Hardy-Weinberg equilibrium and significant linkage disequilibrium. No significant difference in the allele, genotype, and haplotype frequencies was found in both Crohn's disease and ulcerative colitis patients compared with the controls. No correlation with clinical features was found, except for a reduced frequency of extra-intestinal manifestations in Crohn's disease patients with the G2677T genotype (40%) compared with GG2677 and 2677TT genotypes (54% and 58%, respectively) (P = <0.02). No significant difference was also found after stratifying the patients on the basis of their response to medical therapy. CONCLUSION: The investigated polymorphisms of the multidrug resistance 1 gene have no significant role in disease susceptibility and response to medical therapy in our Italian population of inflammatory bowel disease patients.

Idiopathic achalasia is not allelic to alacrima achalasia adrenal insufficiency syndrome at the ALADIN locus.

BACKGROUND: Evidence indicates that patients with familial achalasia associated with Allgrove or triple-A syndrome (i.e. alacrima, achalasia and adrenocorticotropin-resistant adrenal insufficiency with neurological impairment) have mutations of the alacrima achalasia adrenal insufficiency syndrome (AAAS) gene. AIM: The present study was aimed at identifying possible AAAS gene mutations in patients with established idiopathic non-familial achalasia. METHODS: Genomic DNA of 41 patients was isolated from peripheral blood cells using standard methods. The 16 exons of the AAAS gene (or ALADIN) were screened for mutations using the denaturing high-performance liquid chromatography method. RESULTS: Four heterozygous nucleotidic variations have been identified in patients with idiopathic achalasia, among which three were exonic conservative polymorphisms [i.e. D138D (GAT-->GAC), L227L (TTG-->CTG) and F285F (TTC-->TTT) in exons 5, 7 and 9, respectively]. The fourth nucleotidic variation was located in intron 13 (IVS14-23delT). All variants have been regarded as polymorphisms resulting in a normal ALADIN protein since they are either conservative or lying outside the consensus splice sites. CONCLUSIONS: Our data do not support a pathogenetic role for common AAAS gene mutations in patients with idiopathic achalasia as seen in Allgrove syndrome. These findings suggest the participation of different mechanisms in the pathogenesis of idiopathic achalasia.