Genetic basis of chronic pancreatitis

The effect of smoking on expression of IL-6 and antioxidants in pancreatic fluids and tissues in patients with chronic pancreatitis

OBJECTIVES

The present study was conducted to ascertain whether cigarette smoke induces oxidative stress in the human pancreas concurrently with inflammation.

MATERIALS AND METHODS

The influence of tobacco smoking on the serum level of interleukin-6 (IL-6), on the activities of glutathione peroxidase (GPx) and copper-zinc superoxide dismutase (Cu/Zn SOD) as well as on the metallothionein (MT) level in the pancreatic pseudocyst fluid and its immunohistochemical localization in tissues of non-smoking (n = 9) and smoking (n = 12) patients with diagnosed chronic pancreatitis (CP) was measured. The concentration of interleukin-6 and metallothionein was determined by means of ELISA and the radioisotopic method, respectively. The enzyme activities in the fluid were assayed by the colorimetric method. Samples of tissues of normal pancreas (n = 4) and CP (non-smoking n = 7; smoking n = 12) were verified histopathologically and then IL-6, MT and enzymes were localized by immunohistochemical staining using the monoclonal anti-human antibody.

RESULTS

The concentrations of metallothionein and interleukin-6 were significantly higher in smoking patients with CP (as compared with the non-smoking population (p < 0.01; p < 0.001). Interestingly, the ratio of MT/IL-6 in smoking patients with CP was reduced in comparison to non-smoking patients (respectively: 1.1; 5.6). In smoking patients, a significant elevation of the Cu/Zn SOD and GPx activities was revealed as compared with the non-smokers (p < 0.04; p < 0.0007). These studies clearly demonstrate a moderate and strong expression of IL-6 and enzymes in acinar, islet and duct cells of smoking patients.

CONCLUSIONS

These observations favor the role of the oxidative stress in the induction of pancreatitis associated with chronic cigarette smoke inhalation.

Mechanisms and natural history of pain in chronic pancreatitis: a surgical perspective

Pain is a major clinical manifestation of chronic pancreatitis (CP) and a common indication for surgery in these patients. Pathogenesis of pain in CP is multifactorial and the mechanisms of pain may differ from patient to patient. This can explain why one therapeutic method of treatment of pain does not work in all patients and in different stages of the disease. Two main complimentary pathogenetic theories have been proposed to explain the mechanisms of pain in CP, the neurogenic theory and the theory of increased intraductal/intraparenchymal pressures. According to the neurogenic theory, in CP there are alterations of pancreatic/peripancreatic nerves, exposing them to noxious substances and/or activated immune cells, thereby generating pain ("neuroimmune interaction"). The other theory of intraductal/intraparenchymal hypertension suggests that pain in CP is generated as a result of increased pressures within the pancreatic ductal system and/or pancreatic parenchyma, like the pain in the classic compartment syndrome. The theory of intraductal/intraparenchymal hypertension is strongly supported by the good results of drainage procedures in the surgical management of CP. Pancreatic ischemia, oxygen-free radicals, centrally sensitized pain state, acute exacerbations of CP, development of complications from the pancreas (most commonly, pseudocysts) or adjacent organs (usually, duodenal and/or common bile duct stenosis), etc. are other possible contributing factors. Different patterns of pain have been described in idiopathic (early vs. late onset) and in alcoholic CP. Interestingly, pain is automatically relieved during the natural course of the disease in some patients (the "burn-out" phenomenon), after a relatively long time (from a few years to up to 3 decades). However, this is an unpredictable evolution for the individual patient. Therefore, surgery should be offered when pain is intense and after failure of conservative treatment. Surgical management should be individualized, depending on the particular findings of each patient. The knowledge of the pathophysiologic basis and of natural course of pain in CP is of paramount importance for the surgeon to select appropriate therapy for the individual patient with CP.

Assessment of oxidative stress in chronic pancreatitis patients

AIM: To assess the levels of antioxidant capacity and oxidative damage in blood of chronic pancreatitis (CP) patients in comparison with those in healthy control subjects, by using several different analytical techniques.

METHODS: Thirty-five CP patients and 35 healthy control subjects were investigated prospectively with respect to plasma levels of thiols, ferric reducing ability of plasma (FRAP, i.e. antioxidant capacity), levels of protein carbonyls and thiobarbituric acid reactive substances (TBARS). Additionally, we evaluated the production of reactive oxygen species (ROS) in whole blood.

RESULTS: The antioxidative thiols including cysteine, cysteinylglycine and glutathione were significantly lower in CP patients. In addition, the non-enzymatic antioxidant capacity was significantly lower in CP patients, which correlated with the amount of oxidative protein (protein carbonyls) and the extent of lipid damage (TBARS), both were significantly higher in CP patients. The ROS production in whole blood after stimulation with phorbol 12-myritate 13-acetaat, demonstrated a strong tendency to produce more ROS in CP patients.

CONCLUSION: Oxidative stress may contribute to the pathogenesis of chronic pancreatitis by decreasing antioxidant capacity and increasing oxidative damage in CP patients may be a rationale for intervention with antioxidant therapy.

FDG-PET is able to detect pancreatic carcinoma in chronic pancreatitis

PURPOSE

2-(18F)-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is an imaging technique which enables detection of malignancies. FDG-PET has been established as a tool for the diagnosis of pancreatic carcinoma (CA). Early detection is mandatory as cure can only be achieved in non-advanced disease. This is, however, very difficult with conventional radiological techniques. Patients with chronic pancreatitis (CP) are at risk of developing CA. A simple, reliable screening method for malignant degeneration is highly desirable. We set out to investigate whether FDG-PET is able to detect CA in the setting of CP and can fulfil a potential role in the early detection of CA in CP.

METHODS

FDG-PET was performed in 77 CP patients and in six patients with CP complicated by CA (CP + CA). We included 26 CA patients as a positive control. A positive scan was defined as focal FDG accumulation in the pancreas region.

RESULTS

In 67 of the 77 CP (87%) patients, pancreatic FDG accumulation was absent. Six patients had significant accumulation. In CA, 24/26 patients had a positive PET. Five out of the six patients with CP + CA had focal uptake, while minor uptake was seen in one patient. FDG-PET was positive in almost all CA patients and CP + CA patients. FDG-PET was negative in the large majority (87%) of CP patients, which suggests that a positive PET scan in CP patients must lead to efforts to exclude a malignancy.

CONCLUSION

These data suggest that FDG-PET has a potential role as a diagnostic tool for detecting CA in longstanding CP.

Detection of oncogenes in chronic pancreatitis

BACKGROUND

The pathogenesis of chronic pancreatitis (CP) remains poorly understood. Recently, molecular biology has identified the genetic background for many patients with hereditary CP. In addition, a number of studies have focused on the detection of proto-oncogenes and tumour suppressor gene mutations in the pathogenesis of CP. So far, the use of these mutations (with the exception of mutations causing hereditary CP), as diagnostic and prognostic markers is still controversial.

DISCUSSION

It is well known that the risk of pancreatic cancer in patients with CP, especially the hereditary form, is high. At present, there is insufficient evidence to show a clear relationship between the development of pancreatic cancer and certain mutations. New biotechnological methods, such as DNA array expression analysis, expand our knowledge of the molecular pathogenesis of this disease and may help to develop specific diagnostic, prognostic and therapeutic tools. However, until long-term studies examine the safety and efficacy of certain genetic markers, long-term follow-up of patients with CP who harbour mutations is needed.