Polymorphism in the IL-8 gene, but not in the TLR4 gene, increases the severity of acute pancreatitis

Clinical and genetic determinants of severe acute pancreatitis: A genetic association study in the UK Biobank

BACKGROUND AND AIM

The clinical severity of acute pancreatitis is unpredictable, ranging from self-limiting disease to life-threatening inflammation. The determinants of severe acute pancreatitis (SAP) are unclear. We aim to identify clinical variables and single nucleotide polymorphisms (SNP) associated with SAP.

METHODS

We used UK Biobank data to conduct a case-control clinical and genetic association study. Pancreatitis patients were identified through national hospital and mortality records across the United Kingdom. Clinical covariates and SAP were analyzed for associations. Genotyped data that included 35 SNPs were assessed for independent associations with SAP and SNP to SNP interaction.

RESULTS

A total of 665 patients with SAP and 3304 non-SAP patients were identified. Male sex and older age increased odds of developing SAP (odds ratio [OR] 1.48; 95% confiden interval [CI] 1.24-1.78, P < 0.0001) and (OR 1.23; 95% CI 1.17-1.29), P < 0.0001), respectively. SAP was associated with diabetes (OR 1.46; 95% CI 1.15-1.86, P = 0.002), chronic kidney disease (OR 1.74; 95% CI 1.26-2.42, P = 0.001), and cardiovascular disease (OR 2.00; 95% CI 1.54-2.61, P = 0.0001). A significant association was established between IL-10 rs3024498 and SAP (OR 1.24; 95% CI 1.09-1.41, P = 0.0014). Epistasis analysis revealed that the odds of SAP was greater by an interaction between TLR 5 rs5744174 and Factor V rs6025 (ORinteraction 7.53; P = 6.64 × 10-5 ).

CONCLUSION

This study reports clinical risk factors for SAP. We also show evidence for an interaction between rs5744174 and rs6025 as determinants for SAP in addition to rs3024498 independently altering the severity of acute pancreatitis.

Effects of QingYi decoction on inflammatory markers in patients with acute pancreatitis: A meta-analysis

INTRODUCTION

It is widely accepted that inflammatory responses play a key role in acute pancreatitis (AP). We conducted a systematic review and meta-analysis to determine the effect of QingYi decoction on inflammatory markers.

METHODS

The PubMed, EMBASE, Cochrane, CNKI, CBM, and WANFGANG databases were searched for randomized controlled trials published before December 2019. Thirty-nine eligible studies were included in the meta-analysis. The quality of the included studies was assessed using the Cochrane Collaboration risk of bias tool. The standardized mean differences (SMDs) with corresponding 95% CIs were examined for inflammatory markers. The chi-square test and I² statistic were used to assess heterogeneity. We assessed publication bias by Begg's test, Egger's test, and the trim and fill method. In addition, a meta-regression, sensitivity analysis, subgroup analysis, and cumulative meta-analysis were performed to assess the effects of confounding factors. The quality of evidence was evaluated by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

The pooled effect estimate indicated that QingYi decoction treatment significantly reduced the levels of pro-inflammatory IL-6 (SMD = -3.33; 95% CI, -4.17, -2.50; p < 0.001; I²: 97.9%), IL-8 (SMD = -1.55; 95% CI, -2.03, -1.07; p < 0.001; I²: 96.1%), TNF-α (SMD = -1.04; 95% CI, -1.37, -0.72; p < 0.001; I²: 93.9%), IL-1 (SMD = -2.05; 95% CI, -3.21, -0.90; p < 0.001; I²: 93.4%), and IL-1β (SMD = -1.31; 95% CI, -2.42, -0.21; p < 0.001; I²: 89.8%) and elevated the levels of anti-inflammatory IL-10 (SMD = 0.99; 95% CI, 0.60, 1.38; p < 0.001; I²: 91.1%) among patients with AP.

CONCLUSION

The current review and meta-analysis suggest that the therapeutic effect of QingYi decoction may be related to its anti-inflammatory properties. Due to the high heterogeneity across the included studies, additional large-scale and rigorously designed studies are needed to confirm the conclusions of this study.

IL-10-1082G>A polymorphism, use of opioids and age affect the course of acute pancreatitis

PURPOSE

We aimed to determine the association of two of the most important functional polymorphisms of IL-8 and IL-10 with the clinical course and outcome of acute pancreatitis.

METHOD

Ninety-three patients with acute pancreatitis were genotyped for IL-8-251T>A and IL-10-1082G>A using PCR-RFLP. The severity of the disease was determined based on the Atlanta Classification system.

RESULTS

In patients treated with opioids, the odds for severe form of acute pancreatitis, its complications, and death were increased. Advanced age was associated with higher odds of organ/multiple organ failure and other systemic complications. Multivariate logistic regression analyses confirmed the observed effect of age and use of opioids, and revealed higher odds for the development of severe form of acute pancreatitis [P = 0.017, odds ratio (OR): 4.324, 95% confidence interval (CI): 1.305-14.323], its complications in general (P = 0.011, OR: 4.936, 95% CI: 1.442-16.897), pancreatic necrosis (P = 0.032, OR: 3.922, 95% CI: 1.122-13.707) and systemic inflammatory response syndrome (P = 0.037, OR: 3.838, 95% CI: 1.085-13.583) in the absence of IL-10-1082G>A variant allele. The effect of IL-8 -251T>A on acute pancreatitis severity or mortality was not detected.

CONCLUSION

Our study suggests the IL-10 -1082A allele as a protective factor in acute pancreatitis. Opioid analgesics treatment in acute pancreatitis is associated with severity, complications and mortality, while advanced age increases the risk of systemic complications.

The Role of TLR-4 and Galectin-3 Interaction in Acute Pancreatitis

Toll-like receptor-4 (TLR-4) is a member of evolutionarily conserved type I transmembrane proteins that can initiate sterile inflammatory cascade in the pancreas. Expression of TLR-4 is up-regulated in pancreatic tissue, as well as, on peripheral blood innate immune cells in human and experimental models of acute pancreatitis. TLR-4 plays important pro-inflammatory roles during development of acute pancreatitis: it recognize alarmins released from injured acinar cells and promotes activation and infiltration of innate immune cells after the premature and intraacinar activation of tripsinogen. Galectin-3 is β-galactoside-binding lectin that plays pro-inflammatory roles in a variety autoimmune diseases, acute bacterial infections and during tumorigenesis. It is reported that Galectin-3 is alarmin in experimental models of neuroinflammation and binds to TLR-4 promoting the pro-inflammatory phenotype of microglia. Also, in experimental model of acute pancreatitis Galectin-3 is colocalized with TLR-4 on innate inflammatory cells resulted in enhanced production of inflammatory cytokines, TNF-α and IL-1β, increased infiltration of pro-inflammatory N1 neutrophils, macrophages and dendritic cells and increased damage of pancreatic tissue. This review paper discusses the role of TLR-4/Gal-3 axis in the pathogenesis of acute pancreatitis.

Weak association between the interleukin-8 rs4073 polymorphism and acute pancreatitis: a cumulative meta-analysis

Background

Several studies have been performed to investigate the associations between interleukin (IL)-8 rs4073 polymorphism and acute pancreatitis (AP), but the results are inconclusive. We conducted this cumulative meta-analysis for a precise estimate of the relationship between IL-8 rs4073 polymorphism and acute pancreatitis.

Methods

We searched the electronic databases for relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the associations. For a better presentation of how the pooled ORs changed as updated evidence accumulated, we used forest plots from a cumulative meta-analysis method.

Results

Ten studies involving 1646 AP patients and 1816 controls were finally included in this meta-analysis. Cumulative meta-analyses indicated there is a consistent trend toward association after the initial discovery. Under the allelic, dominant, recessive and homozygous models, the pooled ORs were 1.265 (1.147–1.395, p < 0.001), 1.304 (1.127–1.508, p < 0.001), 1.431 (1.203–1.702, p < 0.001), and 1.634 (1.334–2.001, p < 0.001), respectively.

Conclusions

This meta-analysis demonstrated a suggestive result that people who carried the risk A allele of the IL-8 rs4073 polymorphism may be more sensitive to acute pancreatitis.

Electronic supplementary material

The online version of this article (10.1186/s12881-019-0861-4) contains supplementary material, which is available to authorized users.

Gene polymorphisms in the interleukins gene and the risk of acute pancreatitis: A meta-analysis

Single nucleotide polymorphisms (SNPs) within the interleukins (IL) gene may affect the risk of acute pancreatitis. Many epidemiological studies have reported an association between the IL gene and acute pancreatitis risk, but the results remain inconsistent. Given the controversial available data, we carried out a meta-analysis to systematically evaluate and clarify the association between IL gene polymorphisms and AP. A systematic search of studies for this association was obtained from the PubMed, EMBASE, Web of Science and Chinese National Knowledge Infrastructure (CNKI) databases until June 1, 2017. We also searched the references of the included studies to identify additional studies. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were used to pool the effect size. Stata12.0 was used for whole statistical analysis. Fifteen studies that contained 3371 AP cases and 3506 controls were included in final combination. Overall, a significant association was found between the IL-8-251 T/A (rs4073) polymorphism, the IL-10-1082 A/G (rs1800896) polymorphism and the AP risk in four genetic models (homozygote model, recessive model, dominant model, allele model). Meanwhile, individuals with IL-1β+3954 C/T (rs1143634, (homozygote model, recessive model)), IL-1β -511 C/T (rs16944, (dominant model)) and IL-6-634C/G (rs1800796, (allele model)) polymorphism were associated with an increased risk of AP. No evidence of an association was found between IL and 10-592 C/A (rs1800872) and IL-10-819 C/T (rs1800871) polymorphism and AP risk.

TLR4 Asp299Gly and Thr399Ile and TLR2 intron 2 microsatellite gene polymorphism in patients with acute biliary pancreatitis: Does it cause the disease?

OBJECTIVES

There has been coverage of Toll-like receptor 4 and Toll-like receptor 2 gene polymorphisms 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 mutations in Asp299Gly and Thr399Ile of the Toll-like receptor 4 gene, and the intron 2 microsatellite polymorphism of the Toll-like receptor 2 gene on the occurrence of acute biliary pancreatitis.

MATERIAL AND METHODS

The study included 86 patients for the Toll-like receptor 4 Thr399Ile polymorphism, 100 patients for the Toll-like receptor 4 Asp299Gly polymorphism with acute biliary pancreatitis, and 101 healthy volunteers. At the same time, 93 patients and 92 healthy volunteers were included in the study to research the Toll-like receptor 2 intron 2 microsatellite polymorphism. Genotypes were determined using the restriction fragment length polymorphism analysis of PCR products and by an allele-specific PCR.

RESULTS

The Toll-like receptor 4 Thr399Ile homozygotes mutant variants (p=0.005) and Toll-like receptor 2 MM genotype (p<0.001) were detected with a significantly higher frequency in patients with acute biliary pancreatitis than in the healthy blood donors.

CONCLUSION

The Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms and the Toll-like receptor 2 intron 2 microsatellite polymorphism are statistically associated with ABP.

Association of IL-8-251A/T polymorphism with acute pancreatitis susceptibility: A meta-analysis

AIM

To systematically evaluate the association between the rs4073 (-251A/T) polymorphism in the interleukin-18 (IL-18) gene promoter and susceptibility to acute pancreatitis (AP).

METHODS

According to the retrieval strategy, studies about IL-8-251A/T polymorphism and AP were selected from PubMed, EMBASE, Web of Science, CNKI, Wanfang, and VIP electronic databases up to June 2017. We conducted a systematic analysis and meta-analysis to evaluate the association between the polymorphism and AP risk based on the currently available evidence of the literature, including allele genetic model, heterozygous, homozygous, dominant, and recessive genetic models.

RESULTS

A total of eight studies involving 1190 cases and 1369 controls were finally included. We found that the T allele of the IL-8-251A/T polymorphism significantly decreased AP risk (OR = 0.770, 95%CI: 0.686-0.865, P < 0.001). The IL-8-251A/T polymorphism was significantly associated with genetic susceptibility to AP under all genetic models (homozygous: OR = 0.543, 95%CI: 0.368-0.799, P < 0.001; heterozygous: OR = 0.755, 95%CI: 0.602-0.947, P = 0.015; dominant: OR = 0.676, 95%CI: 0.547-0.835, P < 0.001; recessive: OR = 0.738, 95%CI: 0.623-0.873, P < 0.001).

CONCLUSION

The present meta-analysis suggests that the IL-8-251A/T polymorphism might be a protective factor for genetic susceptibility to AP.

The -251 A/T Polymorphism in the IL8 Promoter is a Risk Factor for Acute Pancreatitis

OBJECTIVES

Inflammation in the setting of acute pancreatitis (AP) is partially driven by pathogen recognition receptors that recognize damage-associated molecular patterns. Interleukin (IL)-8 is a chemotactic factor produced by pathogen recognition receptor-expressing cells. A single-nucleotide polymorphism in IL8 promoter region (-251 A/T) has been implicated in inflammatory diseases. We examined whether this IL8 polymorphism confers susceptibility to AP.

METHODS

Patients with AP (n = 357) were prospectively recruited. Clinical data and blood were collected in subjects and controls (n = 347). Severity was defined following the Revised Atlanta Classification. Genotypes were assessed by quantitative polymerase chain reaction using TaqMan probes.

RESULTS

Patients and controls had similar demographics and had no difference in Hardy-Weinberg (patients, P = 0.29; controls, P = 0.66). Twenty-five percent of patients developed severe AP. Compared with controls, the A/A genotype was more common in AP (P = 0.041; odds ratio, 1.42; 95% confidence interval, 1-1.99). Obese patients with the A/A genotype were more likely to develop mild AP (P = 0.047).

CONCLUSIONS

The -251 polymorphism confers susceptibility to AP and disease severity in obese patients. However, its effect is moderate. One potential mechanism for this susceptibility is via increased IL8 production by innate cells, with subsequent enhanced neutrophil influx and pancreatic injury.

Pathogenic mechanisms of pancreatitis

Pancreatitis is inflammation of pancreas and caused by a number of factors including pancreatic duct obstruction, alcoholism, and mutation in the cationic trypsinogen gene. Pancreatitis is represented as acute pancreatitis with acute inflammatory responses and; chronic pancreatitis characterized by marked stroma formation with a high number of infiltrating granulocytes (such as neutrophils, eosinophils), monocytes, macrophages and pancreatic stellate cells (PSCs). These inflammatory cells are known to play a central role in initiating and promoting inflammation including pancreatic fibrosis, i.e., a major risk factor for pancreatic cancer. A number of inflammatory cytokines are known to involve in promoting pancreatic pathogenesis that lead pancreatic fibrosis. Pancreatic fibrosis is a dynamic phenomenon that requires an intricate network of several autocrine and paracrine signaling pathways. In this review, we have provided the details of various cytokines and molecular mechanistic pathways (i.e., Transforming growth factor-β/SMAD, mitogen-activated protein kinases, Rho kinase, Janus kinase/signal transducers and activators, and phosphatidylinositol 3 kinase) that have a critical role in the activation of PSCs to promote chronic pancreatitis and trigger the phenomenon of pancreatic fibrogenesis. In this review of literature, we discuss the involvement of several pro-inflammatory and anti-inflammatory cytokines, such as in interleukin (IL)-1, IL-1β, IL-6, IL-8 IL-10, IL-18, IL-33 and tumor necrosis factor-α, in the pathogenesis of disease. Our review also highlights the significance of several experimental animal models that have an important role in dissecting the mechanistic pathways operating in the development of chronic pancreatitis, including pancreatic fibrosis. Additionally, we provided several intermediary molecules that are involved in major signaling pathways that might provide target molecules for future therapeutic treatment strategies for pancreatic pathogenesis.

The effect of renin angiotensin system genetic variants in acute pancreatitis

OBJECTIVES

We sought association of genetic variants in the renin-angiotensin system (RAS) and vitamin D system with acute pancreatitis (AP) development and severity.

BACKGROUND

The endocrine RAS is involved in circulatory homeostasis through the pressor action of angiotensin II at its AT1 receptor. However, local RAS regulate growth and inflammation in diverse cells and tissues, and their activity may be suppressed by vitamin D. Intrapancreatic angiotensin II generation has been implicated in the development of AP.

METHODS

Five hundred forty-four white patients with AP from 3 countries (United Kingdom, 22; Germany, 136; and The Netherlands 386) and 8487 control subjects (United Kingdom 7833, The Netherlands 717) were genotyped for 8 polymorphisms of the RAS/vitamin D systems, chosen on the basis of likely functionality.

RESULTS

The angiotensin-converting enzyme I (rather than D) allele was significantly associated with alcohol-related AP when all cohorts were combined (P = 0.03). The renin rs5707 G (rather than A) allele was associated with AP (P = 0.002), infected necrosis (P = 0.025) and mortality (P = 0.046).

CONCLUSIONS

The association of 2 RAS polymorphisms with AP suggests the need for further detailed analysis of the role of RAS/vitamin D in the genesis or severity of AP, particularly given the ready potential for pharmacological manipulation of this system using existing marketed agents. However, further replication studies will be required before any such association is considered robust, particularly given the significant heterogeneity of AP causation and clinical course.

Genetics of acute and chronic pancreatitis: An update

Progress made in identifying the genetic susceptibility underlying acute and chronic pancreatitis has benefitted the clinicians in understanding the pathogenesis of the disease in a better way. The identification of mutations in cationic trypsinogen gene (PRSS1 gene; functional gain mutations) and serine protease inhibitor kazal type 1 (SPINK1 gene; functional loss mutations) and other potential susceptibility factors in genes that play an important role in the pancreatic secretory functions or response to inflammation during pancreatic injury has changed the current concepts and understanding of a complex multifactorial disease like pancreatitis. An individual’s susceptibility to the disease is governed by genetic factors in combination with environmental factors. Candidate gene and genetic linkage studies have identified polymorphisms in cationic trypsinogen (PRSS1), SPINK1, cystic fibrosis trans-membrane conductance regulator (CFTR), Chymotrypsinogen C (CTRC), Cathepsin B (CTSB) and calcium sensing receptor (CASR). Individuals with polymorphisms in the mentioned genes and other as yet identified genes are at an enhanced risk for the disease. Recently, polymorphisms in genes other than those involved in “intra-pancreatic trypsin regulatory mechanism” namely Claudin-2 (CLDN2) and Carboxypeptidase A1 (CPA1) gene have also been identified for their association with pancreatitis. With ever growing number of studies trying to identify the genetic susceptibility in the form of single nucleotide polymorphisms, this review is an attempt to compile the available information on the topic.

Functional effect of polymorphisms in the promoter of TNFAIP3 (A20) in acute pancreatitis in the Han Chinese population

BACKGROUND

The zinc finger protein A20 is an important negative regulator of inflammation; polymorphisms in the corresponding gene, TNFAIP3, have been reported to be associated with several inflammation diseases. However, only a few studies have focused on the relationship between TNFAIP3 polymorphisms and acute pancreatitis (AP).

METHODS

We enrolled 201 healthy controls and 190 acute pancreatitis patients (including 47 systemic inflammatory response syndrome patients) for this study and used DNA sequencing to investigate polymorphisms in the TNFAIP3 promoter. The functional effects of these variants on transcriptional activity, A20 expression, NF-κB activity, and TNF-α and IL-1β levels, after in vitro lipopolysaccharide stimulation, were assessed.

RESULTS

Two SNPs (rs59693083 and rs5029924) in the TNFAIP3 promoter were selected based on bioinformatic analysis. Neither of these SNPs was associated with susceptibility to AP; however, acute pancreatitis patients who possessed the T allele of rs5029924 were more likely to experience systemic inflammatory response syndrome. Moreover, rs5029924 was found to affect TNFAIP3 promoter activity. After lipopolysaccharide stimulation, the expression of A20 protein significantly decreased, while the activity of NF-κB and the production of TNF-α and IL-1β significantly increased in whole blood leukocytes from subjects with the T allele.

CONCLUSION

The rs5029924 polymorphism in the TNFAIP3 promoter may alter the risk of systemic inflammatory response syndrome in acute pancreatitis patients by influencing the expression of A20 protein.

Toll-like receptor 4 polymorphisms to determine acute pancreatitis susceptibility and severity: A meta-analysis

AIM: To investigate the correlation of toll-like receptor 4 (TLR4) gene Asp299Gly and Thr399Ile polymorphisms and acute pancreatitis (AP) risk and severity.

METHODS: To get a more precise estimation of the relationship, a comprehensive search was performed to examine all the eligible studies of TLR4 Asp299Gly and Thr399Ile polymorphisms and AP risk. The odds ratios with 95% confidence intervals were used to assess the strength of the association. Publication bias was analyzed by Begg’s funnel plots.

RESULTS: In total, six studies with 1255 cases and 998 controls were included in this meta-analysis. Totally, no significant associations were found between TLR4 Asp299Gly or Thr399Ile polymorphisms and AP risk using five models with high homogeneity (P > 0.05). Furthermore, stratification analysis by ethnicity or assay also found no significant association in these two polymorphisms (P > 0.05), and TLR4 Asp299Gly was not associated with AP severity (P > 0.05). In addition, no publication bias was found in these studies (P > 0.05).

CONCLUSION: Our current meta-analysis suggests that TLR4 Asp299Gly and Thr399Ile polymorphisms may not be risk factors to AP susceptibility.

Influence of interleukin gene polymorphisms on development of acute pancreatitis: a systematic review and meta-analysis

Several epidemiological studies have assessed the associations of interleukin (IL) gene polymorphisms with acute pancreatitis (AP) in different populations. However, the results were inconclusive. Therefore, we performed the present study to comprehensively evaluate the associations of IL gene polymorphisms and susceptibility to AP. Systematic searches of the PubMed, Web of Science, Embase, CNKI, CBMdisc and Google Scholar until February 27, 2013, as well as hand searching of the references of identified articles were performed. Data were extracted using standardized forms and odds ratios (ORs) with 95 % confidence intervals (CIs) were used to assess the strength of associations. All statistical analyses were performed using Stata 11.0. Ten studies were included in our final combined analysis, covering a total of 1,220 AP cases and 1,351 controls. The results showed evidence for significant association between IL-8 -251 T/A (rs4073) polymorphism and AP risk, suggesting that IL-8 -251 A allele was associated with an increased risk of AP (for A allele vs. T allele: OR = 1.36, 95 % CI 1.05-1.76, p = 0.02; for A/A vs. T/T: OR = 2.28, 95 % CI 1.08-4.81, p = 0.03; for A/A+T/A vs. T/T: OR = 1.40, 95 % CI 1.11-1.77, p = 0.005). However, there were no significant associations between IL-1β (IL-1β +3954 C/T (rs1143634) and IL-1β -511 C/T (rs16944)), IL-6 (IL-6 -174 G/C (rs1800795) and IL-6 -634 C/G (rs1800796)) and IL-10 (IL-10 -1082 A/G (rs1800896), IL-10 -819 C/T (rs1800871) and IL-10 -592 C/A (rs1800872)) gene polymorphisms and AP risk. In summary, the current study suggests that the IL-8 -251 T/A polymorphism is associated with an increased risk of AP. In addition, there were no significant associations between IL-1β, IL-6 and IL-10 gene polymorphisms and AP risk.

Genetics of acute and chronic pancreatitis

PURPOSE OF REVIEW

Acute pancreatitis, recurrent acute pancreatitis (RAP) and chronic pancreatitis are interrelated and progressive inflammatory disorders of the pancreas with highly variable and complex susceptibility, severity and outcomes. The role of genetics in acute pancreatitis, RAP and progression to chronic pancreatitis within a new framework is needed.

RECENT FINDINGS

The first genome-wide association study in the pancreas has been published with genome-wide significance linked with noncoding variants at the PRSS1-PRSS2 locus on chromosome seven and the CLDN2 locus on the X chromosome. A new personalized medicine paradigm is being considered to facilitate organization of genetic and other susceptibility risk compared with the risk of disease progression or resolution and risk of complications.

SUMMARY

A new framework for organizing multiple, complex data sets is emerging. The role of genetics in the context of other variables is important in understanding susceptibility to RAP and in the modification of disease severity and progression to chronic pancreatitis. Questions of when to order testing, what to order and how to use the data in real time remains an area for future research and development.

Controversial role of toll-like receptors in acute pancreatitis

Acute pancreatitis (AP) is a common clinical condition with an incidence of about 300 or more patients per million annually. About 10%-15% of patients will develop severe acute pancreatitis (SAP) and of those, 10%-30% may die due to SAP-associated complications. Despite the improvements done in the diagnosis and management of AP, the mortality rate has not significantly declined during the last decades. Toll-like receptors (TLRs) are pattern-recognition receptors that seem to play a major role in the development of numerous diseases, which make these molecules attractive as potential therapeutic targets. TLRs are involved in the development of the systemic inflammatory response syndrome, a potentially lethal complication in SAP. In the present review, we explore the current knowledge about the role of different TLRs that have been described associated with AP. The main candidate for targeting seems to be TLR4, which recognizes numerous damage-associated molecular patterns related to AP. TLR2 has also been linked with AP, but there are only limited studies that exclusively studied its role in AP. There is also data suggesting that TLR9 may play a role in AP.

A novel model of severe gallstone pancreatitis: murine pancreatic duct ligation results in systemic inflammation and substantial mortality

BACKGROUND

Suitable experimental models of gallstone pancreatitis with systemic inflammation and mortality are limited. We developed a novel murine model of duct-ligation-induced acute pancreatitis associated with multiorgan dysfunction and severe mortality.

METHODS

Laparotomy was done on C57/BL6 mice followed by pancreatic duct (PD) ligation, bile duct (BD) ligation without PD ligation, or sham operation.

RESULTS

Only mice with PD ligation developed acute pancreatitis and had 100% mortality. Pulmonary compliance was significantly reduced after PD ligation but not BD ligation. Bronchoalveolar lavage fluid neutrophil count and interleukin-1β concentration, and the plasma creatinine level, were significantly elevated with PD ligation but not BD ligation. Pancreatic nuclear factor κB (p65) and activator protein 1 (c-Jun) were activated within 1 h of PD ligation.

CONCLUSION

PD-ligation-induced acute pancreatitis in mice is associated with systemic inflammation, acute lung injury, multiorgan dysfunction and death. The development of this novel model is an exciting and notable advance in the field.

Polymorphisms of beta defensins are associated with the risk of severe acute pancreatitis

AIMS

Bacterial translocation from the intestinal tract plays an important role in severe acute pancreatitis (AP). Human β-defensins are a family of antimicrobial peptides present at the mucosal surface. The aim of this study was to investigate the relevance of single nucleotide polymorphisms (SNPs) in the DEFB1 gene and copy number polymorphisms of the DEFB4 genes in AP.

METHODS

124 AP patients (30 with mild and 94 with severe disease) and 100 healthy controls were enrolled in the study. Three SNPs of the DEFB1 gene [G-20A (c.-20G→A), C-44G (c.-44C→G) and G-52A (c.-52G→A)] were genotyped by Custom TaqMan assay. The DEFB4 gene copy number was determined by means of a TaqMan real-time PCR assay.

RESULTS

Significantly higher frequencies of the AA genotype of G-20A (c.-20G→A) and the AA genotype of G-52A (c.-52G→A) were observed among the patients with severe AP (SAP) compared with the healthy controls (38 vs. 20 and 41 vs. 18%, respectively). The GG protective genotype of C-44G (c.-44C→G) SNP was much less frequent (1%) among the patients than among the controls (9%). A higher frequency of a lower (<4) copy number of the DEFB4 gene was observed in the patients with SAP compared with the healthy controls (62 vs. 24%, respectively).

CONCLUSIONS

The variations in the genes encoding human β-defensin-1 and -2 may be associated with the risk of SAP. and IAP.

Possible role of toll-like receptor 4 in acute pancreatitis

Because the mechanism underlying the development of acute pancreatitis (AP) has not yet been fully clarified, it has been a hot but difficult topic in basic and clinical research for a long time. Currently, the dominant hypothesis for the pathogenesis of AP is that it is a disease of self-digestive acute chemical inflammation induced by trypsin activation. As proteins to trigger the inflammatory response cascade, Toll-like receptors (TLRs), especially TLR4, provide a new clue for studying the pathogenesis of AP from the source. Some studies have found that when TLR4 is activated by certain factors, it can amplify an inflammatory effect and aggravate the body's inflammatory response through a series of signal transduction. Toll-like receptor 4 may play an important role in the synthesis and release of proinflammatory cytokines, and the up-regulation of the TLR4 gene may be related with the development and progression of multiple organ injury during AP. As the "gate" of inflammatory response, TLR4 may be closely associated with the development and progression of multiple organ injury during AP. Understanding the roles of TLR4 in AP will help to further clarify the pathogenesis of AP and to search a new target for the treatment of AP.

Dominant negative p38 mitogen-activated protein kinase expression inhibits NF-kappaB activation in AR42J cells

BACKGROUND

The role of the p38 mitogen-activated protein (MAP) kinase in acute pancreatitis pathogenesis is controversial. We hypothesize that p38 plays a role in regulating NF-kappaB activation in exocrine pancreatic cells.

METHODS

AR42J cells incorporating an NF-kappaB-responsive luciferase reporter, with and without adenoviral transduction of DNp38, were stimulated with cholecystokinin (CCK) or tumor necrosis factor-alpha (TNF-alpha) prior to measuring NF-kappaB activation.

RESULTS

CCK- or TNF-alpha-stimulated NF-kappaB-dependent gene transcription (luciferase assay) was substantially subdued by DNp38 expression. These findings were confirmed by electrophoretic mobility shift assay. Nuclear translocation of the p65 NF-kappaB subunit following agonist stimulation was evident (supershift). Characterization studies showed excellent adenoviral infection efficiency and cell viability in our AR42J cell model. Agonist-stimulated dose- and time-dependent p38 activation, with inhibition by DNp38 expression, was also confirmed.

CONCLUSION

The p38 MAP kinase regulates NF-kappaB pathway activation in exocrine pancreatic cells, and thus potentially plays a role in the mechanism of acute pancreatitis pathogenesis..

Proposed protective mechanism of the pancreas in the rat

Background

Heparan sulphate is known to have various functions in the animal body, including surveillance of tissue integrity. Administered intraperitoneally, it induces a systemic inflammatory response syndrome and when given locally in the pancreas it initiates a protective inflammatory response. The aim of the present study was to investigate the underlying mechanisms behind cell recruitment following intra-ductal infusion of heparan sulphate.

Methods

Rats were subjected to intraductal-infusion of heparan sulphate, lipopolysaccharide and phosphate buffered saline into the pancreas. Pancreatic tissue was harvested 1, 3, 6, 9 or 48 hours after infusion and stained immunohistochemically for myeloperoxidase, ED-1, CINC-1 and MCP-1, as well as using eosin hematoxylin staining. Furthermore, MPO activity and MCP-1 and CINC-1 concentrations of tissue homogenates were measured. All differences were analyzed statistically using the Mann-Whitney U-test.

Results

During HS infusion, a rapid influx of macrophages/monocytes, as visualized as ED-1 positive cells, was seen reaching a maximum at 6 hours. After 48 hours, the same levels of ED-1 positive cells were noted in the pancreatic tissue, but with different location and morphology. Increased neutrophil numbers of heparan sulphate treated animals compared to control could be detected only 9 hours after infusion. The number of neutrophils was lower than the number of ED-1 positive cells. On the contrary, LPS infusion caused increased neutrophil numbers to a larger extent than heparan sulphate. Furthermore, this accumulation of neutrophils preceded the infiltration of ED-1 positive cells. Chemokine expression correlates very well to the cell infiltrate. MCP-1 was evident in the ductal cells of both groups early on. MCP-1 preceded monocyte infiltration in both groups, while the CINC-1 increase was only noticeable in the LPS group.

Conclusions

Our data suggest that heparan and LPS both induce host defense reactions, though by using different mechanisms of cell-recruitment. This implies that the etiology of pancreatic inflammation may influence how the subsequent events will develop.

-651C/T promoter polymorphism in the CD14 gene is associated with severity of acute pancreatitis in Japan

PURPOSE

This study aimed to clarify the association of the promoter variants in the CD14 gene with pancreatic diseases in Japan.

METHODS

Three hundred forty-six unrelated patients with acute pancreatitis (AP) (107 with severe and 239 with mild), 263 patients with chronic pancreatitis (CP), 264 patients with pancreatic neoplasm, and 319 healthy controls were genotyped for the single nucleotide polymorphisms at positions -260 and -651 from the AUG start codon in the CD14 gene by polymerase chain reaction-restriction enzyme digestion.

RESULTS

The allele and genotype frequencies of the -260C/T and -651C/T polymorphisms did not differ between controls and patients with AP. In subgroup analyses, patients with severe AP had more -651C allele than controls [P = 0.005; odds ratio (OR) 1.71; 95% confidence interval (CI) = 1.18-2.49] or patients with mild AP (P = 0.001; OR 1.95; 95% CI = 1.33-2.85). Genotype -651CC was more common (P = 0.001 vs. controls and P = 0.001 vs. mild AP), and -651CT was less (P = 0.009 vs. controls and P = 0.007 vs. mild AP) in patients with severe AP than in healthy controls or patients with mild AP. The frequencies of pseudocyst development and requirement of surgery were higher in AP patients with -651CC than in those without this genotype. The -260C/T polymorphism was not associated with the severity of AP. The allele and genotype frequencies of both polymorphisms did not differ between controls and patients with CP or pancreatic neoplasm.

CONCLUSION

-651C/T promoter polymorphism in the CD14 gene was associated with severity of AP in Japan.

Microsatellite polymorphism in intron 2 of human Toll-like receptor 2 gene is associated with susceptibility to acute pancreatitis in Japan

This study evaluated the association of the polymorphisms in the Toll-like receptor (TLR)2 and TLR4 genes with acute pancreatitis (AP) in Japan. The numbers of guanine-thymine [(GT)n] repeats in intron 2 of the TLR2 gene were counted in 202 unrelated patients with AP (80 with severe and 122 with mild disease) and in 286 healthy controls, using polymerase chain reaction and Genescan analysis. The alleles were divided into three subclasses: (GT)16 or less as the S allele; between (GT)17 and (GT)22 as the M allele; and (GT)23 or more as the L allele. Asp299Gly and Thr399Ile polymorphisms in the TLR4 gene were examined by polymerase chain reaction-restriction fragment length polymorphism analysis. Patients with AP had more S alleles (p < 0.001; odds ratio = 2.37; 95% confidence interval = 1.78-3.17) and fewer M alleles (p < 0.001; odds ratio = 0.40; 95% confidence interval 0.31-0.52) than did healthy controls. Genotypes SS and SL were more common, whereas MM and ML were less common in patients with AP. In subgroup analyses, the genotypes including S alleles were more common in patients with severe AP than in controls. No Asp299Gly and Thr399Ile polymorphisms were detected. In conclusion, microsatellite polymorphism in intron 2 of the TLR2 gene was associated with susceptibility to AP and its severity in Japan.

Genetic polymorphism of MCP-1-2518, IL-8-251 and susceptibility to acute pancreatitis: a pilot study in population of Suzhou, China

AIM

To study the relationship between MCP-1-2518A/G, IL-8-251A/T polymorphism and acute pancreatitis (AP) in the Han population of Suzhou, China.

METHODS

A case-control study was conducted to compare the distribution of genotype and genetic frequency of MCP-1-2518A/G, IL-8-251A/T gene polymorphism among AP (n = 101), including mild AP (n = 78) and severe AP (n = 23) and control healthy individuals (n = 120) with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, and analyze the relationship between the MCP-1-2518A/G, IL-8-251A/T gene polymorphism and the susceptibility to AP.

RESULTS

Significant differences were found in the distribution of genotype of MCP-1-2518A/G between the healthy control group and mild AP group (chi2 = 32.015, P < 0.001), the same was evident between the healthy control group and severe AP group (chi2 = 12.932, P < 0.05) in Suzhou. However, no difference of genotypic distribution was noted between MAP and SAP (chi2 = 0.006, P = 0.997). The genetic frequencies of G allele in mild AP were 72.4% (113/156) and 76.1% (35/46) in severe AP, both were higher than the controls, 47.1% (113/240) (chi2 = 24.804; P < 0.001, and chi2 = 13.005; P < 0.001), but no difference was found between severe AP and mild AP (chi2 = 0.242; P = 0.623). No difference was found in the distribution of genotype of IL-8-251A/T between the healthy control group and AP group neither in the frequency of A and T allele.

CONCLUSION

The MCP-1-2518 AA genotype of the population in Suzhou may be a protective genotype of AP, while one with higher frequency of G allele is more likely to suffer from pancreatitis. But the genotype of AA and the frequency of G allele could not predict the risk of severe AP. No correlation is found between the IL-8-251 polymorphism and the liability of AP.

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.

Role of Toll-like receptors in the development of sepsis

The outcome of sepsis and septic shock has not significantly improved in recent decades despite the development of numerous drugs and supportive care therapies. To reduce sepsis-related mortality, a better understanding of molecular mechanism(s) associated with the development of sepsis and sepsis-related organ injury is essential. There is increasing evidence that Toll-like receptors (TLRs) play a key role in the mediation of systemic responses to invading pathogens during sepsis. However, the role of TLRs in the development of sepsis and in sepsis-related organ injury remains debatable. In this review, we focus on the biological significance of TLRs during sepsis. Medline was searched for pertinent publications relating to TLRs, with emphasis on their clinical and pathophysiological importance in sepsis. In addition, a summary of the authors' own experimental data from this field was set in the context of current knowledge regarding TLRs. In both animal models and human sepsis, TLRs are highly expressed on monocytes/macrophages, and this TLR expression may not simply be a ligand-specific response in such an environment. The fact that TLR signaling enables TLRs to recognize harmful mediators induced by invading pathogens may be associated with a positive feedback loop for the inflammatory response among different cell populations. This mechanism(s) may contribute to the organ dysfunction and mortality that occurs in sepsis. A better understanding of TLR biology may unveil novel therapeutic approaches for sepsis.

Enteral exclusion increases MAP kinase activation and cytokine production in a model of gallstone pancreatitis

BACKGROUND

We have previously demonstrated that enteral exclusion augments pancreatic p38 mitogen-activated protein (MAP) kinase activation and tumor necrosis factor-alpha (TNF-alpha) production after bile-pancreatic duct ligation in rats.

METHODS

In the present study, we evaluated c-Jun NH(2)-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) activation, and cytokine production, in pancreata of duct-ligated rats with and without duodenal bile-pancreatic juice replacement from a donor rat. We hypothesized that enteral exclusion of bile-pancreatic juice activates stress kinases and induces cytokine production in ligation-induced acute pancreatitis.

RESULTS

Increased JNK and ERK activation after ligation are inhibited by bile-pancreatic juice replacement. Increases in pancreatic production of IL-1beta and IL-12 after ligation are significantly subdued by replacement. In additional in vitro studies, we show that cholecystokinin- or TNF-alpha-stimulated nuclear transcription factor kappa-B activation in AR42J cells is inhibited by dominant negative ERK2.

CONCLUSIONS

Our novel findings using our Donor Rat Model indicate that bile-pancreatic juice exclusion induces MAP kinase activation and exacerbates cell stress and inflammation in this experimental model of gallstone pancreatitis. and IAP.

The Atlanta Classification of acute pancreatitis revisited

BACKGROUND

In a complex disease such as acute pancreatitis, correct terminology and clear definitions are important. The clinically based Atlanta Classification was formulated in 1992, but in recent years it has been increasingly criticized. No formal evaluation of the use of the Atlanta definitions in the literature has ever been performed.

METHODS

A Medline literature search sought studies published after 1993. Guidelines, review articles and their cross-references were reviewed to assess whether the Atlanta or alternative definitions were used.

RESULTS

A total of 447 articles was assessed, including 12 guidelines and 82 reviews. Alternative definitions of predicted severity of acute pancreatitis, actual severity and organ failure were used in more than half of the studies. There was a large variation in the interpretation of the Atlanta definitions of local complications, especially relating to the content of peripancreatic collections.

CONCLUSION

The Atlanta definitions for acute pancreatitis are often used inappropriately, and alternative definitions are frequently applied. Such lack of consensus illustrates the need for a revision of the Atlanta Classification.

The chemokine network. II. On how polymorphisms and alternative splicing increase the number of molecular species and configure intricate patterns of disease susceptibility

In this second review on chemokines, we focus on the polymorphisms and alternative splicings and on their consequences in disease. Because chemokines are key mediators in the pathogenesis of inflammatory, autoimmune, vascular and neoplastic disorders, a large number of studies attempting to relate particular polymorphisms of chemokines to given diseases have already been conducted, sometimes with contradictory results. Reviewing the published data, it becomes evident that some chemokine genes that are polymorphic have alleles that are found repeatedly, associated with disease of different aetiologies but sharing some aspects of pathogenesis. Among CXC chemokines, single nucleotide polymorphisms (SNPs) in the CXCL8 and CXCL12 genes stand out, as they have alleles associated with many diseases such as asthma and human immunodeficiency virus (HIV), respectively. Of CC chemokines, the stronger associations occur among alleles from SNPs in CCL2 and CCL5 genes and a number of inflammatory conditions. To understand how chemokines contribute to disease it is also necessary to take into account all the isoforms resulting from differential splicing. The first part of this review deals with polymorphisms and the second with the diversity of molecular species derived from each chemokine gene due to alternative splicing phenomena. The number of molecular species and the level of expression of each of them for every chemokine and for each functionally related group of chemokines reaches a complexity that requires new modelling algorithms akin to those proposed in systems biology approaches.