Acute pancreatitis--from cellular signalling to complicated clinical course

During Sepsis and COVID-19, the Pro-Inflammatory and Anti-Inflammatory Responses Are Concomitant

The most severe forms of COVID-19 share many features with bacterial sepsis and have thus been considered to be a viral sepsis. Innate immunity and inflammation are closely linked. While the immune response aims to get rid of the infectious agent, the pro-inflammatory host response can result in organ injury including acute respiratory distress syndrome. On its side, a compensatory anti-inflammatory response, aimed to dampen the inflammatory reaction, can lead to immunosuppression. Whether these two key events of the host inflammatory response are consecutive or concomitant has been regularly depicted in schemes. Initially proposed from 2001 to 2013 to be two consecutive steps, the concomitant occurrence has been supported since 2013, although it was proposed for the first time in 2001. Despite a consensus was reached, the two consecutive steps were still recently proposed for COVID-19. We discuss why the concomitance view could have been initiated as early as 1995.

Identification of novel immune-related targets mediating disease progression in acute pancreatitis

Introduction

Acute pancreatitis (AP) is an inflammatory disease with very poor outcomes. However, the order of induction and coordinated interactions of systemic inflammatory response syndrome (SIRS) and compensatory anti-inflammatory response syndrome (CARS) and the potential mechanisms in AP are still unclear.

Methods

An integrative analysis was performed based on transcripts of blood from patients with different severity levels of AP (GSE194331), as well as impaired lung (GSE151572), liver (GSE151927) and pancreas (GSE65146) samples from an AP experimental model to identify inflammatory signals and immune response-associated susceptibility genes. An AP animal model was established in wild-type (WT) mice and Tlr2-deficient mice by repeated intraperitoneal injection of cerulein. Serum lipase and amylase, pancreas impairment and neutrophil infiltration were evaluated to assess the effects of Tlr2 in vivo.

Results

The numbers of anti-inflammatory response-related cells, such as M2 macrophages (P = 3.2 × 10^-3), were increased with worsening AP progression, while the numbers of pro-inflammatory response-related cells, such as neutrophils (P = 3.0 × 10^-8), also increased. Then, 10 immune-related AP susceptibility genes (SOSC3, ITGAM, CAMP, FPR1, IL1R1, TLR2, S100A8/9, HK3 and MMP9) were identified. Finally, compared with WT mice, Tlr2-deficient mice exhibited not only significantly reduced serum lipase and amylase levels after cerulein induction but also alleviated pancreatic inflammation and neutrophil accumulation.

Discussion

In summary, we discovered SIRS and CARS were stimulated in parallel, not activated consecutively. In addition, among the novel susceptibility genes, TLR2might be a novel therapeutic target that mediates dysregulation of inflammatory responses during AP progression.

AGI grade-guided chaiqin chengqi decoction treatment for predicted moderately severe and severe acute pancreatitis (CAP trial): study protocol of a randomised, double-blind, placebo-controlled, parallel-group, pragmatic clinical trial

Background

Acute pancreatitis (AP) is a common digestive disease with increased incidence globally but without internationally licenced pharmacological therapy. Moderately severe and severe acute pancreatitis (MSAP/SAP) contributes predominately for its morbidities and mortality and has been managed in West China Hospital for decades using the traditional Chinese medicinal formula chaiqin chengqi decoction (CQCQD). The current study tests whether the early administration of CQCQD will result in improved clinical outcomes in predicted MSAP/SAP patients.

Methods

This is a single-centre, randomised, controlled, double-blind pragmatic clinical trial. AP patients aged 18–75 admitted within 72 h of onset will be assessed at admission for enrolment. We excluded the predicted mild acute pancreatitis (Harmless Acute Pancreatitis Score > 2 at admission) and severe organ failure (Sequential Organ Failure Assessment [SOFA] score of respiratory, cardiovascular, or renal systems > 3) at admission. Eligible patients will be randomly allocated on a 1:1 basis to CQCQD or placebo control administration based on conventional therapy. The administration of CQCQD and placebo is guided by the Acute Gastrointestinal Injury grade-based algorithm. The primary outcome measure will be the duration of respiratory failure (SOFA score of respiratory system ≥ 2) within 28 days after onset. Secondary outcome measures include occurrence of new-onset any organ failure (SOFA score of respiratory, cardiovascular, or renal system ≥ 2) and new-onset persistent organ failure (organ failure lasts > 48 h), dynamic surrogate biochemical markers and clinical severity scores, gut-centred treatment modalities, local complications status, intensive care need and duration, surgical interventions, mortality, and length of hospital stay. Follow-up will be scheduled on 6, 12, and 26 weeks after enrolment to assess AP recurrence, local complications, the requirement for surgical interventions, all-cause mortality, and patient-reported outcomes.

Discussion

The results of this study will provide high-quality evidence to appraise the efficacy of CQCQD for the early management of AP patients.

Trial registration

Chictr.org.cn Registry (ChiCTR2000034325). Registered on 2 July, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06792-x.

Rhein Protects Against Severe Acute Pancreatitis In vitro and In vivo by Regulating the JAK2/STAT3 Pathway

Rhein is widely used in inflammation treatment in China, but its effects on severe acute pancreatitis (SAP) have not been studied closely. This study investigated rhein’s protective effects against SAP using in vitro and in vivo models to determine whether its protective mechanism regulated the Janus kinase two and signal transducer and activator of transcription 3 (JAK2/STAT3) signalling pathway. Thirty-six male Sprague–Dawley rats were randomised into sham operation, SAP and rhein groups. The SAP model was induced by retrograde pancreatic bile duct injection of sodium taurocholate. Serum TNF-α and interleukin (IL)-6 levels were determined by ELISA, whereas serum amylase and lipase concentrations were measured using test kits. Western blot and/or immunohistochemistry quantified JAK2 and STAT3 expression. Furthermore, histopathological pancreatic changes were detected by haematoxylin and eosin staining. AR42J cells were randomly divided into the control, cerulein and rhein groups. Amylase activity was assessed using an amylase test kit; the tumour necrosis factor-α (TNF-α) expression was determined by enzyme-linked immunosorbent assay (ELISA). JAK2 and STAT3 protein expression were evaluated by western blot. SAP was concomitant with increased JAK2 and STAT3 expressions in vivo. Pre-treatment with rhein attenuated serum TNF–α and IL-6 levels effectively, and notably reduced p-JAK2, p-STAT3, JAK2 and STAT3 protein expression. Rhein significantly alleviated pancreatic histopathology. Compared to untreated groups, rhein significantly reduced amylase activity in supernatants of AR42J cells induced by cerulein in vitro. Furthermore, rhein altered JAK2 and STAT3 protein levels in AR42J cells after cerulein induction. Overall, rhein exerted protective effect on SAP in vitro and in vivo, possibly through the JAK2/STAT3 signalling pathway.

Mortality in acute pancreatitis with persistent organ failure is determined by the number, type, and sequence of organ systems affected

BACKGROUND

Persistent organ failure (POF) is the strongest determinant of mortality in acute pancreatitis (AP). There is a paucity of data regarding the impact of different POF attributes on mortality and the role of different characteristics of systemic inflammatory response syndrome (SIRS) in the risk of developing POF.

OBJECTIVE

We aimed to assess the association of POF dynamic features with mortality and SIRS characteristics with POF.

METHODS

We studied 1544 AP subjects prospectively enrolled at 22 international centers (APPRENTICE consortium). First, we estimated the association of onset, duration, and maximal score of SIRS with POF. Then, we evaluated the risk of mortality based on POF onset, duration, number, type, and sequence of organs affected. Analyses were adjusted for potential confounders.

RESULTS

58% had SIRS, 11% developed POF, and 2.5% died. Early SIRS, persistent SIRS, and maximal SIRS score ≥ 3 were independently associated with higher risk of POF (p < 0.05). Mortality risk in POF was higher with two (33%, odds ratio [OR] = 10.8, 3.3-34.9) and three (48%, OR = 20.2, 5.9-68.6) organs failing, in comparison to single POF (4%). In subjects with multiple POF, mortality was higher when the cardiovascular and respiratory systems failed first or concurrently as compared to when the renal system failed first or concurrently with other organ (p < 0.05). In multivariate regression model, the number and sequence of organs affected in POF were associated with mortality (p < 0.05). Onset and duration of POF had no impact mortality.

CONCLUSION

In AP patients with POF, the risk of mortality is influenced by the number, type, and sequence of organs affected. These results are useful for future revisions of AP severity classification systems.

NLRP3 Inflammasome Regulates Development of Systemic Inflammatory Response and Compensatory Anti-Inflammatory Response Syndromes in Mice With Acute Pancreatitis

BACKGROUND & AIMS

Pancreatitis starts with primarily sterile local inflammation that induces systemic inflammatory response syndrome, followed by compensatory anti-inflammatory response syndrome (CARS). We investigated the mechanisms of these processes in mice and human serum.

METHODS

We induced severe acute pancreatitis by partial duct ligation with caerulein stimulation or intraperitoneal injection of l-arginine in mice with deletion of interleukin (IL)12B, NLRP3, or IL18 and in mice given MCC950, a small molecule inhibitor of the NLRP3-inflammasome. Pancreata were collected from mice and analyzed by histology, and cytokine levels were measured in serum samples. We measured activation of adaptive immune responses in mice with pancreatitis by flow cytometry analysis of T cells (CD25 and CD69) isolated from the spleen. Differentiation of T-helper (Th1) cells, Th2 cells, and T-regulatory cells was determined by nuclear staining for TBET, GATA3, and FOXP3. We performed transcriptome analysis of mouse lymph nodes and bone marrow-derived macrophages after incubation with acini. We measured levels of cytokines in serum samples from patients with mild and severe acute pancreatitis.

RESULTS

Activation of the adaptive immune response in mice was initiated by macrophage-derived, caspase 1-processed cytokines and required activation of NLRP3 (confirmed in serum samples from patients with pancreatitis). Spleen cells from mice with pancreatitis had increases in Th2 cells but not in Th1 cells. Bone marrow-derived macrophages secreted IL1B and IL18, but not IL12, after co-incubation with pancreatic acini. T-cell activation and severity of acute pancreatitis did not differ significantly between IL12B-deficient and control mice. In contrast, NLRP3- or IL18-deficient mice had reduced activation of T cells and no increase in Th2 cell-mediated responses compared with control mice. The systemic type 2 immune response was mediated by macrophage-derived cytokines of the IL1 family. Specifically, IL18 induced a Th2 cell-mediated response in the absence of IL12. MCC950 significantly reduced neutrophil infiltration, T-cell activation, and disease severity in mice.

CONCLUSIONS

In mice with severe pancreatitis, we found systemic inflammatory response syndrome and compensatory anti-inflammatory response syndrome developed in parallel. Infiltrating macrophages promote inflammation and simultaneously induce a Th2 cell-mediated response via IL18. Inhibition of NLRP3 reduces systemic inflammatory response syndrome and compensatory anti-inflammatory response syndrome and might be used to treat patients with severe pancreatitis.

Ward-based Goal-Directed Fluid Therapy (GDFT) in Acute Pancreatitis (GAP) trial: study protocol for a feasibility randomised controlled trial

INTRODUCTION

Acute pancreatitis is an inflammatory disease of the pancreas with high risk of developing multiorgan failure and death. There are no effective pharmacological interventions used in current clinical practice. Maintaining fluid and electrolyte balance is the mainstay of supportive management. Goal-directed fluid therapy (GDFT) has been shown to decrease morbidity and mortality in surgical conditions with systemic inflammatory response. There is currently no randomised controlled trial (RCT) investigating the role of GDFT based on cardiac output parameters in patients with acute pancreatitis in the ward setting. A feasibility trial was designed to determine patient and clinician support for recruitment into an RCT of ward-based GDFT in acute pancreatitis, adherence to a GDFT protocol, safety, participant withdrawal, and to determine appropriate endpoints for a subsequent larger trial to evaluate efficacy.

METHODS AND ANALYSIS

The GDFT in Acute Pancreatitis trial is a prospective two-centre feasibility RCT. Eligible adults admitted with new onset of acute pancreatitis will be enrolled and randomised into ward-based GDFT (n=25) or standard fluid therapy (n=25) within 6 hours from the diagnosis and continuing for the following 48 hours. Cardiac output parameters will be monitored with a non-invasive device (Cheetah NICOM; Cheetah Medical). The intervention group will consist of a protocolised GDFT approach consisting of stroke volume optimisation with crystalloid fluid boluses, while the control group will receive standard care fluid therapy as advised by the clinical team. The primary endpoint is feasibility. Secondary endpoints will include safety of the intervention, complications, mortality, admission to intensive care unit, cost and quality of life.

ETHICS AND DISSEMINATION

Ethics approval was granted by the London Central Research Ethics Committee (17/LO/1235, project ID: 221872). The results of this trial will be presented to international conference with interest in general surgery and acute care and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ISRCTN36077283.

Severe Acute Pancreatitis: Gut Barrier Failure, Systemic Inflammatory Response, Acute Lung Injury, and the Role of the Mesenteric Lymph

BACKGROUND

Severe acute pancreatitis (AP) often leads to distant organ dysfunction with a high morbidity and mortality rate. The most common and earliest organ to fail is the lungs, but the exact pathophysiological mechanisms underlying the disease are still unclear. No successful targeted therapy exists, and treatment is limited to organ supportive care. It is believed that the gut is involved in the development of distant organ failure, as severe AP is associated with changes in the microcirculation, gut permeability/motility, bacterial translocation, and activation of the gut-associated lymphoid tissue (GALT). Experimental evidence implicates the mesenteric lymph as a primary route for these toxic factors to gain access to the systemic circulation. This literature overview was made to survey these mechanisms and the potential of surgical interventions on the thoracic duct as a means of therapy.

METHODS

Review of the pertinent English-language literature.

RESULTS

In experimental studies, interruption of mesenteric lymphatic flow has preventive qualities for acute lung injury (ALI) in the setting of critical illness with various etiologies. Experimentally, diversion of mesenteric lymph is able to prevent ALI if done before its development, whereas a later intervention partially reduces the lung damage. Few studies have investigated surgical approaches to the thoracic duct in human beings under these circumstances, and the ones that have been performed are of low quality and have conflicting results. It seems likely that the intervention would need to be performed prior to the development of ALI to obtain maximum benefits, which complicates its application clinically, because prediction of ALI cannot today be done with high precision.

CONCLUSION

Studies are ongoing to identify the factors carried in mesenteric lymph that may cause end-organ failure (e.g., ALI) and, once recognized, might allow the development of novel targeted agents that would modify the disease course.

Early-phase peritoneal drainage and lavage in a rat model of severe acute pancreatitis

PURPOSE

To evaluate the effects of early-phase drainage on the survival rates and pancreatic pathological changes associated with severe acute pancreatitis (SAP) in a rat model.

METHODS

Sprague-Dawley rats were divided into the following groups: SAP model (control), early drainage and delayed drainage. The 24-h survival rates were compared among the groups. In addition, the serum and ascites concentrations of interleukin (IL)-1β, IL-6, IL-8, IL-10 and tumor necrosis factor (TNF)-α were measured, and pancreatic pathological changes were observed.

RESULTS

The survival rate significantly improved in the early drainage group. Compared with that observed in the control group, the serum TNF-α and IL-8 concentrations in the early drainage group decreased, while the serum IL-10 levels increased, and the ascites concentrations of IL-1β, IL-6, IL-8 and TNF-α decreased, while that of IL-10 increased significantly. In the delayed drainage group, only the ascites concentrations of TNF-α decreased. Meanwhile, the pancreatic pathological changes at 3, 6 and 24 h worsened in the early drainage group; however, the pancreatic lesions in the early drainage group were less mild than those seen in the control group.

CONCLUSIONS

Rebalancing the cytokine levels in ascites after early drainage may be a key factor for enhancing the survival rate in rats.

Serum proteome profiling of pancreatitis using recombinant antibody microarrays reveals disease-associated biomarker signatures

PURPOSE

Pancreatitis is an inflammatory state of the pancreas, for which high-performing serological biomarkers are lacking. The aim of the present study was to evaluate the use of affinity proteomics for identifying potential markers of disease and stratifying pancreatitis subtypes.

EXPERIMENTAL DESIGN

High-content, recombinant antibody microarrays were applied for serum protein expression profiling of 113 serum samples from patients with chronic, acute, and autoimmune pancreatitis, as well as healthy controls. The sample groups were compared using supervised classification based on support vector machine analysis.

RESULTS

This discovery study showed that pancreatitis subtypes could be discriminated with high accuracy. Using unfiltered data, the individual subtypes, as well as the combined pancreatitis cohort, were distinguished from healthy controls with high AUC values (0.96-1.00). Moreover, characteristic protein patterns and AUC values in the range of 0.69-0.95 were observed for the individual pancreatitis entities when compared to each other, and to all other samples combined.

CONCLUSIONS AND CLINICAL RELEVANCE

This study demonstrated the potential of the antibody microarray approach for stratification of pancreatitis. Distinct candidate multiplex serum biomarker signatures for chronic, acute, and autoimmune pancreatitis were defined, which could enhance our fundamental knowledge of the underlying molecular mechanisms, and potentially lead to improved diagnosis.

Rho-kinase signalling regulates trypsinogen activation and tissue damage in severe acute pancreatitis

BACKGROUND AND PURPOSE

Severe acute pancreatitis (SAP) is characterized by trypsinogen activation, infiltration of leucocytes and tissue necrosis but the intracellular signalling mechanisms regulating organ injury in the pancreas remain elusive. Rho-kinase is a potent regulator of specific cellular processes effecting several pro-inflammatory activities. Herein, we examined the role of Rho-kinase signalling in acute pancreatitis.

EXPERIMENTAL APPROACH

Pancreatitis was induced by infusion of taurocholate into the pancreatic duct in C57BL/6 mice. Animals were treated with a Rho-kinase inhibitor Y-27632 (0.5-5 mg·kg⁻¹) before induction of pancreatitis.

KEY RESULTS

Taurocholate infusion caused a clear-cut increase in blood amylase, pancreatic neutrophil infiltration, acinar cell necrosis and oedema formation in the pancreas. Levels of pancreatic myeloperoxidase (MPO), macrophage inflammatory protein-2 (MIP-2), trypsinogen activation peptide (TAP) and lung MPO were significantly increased, indicating local and systemic disease. Inhibition of Rho-kinase activity dose-dependently protected against pancreatitis. For example, 5 mg·kg⁻¹ Y-27632 reduced acinar cell necrosis, leucocyte infiltration and pancreatic oedema by 90%, 89% and 58%, respectively, as well as tissue levels of MPO by 75% and MIP-2 by 84%. Moreover, Rho-kinase inhibition decreased lung MPO by 75% and blood amylase by 83%. Pancreatitis-induced TAP levels were reduced by 61% in Y-27632-treated mice. Inhibition of Rho-kinase abolished secretagogue-induced activation of trypsinogen in pancreatic acinar cells in vitro.

CONCLUSIONS AND IMPLICATIONS

Our novel data suggest that Rho-kinase signalling plays an important role in acute pancreatitis by regulating trypsinogen activation and subsequent CXC chemokine formation, neutrophil infiltration and tissue injury. Thus, these results indicate that Rho-kinase may constitute a novel target in the management of SAP.

A novel recombinant snake venom metalloproteinase from Agkistrodon acutus protects against taurocholate-induced severe acute pancreatitis in rats

Severe acute pancreatitis (SAP) remains a challenging disease to manage, with high mortality, limited understanding of pathogenesis and lack of specific therapy. Recombinant fibrinogenase II (rFII) from Agkistrodon acutus venom has been found to degrade tumor necrosis factor-alpha (TNF-α) which is vital in mortality of SAP. Here we investigate the in vivo effects of rFII in rat SAP and confirm the degradation effect of rFII for TNF-αin vitro. The SAP model was prepared by retrograde infusion of 5% sodium taurocholate into the biliopancreatic duct in male Sprague-Dawley rats. Treatment with 1 mg/kg rFII could significantly increase survival rate of SAP rats (P = 0.006) as well as 8 mg/kg Infliximab treatment did. The pancreatic and pulmonary injury and the peritoneal and systemic inflammatory response were also attenuated by rFII as well as Infliximab. Furthermore, rFII inhibited TNF-α secretion by rat peritoneal macrophages in a time- and concentration-dependent manner but didn't influence interleukin (IL) -1β secretion in vitro. The degradation potency of rFII for human TNF-α was greater than that for rat TNF-α. Our findings suggest that rFII could have protective effect on taurocholate-induced SAP in rats, mainly depending on direct degradation of TNF-α.

Major haemorrhagic complications of acute pancreatitis

Background

Haemorrhage is a rare, potentially fatal complication in acute pancreatitis (AP). The aim was to investigate the incidence, management and outcome related to this complication.

Methods

The medical records of all patients with AP who presented to a single hospital between January 1994 and July 2009 were reviewed retrospectively. Patients who developed at least one in-hospital episode of major haemorrhage were selected. The aetiology, patient characteristics, occurrence of sentinel bleeding, clinical management and outcome were recorded.

Results

Fourteen (1·0 per cent) of 1356 patients diagnosed with AP developed major haemorrhage. Angiography established the diagnosis in four of six patients. Embolization was successful in one patient. Surgery was performed in two patients. Sentinel bleeding occurred in three of four patients with major postoperative bleeding. The overall mortality rate was 36 per cent (5 of 14 patients). Haemorrhage presenting after more than 7 days was associated with a higher mortality rate of 80 per cent (4 of 5 patients). A fatal outcome was at least three times more likely in patients with severe AP and haemorrhagic complications than in those with severe AP but no bleeding.

Conclusion

Major haemorrhagic complications of AP are rare, but clinically important. Major postoperative bleeding is often preceded by sentinel bleeding. Intra-abdominal haemorrhage presenting more than 1 week after disease onset is a highly fatal complication.

Early systemic inflammatory response syndrome is associated with severe acute pancreatitis

BACKGROUND & AIMS

There have been few clinical studies of systemic inflammatory response syndrome (SIRS) in patients with acute pancreatitis. The aim of this study was to evaluate the role of SIRS in assessing severity of acute pancreatitis.

METHODS

We prospectively enrolled 252 consecutive patients with acute pancreatitis who were admitted directly to our institution between 2005-2007. The incidence and duration of SIRS (transient <or=48 hours vs persistent >48 hours) during the first 7 days of hospitalization, and the number of SIRS criteria (0-4) on the first day of hospitalization (day 1) were evaluated with individual markers of severity, including persistent organ failure, pancreatic necrosis, need for intensive care unit, and mortality.

RESULTS

SIRS occurred in 155/252 patients (62%) on day 1. SIRS on day 1 predicted severe disease with high sensitivity (85%-100%). The absence of SIRS on day 1 was associated with a high negative predictive value (98%-100%). Patients with a higher number of systemic inflammatory response (SIR) criteria on day 1 and persistent SIRS had an increased risk for severe disease (P < .01).

CONCLUSIONS

The majority of patients hospitalized with acute pancreatitis have SIRS on day 1. The severity of acute pancreatitis is greater among patients with SIRS on day 1 and, in particular, among those with 3 or 4 SIRS criteria, compared with those without SIRS on day 1.