Jens M. Mayer

Early prediction of severity in acute pancreatitis by urinary trypsinogen activation peptide: a multicentre study.

BACKGROUND There is a pressing clinical requirement for an early simple test of severity in acute pancreatitis. We investigated the use of an assay of trypsinogen activation peptide (TAP). METHODS We undertook a multicentre study in 246 patients (172 with acute pancreatitis [35 with severe disease], 74 controls). We assessed the predictive value of urinary TAP concentrations measured by a validated competitive immunoassay. We compared the results with those for plasma C-reactive protein and three clinicobiochemical scoring systems. TAP and C-reactive protein concentrations were analysed at set times after symptom onset and compared with the clinicobiochemical systems scores at key times during hospital stay. FINDINGS At 24 h after symptom onset, the median urinary TAP concentration was 37 nmol/L (IQR 17-110) for severe and 15 nmol/L (5-35) for mild disease (p<0.001). The respective values for plasma C-reactive protein were 24 mg/L (3-34) and 25 mg/L (6-75; p=0.208). The sensitivity, specificity, positive predictive, and negative predictive values of the test to show severe acute pancreatitis compared with mild acute pancreatitis at 24 h were: for TAP (>35 nmol/L), 58%, 73%, 39%, and 86%, respectively, and for C-reactive protein (>150 mg/L), 0%, 90%, 0%, and 75%. 48 h after admission the values for the clinicobiochemical scoring systems were: APACHE II (> or =8), 56%, 64%, 30%, and 85%; Ranson score (> or =3), 89%, 64%, 38%, and 96%; and Glasgow score (> or =3), 77%, 75%, 44%, and 93%. At 48 h, the values for C-reactive protein were 86%, 61%, 37%, and 94% and for TAP were 83%, 72%, 44%, and 94%. Combined testing of C-reactive protein and TAP was not superior to TAP alone for accuracy. INTERPRETATION Urinary TAP provided accurate severity prediction 24 h after onset of symptoms. This single marker of severity in acute pancreatitis deserves routine clinical application.

Natural Course of Acute Pancreatitis

Acute pancreatitis comprises, in terms of clinical, pathologic, biochemical, and bacteriologic data, four entities. Interstitial edematous pancreatitis and necrotizing pancreatitis are the most frequent clinical manifestations; pancreatic pseudocyst and pancreatic abscess are late complications after necrotizing pancreatitis, developing after 3 to 5 weeks. Determinants of the natural course of acute pancreatitis are pancreatic parenchymal necrosis, extrapancreatic retroperitoneal fatty tissue necrosis, biologically active compounds in pancreatic ascites, and infection of necrosis. Early in the course of acute pancreatitis multiple organ failure is the consequence of various inflammatory mediators that are released from the inflammatory process and from activated leukocytes attracted by pancreatic injury. During the late course, starting the second week, local and systemic septic complications are dominant. Around 80% of deaths in acute pancreatitis are caused by septic complications. The infection of pancreatic necrosis occurs in 8% to 12% of acute pancreatitis and in 30% to 40% of patients with necrotizing pancreatitis. Bacteriologic analysis of intraoperative smears and aspirates reveals predominantly gram-negative germs deriving from the intestine, most frequently Escherichia coli. It has been confirmed that after necrotizing pancreatitis a considerable large group of patients suffer long-lasting exocrine and endocrine insufficiency.RésuméSous le terme de pancréatite aiguë se regroupe une large gamme d’entités pathologiques en termes de données cliniques, pathologiques, biochimiques et bactériologiques. La pancréatite oedémateuse interstitielle et la pancréatite nécrosante sont les variétés cliniques les plus fréquemment rencontrées. Les faux kystes et les abcès pancréatiques sont des complications tardives que l’on rencontre après évolution de la pancréatite nécrosante pendant 3 à 5 semaines. Dans l’évolution de la pancréatite aiguë, la nécrose du parenchyme, la nécrose des tissus graisseux rétropéritonéaux extrapancréatiques, la richesse en amylase de l’ascite pancréatique et l’infection de la nécrosc sont déterminants. La défaillance polyviscérale, conséquence de multiples médiateurs inflammatoires qui sont libérés à partir de l’inflammation et des leucocytes activés par la lésion pancréatique, est un facteur pouvant jouer un rôle très tôt dans l’évolution de la pancréatite. Plus tardivement, 15 jours environ après le début de la maladie, ce sont les complications infectieuses qui dominent. Environ 80% des décès dans la pancréatite aiguë sont en rapport avec des complications infectieuses. L’infection de la nécrose pancréatique se voit dans 8–12% des cas de pancréatite aiguë et chez 30–40% des patients ayant une nécrose pancréatique. L’analyse bactériologique des ensemencements provenant des prélèvements peropératoires révèlent des bactéries gram négatives en provenance de la lumière digestive et en particulier, l’E. Coli. On a confirmé également qu’après la pancréatite nécrosante, une large proportion des patients ont une insuffisance pancréatique exocrine et endocrine persistante.ResumenLa pancreatitis aguda comprende, en términos de sus manifestaciones clìnicas, patológicas, bioquímicas y bacteriológicas, diferentes entidades de la enfermedad. La pancreatitis edematosa intersticial y la pancreatitis necrotizante son sus manifestaciones más frecuentes; el pseudoquiste y el absceso pancreático son complicaciones tardías de la pancreatitis necrotizante, las cuales se desarrollan a las 3–5 semanas. Factores determinantes del curso natural de la pancreatitis aguda son: la necrosis parenquimatosa del páncreas, la necrosis extrapancreética de los tejidos grasos retroperitoneales, la presencia de compuestos biológicamente activos en la ascitis pancreática y la infection de los tejidos necróticos. La falla orgánica múltiple que aparece en las fases tempranas de la pancreatitis aguda es la consecuencia de diversos mediadores inflamatorios generados por el proceso inflamatorio y por leucocitos activados que han sido atraídos por la lesión pancreática. Mas tardíamente en el curso de la enfermedad, comenzando en la segunda semana, son dominantes las complicaciones sépticas, tanto locales como sistémicas. La infección de la necrosis pancreática ocurre en 8–12% de los casos de pancreatitis aguda y en 30–40% de los pacientes con pancreatitis necrotizante. El análisis bacteriológico de frotis y de aspirados intraoperatorios revela predominancia de gérmenes gram-negativos derivados del intestino, especialmente de E.coli. Se ha confirmado que luego de una pancreatitis necrotizante, un grupo considerable de pacientes desarrolla insuficiencia pancreático exocrina y endocrina.

Therapeutic Application of Caspase 1/Interleukin-1β-Converting Enzyme Inhibitor Decreases the Death Rate in Severe Acute Experimental Pancreatitis

ObjectiveTo assess the effect of therapeutic inhibition of interleukin 1&bgr;-converting enzyme (ICE) in an experimental model of severe acute pancreatitis (SAP). Summary Background DataSeveral lines of evidence suggest that cytokines activated by ICE play an instrumental role in the course of acute pancreatitis. Recent studies have shown that pharmacologic or genetic blockade of ICE significantly ameliorates the overall severity of and the death rate in SAP. MethodsSevere acute pancreatitis was induced by infusion of 5% sodium taurocholate in Wistar rats. A new, highly selective, irreversible inhibitor of ICE was intraperitoneally applied at a dosage of 0.25 mg every 12 hours. Control animals in group 1 received treatment with saline; in group 2 rats, ICE inhibition was started 6 hours after the onset of pancreatitis; and in group 3 rats, ICE inhibition was started 12 hours after the onset of pancreatitis. After a 7-day observation period, surviving rats were killed and blood, plasma, pancreas, lung, and liver were used for subsequent analysis. ResultsInhibition of ICE decreased the 7-day death rate from 87.5% to 38.9% irrespective whether treatment was started 6 hours or 12 hours after induction of SAP. Morphometric analysis revealed a significant reduction of acinar cell necrosis in both treated groups, whereas pancreatitis-associated pulmonary and hepatic damage was uniformly low and not influenced by ICE inhibition. Tissue myeloperoxidase concentrations were dramatically decreased in the pancreas and the lung after either regimen of ICE inhibitor treatment. In contrast to lung and liver, marked upregulation of interleukin 1&bgr;, tumor necrosis factor &agr;, and ICE mRNA was observed in the pancreas, with levels of interleukin 1&bgr; and tumor necrosis factor &agr; being reduced in ICE-inhibited animals. Compared with nontreated rats, plasma amylase levels were higher in both treatment groups, whereas lipase and hematocrit showed no difference. Changes of the differential white blood count including neutrophils, lymphocytes, and monocytes were attenuated in both groups after ICE inhibitor treatment. ConclusionsPharmacologic inhibition of ICE significantly improves the overall severity of and the death rate in SAP. A substantial reduction of neutrophil-mediated tissue injury in pancreas and lung seems to contribute to the beneficial effects of this approach. Moreover, ICE inhibition is still effective after a therapeutic window of 12 hours. Based on the current findings, future studies on the clinical application of ICE-inhibiting substances in acute pancreatitis seem to be promising.

Clinical relevance of caspase-1 activated cytokines in acute pancreatitis: high correlation of serum interleukin-18 with pancreatic necrosis and systemic complications.

ObjectivesThere is recent experimental evidence that caspase-1 activation plays an instrumental role in the pathomechanism of severe acute pancreatitis. Besides interleukin-1&bgr;, interleukin-18, a recently described proinflammatory cytokine, is cleaved into its biologically active form by caspase-1 as well. Interleukin-18 is known to have potent properties concerning the activation of the Th1-lymphocyte subset via costimulation of interferon-&ggr; production. In contrast to interleukin-1&bgr;, little is known about the clinical impact of interleukin-18 in the course of acute pancreatitis. DesignCohort study comparing patients with mild and severe acute pancreatitis associated with local and systemic complications during the course of the disease. SettingSurgical and anesthesiological intensive care unit as well as wards of the department of general surgery. PatientsWe included 68 patients with acute pancreatitis in the present study. In terms of local complications, pancreatic necrosis was present in 37 patients, of whom 21 developed pancreatic infections. Systemic complications included pulmonary, renal, or cardiocirculatory insufficiency and were observed in 40, 18, and 25 patients, respectively. Severe multiple-organ dysfunction syndrome involving all three organ systems occurred in 18 patients, all suffering from pancreatic necrosis. InterventionsSerum samples were collected over 14 consecutive days after study inclusion. Ascites or peripancreatic exudate was obtained by ultrasound-guided fine needle aspiration in 14 cases. Sera and local aspirates were stored at −70°C until analysis. Measurements and Results Interleukin-18 and interferon-&ggr; were measured by commercially available enzyme-linked immunosorbent assays. Interleukin-18 concentrations were significantly increased after the fourth day of disease onset until the end of the observation period in patients who developed pancreatic necrosis and systemic complications such as pulmonary, renal, and cardiocirculatory failure as well as severe multiple-organ dysfunction syndrome. However, no correlation was found between the development of pancreatic infections and interleukin-18 concentrations. In contrast with interleukin-18, interferon-&ggr; concentrations did not show any significant difference with respect to the presence or absence of either systemic or local complications. Local interleukin-18 concentrations in ascites or peripancreatic exudate were up to 20-fold higher than systemic concentrations, whereas interferon-&ggr; concentrations did not differ. ConclusionsSerum interleukin-18 concentrations are significantly elevated in patients with acute pancreatitis complicated by pancreatic necrosis and remote organ failure. The present data suggest an important role of caspase-1 dependent cytokine activation in the pathomechanism of severe acute pancreatitis beyond the experimental setting. In this context, interleukin-18 may serve as a potential target for new therapeutic approaches.

Pancreatic Injury in Severe Trauma: Early Diagnosis and Therapy Improve the Outcome

Background: Pancreatic injury is a dangerous complication in multiple injury, and experience with its diagnosis and treatment is usually limited. Method: Retrospective analysis of 3,840 patients admitted after multiple trauma from January 1, 1982, until May 31, 2000. Results: A laparotomy was performed in 121 cases (3.15%) due to suspected intra-abdominal lesion. 32% of the patients (39/121) had a pancreatic lesion; 23% (9/39) had a rupture of the major pancreatic duct. Primary laparotomy was performed in 72% of the patients (28/39). Superficial lesions were treated by explorative laparotomy alone (n = 7), debridement and external drainage (n = 20), or necrosectomy and lavage (n = 3). Complex pancreatic lesions were treated by pancreatojejunostomies (n = 5), pancreatic left resections (n = 2), or exploration alone (n = 2). 8 of 39 patients died (20%), 4 intraoperatively. Of the surviving 35 patients, a pancreas-associated complication developed in 8 patients (23%): pancreatic abscesses (n = 4), traumatic pancreatitis (n = 3), pancreatic fistulas (n = 2), and pseudocysts (n = 2). Conclusions: Pancreatic injury is an infrequent but dangerous complication in severe trauma. Superficial lesions not affecting the major pancreatic duct can be managed by debridement and external drainage. If the major pancreatic duct is ruptured, organ-preserving, complex reconstructive procedures are necessary. When diagnosed timely and treated according to severity and overall situation, pancreatic injuries have an acceptable morbidity, but usually a high mortality.

Secretory phospholipase A2 in patients with infected pancreatic necroses in acute pancreatitis

Secretory synovial-type PLA2 (sPLA2-II) in peripheral blood is known to be associated with systemic complications in patients with severe diseases. Being the pacemaking enzyme in eicosanoid synthesis, sPLA2-II is a mediator of the inflammatory response and plays a role in host defense against bacterial infection. We evaluated the clinical role of systemic sPLA2-II in bacterial infection of pancreatic necroses in severe acute pancreatitis. In 58 patients with acute pancreatitis, pancreatic and sPLA,-I and sPLA2-II were measured daily for the first 14 days of hospital treatment by a time-resolved fluoroimmunoassay. All 36 patients with necrotizing pancreatitis underwent regular fine needle aspiration (FNA) to monitor bacterial infection. In 10 patients, infected necroses were found on FNA and postoperative examination. On admission and at most days throughout the observation period, systemic sPLA2-II was significantly higher in patients with infected necroses than in patients with sterile necroses or interstitial pancreatitis. This difference was not found for sPLA,-I, but values were higher in necrotizing pancreatitis than in interstitial pancreatitis at the first 2 days of hospital treatment. If sPLA,-II was >300 ng/ml on 2 successive days within the first 4 days, infected necroses could be predicted with a sensitivity of 89%, a specificity of 8856, and a negative predictive value of 95%. Systemic sPLA2-II has the potential to identify patients at risk of bacterial infection of pancreatic necroses and its routine measurement may therefore, in combination with FNA2 offer a valuable tool in monitoring patients with acute necrotizing pancreatitis.

Systemic lymphocyte activation modulates the severity of diet-induced acute pancreatitis in mice

To examine the role of lymphocyte activation in the development of local and systemic complications in acute pancreatitis, we compared disease severity of choline-deficient, 0.5% ethionine supplemented (CDE) diet-induced acute pancreatitis in T- and B-cell deficient SCID mice and immunocompetent C.B-17 mice. Twenty-five female SCID and 17 female C.B-17 mice were fasted for 24 h and fed a CDE diet for 72 h. Twenty SCID and 12 C.B-17 mice were bled and their organs removed for histologic evaluation. Five control animals of both kinds were fed a regular diet for 6 days. Lung, kidney, and pancreas were examined microscopically, and pancreatic damage scored. Apoptosis was detected by DNA nick-end labeling and confirmed by DNA laddering. Trypsinogen-activation peptide was measured by enzyme-linked immunosorbent assay (ELISA), and the catalytic activity of PLA2 was determined by a radiometric assay. Four-day mortality was 10% in SCID and 33% in C.B-17 mice, and 10-day mortality was 0 in SCID and 60% in C.B-17 mice. SCID mice had mild pulmonary damage, whereas pulmonary injury was severe in C.B-17 mice. Pancreatic damage was severe in both groups. Even though in situ staining of apoptotic cells was found in all pancreatitis animals, apoptosis was confirmed by DNA laddering only in C.B-17 mice. In SCID mice, apoptotic cell staining positively correlated with necrosis (r = 0.91; p < 0.001). Plasma TAP and PLA2 catalytic activity did not differ significantly between the groups. In conclusion, the absence of T and B lymphocytes prevents severe pulmonary injury resulting from acute pancreatitis but does not influence pancreatic or renal damage. Our results suggest that systemic lymphocyte activation does not affect the initiating events that trigger pancreatic injury but modulates the systemic response, in particular, pulmonary injury caused by acute pancreatitis.

Stimulation of stellate cells by injured acinar cells: a model of acute pancreatitis induced by alcohol and fat (VLDL)

Mechanisms leading to acute pancreatitis after a fat-enriched meal combined with excess alcohol are incompletely understood. We have studied the effects of alcohol and fat (VLDL) on pancreatic acinar cell (PAC) function, oxidative stress, and repair mechanisms by pancreatic stellate cells (PSC) leading to fibrogenesis. To do so, PAC (rat) were isolated and cultured up to 24 h. Ethanol and/or VLDL were added to PAC. We measured PAC function (amylase, lipase), injury (lactic dehydrogenase), apoptosis (TUNEL, Apo2.7, annexin V binding), oxidative stress, and lipid peroxidation (conjugated dienes, malondialdehyde, chemoluminescence); we also measured PSC proliferation (bromodeoxyuridine incorporation), matrix synthesis (immunofluorescence of collagens and fibronectin, fibronectin immunoassay), and fatty acids in PAC supernatants (gas chromatography). Within 6 h, cultured PAC degraded and hydrolyzed VLDL completely. VLDL alone (50 microg/ml) and in combination with alcohol (0.2, 0.5, and 1% vol/vol) induced PAC injury (LDL, amylase, and lipase release) within 2 h through generation of oxidative stress. Depending on the dose of VLDL and alcohol, apoptosis and/or necrosis were induced. Antioxidants (Trolox, Probucol) reduced the cytotoxic effect of alcohol and VLDL. Supernatants of alcohol/VLDL-treated PAC stimulated stellate cell proliferation and extracellular matrix synthesis. We concluded that, in the presence of lipoproteins, alcohol induces acinar cell injury. Our results provide a biochemical pathway for the clinical observation that a fat-enriched meal combined with excess alcohol consumption can induce acinar cell injury (acute pancreatitis) followed by repair mechanisms (proliferation and increased matrix synthesis in PSC).

Single doses of FK506 and OKT3 reduce severity in early experimental acute pancreatitis

OBJECTIVE To find out if two immunomodulatory drugs used in organ transplantation (FK506 (tacrolimus) and OKT3 (Orthoclone) would reduce early inflammatory complications in experimental acute pancreatitis. DESIGN Laboratory study. SETTING University hospital, Germany. ANIMALS 36 Balb/c mice. INTERVENTIONS Pancreatitis induced by 7 intraperitoneal injections of cerulein 50 microg/kg at hourly intervals followed by FK506 0.32 mg/kg, OKT3 0.6 mg/kg, or 0.9% sodium chloride (controls) (n = 12 in each group). 12 hours after induction of pancreatitis the animals were killed. MAIN OUTCOME MEASURES Serum amylase activity and interleukin-6 (IL-6) concentrations; histological damage to pancreas and lungs, apoptotic cells in pancreas; and myeloperoxidase activity in lungs. RESULTS No animal died during the experiment. At 12h serum amylase activity and IL-6 concentrations were increased in all 3 groups, but highest in the OKT3 group. The pancreatic histological score, apoptosis, and inflammatory infiltration were lower in the two experimental groups than controls, but the degree of vacuolisation of acinar cells was similar. Packed cell volume was higher in the control than the experimental groups, and pulmonary damage and myeloperoxidase activity were less in the experimental groups than the controls. CONCLUSION Single therapeutic doses of FK506 and OKT3 reduced the early severity of pancreatitis, pulmonary damage, and haemoconcentration in mice. Single doses of FK506 or OKT3 may therefore be effective in preventing the early complications of pancreatitis.

Severe acute pancreatitis is related to increased early urinary levels of the activation peptide of pancreatic phospholipase A2

Background/Aim: In acute pancreatitis, it is believed that generalized activation of pancreatic zymogens leads to autodigestion of the pancreas and if excessive to systemic organ injury. Under physiological circumstances, secretory phospholipase A2 type I (sPLA2-I) is activated by trypsinogen, but the extent of this activation in acute pancreatitis is unclear. The aim of this study was to assess time course and level of activation of sPLA2-I and trypsinogen in acute pancreatitis, relative to severity. Methods: 246 patients were enrolled into a prospective European multicenter study. 137 patients had mild and 35 had severe acute pancreatitis, and there were 74 control patients. Urinary samples were taken on admission and at 6-hour intervals for 48 h, then every 12 h up to 72 h, and finally daily for at least 5 days for measurement of the activation peptide of sPLA2-I (pro-phosphatase A2; PROP) and trypsinogen activation peptide. Results: The median maximum PROP values were significantly elevated 48 h after symptom onset in patients with severe acute pancreatitis [1.52 (95% CI 0.8–2.9) nmol/l] as compared with patients with mild acute pancreatitis [0.72 (0.55–1) nmol/l, p = 0.002] and controls [0.49 (0.22–1.2) nmol/l, p = 0.001], but not before or after this time point. The best cutoff point for urinary PROP to predict overall severity was >1 nmol/l ≤48 h after symptom onset (negative predictive value = 88%), but the PROP levels failed to predict the development of multi-organ dysfunction. Conclusions: Activation of sPLA2-I is associated with the early pathogenesis of acute pancreatitis, but not in the development of distant organ damage. This observation raises questions as to the theory of generalized zymogen activation being a principle mechanism involved in the pathogenesis of distant organ damage in acute pancreatitis.