Genetic polymorphism of interleukin-8 (IL-8) is associated with Helicobacter pylori-induced duodenal ulcer

BACKGROUND AND AIMS: Helicobacter pylori infection almost invariably causes chronic gastritis, but only a proportion of the infected subjects develop peptic ulcers. The local inflammation associated with H. pylori infection is characterized by an increased production of the proinflammatory cytokines IL-1-B, IL-6, IL-8 and TNF-alpha. Since such cytokine production is often determined by the genetic polymorphism of regions regulating cytokine gene expression, we investigated the relationship between TNF-alpha and IL-8 polymorphisms and the development of duodenal ulcer disease. We also sought a correlation between the promoter polymorphism of the lipopolysaccharide (LPS) receptor CD14 and the formation of peptic ulcer, because CD14 plays a crucial role in the initiation of the cytokine cascade. METHODS: Genomic DNA extracted from the peripheral blood of 69 patients with H. pylori-positive duodenal ulcer disease and 47 H. pylori-positive healthy controls was analyzed for TNF-alpha -308 promoter polymorphism by RFLP, and for IL-8 -251 polymorphism by ARMS. Genetic polymorphism within the promoter of the CD14 gene was identified using the LightCycler instrument via melting point analysis. RESULTS: No significant correlation could be revealed between the TNF-alpha and CD14 promoter polymorphisms and the clinical outcome of H. pylori infection. The IL-8 A/T heterozygote mutant variant was detected with a significantly higher frequency (65.22%) among the ulcer patients than among the healthy, H. pylori-positive blood donors (36.17%), while the frequency of the normal allelic genotype (TT) was significantly higher in the control group (44.6% vs 15.9%). CONCLUSION: Analysis of the genetic predisposition to enhanced cytokine production revealed a significant association only for the IL-8 polymorphism. This observation draws attention to the possible importance of IL-8 polymorphism as a genetic predisposing factor in the pathomechanism of H. pylori-induced duodenal ulcer disease, and to the relative protection from duodenal ulcer disease that is associated with the TT genotype.     

Influence of polymorphisms in the NOD1/CARD4 and NOD2/CARD15 genes on the clinical outcome of Helicobacter pylori infection

Host immune response influences the clinical outcome of Helicobacter pylori infection leading to ulcer disease, gastric carcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. A genetic risk profile for gastric cancer has been identified, but genetic susceptibility to develop MALT lymphoma is still unclear. We investigated the role of NOD1 and NOD2 as intracellular recognition molecules for pathogen-associated molecules in H. pylori infection in vitro and analysed the influence of single nucleotide polymorphisms on susceptibility to ulcer disease and MALT lymphoma. Expression of NOD1 and NOD2 significantly sensitized HEK293 cells to H. pylori-induced NF-kappaB activation in a cag pathogenicity island (cagPAI)-dependent manner. In cells carrying the Crohn-associated NOD2 variant R702W the NF-kappaB response was significantly diminished. NOD1/NOD2 expression levels were induced in the gastric epithelium in H. pylori-positive patients. No mutations were found to be associated with gastritis or gastric ulcer development. However, the R702W mutation in the NOD2/CARD15 gene was significantly associated with gastric lymphoma. Carrier of the rare allele T had a more than doubled risk to develop lymphoma than controls [odds ratio (OR): 2.4, 95% confidence interval (CI): 1.2-4.6; P < 0.044]. H. pylori-induced upregulation of NOD1 and NOD2 in vivo may play a critical role in the recognition of this common pathogen. A missense mutation in the leucine-rich region of CARD15 is associated with gastric lymphoma.     

The effects of genetic polymorphisms of IL-1 and TNF-A on Helicobacter pylori-induced gastroduodenal diseases in Korea

OBJECTIVE: To evaluate whether or not genetic polymorphism of IL-1B, IL-1RN, and TNF-Alpha is an important factor in the different expression of gastroduodenal diseases after Helicobacter pylori infection. METHODS: This study consisted of 1360 subjects: control, gastric cancer (GC, intestinal type, and diffuse type), benign gastric ulcer (BGU), duodenal ulcer, and first-degree gastric cancer relative (GCR). IL-1Beta-511 and TNF-A-308 biallelic polymorphism were genotyped by 5' nuclease polymerase chain reaction (PCR) assays, and PCR-restriction fragment length polymorphism (PCR-RFLP). IL-1RN penta-allelic variable number of tandem repeats was genotyped by PCR. RESULTS: There was no difference in the genetic polymorphism of IL-1Beta-511, IL-1RN and TNF-A in the patients with gastric cancer regardless of H. pylori positivity compared with control. However, the frequencies of IL-1B-511 C/T (OR: 0.5, 95% CI: 0.3-0.7) and T carrier (OR: 0.6, 95% CI: 0.4-0.8) were lower in the H. pylori-positive BGU patients. The IL-1RN 2/2 was higher (OR: 5.5, 95% CI: 1.1-28.5) in the H. pylori-positive GCR. There was no significance in the polymorphism of TNF-Alpha-308 regardless of H. pylori-induced gastroduodenal diseases. CONCLUSIONS: The IL-1Beta-511 T-carrier polymorphism has a negative effect on the development of H. pylori-positive BGU, and high frequency of IL-1RN 2/2 was found in the H. pylori-positive relatives of GC patients, which suggest that this genetic polymorphism could play some role in the H. pylori-induced gastroduodenal diseases in Korea.     

Toll-like receptor (TLR2, TLR4 and TLR5) gene polymorphisms and Helicobacter pylori infection in children with and without duodenal ulcer

Helicobacter pylori infection is mainly acquired in childhood, and polymorphisms in the host genes coding for Toll-like receptors (TLRs) may influence the innate and adaptive immune response to the infection, affecting the susceptibility to H. pylori or the disease outcomes. Our aim was to investigate whether TLR4, TLR2, and TLR5 polymorphisms were associated with H. pylori susceptibility and risk for duodenal ulcer in children. Gastric biopsy specimens were obtained at endoscopy for evaluation of H. pylori status, TLR4, TLR2 and TLR5 polymorphisms from 486 children (254 H. pylori-negative and 232 H. pylori-positive: 72 with and 160 without duodenal ulcer). cagA status of H. pylori infection was investigated by PCR. The levels of gastric cytokines were detected by ELISA. H. pylori-positivity or duodenal ulcer were not associated with TLR2, TLR4 or TLR5 polymorphisms. Otherwise, the presence of TLR4 polymorphic allele was associated with infection by cagA-positive strains and with increased gastric levels of interleukin-8 and interleukin-10. TLR4 polymorphism might ultimately contribute to more severe consequences of the infection in adulthood since it was associated with susceptibility to cagA-positive H. pylori infection early in life.     

Local and peripheral cytokine response and CagA status of Helicobacter pylori-positive patients with duodenal ulcer

The mucosal production of TNF-alpha, IL-6, IL-8, IL-10 and nitrotyrosine was investigated in H. pylori-positive patients with duodenal ulcer (DU). The concentrations of these cytokines in gastric antrum mucosal specimens from patients infected with H. pylori (n = 40) were determined by ELISA and compared with data on mucosal specimens from H. pylori-negative patients (n = 12). Nitrotyrosine was determined by ECL Western blotting. It was additionally investigated whether the tissue levels of the cytokines correlated with the peripheral cytokine levels, and the CagA status of the patients. The local TNF-a, IL-6 and IL-8 concentrations in the antral biopsy samples were significantly higher (p < 0.001) in the patients infected with H. pylori than in the samples from the H. pylori-negative subjects. There was a negative correlation between the TNF-alpha and IL-10 concentrations. Further more, in 23 of the 40 biopsy specimens, considerable nitrotyrosine production was detected by ECL Western blotting. There was no significant difference in peripheral TNF-a and IL-6 production between the DU patients and healthy blood donors (n = 100; 58% of whom were also H. pylori-positive). Only the in vitro IL-8-producing capacity was higher in the peripheral blood of the DU group after ex vivo induction with H. pylori. CagA positivity was demonstrated in 39 (97.5%) of the 40 patients with DU, and in 41 (70.7%) of the 58 H. pylori-positive, healthy blood donors. This study suggests that besides the bacterial virulence factor, the host response, with an increased mucosal production of inflammatory cytokines and reactive oxygen and nitrogen species could be relevant to the gastric pathophysiology in H. pylori-induced DU. There is no generalized cytokine overproduction in these DU patients, but the moderate increase in in vitro IL-8 production might be of pathophysiological importance.     

Interleukin-2 gene polymorphisms associated with increased risk of gastric atrophy from Helicobacter pylori infection

BACKGROUND: Gastric atrophy induced by Helicobacter pylori is thought to predispose patients to noncardiac gastric cancer development. However, the host genetic factors that influence the progression of gastric atrophy have not been elucidated. In this study, we examined the effects of cytokine polymorphisms on H. pylori-induced gastric atrophy. METHODS: Blood samples were taken from 454 Japanese subjects. The interleukin-2 (IL-2; T-330G), IL-4 (C-33T), and IL-13 (C-1111T) polymorphisms were genotyped by polymerase chain reaction with confronting two-pair primers (PCR-CTPP). Anti-H. pylori IgG antibody and pepsinogen I and II were measured to diagnose H. pylori infection and atrophic gastritis. RESULTS: The odds ratios (ORs) for the association between IL-2 polymorphism [OR = 2.78, 95% CI (confidence interval) = 1.26-6.17 (T/T to G/G)] or IL-4 polymorphism [OR = 2.22, 95% CI = 1.01-4.89 (T/C to C/C)] were increased significantly with gastric atrophy, whereas the corresponding OR of IL-13 polymorphism was decreased with gastric atrophy [OR = 0.61, 95% CI = 0.39-0.96 (C/T and T/T to C/C)]. There were no significant H. pylori seropositivity-related differences between these polymorphisms. We examined the relationship between these polymorphisms and gastric atrophy separately in H. pylori-seropositive and -seronegative groups. In the H. pylori-seropositive group, the IL-2 T/T (OR = 2.78, 95% CI = 1.12-6.93) had a significant association with gastric atrophy. CONCLUSIONS: These results reveal that the IL-2 gene polymorphism is associated with an increased risk of gastric atrophy induced by H. pylori infection and might predispose to gastric cancer.     

Helicobacter pylori-induced immunological responses in patients with duodenal ulcer and in patients with cardiomyopathies

The interaction between the bacteria and the host is a key factor determining the clinical consequences of H. pylori infection. The immune system plays an important role in either promoting or preventing the disease. The mucosal production of TNF-alpha, IL-6, IL-8 and IL-10 and the CagA status were investigated in H. pylori-positive patients with duodenal ulcer (DU). The concentrations of these cytokines in gastric antral mucosal specimens from patients infected with H. pylori (n = 40) were determined by ELISA and compared with data on mucosal specimens from H. pylori-negative patients (n = 12). The local TNF-alpha, IL-6 and IL-8 concentrations in the antral biopsy samples were significantly higher (p < 0.001) in the patients infected with H. pylori than in the samples from the H. pylori-negative subjects. CagA positivity was demonstrated in 39 (97.5%) of the 40 patients with DU, and in 41 (70.7%) of H. pylori-positive (58 of 100) healthy blood donors. In complementary studies focusing on extragastric disease, it was found that 57% of patients with ischaemic heart disease were seropositive as concerns H. pylori, and 91% of them had antibodies against human heat shock protein 60, too. This study suggests that, besides the bacterial virulence factor, the host response of an increased mucosal production of inflammatory cytokines can be relevant to the gastric pathophysiology in H. pylori-induced DU. At the same time, in ischaemic heart diseases the role of autoimmune processes induced by H. pylori cannot be excluded.     

MDR1 C3435T polymorphism has no influence on developing Helicobacter pylori infection-related gastric cancer and peptic ulcer in Japanese

AIMS: P-glycoprotein, the gene product of multidrug-resistant transporter-1 (MDR1), confers multidrug resistance against antineoplastic agents but also affects the kinetic disposition of some drugs and carcinogens. MDR1 C3435T polymorphism influences the development of colon cancer and adult acute myeloid leukemia by the association with transporting carcinogen. The aim of this study was to clarify the association of MDR1 C3435T polymorphism with susceptibility to gastric cancer and peptic ulcers in patients with Japanese H. pylori infection. MAIN METHODS: We assessed the MDR1 C3435T polymorphism in H. pylori-positive gastritis alone patients (n=150), gastric cancer (n=292), gastric ulcer (n=215), and duodenal ulcer (n=163) and H. pylori-negative subjects (n=168) as control by a PCR-based method. KEY FINDINGS: No significant difference existed in frequencies of MDR1 C3435T polymorphisms between H. pylori-negative controls and H. pylori-positive gastritis alone patients. Moreover, MDR1-3435 T allele carriage didn't affect the risk of gastric cancer or peptic ulcer development. The age- and sex-adjusted odds ratios (ORs) of MDR1 3435 T allele carriers relative to the C/C genotype group for gastric cancer, gastric ulcer and duodenal ulcer risk were 0.96 (95%CI: 0.56-1.66), 1.16 (95%CI: 0.72-1.84) and 1.00 (95%CI: 0.61-1.62), respectively. SIGNIFICANCE: In this preliminary data, the association with MDR1 C3435T polymorphism and risk for developing H. pylori-related gastric cancer and peptic ulcer in Japanese was low. P-glycoprotein might not be involved in the carcinogenesis of H. pylori-related gastric cancer.     

The lL-8 and IL-13 gene polymorphisms in inflammatory bowel disease and colorectal cancer

Inflammatory bowel diseases (IBD) and colorectal cancer (CRC) are disorders that originate from immune disturbances. In our study, we evaluated the association between the -251 T/A interleukin (IL)-8 and the -1112 C/T IL-13 polymorphisms, the risk of IBD, and CRC development. Genotypes were determined by PCR-restriction fragment length polymorphism in 191 patients with CRC, 150 subjects with IBD, and 205 healthy controls. We found an association between CRC and the presence of the -251 TA genotype and A allele of the IL-8 gene (odds ratios [ORs] 2.28 and 1.65). A similar relationship was observed between these polymorphic variants and ulcerative colitis (OR 2.05 for the -251 TA genotype and OR 1.47 for the -251 A allele) as well as Crohn's disease (ORs 3.11 and 1.56, respectively). Our research also revealed that the CT and TT genotypes of the IL-13 -1112 C/T polymorphism may be connected with a higher risk of CRC (ORs 2.28 and 1.65). The same genotypes affected the susceptibility of IBD (ORs 2.26 and 3.72). Our data showed that the IL-8 -251 T/A and IL-13 -1112 C/T polymorphisms might be associated with the IBD and CRC occurrence and might be used as predictive factors of these diseases in a Polish population.     

Prevalence of cagA and vacA genes in isolates from patients with Helicobacter pylori-associated gastroduodenal diseases in Recife, Pernambuco, Brazil

Geographical differences in the prevalence of Helicobacter pylori genes and their association with disease severity have been identified. This study analyzes the prevalences of the cagA gene and alleles of the vacA gene in H. pylori-associated gastroduodenal diseases in isolates from Recife, PE, Brazil. Gastric biopsy of 61 H. pylori-positive patients were submitted to DNA extraction and gene amplification by polymerase chain reaction. Among the 61 patients, 21 suffered from duodenal ulcer (DU) and 40 from gastritis (GT). The prevalence of H. pylori strains harbouring the cagA gene was higher in the DU group (90.5%) than in the GT group (60%) (p=0.02). The vacA gene was amplified in 56 out of 61 biopsies, of which 43 (76.8%) contained bacteria carrying the s1 allele and 13 (23.2%) the s2. However, the prevalence of the vacA s1 genotyping was the same in either DU or GT group. The majority of the s1-typed strains, 39 (90.7%) out of 43, were subtype s1b. In resume there was a strong association between the H. pylori cagA+ gene and DU. However, there were no differences between the DU and GT groups in relation to the vacA s1 and s2 alleles distribution, albeit the subtype s1b was predominant.     

Helicobacter pylori environmental interactions: effect of acidic conditions on H. pylori-induced gastric mucosal interleukin-8 production

To explore the interactions between the host, environment and bacterium responsible for the different manifestations of Helicobacter pylori infection, we examined the effect of acidic conditions on H. pylori-induced interleukin (IL)-8 expression. AGS gastric epithelial cells were exposed to acidic pH and infected with H. pylori[wild-type strain, its isogenic cag pathogenicity island (PAI) mutant or its oipA mutant]. Exposure of AGS cells to acidic pH alone did not enhance IL-8 production. However, following exposure to acidic conditions, H. pylori infection resulted in marked enhancement of IL-8 production which was independent of the presence of the cag PAI and OipA, indicating that H. pylori and acidic conditions act synergistically to induce gastric mucosal IL-8 production. In neutral pH environments H. pylori-induced IL-8 induction involved the NF-kappaB pathways, the extracellular signal-regulated kinase (ERK)-->c-Fos/c-Jun-->activating protein (AP-1) pathways, JNK-->c-Jun-->AP-1 pathways and the p38 pathways. At acidic pH H. pylori-induced augmentation of IL-8 production involved markedly upregulated the NF-kappaB pathways and the ERK-->c-Fos-->AP-1 pathways. In contrast, activation of the JNK-->c-Jun-->AP-1 pathways and p38 pathways were pH independent. These results might explain the clinical studies in which patients with duodenal ulcers had higher levels of IL-8 in the antral gastric mucosa than patients with simple H. pylori gastritis.     

E-cadherin gene promoter hypermethylation in H. pylori-induced enlarged fold gastritis

BACKGROUND: Promoter hypermethylation of E-cadherin plays an important role on gastric carcinogenesis. We have previously reported that the odds ratio for gastric carcinoma and the prevalence of diffuse-type early gastric carcinoma in Helicobacter pylori-induced enlarged fold gastritis increased with increasing fold width. Thus, we examined E-cadherin methylation in gastric mucosa from H. pylori-induced enlarged fold gastritis before and after H. pylori eradication. Moreover, we analyzed the mechanism of H. pylori infection-induced E-cadherin hypermethylation. MATERIALS AND METHODS: Twenty-three H. pylori-positive patients with enlarged folds, 18 H. pylori-positive and seven H. pylori-negative patients without enlarged folds, were involved in the study. E-cadherin promoter methylation was studied using quantitative methylation-specific polymerase chain reaction. We investigated methylation percentage and DNA methyltransferase activity in gastric cancer cell lines treated with EGF, TNFalpha, and MG132. RESULTS: E-cadherin methylation percentage of the gastric antral and body mucosa in H. pylori-positive patients with enlarged folds was much greater than that in both H. pylori-positive and -negative patients without enlarged folds. After H. pylori eradication, the methylation percentage in six patients with enlarged fold gastritis decreased significantly from 15.6 +/- 3.9 to 8.8 +/- 2.2 (p < .05). Moreover, the methylation was induced by TNFalpha, MG132, and EGF treatment, and DNA methyltransferase activity was induced by EGF treatment in MKN-1 cells. CONCLUSIONS: Our findings suggest that the hypermethylation of E-cadherin promoter might be involved in the process of gastric carcinoma through the specialized factors in H. pylori-induced enlarged fold gastritis.     

Serum and gastric fluid levels of cytokines and nitrates in gastric diseases infected with Helicobacter pylori

This case control study presents data on the concentrations of nitrite and nitrate and a variety of pro-inflammatory cytokines such as interleukin-1 beta (IL-1 beta), interleukin-2R (IL-2R), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor TNF-alpha in gastric fluid and serum. Patients with gastritis, gastric ulcer and gastric cancer are studied and grouped according to infection by Helicobacter pylori. The 208 patients who underwent upper gastrointestinal endoscopic examination were classified as follows; H. pylori-positive gastritis (n = 32), H. pylori-negative gastritis (n = 32), H. pylori-positive ulcers (n = 34), H. pylori-negative ulcers (n = 34), 43 patients with H. pylori-positive gastric cancer in addition to 33 H. pylori-negative healthy control individuals. Gastric fluids and blood samples were taken concomitantly. Cytokines and nitrite and nitrate determinations were attempted as soon as possible after collection of the samples. Nitrite and nitrate levels of serum and gastric fluids of H. pylori-positive gastritis and ulcers were higher than H. pylori-negative gastritis and ulcers. The concentrations of total nitrite and nitrate and cytokines (TNF-alpha, IL-2R, IL-6, and IL-8) in gastric fluids and sera of H. pylori-positive gastric cancer patients were higher than H. pylori-negative control groups. IL-1 beta level was significantly elevated in gastric fluid of infected cancer patients but not in serum. Taken together, the results suggest that an increase in cytokine-NO combination in gastric mucosa previously reported by many studies is not restricted to local infected gastric tissue but also detected in gastric fluid and sera of H. pylori-positive subjects and may have an important role in the pathogenesis and development of common gastric diseases.     

The IL-8 gene polymorphisms and the risk of the hepatitis B virus/infected patients

Interleukin-8 (IL-8) belongs to the superfamily of CXC chemokines, contributing to human cancer progression through potential mitogenic, angiogenic, and motogenic functions. We hypothesize that the functional polymorphism of IL-8 may influence the inflammatory process during pathological stage from hepatitis to hepatocellular carcinoma (HCC). Two polymorphisms in the IL-8 gene (-251A/T and +781C/T) were examined in 160 cases of chronic hepatitis B, 80 cases of hepatitis B virus (HBV)-related liver cirrhosis (LC), 150 cases of HBV-related HCC, and 150 healthy controls using polymerase chain reaction-restriction fragment length polymorphism method and DNA sequencing. In the LC group, the AA genotypes were associated with a significantly decreased risk of LC compared with the TT genotype (OR=0.14, 95% CI 0.02-0.87, p=0.035). The data also revealed that subjects with the A allele appeared to have lower susceptibility to LC than those with the T allele (OR=0.48, 95% CI 0.25-0.92, p=0.027). The +781C/T polymorphism of IL-8 was not found relevant to the liver diseases. This study indicated that the IL-8 gene -251 AA genotype might be a protect factor for LC.     

Toll-like receptor 4 Asp299Gly/Thr399Ile polymorphisms are a risk factor for Candida bloodstream infection

Toll-like receptor (TLR)-4 is an important pattern recognition receptor for Candida albicans, playing a role in innate host defense. We investigated whether there is an association between the TLR4 Asp299Gly or TLR4 Thr399Ile polymorphism, and the occurrence of Candida bloodstream infection. We performed a case-control study, involving 43 patients with a Candida bloodstream infection and 166 healthy individuals. TLR4 Asp299Gly and Thr399Ile polymorphisms were assessed, as well as cytokine production after stimulation of peripheral blood mononuclear cells (PBMC) with Candida albicans. We observed that the prevalence of TLR4 Asp299Gly polymorphism was found to be higher in patients with Candida bloodstream infection than in controls (26% versus 10%; OR 3.0; 95%CI 1.3-6.9). All patients bearing the Asp299Gly polymorphism were also positive for the Thr399Ile allele, a linkage well described in literature. IL-10 production was higher in C. albicans-stimulated PBMC from volunteers bearing the TLR4 Asp299Gly polymorphism, and a similar tendency was observed in TLR4 Asp299Gly heterozygous patients who had recovered from candidemia. These findings show that the TLR4 Asp299Gly/Thr399Ile polymorphisms are associated with an increased susceptibility to Candida bloodstream infections, and an increased production of IL-10 is probably involved in this effect.     

Toll-like receptor 2 and Toll-like receptor 4 polymorphisms in invasive pneumococcal disease

BACKGROUND: Toll-like receptors (TLRs) recognize distinct pathogen-associated molecular patterns and trigger anti-microbial host defense responses. Several in vitro and in vivo studies in mice indicate that TLR2 and TLR4 are involved in the defense against Streptococcus pneumoniae. Studies have revealed associations between polymorphisms in TLRs and human diseases. The effect of polymorphisms in TLR2 and TLR4 in the human defense to S. pneumoniae has not been studied. METHODS: We genotyped 99 Caucasian patients with invasive pneumococcal disease and 178 Caucasian controls for the known R579H, P631H and R753Q polymorphisms in TLR2 and the D299G polymorphism in TLR4 with PCR-RFLP methods. RESULTS: The distribution of the TLR2 R579H, P631H and R753Q and TLR4 D299G variants was not significantly different between the patients and the controls. After stratification of the patient population by age, sex, diagnosis, and mortality no significant differences for the TLR2 R753Q genotype and TLR4 D299G genotype were found between various patient subgroups and between patient subgroups and the control population. It should be mentioned that for the TLR2 polymorphisms neither the control group nor the patient group contains homozygous mutant individuals. CONCLUSION: We found no association between TLR2 and TLR4 polymorphisms and invasive pneumococcal infection.     

TLR and MBL gene polymorphisms in severe acute pancreatitis

BACKGROUND AND OBJECTIVE: Mannose-binding lectin (MBL) and toll-like receptor (TLR)-4 gene polymorphisms have been implicated in inflammatory episodes in a number of studies. In view of the inflammatory nature of acute pancreatitis, we aimed to determine the predictive value of two point mutations in the promoter region at position -550 (H/L variants) and -221 (X/Y variants) of the MBL2 gene, and the Asp299Gly and 119C>A polymorphisms of the TLR4 gene on the occurrence of severe acute pancreatitis (SAP). METHODS: The study included 132 patients with SAP, 106 with mild acute pancreatitis (MAP), and 121 healthy volunteers. Genotypes were determined using restriction fragment length polymorphism analysis of PCR products and by allele-specific PCR. RESULTS: No significant difference in genotype frequency was noted between the patients with acute pancreatitis and controls for any of the gene loci studied. The distributions of the HY/HY, HY/LY, LY/LY, and LY/LX genotypes of MBL2 gene promoter and 119C>A genotype of the TLR4 gene were similar in patients with mild or severe acute pancreatitis. HY/LX genotype frequency was significantly higher in patients with SAP compared with MAP (26% vs 14%; p = 0.028). CONCLUSION: Results indicate that the MBL2 HY/LX genotype plays an important role in the determination of disease severity to acute pancreatitis.     

Activation of human neutrophils with Helicobacter pylori and the role of Toll-like receptors 2 and 4 in the response

The innate immune response to Helicobacter pylori infection is beginning to be understood and recent works support a role for Toll-like receptors (TLRs). Our aim was to study the response of human neutrophils to H. pylori and to elucidate the role of TLR2 and TLR4. Neutrophils from healthy H. pylori-negative volunteers were cocultured with H. pylori 26695 strain. The release of IL-8, IL-1beta, tumor necrosis factor (TNF)-alpha and IL-10 was measured. The role of TLR2 and TLR4 was investigated with blocking assays using monoclonal antibodies against TLRs. Neutrophils produced a significant increase of IL-8, IL-1beta and TNF-alpha after 3, 6 and 24 h of H. pylori challenge, respectively, whereas IL-10 increased after 24 h. Helicobacter pylori challenge increased TLR2 and TLR4 expression; and antibodies against TLR2 and TLR4 diminished significantly the H. pylori-induced production of IL-8 and IL-10. In human neutrophils, H. pylori induces an early inflammatory response, partially mediated via TLR2 and TLR4 activation.     

Relevance of transforming growth factor-beta1, interleukin-8, and tumor necrosis factor-alpha polymorphisms in patients with chronic pancreatitis

Cytokine regulation may be an important factor in the susceptibility for the development of chronic pancreatitis; transforming growth factor-beta1 (TGF-beta1) plays a central role in the pathogenesis of pancreatic fibrogenesis. The aim of our study was to analyse the relevance of TGF-beta1, interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) polymorphisms in patients with chronic pancreatitis. PATIENTS: of the 83 patients enrolled in the study, 43 were treated medically and 40 patients underwent surgical intervention. Healthy blood donors (n=75) served as controls. METHODS: the polymorphisms of TGF-beta1 +869 T--> C and IL-8 -251 T-->A were determined by the ARMS method, while that of TNF-alpha -308 was investigated using NcoI RFLP. RESULTS: there was a higher frequency (50%) of the TT genotype of TGF-beta1 +869, with a concomitantly higher TGF-beta1 level in the plasma (5.2 +/- 1.7 ng/mL) of patients with chronic pancreatitis than in healthy blood donors (28% and 2.8 +/- 0.9 ng/mL respectively). The number of TT homozygotes differed significantly between the patients who underwent surgical intervention and the controls, and even between the surgical and the non-surgical patients. The frequency of the T/A genotype with higher IL-8 production, was significantly higher in both groups of patients than in the controls (58% and 58% versus 40%). No correlation was found between the TNF-alpha -308 polymorphism and chronic pancreatitis. CONCLUSIONS: correlations of the TGF-beta1 and IL-8 single nucleotide polymorphisms (SNPs) with chronic pancreatitis underline the importance of these cytokines in the pathomechanism of the disease. Moreover, it seems that the TT genotype of +869 TGF-beta1 might be a risk factor for the development of a severe form of chronic pancreatitis, and could serve as a prognostic sign for any future surgical intervention or even repeat surgery. Further studies on a larger group of patients, in addition to a follow-up study, are necessary to confirm this preliminary observation.