The importance of interleukin 18, glutathione peroxidase, and selenium concentration changes in acute pancreatitis

Fire in the belly: A scoping review of the immunopathological mechanisms of acute pancreatitis

Introduction

Acute pancreatitis (AP) is characterised by an inflammatory response that in its most severe form can cause a systemic dysregulated immune response and progression to acute multi-organ dysfunction. The pathobiology of the disease is unclear and as a result no targeted, disease-modifying therapies exist. We performed a scoping review of data pertaining to the human immunology of AP to summarise the current field and to identify future research opportunities.

Methods

A scoping review of all clinical studies of AP immunology was performed across multiple databases. Studies were included if they were human studies of AP with an immunological outcome or intervention.

Results

205 studies met the inclusion criteria for the review. Severe AP is characterised by significant immune dysregulation compared to the milder form of the disease. Broadly, this immune dysfunction was categorised into: innate immune responses (including profound release of damage-associated molecular patterns and heightened activity of pattern recognition receptors), cytokine profile dysregulation (particularly IL-1, 6, 10 and TNF-α), lymphocyte abnormalities, paradoxical immunosuppression (including HLA-DR suppression and increased co-inhibitory molecule expression), and failure of the intestinal barrier function. Studies including interventions were also included. Several limitations in the existing literature have been identified; consolidation and consistency across studies is required if progress is to be made in our understanding of this disease.

Conclusions

AP, particularly the more severe spectrum of the disease, is characterised by a multifaceted immune response that drives tissue injury and contributes to the associated morbidity and mortality. Significant work is required to develop our understanding of the immunopathology of this disease if disease-modifying therapies are to be established.

Downregulating Gasdermin D Reduces Severe Acute Pancreatitis Associated with Pyroptosis

Background

Intestinal injury plays a key role in the pathogenesis of severe acute pancreatitis (SAP). In this study, we investigated the protective function of downregulated Gasdermin D (GSDMD) in intestinal damage in a mouse model of severe acute pancreatitis (SAP).

Material/Methods

Twenty-four healthy male C57BL/6 mice were randomly divided into 4 groups – the NS group, the siRNA-NS group, the SAP group, and the siRNA-SAP group – with 6 mice in each group. SAP was induced in mice by intraperitoneal injection of caerulein and lipopolysaccharide. The pathological changes of pancreatic and the intestinal mucosa and the relative gene and protein expressions in each group were compared, and the levels of GSDMD and serum IL-1β and IL-18 were evaluated after induction of the SAP model.

Results

The mice in the SAP group were in more serious condition than those in the siRNA-SAP group, with various degrees of edema and hemorrhage in the intestinal tract. Under an optical microscope, the pathological changes of pancreatic tissue such as edema, inflammatory cell infiltration, and the damage of lobular structural were gradually increased in the SAP group and the siRNA-NS group. In addition, intestinal mucosal damage and intestinal villus breakage were found in the SAP group and the siRNA-NS group, and the latter was lighter than the former. Compared with the SAP group, the level of GSDMD protein expression in the siRNA-SAP group was lower, and the serum levels of IL-1β and IL-18 were higher in the SAP group and siRNA-SAP group (P<0.05). Immunohistochemical analysis showed the occludin and ZO-1 proteins in the NS group had a strong brown linear signal, while the brown-positive signals were weaker in the siRNA-SAP group and the SAP group.

Conclusions

Downregulating GSDMD protein can reduce pancreatitis associated with pyroptosis.

The role of interleukin-18 in pancreatitis and pancreatic cancer

Originally described as an interferon (IFN)-γ-inducing factor, interleukin (IL)-18 has been reported to be involved in Th1 and Th2 immune responses, as well as in activation of NK cells and macrophages. There is convincing evidence that IL-18 plays an important role in various pathologies (i.e. inflammatory diseases, cancer, chronic obstructive pulmonary disease, Crohn's disease and others). Recently, IL-18 has also been shown to execute specific effects in pancreatic diseases, including acute and chronic pancreatitis, as well as pancreatic cancer. The aim of this study was to give a profound review of recent data on the role of IL-18 and its potential as a therapeutic target in pancreatic diseases. The existing data on this topic are in part controversial and will be discussed in detail. Future studies should aim to confirm and clarify the role of IL-18 in pancreatic diseases and unravel their molecular mechanisms.

Prophylactic Administration of Silybin Ameliorates L-Arginine-Induced Acute Pancreatitis

Background

Oxidative stress have been shown to play a role in the pathogenesis of acute pancreatitis. The aim of this study was to investigate the potential effect of silybin, a potent antioxidant, on L-arginine-induced acute pancreatitis in an experimental rat model.

Material/Methods

Forty female Wistar Albino rats were divided into 5 groups as follows: Group 1 (C): control group (n=8), Group 2 (SL): silybin group (n=8), Group 3 (LA): acute pancreatitis group (n=8), Group 4 (SLLA): prophylaxis group (n=8), and Group 5 (LASL): treatment group (n=8). Group C (control) received 2 intraperitoneal (i.p.) injections of physiological saline at an interval of 1 h. Group SL received only a single i.p. injection of silybin. The SLLA group received a single i.p. injection of silybin before the induction of acute pancreatitis with L-arginine, whereas the LASL group received the same injection after the induction of acute pancreatitis with L-arginine. Pancreatic tissues were histopathologically examined. Levels of amylase and oxidative stress markers (total oxidant status and total anti-oxidant status) were determined in the blood samples. Oxidative stress index was calculated.

Results

In comparison to the LA, the prophylaxis and treatment groups showed significant improvements in serum oxidative stress parameters (p=0.001 and p=0.005, respectively). Histopathological analysis showed that the treatment group had significant improvements in edema scores only (p=0.006), whereas the prophylaxis group had the same improvements in inflammation and necrosis scores as well as in total scores (p=0.004, 0.006, and 0.004, respectively).

Conclusions

When used for prophylactic rather than therapeutic purposes, silybin ameliorates serum oxidative stress parameters and improves histopathological results via its antioxidant and anti-inflammatory properties.

Role of Biomarkers in Diagnosis and Prognostic Evaluation of Acute Pancreatitis

Acute pancreatitis is a potentially life threatening disease. The spectrum of severity of the illness ranges from mild self-limiting disease to a highly fatal severe necrotizing pancreatitis. Despite intensive research and improved patient care, overall mortality still remains high, reaching up to 30–40% in cases with infected pancreatic necrosis. Although little is known about the exact pathogenesis, it has been widely accepted that premature activation of digestive enzymes within the pancreatic acinar cell is the trigger that leads to autodigestion of pancreatic tissue which is followed by infiltration and activation of leukocytes. Extensive research has been done over the past few decades regarding their role in diagnosis and prognostic evaluation of severe acute pancreatitis. Although many standalone biochemical markers have been studied for early assessment of severity, C-reactive protein still remains the most frequently used along with Interleukin-6. In this review we have discussed briefly the pathogenesis and the role of different biochemical markers in the diagnosis and severity evaluation in acute pancreatitis.

Interleukin 18 as an early marker or prognostic factor in acute pancreatitis

INTRODUCTION

Acute pancreatits (AP) still reqiures better diagnostic and therapeutic options to be introduced in order to decrease its morbidity and mortality. It appears that the assessment of serum levels of interleukin 18 (IL-18) and its correlation with C-reactive protein (CRP) may provide adequate prognostic value.

AIM

To measure serum concentrations of IL-18 and inflammation markers such as CRP in patients with AP during subsequent hospital stay days and to assess the role of IL-18 as an early AP marker and prognostic factor.

MATERIAL AND METHODS

Thirty-two patients aged 47 ±16.7 years were included into the study (17 males and 15 females), in whom AP was diagnosed based on ultrasound and computer aided tomography imaging and amylase. Serum amylase, CRP, and IL-18 levels were measured on the 1(st), 2(nd), 3(rd), and 5(th) days of hospital stay. All patients were scored "B" according to Balthazar and mild AP based on Ranson criteria. The control group consisted of 30 healthy volunteers aged 50.7 ±12.4 years (15 males and 15 females).

RESULTS

The average IL-18 serum level in the control group was 86.91 ±4.94 pg/ml. Mean IL-18 study group levels were 128.4 ±7.6 pg/ml on the 1(st), 112.0 ±4.4 pg/ml on the 3(rd), and 122.8 ±6.8 pg/ml on the 5(th) day of AP, and were significantly higher than those in the control group, accordingly: p < 0.001, p < 0.005, p < 0.001. A positive correlation between IL-18 and CRP serum concentrations was observed. A slight increase in correlation was observed as the days went by.

CONCLUSIONS

We concluded that the serum IL-18 level increases in the initial phase of AP, and it may be used as an inflammatory reaction marker in patients with AP, and it is correlated with CRP, which may indicate its prognostic role in AP.

Emodin has a protective effect in cases of severe acute pancreatitis via inhibition of nuclear factor‑κB activation resulting in antioxidation

Severe acute pancreatitis (SAP) accounts for up to 20% of acute pancreatitis (AP) cases. The absence of effective treatment options has resulted in a high rate of morbidity and mortality. Emodin is a major component of the Chinese herb rhubarb, which has been widely used in the treatment of numerous diseases, including inflammation and cancer. There are a limited number of studies however, that have investigated the effectiveness of emodin in the treatment of SAP. The present study used a rat model of SAP, to investigate the effect and molecular mechanisms of emodin treatment. Administration of emodin was identified to significantly attenuate SAP, as determined by serum amylase analysis and histological assessment of edema, vacuolization, inflammation and necrosis (P<0.01). Furthermore, treatment with emodin markedly inhibited nuclear factor (NF)‑κB DNA‑binding activity (P<0.01) and the serum expression levels of tumor necrosis factor‑α, interleukin (IL)‑6 and IL‑1β (P<0.05). This attenuation was associated with decreased malondialdehyde and increased superoxide dismutase levels in the pancreatic tissues and serum (P<0.05). This study indicated that administration of exogenous emodin had therapeutic effects on the severity of SAP. The mechanism may be due to inhibition of NF‑κB activation resulting in an antioxidation response, which can subsequently suppress the expression of cytokines.

Free radicals and acute pancreatitis: much ado about … something

There is a convincing body of evidence that oxidative stress is involved in the pathogenesis of acute pancreatitis. The effects of different radical scavengers suggested that reactive oxygen metabolites are generated at very early stage of disease and contribute to amplify the pancreatic damage. Oxidative stress is also involved in the progression of the disease from a local damage to a systemic organ failure. However, therapeutic use of antioxidants failed to clearly show a clinical benefit in different trials. Therefore, although antioxidants alone seem to be not enough for the treatment of severe acute pancreatitis, future combined therapeutic strategies should include antioxidants in its composition.

Ulinastatin in combination with glutamine dipeptide reduces serum levels of TNF-α, endotoxin and IL-6 in patients with severe acute pancreatitis

AIM: To evaluate the impact of protease inhibitor ulinastatin in combination with glutamine dipeptide on serum levels of TNF-α, endotoxin, IL-6 and IL-18 in patients with severe acute pancreatitis (SAP).

METHODS: Sixty-four SAP patients were divided into two groups: treatment group (n = 32) and control group (n = 32). The control group was treated with ulinastatin alone, while the treatment group was treated with ulinastatin in combination with glutamine dipeptide. The treatment lasted for 10 days. The changes in serum levels of TNF-α, endotoxin, IL-6 and IL-18 were determined by ELISA.

RESULTS: Compared to the control group, serum levels of TNF-α and endotoxin on days 7 and 10 (7 d: 38.83 ± 14.71 vs 51.92 ± 18.29; 0.46 ± 0.13 vs 0.71 ± 0.19; 10 d: 31.49 ± 12.65 vs 48.36 ± 15.43; 0.22 ± 0.07 vs 0.43 ± 0.15; all P < 0.05) and that of IL-6 on day 7 (117.68 ± 14.87 vs 163.43 ± 19.76, P < 0.05) were significantly lower in the treatment group. There was no significant difference in serum level of IL-18 between the two groups of patients (P > 0.05).

CONCLUSION: Ulinastatin in combination with glutamine dipeptide can reduce serum levels of TNF-α, endotoxin and IL-6 in SAP patients.

Pinealectomy aggravates acute pancreatitis in the rat

Melatonin, a pineal indoleamine, protects the pancreas against acute damage; however, the involvement of the pineal gland in the pancreatoprotective action of melatonin is unknown. The primary aim of this study was to determine the effects of pinealectomy on the course of acute caerulein-induced pancreatitis (AP) in rats. AP was induced by a subcutaneous infusion of caerulein (25 μg/kg) into pinealectomized or sham-operated animals. Melatonin (5 or 25 mg/kg) was given via intraperitoneal (ip) injection 30 min prior to the induction of AP. The pancreatic content of the lipid peroxidation products malondialdehyde and 4-hydroxynonenal (MDA + 4HNE) and the activity of an antioxidative enzyme, glutathione peroxidase (GSH-Px), were measured in each group of rats. Melatonin blood levels were measured by radioimmunoassay (RIA). In the sham-operated rats, AP was confirmed with histological examination and manifested as pancreatic edema and an increase in the blood lipase level (by 1,500%). In addition, the pancreatic content of MDA+ 4HNE was increased by 200%, and pancreatic glutathione peroxydase (GSH-Px) activity was reduced by 40%. Pinealectomy significantly aggravated the histological manifestations of AP, reduced the GSH-Px activity and markedly augmented the levels of MDA+ 4HNE in the pancreas of rats with or without AP as compared to sham-operated animals. Melatonin was undetectable in the blood of the pinealectomized rats with or without AP. Treatment with melatonin (25 mg/kg, ip) prevented the development of AP in the sham-operated rats and significantly reduced pancreatic inflammation in the animals previously subjected to pinealectomy. In conclusion, pineal melatonin contributes to the pancreatic protection through the activation of the antioxidative defense mechanism in pancreatic tissue as well as its direct antioxidant effects.

Protein alterations associated with pancreatic cancer and chronic pancreatitis found in human plasma using global quantitative proteomics profiling

Pancreatic cancer is a lethal disease that is difficult to diagnose at early stages when curable treatments are effective. Biomarkers that can improve current pancreatic cancer detection would have great value in improving patient management and survival rate. A large scale quantitative proteomics study was performed to search for the plasma protein alterations associated with pancreatic cancer. The enormous complexity of the plasma proteome and the vast dynamic range of protein concentration therein present major challenges for quantitative global profiling of plasma. To address these challenges, multidimensional fractionation at both protein and peptide levels was applied to enhance the depth of proteomics analysis. Employing stringent criteria, more than 1300 proteins total were identified in plasma across 8-orders of magnitude in protein concentration. Differential proteins associated with pancreatic cancer were identified, and their relationship with the proteome of pancreatic tissue and pancreatic juice from our previous studies was discussed. A subgroup of differentially expressed proteins was selected for biomarker testing using an independent cohort of plasma and serum samples from well-diagnosed patients with pancreatic cancer, chronic pancreatitis, and nonpancreatic disease controls. Using ELISA methodology, the performance of each of these protein candidates was benchmarked against CA19-9, the current gold standard for a pancreatic cancer blood test. A composite marker of TIMP1 and ICAM1 demonstrate significantly better performance than CA19-9 in distinguishing pancreatic cancer from the nonpancreatic disease controls and chronic pancreatitis controls. In addition, protein AZGP1 was identified as a biomarker candidate for chronic pancreatitis. The discovery and technical challenges associated with plasma-based quantitative proteomics are discussed and may benefit the development of plasma proteomics technology in general. The protein candidates identified in this study provide a biomarker candidate pool for future investigations.

High-throughput quantification of selenium in individual serum proteins from a healthy human population using HPLC on-line with isotope dilution inductively coupled plasma-MS

In this study, a method, based on dual column affinity chromatography hyphenated to isotope dilution inductively coupled plasma-quadrupole MS, was developed for selenium determination in selenoprotein P, glutathione peroxidase, and selenoalbumin in human serum samples from a group of healthy volunteers (n=399). Method improvement was achieved using methanol-enhanced isotope dilution which resulted in improved sensitivity and removal of isobaric interferences. Although no human serum reference materials are currently certified for their selenium species levels, method development was conducted using human serum reference material BCR 637 and 639 as their Se species content has been reported in the previous studies, and thus comparisons were possible. The mean selenium concentrations determined for the 399 healthy volunteer serum samples were 23 ± 10 ng Se mL(-1) for glutathione peroxidase, 49 ± 15 ng Se mL(-1) for selenoprotein P and 11 ± 4 ng Se mL(-1) for selenoalbumin. These values are found to be in close agreement with published values for a limited number of healthy volunteer samples, and to establish baseline Se levels in serum proteins for an apparently healthy group of individuals, thus allowing for subsequent comparisons with respective values determined for groups of individuals with selenium related health issues, as well as assist in the discovery of potential selenium biomarkers. Also, the relationship between Se serum protein levels and some anthropometric characteristics of the volunteer population were investigated. Additionally, further development of the analytical method used in this study was achieved by adding a size exclusion chromatography column after the two affinity columns via a switching valve. This allowed for the separation of small selenium-containing molecules from glutathione peroxidase and thus enhanced the overall confidence in its identification.

Usefulness of assessing circulating levels of resistin, ghrelin, and IL-18 in alcoholic acute pancreatitis

OBJECTIVES

Acute pancreatitis (AP) is a severe inflammatory disease with high mortality and morbidity rates. We have previously demonstrated that resistin may represent an early marker of inflammation in AP. It was also revealed that ghrelin may have anti-inflammatory potential. However, the role of adipohormones in AP-resistin and ghrelin as well as the proinflammatory cytokine interleukin (IL)-18-has not yet been fully elucidated.

METHODS

The study group comprised 32 patients with alcoholic AP and 30 controls matched for age, sex, and body mass index (BMI). In all cases AP was classified as grade C according to Balthazar's computed tomography (CT) score and as severe (3 points) according to Ranson's criteria. Serum levels of resistin, ghrelin, and IL-18 were measured on first, third, and fifth day of hospitalization by enzyme-linked immunosorbent assay (ELISA).

RESULTS

On first day of hospitalization the mean serum resistin concentration in AP patients was significantly higher than in controls (P < 0.05) and further increased on third and fifth day of hospitalization (17.4 ± 4.23 ng/ml and 25.8 ± 8.14 ng/ml, respectively). On first day of hospitalization the mean serum IL-18 concentration in AP patients was significantly higher than in controls (P < 0.05), on third day its level further increased, and on fifth day it decreased to a level similar to that observed on admission. The serum ghrelin concentrations on first, third, and fifth day of hospitalization were comparable, and significantly higher than in controls (P < 0.01). Significant correlation between C-reactive protein (CRP) and resistin levels (r = 0.43; P < 0.05) and between CRP and IL-18 (r = 0.58; P <0.05) on day of admission was found.

CONCLUSIONS

Serum concentration of IL-18 and resistin may contribute to inflammatory response and may be useful as an early marker of inflammation in AP. We also suspect that ghrelin affects the course of AP and plays an important role in inflammatory response.

Infectious complications in patients with severe acute pancreatitis

This study aims to investigate the clinical characteristics of infectious complications in severe acute pancreatitis (SAP). From September 2003 to March 2005, 140 patients with SAP were retrospectively identified. SAP was defined by the diagnostic criteria formulated for SAP at the 2002 Bangkok World Congress of Gastroenterology in Thailand. Clinical data of the infected and non-infected patients was compared and the characteristics of infection were also analyzed. There were 44 patients who developed infectious complications with a rate of 31.4% (44/140). The severity index, the incidence of complications and mortality, was significantly higher in the infected patients than in the non-infected patients (P<0.05). Of 65 episodes of infection, infected (peri) pancreatic necrosis accounted for 47.7% (31/65), pneumonia for 27.7% (18/65), bacteremia for 10.8% (7/65), urinary tract infection for 6.1% (4/65), and gastrointestinal tract infection for 7.7% (5/65). The earliest infection was observed in pneumonia (10.7±2.5 days), followed by bacteremia (13.7±1.5 days), gastrointestinal tract infection (16.8±3.9 days), infected (peri)pancreatic necrosis (17.6±2.9 days), and urinary tract infection (20.5±4.8 days). Gram-negative bacteria were preponderantly found, comprising 56.6% (64/113) of the isolated strains. Gram-positive bacteria and fungus accounted for 22.1% (25/113) and 21.2% (24/113) of the isolated strains, respectively. Infectious complications in patients with SAP occurred in those who had severe episodes, and consequently complicated the clinical courses. Infected (peri)pancreatic necrosis is the most susceptible and pneumonia is the earliest. Gram-negative bacteria were predominant in multi-microorganisms.

Role of oxidative stress in pancreatic inflammation

Reactive oxygen and reactive nitrogen species (ROS/RNS) have been implicated in the pathogenesis of acute and chronic pancreatitis. Clinical and basic science studies have indicated that ROS/RNS formation processes are intimately linked to the development of the inflammatory disorders. The detrimental effects of highly reactive ROS/RNS are mediated by their direct actions on biomolecules (lipids, proteins, and nucleic acids) and activation of proinflammatory signal cascades, which subsequently lead to activation of immune responses. The present article summarizes the possible sources of ROS/RNS formation and the detailed signaling cascades implicated in the pathogenesis of pancreatic inflammation, as observed in acute and chronic pancreatitis. A therapeutic ROS/RNS-scavenging strategy has been advocated for decades; however, clinical studies examining such approaches have been inconsistent in their results. Emerging evidence indicates that pancreatitis-inducing ROS/RNS generation may be attenuated by targeting ROS/RNS-generating enzymes and upstream mediators.

Severe acute pancreatitis: Pathogenetic aspects and prognostic factors

Approximately 20% of patients with acute pancreatitis develop a severe disease associated with complications and high risk of mortality. The purpose of this study is to review pathogenesis and prognostic factors of severe acute pancreatitis (SAP). An extensive medline search was undertaken with focusing on pathogenesis, complications and prognostic evaluation of SAP. Cytokines and other inflammatory markers play a major role in the pathogenesis and course of SAP and can be used as prognostic markers in its early phase. Other markers such as simple prognostic scores have been found to be as effective as multifactorial scoring systems (MFSS) at 48 h with the advantage of simplicity, efficacy, low cost, accuracy and early prediction of SAP. Recently, several laboratory markers including hematocrit, blood urea nitrogen (BUN), creatinine, matrix metalloproteinase-9 (MMP-9) and serum amyloid A (SAA) have been used as early predictors of severity within the first 24 h. The last few years have witnessed a tremendous progress in understanding the pathogenesis and predicting the outcome of SAP. In this review we classified the prognostic markers into predictors of severity, pancreatic necrosis (PN), infected PN (IPN) and mortality.

Interleukin-18: a pro-inflammatory cytokine that plays an important role in acute pancreatitis

A large body of clinical and experimental evidence suggests that cytokines play a key role in the pathogenesis of local and systemic complications of acute pancreatitis. IL-18 is a pro-inflammatory cytokine that plays a key role in many human diseases, including acute pancreatitis. This review focuses on the present understanding in IL-18 and its potential role in acute pancreatitis. IL-18 levels reflect the severity of acute pancreatitis and display a significant negative correlation with the concentrations of antioxidative damage factors, serum selenium and glutathione peroxidases (GPx). The relationship between IL-18 and other pro-inflammatory cytokines shows that IL-18 is one of the key mediators of inflammation in the pathogenesis of acute pancreatitis. Elevation of serum IL-18 levels may mediate acute pancreatitis associated liver injury. The use of IL-18 antagonists as direct routes to block IL-18 activity and P2X7 receptor antagonists and interleukin-1beta-converting enzyme (ICE) inhibitors as indirect routes to block IL-18 activity suggest that specific therapeutic inhibition of IL-18 is a promising therapeutic approach for acute pancreatitis.

Significant elevation of serum interleukin-18 levels in patients with acute pancreatitis

BACKGROUND

We have reported that peripheral lymphocyte reduction due to apoptosis is linked to the development of subsequent infectious complications in patients with severe acute pancreatitis and that Th1 (helper T cell type 1)/Th2 (helper T cell type 2) balance tends to cause Th1 suppression in experimental severe acute pancreatitis. It has been reported that interleukin (IL)-18 is a cytokine produced from Kupffer cells and activated macrophages, and that IL-18 acts on Th1 cells and in combination with IL-12 strongly induces production of interferon-gamma. However, the role of IL-18 in acute pancreatitis has not yet been fully understood.

METHODS

Serum IL-18 concentrations were determined by an enzyme-linked immunosorbent assay in 43 patients with acute pancreatitis at the time of admission. The relationships with etiology, pancreatic necrosis, severity, blood biochemical parameters on admission, infection, and organ dysfunction during the clinical course and prognosis were analyzed.

RESULTS

Serum IL-18 levels in patients with acute pancreatitis (656+/- 11pg/ml) were significantly higher than those in healthy volunteers (126+/- pg/ml). Serum IL-18 levels were significantly positively correlated with the Ranson score and Japanese severity score. Among the blood biochemical parameters on admission, base excess and total protein were significantly negatively correlated with serum IL-18 levels. Moreover, the CD4/CD8 rate of lymphocytes, serum IL-6 levels, and serum IL-8 levels were significantly positively correlated with serum IL-18 levels. On day 7 after admission, the CD4/CD8 rate of lymphocytes and the rate of CD4-positive lymphocytes were significantly positively correlated with serum IL-18 levels. Furthermore, serum IL-18 levels in patients with hepatic dysfunction (980+/- 25pg/ml) were significantly higher than those without hepatic dysfunction (464+/- 8pg/ml). Serum IL-18 levels were not related to infection or prognosis. Elevation of serum IL-18 levels continued during 4 weeks after admission.

CONCLUSIONS

These results suggest that serum IL-18 levels are significantly elevated and are correlated with severity in patients with acute pancreatitis and that IL-18 may be closely related to helper T cell response and hepatic dysfunction in this disease.

Especies reactivas de oxígeno en las enfermedades inflamatorias del páncreas: ¿una posible diana terapéutica?

Chronic and acute pancreatitis can be understood as distinct stages of an inflammatory spectrum in the pancreas. Although its pathogenesis is not well defined, oxidative stress seems to be clearly involved in its development. During acute pancreatitis, there is an extraordinary and rapid formation of reactive oxygen species that leads to the extinction of pancreatic antioxidant reserves, causes direct tissue damage and activates oxidative cellular mediators, giving rise to the lesion. However, classical antioxidants have not been shown to have clear benefits in patients with acute pancreatitis. Chronic pancreatitis seems to be the result of a recurrent lesion and defective repair, leading to pancreatic atrophy and fibrosis. In this process, oxidative stress is an efficient stimulus to maintain pancreatic stellar cells active, the fibrogenic motor of chronic pancreatitis. Although antioxidant supplements relieve abdominal pain in these patients, the direction of future antioxidant therapies lies in identifying oxidative mechanisms with the potential for intervention.