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.