Monitoring of serum proteinase--antiproteinase balance and systemic inflammatory response in prognostic evaluation of acute pancreatitis. Results of a prospective multicenter study

Ranson score to stratify severity in Acute Pancreatitis remains valid - Old is gold

Introduction: Acute pancreatitis (AP) is a common gastrointestinal disease with a wide spectrum of severity and morbidity. Developed in 1974, the Ranson score was the first scoring system to prognosticate AP. Over the past decades, while the Ranson score remains widely used, it was identified to have certain limitations, such as having low predictive power. It has also been criticized for its 48-hour requirement for computation of the final score, which has been argued to potentially delay management. With advancements in our understanding of AP, is the Ranson score still relevant as an effective prognostication system for AP?Areas covered: This review summarizes the available evidence comparing Ranson score with other conventional and novel scoring systems, in terms of prognostic accuracy, benefits, limitations and clinical applicability. It also evaluates the effectiveness of Ranson score with regard to the Revised Atlanta Classification.Expert opinion: The Ranson score consistently exhibits comparable prognostic accuracy to other newer scoring systems, and the 48-hour timeframe for computing the full Ranson score is an inherent strength, not a weakness. These aspects, coupled with relative ease of use, practicality and universality of the score, advocate for the continued relevance of the Ranson score in modern clinical practice.

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.

Scoring of human acute pancreatitis: state of the art

BACKGROUND

Acute pancreatitis remains as one of the most difficult and challenging digestive disorder to predict in terms of clinical course and outcome. Every case has an individual course and therefore acute pancreatitis remains challenging and fascinating. Due to this variability, many different scoring systems have evolved during the last decades. Every scoring system has advantages and disadvantages. Not every scoring system is capable of assessing the clinical time course of the disease, some are only suitable for the time of initial presentation.

AIM

This paper will give an overview on the development of different widely used scoring systems and their performance in assessing severity and prognosis of acute pancreatitis.

CONCLUSION

Severity assessment means objective quantification of overall severity of illness. Early and reliable stratification of severity is required to decide best treatment of the individual patient, preparation for possible evolving complications or for referral to specialist centers. No single scoring system is able to cover the entire range of problems associated with treatment and assessment of acute pancreatitis. In our clinical experience, we recommend hematocrit upon admission, daily sequential organ failure assessment score and procalcitonin, C-reactive protein on day 3 and CT severity index beyond the first week. These scoring tools together with close clinical follow-up of the patient ultimately lead to an optimized treatment of this challenging disease.

Rosiglitazone attenuates the severity of sodium taurocholate-induced acute pancreatitis and pancreatitis-associated lung injury

BACKGROUND AND AIMS

In addition to the effect of regulating adipocyte differentiation and insulin sensitivity, peroxisome proliferator activated receptor-gamma (PPAR-gamma) ligands also exhibit anti-inflammatory effect. However, the mechanisms concerning how PPAR-gamma ligands affect acute pancreatitis and pancreatitis-associated lung injury have not been fully elucidated. This study investigated the effect of rosiglitazone, a PPAR-gamma ligand, on acute pancreatitis and pancreatitis-associated lung injury in the rat pancreatitis model induced by sodium taurocholate.

METHODS

Acute pancreatitis was induced by retrograde infusion of 5% sodium taurocholate (1 mL/kg) into the bile-pancreatic duct. Rosiglitazone (6 mg/kg) was administered via the femoral vein 30 min prior to the infusion of sodium taurocholate. The severity of pancreatitis was evaluated by serum amylase level, myeloperoxidase activity, and pathology. Pancreatitis-associated lung injury was evaluated by myeloperoxidase activity, the magnitude of pulmonary edema and pathology. Intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor-alpha mRNA expression were studied using reverse transcriptase polymerase chain reaction. ICAM-1 protein expression was studied using Western blot analysis.

RESULTS

Prophylactic administration of rosiglitazone attenuated (1) serum amylase level; (2) myeloperoxidase activity of pancreatic and pulmonary tissue; (3) expression of tumor necrosis factor-alpha and ICAM-1 in pancreas and lung; (4) pancreas and lung pathological damage.

CONCLUSIONS

Our study demonstrated that rosiglitazone exerts a protective effect against sodium taurocholate-induced pancreatic and pulmonary injury.

The role of inflammatory and parenchymal cells in acute pancreatitis

The infiltration of inflammatory cells into the pancreas is an early and central event in acute pancreatitis that promotes local injury and systemic complications of the disease. Recent research has yielded the important finding that resident cells of the pancreas (particularly acinar and pancreatic stellate cells) play a dynamic role in leukocyte attraction via secretion of chemokines and cytokines and expression of adhesion molecules. Significant progress has been made in recent years in our understanding of the role of leukocyte movement (adhesion to the blood vessel wall, transmigration through the blood vessel wall and infiltration into the parenchyma) in the pathophysiology of acute pancreatitis. This review discusses recent studies and describes the current state of knowledge in the field. It is clear that detailed elucidation of the numerous processes in the inflammatory cascade is an essential step towards the development of improved therapeutic strategies in acute pancreatitis. Studies to date suggest that combination therapy targeting different steps of the inflammatory cascade may be the treatment of choice for this disease.

Association of plasma neutrophil elastase levels with other inflammatory mediators and clinical features in adult patients with moderate and severe pneumonia

BACKGROUND

Plasma levels of neutrophil elastase (NE) are elevated in several inflammatory diseases and thus this enzyme might be a critical inflammatory marker. However, the role of NE in the pathogenesis of pneumonia has not been determined. The association between the severity of pneumonia and blood levels of inflammatory markers could be relevant to developing a useful indicator of severity and new therapeutic strategies for pneumonia.

METHODS

We searched for a useful predictive marker and a new therapeutic strategy against pneumonia, using a prospective, multicenter, population-based investigation. Several inflammatory markers in the circulation including NE, cytokines, defensins, C-reactive protein (CRP) and white blood cell (WBC) counts as well as clinical features were prospectively monitored in 28 adult patients with moderate (n=11) and severe pneumonia (n=17) over a period of 14 days.

RESULTS

The value of plasma NE was the highest at entry and significantly declined 2 days later. Trends of cytokines, defensins, CRP and WBC counts were similar but blunter. Microorganisms and the outcome of initial treatment did not significantly affect plasma NE levels. Baseline values of plasma NE were significantly higher in severe, than in moderate pneumonia and this difference between the two types of pneumonia persisted longer than those of any other markers.

CONCLUSIONS

Neutrophil elastase appears to play a critical role in severe pneumonia and determination of its concentration in blood could be a useful indicator of severity. Furthermore, clinical trials of anti-NE drugs in patients with severe pneumonia should be promising.

Timing of antibiotic prophylaxis in acute pancreatitis: a controlled randomized study with meropenem

OBJECTIVES

Antibiotic prophylaxis improves the outcome of acute pancreatitis. Since bacterial translocation from the gut occurs in the first h of disease, early therapy is likely to achieve the maximal effect. The study compares early antibiotic treatment with treatment started after the demonstration of pancreatic necrosis.

METHODS

Two hundred fifteen patients with pancreatitis were randomized to either group A (N=108), who started antibiotic therapy (meropenem 500 mg t.i.d.) at admission, or group B (N=107), who received antibiotics after the demonstration of necrosis at computed tomography (CT). CT was performed in both groups after at least 48 hr of hospitalization. The clinical course of disease was compared in the two groups.

RESULTS

Thirty patients in group A and 29 in B showed necrosis on CT. The two groups were similar in demographics and characteristics of disease. Antibiotic treatment was started after 4.56+/-1.2 days from hospitalization in group B and after 1.07+/-0.6 days in A. Pancreatic infection occurred in four patients in group A (13.3%) and in nine in B (31%) (p=0.1). Extrapancreatic infection occurred in 16.6% of patients in group A and in 44.8% in B (p<0.05). Need for surgery and length of hospitalization were also higher in group B. Mortality rates were similar in the two groups, but, 3 of 4 patients with infected necrosis in group A and only 2 of 9 in group B died.

CONCLUSIONS

Early antibiotic treatment is associated with a significant improvement in the prognosis of necrotizing acute pancreatitis (AP), because of a reduction in the occurrence of septic complications.

Accuracy of plasma levels of polymorphonuclear elastase as early prognostic marker of acute pancreatitis in routine clinical conditions

OBJECTIVES

The early prognostic evaluation of acute pancreatitis (AP) is a key step in the appropriate management of the disease. Plasma levels of polymorphonuclear elastase have proved to be an accurate early prognostic marker of AP in research conditions. Whether the test remains sufficiently accurate in routine clinical conditions has been questioned. The aim of our study was to evaluate the accuracy of plasma polymorphonuclear-elastase levels for the early prognostic evaluation of AP in the clinical setting.

METHODS

A total of 224 consecutive patients with AP admitted to our Gastroenterology Department were included. A blood sample for polymorphonuclear-elastase quantification was obtained from all of them in the first morning of hospital stay, together with samples for routine haematological and biochemical analysis. Blood samples for polymorphonuclear-elastase evaluation were sent to the laboratory and managed there according to routine protocols. AP was classified as mild or severe according to the Atlanta classification, whereas polymorphonuclear-elastase results were kept blind. Results were shown as mean+/-SD and compared using Student's t-test for unrelated samples. The accuracy of the test for the prognostic evaluation of AP was calculated after drawing the corresponding receiver operator curve.

RESULTS

Fifty patients (23%) suffered from severe AP. The plasma levels of polymorphonuclear elastase were 217.8+/-93.5 microg/l in patients with severe AP and 68.1+/-32.7 microg/l in those with mild disease (P<0.001). The sensitivity and specificity of the test for the detection of severe AP were 92 and 91%, respectively, for an optimal cut-off value of 110 microg/l. The positive and negative predictive values for a prevalence of severe disease of 20% were 78 and 96%, respectively. The area under the receiver operator curve was 0.956.

CONCLUSION

Quantification of plasma polymorphonuclear-elastase levels is a very accurate method for the early prognostic evaluation of AP, and is easily applicable in the clinical setting.

Extracellular cleavage of E-cadherin by leukocyte elastase during acute experimental pancreatitis in rats

BACKGROUND & AIMS

Cadherins play an important role in cell-cell contact formation at adherens junctions. During the course of acute pancreatitis, adherens junctions are known to dissociate-a requirement for the interstitial accumulation of fluid and inflammatory cells-but the underlying mechanism is unknown.

METHODS

Acute pancreatitis was induced in rats by supramaximal cerulein infusion. The pancreas and lungs were either homogenized for protein analysis or fixed for morphology. Protein sequencing was used to identify proteolytic cleavage sites and freshly prepared acini for ex vivo studies with recombinant proteases. Results were confirmed in vivo by treating experimental pancreatitis animals with specific protease inhibitors.

RESULTS

A 15-kilodalton smaller variant of E-cadherin was detected in the pancreas within 60 minutes of pancreatitis, was found to be the product of E-cadherin cleavage at amino acid 394 in the extracellular domain that controls cell-contact formation, and was consistent with E-cadherin cleavage by leukocyte elastase. Employing cell culture and ex vivo acini leukocyte elastase was confirmed to cleave E-cadherin at the identified position, followed by dissociation of cell contacts and the internalization of cleaved E-cadherin to the cytosol. Inhibition of leukocyte elastase in vivo prevented E-cadherin cleavage during pancreatitis and reduced leukocyte transmigration into the pancreas.

CONCLUSIONS

These data provide evidence that polymorphonuclear leukocyte elastase is involved in, and required for, the dissociation of cell-cell contacts at adherens junctions, the extracellular cleavage of E-cadherin, and, ultimately, the transmigration of leukocytes into the epithelial tissue during the initial phase of experimental pancreatitis.

Compartmentalization of the protease-antiprotease balance in early severe acute pancreatitis

OBJECTIVE

To assess the balance between trypsin and protease inhibitors simultaneously in the systemic circulation and in the thoracic lymph and peritoneal exudate.

METHODS

Twenty patients with early severe acute pancreatitis were studied. Enzymatically active and immunoreactive trypsin in conjunction with its major inhibitors were measured in the 3 compartments at the onset of end-organ failure(s). The molecular forms of trypsin were determined in the lymph and ascites by gel filtration chromatography to separate trypsinogen and free-and inhibitor-bound trypsin.

RESULTS

Both enzymatically active trypsin and immunoreactive trypsin levels were highest in ascites and lymph compared with the systemic circulation. Intracompartmental alpha1- protease inhibitor gradient moved in the opposite direction, whereas alpha2 macroglobulin concentration was highest in ascites and lowest in the lymph. Although most of the enzymatically and immunoreactive material in ascites and lymph consisted of trypsin complexed with alpha2 macroglobulin and trypsinogen, respectively, free active trypsin was detected in more than 80% of the samples.

CONCLUSIONS

In patients with early severe acute pancreatitis, there is a significant trypsinogen activation resulting in protease-antiprotease imbalance and thereby free enzymatically active trypsin in the 2 body fluid compartments in close vicinity to the inflammatory process. This may be involved in the pathophysiology of local and distant tissue damage.

Structural evaluation of plasma α2-macroglobulin in acute pancreatitis

In this work we evaluate the proteolytic state of plasma α

Cholecystokinin blockade alters the systemic immune response in rats with acute pancreatitis

Acute pancreatitis (AP) is characterized by initial pancreatic injury resulting from the activation of digestive enzymes and, later, widespread inflammation to distant organs. The aim of this study was to study whether the time-course of inflammatory events during AP induced by bile-pancreatic duct obstruction (BPDO) varies after lowering the acinar enzyme content by L364,718 (0.1 mg/kg/day) administration over 7 days before inducing AP. Flow cytometric immunophenotyping was used to analyse the following at different AP stages: distribution of major circulating leucocyte subsets, activation state of circulating neutrophils and monocytes as reflected by CD11b expression and tumour necrosis factor-alpha (TNF-alpha) production and the contribution of T-cell-derived pro-(TNF-alpha) and anti-(IL-10) inflammatory mediators. TNF-alpha plasma levels and neutrophil infiltration in pancreas and lung were also measured. At early BPDO times, L364,718 treatment partially inhibited leukocytosis and increase in peripheral blood neutrophils and monocytes as well as TNF-alpha expression by monocytes. However, from 6 h onwards after BPDO, L364,718 treatment was unable to prevent either pancreatic and lung neutrophil infiltration or the release of TNF-alpha from activated monocytes. By its action on circulating lymphocytes, L364,718 treatment enhanced the severity of the inflammatory response induced by BPDO. Peripheral blood lymphocytes were recruited from earlier BPDO times, and 12 h after BPDO, T cells displayed a significantly higher reserve of TNF-alpha able to be released under stimulation but lower functional reserve of interleukin-10 (IL-10) than observed in untreated rats. It is concluded that lowering the acinar enzyme content through L364,718 treatment prevents earlier systemic immune events in BPDO-induced AP. However, at the point of maximal injury, the inflammatory response became pronounced, largely due to the role played by activated T lymphocytes.

Rosiglitazone, a ligand of the peroxisome proliferator-activated receptor-gamma, reduces acute pancreatitis induced by cerulein

OBJECTIVE

In the present study, we investigated the effects of rosiglitazone (10 mg/kg, i.p.), a PPAR-gamma agonist, on the development of acute pancreatitis.

DESIGN

Intraperitoneal injection of cerulein in mice induced an acute pancreatitis characterized by edema, neutrophil infiltration elevated serum levels of amylase and lipase. This experimental model was performed to test the anti-inflammatory activity of rosiglitazone. SETTING. University research laboratory.

INTERVENTIONS

Male CD mice (20-22 g) were allocated into four groups (n=10 for each group): (a) Cerulein+vehicle group. Mice were treated hourly (x 5) with cerulein (50 microg/kg, in saline solution, i.p.); (b) Rosiglitazone group (same as the Cerulein+vehicle group but were administered rosiglitazone, 10 mg/kg bolus, 30 min prior to cerulein); (c) Sham+saline group. Mice were treated with saline instead of cerulein; (d) Sham+Rosiglitazone. Identical to Rosiglitazone group except that the saline was administered instead of cerulein. Mice were killed at 6 h after the induction of pancreatitis. Blood samples, pancreas, and lungs were collected.

MEASUREMENTS AND RESULTS

Infiltration of pancreatic and lung tissue with neutrophils was associated with enhanced lipid peroxidation. Immunohistochemical examination demonstrated a marked increase in immunoreactivity for nitrotyrosine and for ICAM-1 in the pancreas of cerulein-treated mice. In contrast, the degree of (a) pancreatic inflammation and tissue injury, (b) upregulation/formation of ICAM-1 and nitrotyrosine, and (c) neutrophils infiltration was markedly reduced in pancreatic tissue obtained from rosiglitazone-treated mice.

CONCLUSION

These findings support the view that rosiglitazone and other potent PPAR-gamma agonists may be useful in the therapy of acute pancreatitis.

Useful markers for predicting severity and monitoring progression of acute pancreatitis

BACKGROUND

The main problem in staging acute pancreatitis is the lack of accurate predictors of disease severity and of markers for progression of acute pancreatitis.

METHODS

We reviewed the literature for all candidate markers of acute pancreatitis and graded their usefulness and practicability for prediction of severe pancreatitis and for monitoring disease progression.

RESULTS

Several markers can differentiate mild and severe cases of acute pancreatitis with a high positive predictive value. Trypsinogen activation peptide and procalcitonin show significant differences in patients with mild and severe disease already on admission. While most parameters peak early and decrease rapidly thereafter, C-reactive protein (CRP), phospholipase A(2), procalcitonin and serum amyloid A are reliable predictors with persistently elevated levels in severe disease. CRP is still the reference parameter of all predictors indicating severe disease and pancreatic necrosis. So far, no single parameter has been developed which is suitable for early prediction of infected pancreatic necrosis.

CONCLUSION

Of all markers available today, CRP is the 'gold standard' in predicting the severity of acute pancreatitis, but procalcitonin seems to be a promising tool to monitor the progression of the disease. CRP has already been established in clinical routine. For procalcitonin, a practicable assay is also available and could easily be adopted into clinical routine.

5-lipoxygenase knockout mice exhibit a resistance to acute pancreatitis induced by cerulein

Here we compare the degree of pancreatitis caused by cerulein in mice lacking 5-lipoxygenase (5-LO) and in the corresponding wild-type mice. Intraperitoneal injection of cerulein in mice resulted in severe, acute pancreatitis characterized by oedema, neutrophil infiltration and necrosis and elevated serum levels of amylase and lipase. Infiltration of pancreatic and lung tissue with neutrophils (measured as increase in myeloperoxidase activity) was associated with enhanced lipid peroxidation (increased tissue levels of malondialdehyde). Immunohistochemical examination demonstrated a marked increase in immunoreactivity for intracellular adhesion molecule-1 (ICAM-1), P-selectin and E-selectin in the pancreas and lung of cerulein-treated mice. In contrast, the degree of (1) pancreatic inflammation and tissue injury (histological score), (2) up-regulation/expression of P-selectin, E-selectin and ICAM-1, and (3) neutrophil infiltration was markedly reduced in pancreatic and lung tissue obtained from cerulein-treated 5-LO-deficient mice. These findings support the view that 5-LO plays an important, pro-inflammatory role in the acute pancreatitis caused by cerulein in mice.

Pancreas: healing response in critical illness

OBJECTIVE

The pathophysiology of acute pancreatitis represents a diverse mix of congenital, hereditary, and acquired problems associated with or causing acute pancreatic inflammation. Acute pancreatitis is characterized by acinar cell injury that may involve regional and systemic inflammatory responses. The systemic manifestations of acute pancreatitis are responsible for the majority of pancreatitis-associated morbidity and are due to the actions of specific inflammatory cytokines. This report summarizes this pancreatic injury, the role of cytokines in the pathogenesis of acute pancreatitis, and the pancreatic healing response that follows.

DESIGN

A comprehensive literature review of experimental pancreatitis as well as reports of cytokine involvement and healing response during clinical pancreatitis was performed.

RESULTS

Histamine release, bradykinin generation, and cytokine release play a significant role during acute pancreatic inflammation. Following an experimental insult, there is rapid expression of tumor necrosis factor-alpha, interleukin-6, interleukin-1, and chemokines by pancreatic acinar cells and/or transmigrated leukocytes. Preventing the action of these mediators has a profound beneficial effect in experimental animals. Pancreatic fibrosis is a central histologic response after pancreatitis. Transient collagen deposition with acinar necrosis occurs in acute pancreatitis; in chronic pancreatitis, permanent and disorganized pancreatic fibrosis and parenchymal cell atrophy occur.

CONCLUSIONS

Inflammatory mediators are responsible for the systemic manifestations of acute pancreatitis and the associated distant organ dysfunction. After the acute injury, regeneration or pancreatic repair is characterized by decreased release of proinflammatory mediators and decreased infiltrating inflammatory cells. Differentiation and proliferation of pancreatic myofibroblasts or "stellate" cells may be responsible for increased extracellular matrix production. The predictable nature in which the inflammation and fibrosis are produced may stimulate novel approaches to disease treatment.

[Value of C-reactive protein level in the detection of necrosis in acute pancreatitis]

OBJECTIVES

To evaluate the utility of C-reactive protein (CRP) in the detection of necrosis in acute pancreatitis and to determine the best cut-off point for CRP used for this purpose.

MATERIAL AND METHODS

We performed a retrospective study of 157 patients with acute pancreatitis who underwent computed tomography (CT) with intravenous contrast material between 72 h and 8 days after the onset of symptoms and whose serum CRP values were determined by nephelometry 24 h or later after the onset of pain.

RESULTS

Ninety-four patients were men and 63 were women, with a mean age of 61 years (range, 15-96 years). The cause of pancreatitis was biliary lithiasis in 53.5%, alcohol in 20.4%, and idiopathic in 10.8%. Other causes were found in 15.3%. The mean (standard deviation) time elapsed between symptom onset and extraction to evaluate CRP was 3.21 (1.7) days. The patients were divided into two groups according to the results of CT: 132 patients with acute intersitial edematous pancreatitis and 25 patients with acute necrotizing pancreatitis. The mean CRP concentrations were: 322 mg/l (range, 10.7-538) in patients with acute necrotizing pancreatitis and 133 mg/l (range, 3-442) in those with acute interstitial pancreatitis; this difference was statistically significant (p < 0.001). The area under the ROC curve of CRP vs. the occurrence of necrosis was 0.862 (95% CI, 0.778, 0.946). To evaluate the presence of pancreatic necrosis a cut-off level of 200 mg/l showed a sensitivity of 88% and a specificity of 75% while a cut-off level of 279 mg/l presented a sensitivity of 72% and a specificity of 88%.

CONCLUSIONS

In acute pancreatitis, a CRP value of less than or equal to 200 mg/l obtained at 72 h of symptom onset is useful for ruling out, with a high degree of probability, the presence of necrosis. With higher values, additional investigations should be performed to determine the presence of pancreatic necrosis; nevertheless, with values higher than 279 mg/l the risk of necrosis markedly increases.

Soluble thrombomodulin plasma levels are an early indication of a lethal course in human acute pancreatitis

BACKGROUND

The potential to predict severe disease and lethality by using plasma soluble thrombomodulin (sTM) and C-reactive protein (CRP) levels in 73 patients with acute pancreatitis was analyzed in a prospective 5-year investigation performed at a single institution.

METHODS

According to the Atlanta criteria, pancreatitis was classified as mild in 23 patients and as severe in 50 patients. Blood was collected on days 1, 3, 5, 7, 10, 14, 21, and 28 after the onset of pain and analyzed for sTM and CRP.

RESULTS

During the period between days 3 and 10 of acute pancreatitis when most of the admissions occurred, sTM levels at a cutoff of 75 ng/mL on day 3 (sensitivity, 100%; specificity, 77%; positive predictive value, 38%; negative predictive value, 100%) and 71 ng/mL on day 10 (sensitivity, 100%; specificity, 77%; positive predictive value, 41%; negative predictive value, 100%) were predictive of a lethal outcome. With sTM levels, it was not possible to differentiate patients with mild pancreatitis from those with severe pancreatitis (Atlanta classification). In contrast, CRP levels at a cutoff of 113 mg/L on day 3 differentiated severe from mild courses with a diagnostic sensitivity of 84%, a specificity of 60%, a positive predictive value of 78%, and a negative predictive value of 69%. CRP levels at a cutoff of 122 mg/L on day 10 differentiated mild from severe courses (nonsurvivors) with a diagnostic sensitivity of 72%, a specificity of 72%, a positive predictive value of 86%, and a negative predictive value of 53%. In contrast, differentiation of mild forms of acute pancreatitis from severe pancreatitis (survivors) on day 10 was not possible.

CONCLUSIONS

CRP is a valuable marker of disease severity in acute pancreatitis especially in the first period of pancreatitis, whereas sTM identifies early those patients with the most severe courses and a high risk of dying (negative predictive value, 100%). Determination of sTM in addition to CRP offers the opportunity of identifying early those patients who require intensive care most urgently. Of course, further investigations of sTM in acute pancreatitis are indicated to confirm our results.

New laboratory tests in acute pancreatitis

Acute pancreatitis (AP) is a common disease with wide variation of severity. The diagnosis of AP is usually based on high serum amylase or lipase values but the accuracy of these methods is considered unsatisfactory. One in five of the patients develops a severe disease and carries a considerable risk of development of organ failure and high mortality. Early detection of patients with severe AP and especially those with increased risk of organ failure is importance since such patients seem to benefit from treatment in an intensive care unit started as soon as possible after presentation. In addition to enzymological methods, increasing interest has been focused on laboratory markers reflecting the level of inflammatory response in AP. At present, in routine clinical work the most commonly used severity marker is serum C-reactive protein, the concentration of which rises too slowly to be used for early prediction of severity. New therapies aiming at modifying the course of systemic inflammation in AP are being developed and therefore monitoring the patient's immune inflammatory status is needed. In this review article we present the current knowledge of laboratory tests, which has been evaluated for diagnostic and prognostic purposes in AP.

Relationship between plasma cytokine concentration and multiple organ failure in patients with acute pancreatitis

The dynamic aspects of circulating cytokines and cytokine modulators and their relationship with development of multiple organ failure (MOF) in patients with acute pancreatitis were analyzed. All cytokine and C-reactive protein levels in the circulation were higher than those in the MOF group. In particular, plasma concentrations of soluble tumor necrosis factor receptors (sTNF-RI and sTNF-RII) were significantly higher in patients with MOF than in those without even at admission. Furthermore, plasma concentrations of sTNF-Rs and interleukin-1 (IL-1) receptor antagonist (IL-1ra) were much higher than those of their counterparts, TNFalpha and IL-beta, respectively. These results suggest that the plasma concentrations of sTNF-Rs are useful predictors for the development of MOF, and actions of TNF-alpha and IL-1beta could be regulated by their modulators (soluble receptor and receptor antagonist, respectively) in the pathologic condition of severe acute pancreatitis.

Reduced capacity to inhibit elastase in abdominal aortic aneurysm

BACKGROUND

Loss of elastin in the aortic wall is an early event in abdominal aortic aneurysm (AAA). An imbalance in the protease-antiprotease system is proposed to be one of the factors that promote connective tissue destruction. We hypothesize that plasma from AAA patients will have a reduced inhibitory capacity in comparison to normal controls.

MATERIALS AND METHODS

Using an assay we developed, plasma (10 microliters), collected from AAA patients (n = 14) and normal controls (n = 13), was added to the elastase inhibition assay containing succinylated elastin substrate. The reaction was initiated with 13.9 units porcine pancreatic elastase (PPE). Elastase activity in the presence and absence of plasma was compared. Plasma elastase was also determined using the Merck PMN-elastase kit.

RESULTS

The relative activity of exogenous elastase (%) in the presence of AAA plasma (n = 14, mean age 73.4 years +/- 1.7 SEM) was 42.59% +/- 4.3 SEM, while that in the presence of control plasma (n = 13, mean age 73.9 years +/- 2.1 SEM) was 10.23% +/- 2.1 SEM (P < 0.0001). Analysis of plasma elastase (microgram/L) indicated that there was no significant difference between normal (n = 9, 207.33 microgram/L +/- 58.67 SEM) and AAA (n = 9, 145.34 microgram/L +/- 29.54 SEM) (P = 0.359).

CONCLUSION

There is a significant reduction in the plasma inhibitory capacity of elastase in AAA patients in comparison to normal controls, though plasma elastase level was not significantly different. The data presented here give experimental evidence to the protease-antiprotease imbalance in AAA patient plasma and may lead to the development of a measurable parameter to monitor AAA.

Blood concentrations of polymorphonuclear leucocyte elastase and interleukin-6 are indicators for the occurrence of multiple organ failures at the early stage of acute pancreatitis

We studied potential indicators of severe acute pancreatitis by measuring the blood concentrations of various cytokines, polymorphonuclear leucocyte elastase (PMN-E), acute phase reactants, pancreatic amylase (P-AMY), pancreatic elastase-1 (E-1) and white blood cell (WBC) counts in patients with acute pancreatitis. In addition, the presence of multiple organ damage was assessed. Subjects consisted of 22 patients with acute pancreatitis including severe (n = 11), moderate (n = 4) and mild (n = 7) cases. A significant positive correlation was observed between the number of organs damaged and the peak concentrations of interleukin (IL)-6, PMN-E, C-reactive protein (CRP) and pancreatic secretory trypsin inhibitor (PSTI). Among these markers, blood concentrations of PMN-E and IL-6 rapidly increased and peaked at the early phase of acute pancreatitis whereas CRP and PSTI did not. The elevation of PMN-E and IL-6 was greater the more severe the symptoms. However, no significant correlation was observed between the number of organs damaged and the maximum serum concentrations of P-AMY and E-1, or the WBC count, which have been considered to be markers of pancreatitis. These results suggest that PMN-E and IL-6 concentrations are useful indicators of severity and prognosis and their determination facilitates the selection of appropriate treatment in the early stages of disease to prevent the aggressive progression of acute pancreatitis.

Neopterin in acute pancreatitis

BACKGROUND

Activation of the cellular immune system may play a role in the pathogenesis of acute pancreatitis (AP); it has recently been proposed that excessive leukocyte stimulation may lead to the most severe forms of AP. The aim of this study was to investigate serum neopterin, a useful in vivo marker of macrophage activation, in mild and severe AP and its relationship with other markers of leukocyte activation, such as interleukin-6 (IL-6) and tumor necrosis factor (TNF).

METHODS

Serum levels of neopterin (mmol/ml), IL-6 (pg/ml), and TNF (pg/ml) were measured on the 1st and 7th day of hospitalization in 17 patients with severe AP and 24 with mild AP. Severe AP was defined in accordance with the Atlanta criteria: all patients have necrosis at contrast-enhanced computerized tomography scan.

RESULTS

Day 1: Neopterin and IL-6 levels were significantly higher in severe than in mild AP and normal controls; mild AP values were also significantly higher than in normal controls. The best neopterin cutoff level we obtained (30 mmol/ml) reached a specificity of 76% and a sensitivity of 46% in distinguishing severe from mild AP. Day 7: Neopterin was significantly higher in severe AP than in mild AP and in normal controls; no difference was seen between mild AP values and normal controls; neopterin serum levels were significantly higher on day 7 than on day 1 in severe AP but not in mild AP; in both groups of patients IL-6 was significantly higher on day 1 than on day 7. Using a neopterin cutoff level of 40 mmol/ml, we found specificity and sensitivity value of 92% in differentiating severe from mild AP. With regard to TNF values, no difference was seen on day 1 and 7 in the two groups of patients in comparison with normal controls. Neopterin serum values did not correlate with IL-6 and TNF on either day.

CONCLUSIONS

These results confirm the activation of the cellular immune system in AP. Initially enhanced NEOP and IL-6 serum levels reflect the severity of the disease; neopterin may be considered a reliable prognostic indicator also at a distance from AP onset because its levels increase during the 1st week of AP in patients with severe forms only.

Evidence for early oxidative stress in acute pancreatitis. Clues for correction

Pancreatic oxidative stress with depletion of pancreatic glutathione is an early feature in all tested models of acute pancreatitis, and sooner or later the problem extends to the lung, irrespective of disease severity, whether toward spontaneous recovery or death from multisystem organ failure. We, therefore, sought evidence of oxidative stress in the human disease by analyzing admission blood samples. We found it from high concentrations of oxidatively altered linoleic acid in serum and vitamin C in plasma (p < 0.001 vs controls or a group of other acute abdominal crises where the proportion of patients with admission Apache II scores < or > 8 was similar). These changes were accompanied by subnormal levels of ascorbic acid in plasma (p < 0.001); selenium (p < 0.001), beta-carotene (p < 0.001), and alpha-tocopherol in serum (p = 0.005 for its molar ratio to cholesterol). Paradoxically, the plasma concentration of S-adenosylmethionine was elevated (p = 0.02), suggesting that this proximate bioactive metabolite of the essential amino acid had backtracked because its intracellular metabolism down the methionine trans-sulfuration pathway toward glutathione synthesis was disrupted. The aberrations transcended putative etiological factor, duration of symptoms, or disease severity. We conclude: (1) that oxidative stress has pervaded the vascular compartment by the time of admission in patients with acute pancreatitis, and, (2) that blood micronutrient antioxidant profiles at this stage are consistent not only with compromised intracellular capacity to synthesize/refurbish glutathione, but also vulnerability of intra- and extracellular lipid targets.

Inflammatory mediators in acute pancreatitis

The cellular events leading to acute pancreatitis are not well defined and the mechanism by which known aetiological factors initiate the disease process remains to be established. Inflammatory mediators have recently been implicated as potential early markers of disease severity and may help elucidate the pathophysiology of the disease. Oxidative stress is emerging as a common effector of the acinar cell injury in experimental acute pancreatitis and clinical findings indicate that neutrophil activation is a significant early event. In common with neutrophil-mediated tissue damage in states of tissue hypoperfusion, acute pancreatitis shows many features of an ischaemia-reperfusion injury. Increased levels of phospholipase A2 have been demonstrated; this enzyme induces synthesis of prostaglandins and platelet-activating factor, a potent inflammatory mediator. New therapeutic approaches to the complications of acute pancreatitis may be through manipulation of such mediators of inflammation.