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.