Chronic pancreatitis: diagnosis and treatment

Neurokinin-2 receptor levels correlate with intensity, frequency, and duration of pain in chronic pancreatitis

OBJECTIVE

Generation and maintenance of pain in chronic pancreatitis (CP) have been shown to be partially attributable to neuroimmune interactions, which involve neuropeptides such as substance P (SP). So far, expression of SP receptors NK-2R, NK-3R, the SP-encoding gene preprotachykinin A (PPT-A), and the SP degradation enzyme neutral endopeptidase (NEP) and their relation to pain in CP have not been determined.

METHODS

Tissue samples from patients with CP (n = 25) and from healthy donors (n = 20) were analyzed for PPT-A, NK-2R, NK-3R, and NEP expression using quantitative RT-PCR. NEP protein levels were examined by immunoblot analysis and its localization was determined using immunohistochemistry. A scoring system was used to grade the extent of fibrosis on hematoxylin and eosin- and Masson-Trichrome-stained sections. Messenger RNA levels and the extent of pain were analyzed for correlations.

RESULTS

In CP tissues, NK-2R and PPT-A expression was increased, whereas NK-3R and NEP mRNA levels were comparable with normal pancreas. Overexpression of NK-2R was related to the intensity, frequency, and duration of pain in CP patients. NK-1R and NEP expression was significantly related to the extent of fibrosis.

CONCLUSIONS

Expression of NK-2R and PPT-A is increased in CP and is associated with pain. Failure to up-regulate NEP may contribute to the disruption of the neuropeptides loop balance in CP and thus may exacerbate the severe pain syndrome.

Nerve growth factor and its high-affinity receptor in chronic pancreatitis

OBJECTIVE

To study the mechanisms that are involved in nerve growth and contribute to pain generation in chronic pancreatitis (CP).

SUMMARY BACKGROUND DATA

Chronic pancreatitis is a painful disease associated with characteristic nerve changes, including an increase in nerve number and diameter. The mechanisms that influence nerve growth are not known. Nerve growth factor (NGF) and its high-affinity tyrosine kinase receptor A (TrkA) are involved in neural development and survival and growth of central and peripheral nerves.

METHODS

Nerve growth factor and TrkA were investigated by Northern blot analysis, in situ hybridization, and immunohistochemical staining in the pancreases of 24 patients with CP, and the findings were correlated with clinical parameters.

RESULTS

By Northern blot analysis, NGF and TrkA mRNA expression were increased in 42% (13.1-fold) and 54% (5.5-fold) of the CP samples (p < 0.01), respectively. In situ hybridization revealed that in CP, enhanced NGF mRNA expression was present in metaplastic ductal cells, in degenerating acinar cells, and in acinar cells dedifferentiating into tubular structures. TrkA mRNA was intensely present in the perineurium. Further, enhanced NGF and TrkA mRNA signals were also present in intrapancreatic ganglia cells in CP samples. Immunohistochemistry confirmed the in situ hybridization findings. Analysis of the molecular findings with clinical parameters revealed a significant relation (p < 0.05) between NGF mRNA levels and pancreatic fibrosis (r = 0.64) and acinar cell damage (r = 0.74) and between TrkA mRNA and pain intensity (r = 0.84).

CONCLUSION

Activation of the NGF/TrkA pathway occurs in CP. It might influence neural morphologic changes and the pain syndrome in this disorder.

Management of Pancreatitis

Acute pancreatitis can be mild or severe. Identifying causes helps in preventing recurrent episodes, management of complications, treatment of the underlying disorder, and/ or removal of an etiologic agent. Supportive care, pain control, nutrition, and antibiotic use are discussed. Overall, the goal is to prevent and minimize complications and reduce mortality. Chronic pancreatitis is complex, and the etiology of the abdominal pain is multifactorial. The goal is to eliminate causes and treat underlying disorders that may contribute to the inflammatory process. Management of pain, pancreatic insufficiency, and complications is essential. If medical management is not successful, surgical options should be considered.

Distant processing of pancreas islets for autotransplantation following total pancreatectomy

BACKGROUND

Small duct chronic pancreatitis is associated with intractable pain and failure to thrive, usually unresponsive to conventional management approaches. Total pancreatectomy is considered after failure of medical intervention. The major morbidity following total pancreatectomy is diabetes mellitus with its associated complications. This adverse outcome can be mitigated through autotransplantation of islets recovered from the pancreatectomy specimen. This approach has been limited historically owing to the absence of an on-site islet processing facility. We present the results from 5 pancreatectomized patients whose islets were prepared 1,500 miles away.

METHODS

Five patients (4 women, 1 man, average age 42 years) who failed medical therapy and were not candidates for longitudinal pancreaticojejunostomy underwent total/completion pancreatectomy (4 total, 1 completion) for intractable symptoms from idiopathic small duct chronic pancreatitis. The resected pancreata were preserved in ViaSpan solution and were transferred to an islet processing laboratory by commercial airliner and returned. The dispersed pancreatic islet tissue was infused into a portal vein tributary through an operatively placed catheter after systemic heparinization.

RESULTS

All 5 patients experienced complete relief from pancreatic pain; 2 had significant residual discomfort from underlying Crohn's disease. Three of the 5 patients had minimal or no insulin requirement after autotransplantation (median follow-up of 23 months); 1 patient continued with glycemic control difficulties related to Crohn's disease. One patient died 17 months following autotransplantation from an unrelated pneumonia.

CONCLUSION

Total pancreatectomy with autologous islet transplantation can offer patients with idiopathic small duct chronic pancreatitis pain relief without the sequelae of diabetes mellitus and can be performed without an on-site islet processing facility. All patients undergoing total/ completion pancreatectomy should be considered candidates for this procedure.

Tropical calcific pancreatitis

Tropical calcific pancreatitis is a special type of chronic pancreatitis that has features quite different from those of alcoholic pancreatitis and is seen almost exclusively in tropical countries. It is characterized by recurrent severe pain in the abdomen, insulin-requiring but ketosis-resistant diabetes and large pancreatic calculi in malnourished male adolescents. The clinical course of tropical calcific pancreatitis is protracted with malnutrition, recurrent infections and poorly controlled diabetes. Pancreatic cancer may complicate the natural course in up to 10% of cases. However, in the community a much milder form of the disease occurs with a female preponderance and a prevalence of 0.13% or one in 793. Malnutrition with deficiency of proteins and micronutrients with antioxidant properties and food-based toxins, such as cassava, which contain cyanogenic glycosides have been suspected as possible aetiological factors. Impaired immune response, a presumed infection (possibly viral) and genetic susceptibility are some of the other factors suspected in the aetiopathogenesis of this disease. Besides controlling diabetes with insulin, relief from pain is obtained by the administration of analgesics and pancreatic enzymes and, in severe cases, by performing endoscopic or surgical decompression of dilated pancreatic ducts with removal of pancreatic calculi.