Tropical pancreatitis

Changing phenotype and disease behaviour of chronic pancreatitis in India: evidence for gene-environment interactions

BACKGROUND

The idiopathic variety of chronic pancreatitis (CP) in India particularly in Kerala state was earlier called 'tropical pancreatitis' with peculiar features: early age of onset, severe malnutrition, diabetes and poor prognosis. A change in disease phenotype and behaviour has been observed recently.

OBJECTIVE

To review the changing profile of CP in India and examine its relationship with environmental influences and socio-economic development.

METHODS

Relevant studies on CP in India were reviewed along with social and economic parameters in Kerala over the past 4 decades.

RESULTS

There has been a definite change in the phenotype of CP in India with onset in mid twenties, better nutritional status, and a much better prognosis compared with the reports in 1970s. Genetic susceptibility due to genetic mutations particularly in SPINK1, CFTR, CTRC, and CLDN2/MORC4 genes is the most important factor and not malnutrition or dietary toxins for idiopathic CP suggesting the term 'tropical pancreatitis' is a misnomer. We observed a close relationship between socio-economic development and rising income in Kerala with late onset of disease, nutritional status, and better prognosis of CP.

CONCLUSION

Changing profile of CP in India and better understanding of risk factors provide evidence for gene-environmental interactions in its pathobiology.

Chronic pancreatitis in India and Asia

Chronic pancreatitis (CP) is widely prevalent in Asian countries much more so in India and Japan. The phenotype of CP is somewhat similar to that reported from western countries. The prevalent types of CP are mainly idiopathic and alcohol related. Current evidence suggests that the term "tropical pancreatitis" used for idiopathic CP from India is a misnomer. Gallstones' association with CP reported from China remains controversial. There has been ample evidence that mutations in the SPNIK1 and CFTR genes are strongly associated with idiopathic CP in patients from different ethnic backgrounds. Oxidative stress is important in the pathophysiology and antioxidants have been shown to result in significant pain relief with CP. Home-made balanced diet is effective for treating malnutrition in patients with CP. Endoscopic therapy combined with ESWL may provide significant relief in patients with pancreatic ductal calculi/stricture. Surgery is quite effective in CP and may be better than endotherapy.

Oxidative stress in chronic pancreatitis: pathophysiological relevance and management

SIGNIFICANCE

Chronic pancreatitis (CP) is a progressive, inflammatory disease of the pancreas leading to slow destruction of pancreatic parenchyma and progressive fibrosis. The pathophysiological mechanism of CP is not well understood.

RECENT ADVANCES

A pathophysiologic role of oxidative stress in CP has, however, been suggested in recent years. Pancreatic acinar cells contain phase I cytochrome P450 (CYP 450) biotransforming enzymes and phase II conjugation reactions for the metabolism of xenobiotics. The oxidative stress in the acinar cell may result from generation of free radicals through CYP induction, concurrent exposure to a chemical that undergoes bioactivation, and insufficiency of micronutrients that are required to sustain antioxidant (AO) capacity.

CRITICAL ISSUES

Studies have shown that there is indeed a state of oxidative stress as evidenced by increased levels of products of oxidative stress and reduced AO capacity in patients with CP. A recent randomized, controlled trial has shown beneficial effect of AO therapy in CP; a combination of AOs (0.54 g ascorbic acid, 9000 IU β-carotene, 270 IU α-tocopherol, 600 μg organic selenium, and 2 g methionine per day in divided doses) led to significant reductions in pain and oxidative stress in patients with CP.

FUTURE DIRECTIONS

Similar studies from other centers and multicenter studies should confirm that oxidative stress plays an important role in the pathophysiology of CP and supplementation with AOs leads to significant pain relief in patients with this disease.

Progress in understanding the etiology of chronic pancreatitis

Chronic pancreatitis (CP) is irregularly distributed around the world, and the pathogenic factors and incidence rates of CP vary greatly among different countries and regions. The main pathogenic factor for CP is alcohol in Western countries and biliary tract disease in China. Changes in the lifestyle also change the main pathogenic factors for CP. In recent years, alcohol has gradually replaced biliary tract disease to become the main etiological factor for CP in China. A deeper understanding of the etiology of CP provides new insights into the treatment of the disease.

Pancreatic secretory trypsin inhibitor: More than a trypsin inhibitor

Kazal-type serine protease inhibitor is one of the most important and widely distributed protease inhibitor families. Pancreatic secretory trypsin inhibitor (PSTI), also known as serine protease inhibitor Kazal type I(SPINK1), binds rapidly to trypsin, inhibits its activity and is likely to protect the pancreas from prematurely activated trypsinogen. Therefore, it is an important factor in the onset of pancreatitis. Recent studies found that PSTI/SPINK1 is also involved in self-regulation of acinar cell phagocytosis, proliferation and growth of a variety of cell lines. In addition, it takes part in the response to inflammatory factor or injury and is highly related to adult type II citrullinemia.

Tropical malabsorption

Malabsorption is an important clinical problem both in visitors to the tropics and in native residents of tropical countries. Infections of the small intestine are the most important cause of tropical malabsorption. Protozoal infections cause malabsorption in immunocompetent hosts, but do so more commonly in the setting of immune deficiency. Helminth infections occasionally cause malabsorption or protein-losing enteropathy. Intestinal tuberculosis, chronic pancreatitis and small-bowel bacterial overgrowth are important causes of tropical malabsorption. In recent years, inflammatory bowel disease and coeliac disease have become major causes of malabsorption in the tropics. Sporadic tropical sprue is still an important cause of malabsorption in adults and in children in South Asia. Investigations to exclude specific infective, immunological or inflammatory causes are important before considering tropical sprue as a diagnosis. This article briefly reviews the management of tropical sprue and presents an algorithm for its investigation and management.

Chronic pancreatitis

Chronic pancreatitis (CP) is characterised by pancreatic inflammation and fibrosis leading eventually to destruction of pancreatic parenchyma and loss of exocrine and endocrine function. A model of interactions between environmental triggers of pancreatic inflammation and disease susceptibility or modifying genes (including PRSS1, SPINK1 and CFTR) provides a framework within which to understand disease pathogenesis. Early in the disease, when fibrosis is mild and pancreatic damage limited, it is difficult to distinguish CP from recurrent acute pancreatitis (RAP) although it is likely these represent opposite ends of a spectrum of disease with a common aetiology in which CP represents either a later disease stage or disease in individuals predisposed to generate a chronic fibrogenic inflammatory response. Pain is a dominant feature resulting in part from neuroimmune interactions within the pancreas. Diagnosis at an early stage of disease is challenging, though in later stages is dependent upon the demonstration of pancreatic fibrosis and duct ectasia using one or more imaging modalities including transabdominal and endoscopic ultrasound, CT and MRCP or ERCP. Current treatments are largely supportive and reactive. The challenge for pediatricians is to achieve diagnosis at an early stage of the disease and to develop treatments that can alter its natural history.

Laparoscopic lateral pancreaticojejunostomy: a new remedy for an old ailment

BACKGROUND

Lateral pancreaticojejunostomy is considered as the standard surgery for chronic pancreatitis. Yet there are very few reports of this procedure being done laparoscopically. We present our experience with laparoscopic lateral pancreaticojejunostomy till date and describe our technique.

MATERIAL AND METHOD

Since 1997, we have done 12 laparoscopic lateral pancreatojejunostomies. There were 9 females and 3 males and the average age was 29.3 years. The indication for surgery in all patients was intractable abdominal pain and significant weight loss. Additionally, two patients were also suffering from pancreatic ascites.

RESULTS

The average diameter of the pancreatic duct was 14.7 mm. We used a four-port technique. All surgeries were completed without any conversion to open surgery. Post-operatively, there were no major morbidity and nil mortality. The average operating time was 172 minutes. Post-operative stay was short (average 5 days) and on median follow-up of 4.4 years, 83.3% patients had complete pain relief while 16.7% had partial relief. All patients had significant weight gain.

CONCLUSIONS

Laparoscopic lateral pancreaticojejunostomy is safe, effective and feasible in experience hands. Mastery of intracorporeal knotting and suturing techniques is mandatory before embarking on this surgery.