Jens Mayer

BACKGROUND: The time course and relationship between circulating and local cytokine concentrations, pancreatic inflammation, and organ dysfunction in acute pancreatitis are largely unknown. PATIENTS AND METHODS: In a prospective clinical study, we measured the proinflammatory cytokines interleukin (IL)-1 beta, IL-6 and IL-8, the anti-inflammatory cytokine IL-10, interleukin 1 beta receptor antagonist (IL-1RA), and the soluble IL-2 receptor (sIL-2R), and correlated our findings with organ and systemic complications in acute pancreatitis. In 51 patients with acute pancreatitis admitted within 72 hours after the onset of symptoms, these parameters were measured daily for seven days. In addition, 33 aspirates from ascites and the lesser sac were measured. RESULTS: Sixteen patients had mild acute pancreatitis (AP) and 35 severe AP (Atlanta classification); 18 patients developed systemic complications requiring treatment. All mediators were increased in AP. sIL-2R, IL-10, and IL-6 were significantly elevated in patients with distant organ failure. An imbalance in IL-1 beta/IL-1RA was found in severe AP and pulmonary failure. Peak serum sIL-2R predicted lethal outcome and IL-1RA was an early marker of severity. IL-6 was the best prognostic parameter for pulmonary failure. CONCLUSION: Our results suggest that local mediator release, with a probable IL-1 beta-IL-1RA imbalance in severe cases, is followed by the systemic appearance of pro- and anti-inflammatory mediators. The pattern of local and systemic mediators in complicated AP suggests a role for systemic lymphocyte activation (triggered by local release of mediators) in distant organ complications in severe AP.

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.

BACKGROUND: Infection of pancreatic necrosis has a major impact on clinical course, management, and outcome in acute pancreatitis. Currently, guided fine needle aspiration is the only means for an early and accurate diagnosis of infected necrosis. Procalcitonin (PCT), a 116 amino acid propeptide of calcitonin, and interleukin 8 (IL-8), a strong neutrophil activating cytokine, are markers of severe inflammation and sepsis. AIMS: To analyse the clinical value of PCT and IL-8 as biochemical parameters for predicting infected necrosis in acute pancreatitis. PATIENTS AND METHODS: Fifty patients with acute pancreatitis entered this prospective study and were stratified into three groups according to morphological and bacteriological findings: 18 patients with oedematous pancreatitis (group I), 14 patients with sterile necrosis (group II), and 18 patients who developed infected necrosis a median of 13.5 days after the onset of symptoms (group III). After admission serum samples were drawn daily for two weeks. Concentrations of PCT and IL-8 were measured by chemoluminescent immunoassays (upper reference range 0.5 ng/ml for PCT and 70 pg/ml for IL-8). The routine parameter C-reactive protein was determined by laser nephelometry (upper reference range 10 mg/l). RESULTS: Median concentrations of PCT and IL-8 were significantly higher in patients with infected necrosis than in those with sterile necrosis during the observation period, whereas there was no difference in C-reactive protein. In oedematous pancreatitis overall median concentrations of all three parameters were low. By receiver operating characteristics best cut off levels for predicting infected necrosis or persisting pancreatic sepsis were 1.8 ng/ml for PCT and 112 pg/ml for IL-8. If these cut off levels were reached on at least two days, sensitivity, specificity, and accuracy for the prediction of infected necrosis were 94%, 91%, and 92% for PCT and 72%, 75%, and 74% for IL-8, respectively. After surgical treatment of infected necrosis median PCT and IL-8 values continued to be significantly higher in patients with persisting pancreatic sepsis (n = 11) compared with those having an uneventful postoperative course (n = 7). For the preoperative differentiation between infected necrosis and sterile necrosis guided fine needle aspiration was performed in 24 patients with necrotising pancreatitis and reached a diagnostic accuracy of 84% compared with 87% for PCT, and 68% for IL-8. There was no correlation between the aetiology of acute pancreatitis or the extent of necrosis and PCT or IL-8. CONCLUSION: PCT and IL-8 are found in high concentrations in infected necrosis and associated systemic complications in patients with acute pancreatitis. The course of PCT shows the closest correlation with the presence of infected necrosis. Monitoring of serum PCT is a potential new marker for the non-invasive and accurate prediction of infected necrosis as well as for the selection of patients with persisting septic complications after surgical debridement.

BACKGROUND: Early detection of infected pancreatic necrosis has a major impact on further management and outcome in acute pancreatitis. The aim of this study was to evaluate the clinical value of ultrasonographically guided fine-needle aspiration cytology (FNAC) in patients with necrotizing pancreatitis over an 8-year period. METHODS: From January 1988 to September 1996 193 (mean 2.0 (range 1-9) aspirations per patient) prospectively assessed FNACs guided ultrasonographically were performed in 98 patients with necrotizing pancreatitis proven by contrast-enhanced computed tomography. Aspirates were considered infected if either Gram stain and/or culture revealed micro-organisms. RESULTS: Ultrasonographically guided FNAC correctly diagnosed infection in 29 of 33 patients with infected necrosis a median of 13 days after onset of symptoms. Of 61 patients with sterile necrosis 55 were identified correctly as sterile by FNAC. There were six false-positive and four false-negative aspirates of which nine occurred during the first week of the disease. In four patients who did not undergo operation FNAC revealed Gram-negative organisms; however, in the absence of repeated aspirations, the positive results remained unconfirmed. An overall sensitivity of 88 per cent and a specificity of 90 per cent was obtained. No difference was found in biochemical and clinical parameters indicating systemic inflammatory response syndrome before each FNAC between patients with proven sterile or infected necrosis. All patients tolerated the procedure well and no major complications were observed. CONCLUSION: Ultrasonographically guided FNAC is a fast and reliable technique for the diagnosis of infected necrosis. As complication rates are very low, the procedure can be repeated at short intervals to improve the diagnostic accuracy. Ultrasonographically guided FNAC is recommended for all patients with necrotizing pancreatitis in whom systemic inflammatory response syndrome persists beyond the first week after onset of symptoms.

A significant proportion of the human genome consists of stably inherited retroviral sequences. Most human endogenous retroviruses (HERVs) became defective over time. The HERV-K(HML-2) family is exceptional because of its coding capacity and the possible involvement in germ cell tumor (GCT) development. HERV-K(HML-2) transcription is strongly upregulated in GCTs. However, regulation of HERV-K(HML-2) transcription remains poorly understood. We investigated in detail the role of CpG methylation on the transcriptional activity of HERV-K(HML-2) long terminal repeats (LTRs). We find that CpG sites in various HERV-K(HML-2) proviral 5' LTRs are methylated at different levels in the cell line Tera-1. Methylation levels correlate with previously observed transcriptional activities of these proviruses. CpG-mediated silencing of HERV-K(HML-2) LTRs is further corroborated by transcriptional inactivity of in vitro-methylated 5' LTR reporter plasmids. However, CpG methylation levels do not solely regulate HERV-K(HML-2) 5' LTR activity, as evidenced by different LTR activities in the cell line T47D. A significant number of mutated CpG sites in evolutionary old HERV-K(HML-2) 5' LTRs suggests that CpG methylation had already silenced HERV-K(HML-2) proviruses millions of years ago. Direct silencing of HERV-K(HML-2) expression by CpG methylation enlightens upregulated HERV-K(HML-2) expression in usually hypomethylated GCT tissue.