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).

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.

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%).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

HLA-DRB1 alleles may influence disease phenotype in patients with inflammatory bowel disease: a critical reappraisal with review of the literature

PURPOSE

The HLA region has been implicated in determining the disease susceptibility or the clinical phenotype of inflammatory bowel disease. The aim of this study was to assess the relation between HLA-DRB1 alleles with the clinical features of Crohn's disease and ulcerative colitis and the presence of anti-neutrophil cytoplasmic and anti-Saccharomyces cerevisiae antibodies.

METHODS

Blood samples were obtained from 102 Crohn's disease patients, 114 ulcerative colitis patients, and 264 unrelated healthy controls. Anti-neutrophil cytoplasmics were detected by a standard immunofluorescence method, and anti-Saccharomyces cerevisiaes were examined by an enzyme-linked immunosorbent assay immunoglobulin G/immunoglobulin A commercial assay. HLA-DRB1 typing of 26 alleles was performed by polymerase chain reaction sequence-specific primes. Patients were phenotyped according to gender, disease location, extent, and behavior, surgical resection, need of steroid, and anti-neutrophil cytoplasmic/anti-Saccharomyces cerevisiae status.

RESULTS

As a whole, after applying Bonferroni's correction for multiple comparisons, no significant association of HLA-DRB1 alleles with Crohn's disease or ulcerative colitis was found. After stratifying HLA-DRB1 alleles by clinical phenotypes of patients with ulcerative colitis, an excess of DRB1*1309*1320*1325*1329 allele (DR13) was found in conjunction with pancolitis (P < 0.0001), surgical resection (P < 0.0003), and extraintestinal manifestations (P < 0.0001). In Crohn's disease patients, an excess of DRB1*0304*0305*0307*0309 allele (DR3) was found in those with colonic disease (P < 0.0001) and patients with extraintestinal manifestations (P = 0.0003). This statistical association, however, emerged in only 3 of 114 patients with ulcerative colitis and in 3 of 102 patients with Crohn's disease. We found no association with the presence of anti-Saccharomyces cerevisiae or anti-neutrophil cytoplasmic.

CONCLUSIONS

Some clinical features of Crohn's disease and ulcerative colitis may be influenced by specific HLA-DR alleles; in particular, in ulcerative colitis some alleles appear to segregate with more aggressive disease, whereas in Crohn's disease different alleles cosegregate in patients with colonic disease and extraintestinal manifestations.

Anti-Saccharomyces cerevisiae mannan antibodies in inflammatory bowel disease: comparison of different assays and correlation with clinical features

BACKGROUND

Anti-Saccharomyces cerevisiae mannan antibodies have been proposed as a new serological marker associated with Crohn's disease. However, their clinical value is still unclear; furthermore, a standardization of anti-S. cerevisiae mannan measurements is lacking.

AIM

In this study, we aimed to assess the correlation between anti-S. cerevisiae mannan detection and specific clinical features in Crohn's disease and ulcerative colitis. Moreover, we tested the concordance of four different anti-S. cerevisiae mannan assays.

MATERIALS AND METHODS

Serum samples from 196 patients with Crohn's disease, 197 patients with ulcerative colitis and 100 unrelated healthy controls were tested for anti-S. cerevisiae mannan with a standard enzyme-linked immunosorbent assay method (Lille) by one of the authors (VP). Subsequently, 60 randomly selected serum samples (27 Crohn's disease, 28 ulcerative colitis and five healthy controls) were tested for anti-S. cerevisiae mannan with three different commercial kits.

RESULTS

With the Lille assay, anti-S. cerevisiae mannan were detected in 100 of 196 patients with Crohn's disease (51%; P < 0.0001 vs. controls), 32 of 197 patients with ulcerative colitis (16%; P < 0.02 vs. controls), and six of 100 controls (6%). No correlation between presence of anti-S. cerevisiae mannan and specific clinical features was found in both ulcerative colitis and Crohn's disease patients. The percentages of anti-S. cerevisiae mannan detected with four different assays ranged from 28 (Bouty) up to 43% (Inova), but these differences did not reach statistical significance. The concordance rate of anti-S. cerevisiae mannan detection in the four assays was very low (11 concordant results of 60 samples, 18.3%) (k = 0.15). No improvement of the concordance rate was obtained by modifying the suggested cut-off values (k = 0.20).

CONCLUSION

In this study, we confirm that anti-S. cerevisiae mannan are significantly more frequent in Crohn's disease patients compared with ulcerative colitis patients (P < 0.0001) and controls. However, no correlation with clinical features was found in both ulcerative colitis and Crohn's disease. The low prevalence of anti-S. cerevisiae mannan, at least in our population, and the low concordance rate between different assays, makes the clinical role of this marker questionable.

Acute intestinal obstruction and NOD2/CARD15 mutations among Italian Crohn's disease patients

Three CARD15 mutations (SNP8, SNP12, SNP13) were significantly associated with CD, however ethnic variations and genotype-phenotype relationships are still to be defined.

AIMS

To evaluate the prevalence of three CARD15 mutations in 91 in-out consecutive CD, 109 Ulcerative Colitis (UC), 101 healthy controls; to examine the genotype-phenotype relationships among italian pts with CD.

MATERIAL AND METHODS

The three mutations were determined by direct sequencing analysis. In CD were evaluated several feature of disease phenotype. Data analysis was performed by using c2 or Fisher Test applying Bonferroni's correction.

RESULTS

The allelic and genotype frequencies of CARD15 mutations were significantly associated to CD. None of controls or UC were homozygotes (OM) or compound heterozigotes (CET). In CD the carriers of at least one mutation were 26/91 (28.6%). The frequencies of simple heterozygotes (ET), CET and OM were: 19/26, 4/26, 3/26 respectively. A significant positive association was found between small bowel location and an acute intestinal obstruction at diagnosis and the carriers of at least one mutation (p = 0.036, OR:0.33 [0.12-0.9] and p = 0.0025, OR:0.125 [0.03-0.5], respectively), particularly with OM and CET genotype (p = 0.005, OR:0.07 [0.01-0.6]). A positive trend between the number of surgery and the carriers of at least one mutation was found, but it didn't reach statistical significance (p = 0.0469, OR:0.3 [0.1-0.96]). No relationship between CARD15 mutations and the other phenotype characteristics was found.

CONCLUSIONS

Our data confirms that CARD15 mutations are significantly associated with CD also in Italian population and with small bowel location (OM and CET genotype). A new positive association was also found between the carriers of at least one mutation and the acute intestinal obstruction at diagnosis.

Frequency of NOD2/CARD15 variants in both sporadic and familial cases of Crohn's disease across Italy. An Italian Group for Inflammatory Bowel Disease Study

BACKGROUND

Three variants of the NOD2/CARD15 gene are strongly associated with susceptibility to Crohn's disease; however, striking racial and geographic differences of their frequency have been described.

AIMS

We have compared the allele frequencies of familial cases of Crohn's disease recruited in a multicentre study across Italy, in order to disclose possible geographic heterogeneity. Moreover, we also compared the allele frequencies in sporadic cases of Crohn's disease and healthy controls from Southern Italy with those reported in other two populations from Central and Northern Italy.

SUBJECTS AND METHODS

A total of 731 subjects were genotyped for the polymorphism of three main variants (R702W, G908R and 1007 fs): 152 patients were familial cases of Crohn's disease, 183 were healthy first-degree relatives, 180 were sporadic cases of Crohn's disease, and 216 were unrelated healthy subjects.

RESULTS

The frequency of the frameshift mutation (1007 fs) was significantly higher in both familial and sporadic cases of Crohn's disease (P = 0.000001), and healthy first-degree relatives (P = 0.0001) compared to controls. At least one risk allele was found in 44% of familial Crohn's disease patients, compared to 7% of healthy controls (OR = 4; CI = 2-6.5). Two risk alleles were found in 14% of familial Crohn's disease, compared to less than 1% of controls (OR = 26: CI = 4-129).

CONCLUSIONS

Our data confirm the strong correlation between the 1007 fs variant and Crohn's disease, in both familial and sporadic cases. Moreover, no significant difference of allele frequencies was detected in familial cases, sporadic cases and healthy controls among different geographic areas of Italy.

Genetics of inflammatory bowel disease: the beginning of the end or the end of the beginning?

Recent identification of the first susceptibility gene for Crohn's disease has led to increasing enthusiasm for the investigation and dissection of inflammatory bowel disease. In the future, identification of additional genes and careful correlation of the genetic background with clinical features of the disease will help to elucidate the causes and cure of inflammatory bowel disease. However, caution is still needed in the short term since our present knowledge has limited influence on clinical management. This review focuses on the genetic background of inflammatory bowel disease, the process of discovering the mutations of the NOD2/CARD15 gene in Crohn's disease patients, and the functional clues of the genetic variants of this gene in relation to clinical features.

Familial expression of anti-Saccharomyces cerevisiae Mannan antibodies in Crohn's disease and ulcerative colitis: a GISC study

OBJECTIVES

Recent studies in familial Crohn's disease (CD) have suggested that anti-Saccharomyces cerevisiae mannan antibodies (ASCAs) may represent a new specific marker of genetic susceptibility. In this study we aimed to assess the importance of ASCAs by comparing their presence in a large number of patients with sporadic and familial occurrence of CD or ulcerative colitis (UC) and their unaffected relatives.

METHODS

Serum samples from 96 patients with sporadic CD, 97 patients with sporadic UC, and 50 unrelated healthy controls were tested for ASCAs by a standard ELISA method. Moreover, 73 families with two or more members affected by CD and/or UC were recruited. From these families 58 CD patients, 84 UC patients, and 216 unaffected first degree relatives were investigated.

RESULTS

ASCAs were detected in 34 of 96 patients with sporadic CD (35%, p < 0.01 vs controls), 11 of 97 patients with sporadic UC (12%), and two of 50 controls (4%). ASCAs were significantly (p < 0.04) more frequent in patients with familial CD (55%) and familial UC (25%) than in sporadic cases. Moreover, ASCAs were found in 25% of unaffected relatives, and this rate did not significantly differ in CD, UC, and mixed families (28%, 26%, and 22%, respectively).

CONCLUSIONS

In this study we confirm that ASCAs occur particularly frequently in CD patients, especially with the presence of a positive family history. However, they are also significantly increased in UC patients with a family history and in a considerable number of unaffected relatives of inflammatory bowel disease families, irrespective of the characteristics of their families (UC, CD, mixed, ASCA positive, and ASCA negative). The presence of ASCAs in unaffected relatives might point toward a genetic predisposition to either CD or UC.

Combined segregation and linkage analysis of inflammatory bowel disease in the IBD1 region using severity to characterise Crohn's disease and ulcerative colitis. On behalf of the GISC

Inflammatory bowel disease (IBD) is a chronic relapsing disorder affecting the gastro-intestinal tract and is subdivided into two main subtypes: Crohn's disease (CD) and ulcerative colitis (UC). Although the aetiology of IBD is unknown, a strong genetic susceptibility is suggested and different candidate regions have been identified for both CD and UC. The IBD1 region on chromosome 16 has been confirmed to be important for susceptibility to CD, whereas conflicting evidence has been obtained for UC. We performed a combined linkage and segregation analysis in the identified IBD1 region on a sample of 82 extended families with IBD using a parametric method implemented in the computer program COMDS. This approach allows simultaneous evaluation of linkage while estimating the mode of inheritance and to include severity of the trait to characterise the CD and UC phenotypes. Our results are consistent with the presence of a major gene in the IBD1 region close to D16S408 involved in both UC and CD. Furthermore, our data support evidence that a single mutation in the gene leads more frequently to UC, whereas inheritance of two mutant alleles results in the more severe CD. In our study the IBD1 locus was found to have a major role in IBD predisposition in the Italian population.

Antineutrophil cytoplasmic antibodies in inflammatory bowel disease: clinical role and review of the literature

PURPOSE

Perinuclear antineutrophil cytoplasmic antibodies have been found consistently in patients with ulcerative colitis; however, their pathogenetic and clinical role is still uncertain. In this study we tested the prevalence of perinuclear antineutrophil cytoplasmic antibodies in a large population of patients with ulcerative colitis and Crohn's disease, with particular attention to the possible correlation with clinical features.

METHODS

Perinuclear antineutrophil cytoplasmic antibody reactivity was investigated with indirect immunofluorescence in 279 patients with ulcerative colitis, 110 patients with Crohn's disease, and 252 unrelated healthy subjects.

RESULTS

Perinuclear antineutrophil cytoplasmic antibodies were found in 84 of 279 patients with ulcerative colitis (30 percent), 10 of 110 patients with Crohn's disease (9 percent), and 2 of 252 healthy subjects (<1 percent; P < 0.001), respectively. Perinuclear antineutrophil cytoplasmic antibodies were significantly more frequent in patients with ulcerative colitis with higher relapse rate (43 vs. 27 percent; P < 0.002), and patients with Crohn's disease with colitis (27 vs. 2.5 percent; P < 0.0003). Perinuclear antineutrophil cytoplasmic antibodies were also significantly less frequent in patients with ulcerative colitis in remission (18 vs. 34 percent; P < 0.0025).

CONCLUSIONS

In this study we confirm the relative specificity of perinuclear antineutrophil cytoplasmic antibodies, either for ulcerative colitis or for Crohn's disease involving the colon. Perinuclear antineutrophil cytoplasmic antibodies were more frequently found in patients with ulcerative colitis with a more aggressive clinical behavior; however, their presence had a limited value in identifying homogeneous subgroups of patients in our population.

Genetic analysis in Italian families with inflammatory bowel disease supports linkage to the IBD1 locus--a GISC study

Epidemiological studies suggest that inherited factors influence susceptibility to inflammatory bowel disease (IBD), and some candidate loci have been described. In order to verify whether the same loci are responsible for predisposition to IBD in our population, we carried out a linkage study in a series of 58 Italian families with Crohn's disease (CD) and ulcerative colitis (UC). HLA-DQ alleles, motilin gene, and 34 microsatellites flanking the previously described loci on chromosomes 3, 6, 7, 12 and 16 were analysed by non-parametric linkage analysis in 16 and 23 families with CD and UC, respectively, and in 19 families where CD and UC coexisted. Non parametric analysis using GENEHUNTER yielded maximum NPL scores for marker D16S408 in all IBD families combined (2.71, P = 0.003), for marker D16S419 in CD (1.97, P = 0.026) and for marker D16S514 in UC families (2.44, P = 0.007). These markers map in the previously described IBD1 region. No significant linkage was found for markers of chromosomes 3, 6, 7 and 12. The present study performed in a Southern European population provides additional support for the conclusion with the IBD1 locus has a clear role in the genetic susceptibility to IBD.

Helicobacter pylori infection and growth delay in older children

It is thought that Helicobacter pylori infection may influence growth rate in children. The aim of this study was to evaluate the prevalence of H pylori infection in healthy Italian children, and to look for differences in height between infected and non-infected subjects. Two hundred and sixteen children, aged 3 to 14 years, were tested for H pylori infection by 13C-urea breath test. Centile values for height were calculated. Composite indices for socioeconomic class and household crowding were also determined. Forty nine of 216 children (22.7%) were H pylori positive. The prevalence of infection increased with age. Eight of 49 H pylori positive children (16.3%) were below the 25th centile for height, compared with 13 of 167 H pylori negative children (7.8%). This difference became significant in children aged 8.5 to 14 years; in this group (n = 127), eight of 31 infected children (25.8%) were below the 25th centile for height, compared with eight of 96 non-infected children (8.3%). A significant correlation was found between socioeconomic conditions, household crowding, and H pylori status. By using stepwise logistic regression, only the centile value for height was significantly related to H pylori status in older children. Thus H pylori infection was associated with growth delay in older children, poor socioeconomic conditions, and household overcrowding. This finding is consistent with the hypothesis that H pylori infection is one of the environmental factors capable of affecting growth.