TY - JOUR T1 - Interpretations: How to use faecal elastase testing JF - Archives of disease in childhood - Education & practice edition JO - Arch Dis Child Educ Pract Ed SP - 119 LP - 123 DO - 10.1136/adc.2009.174359 VL - 95 IS - 4 AU - N Nandhakumar AU - M R Green Y1 - 2010/08/01 UR - http://ep.bmj.com/content/95/4/119.abstract N2 - A number of tests of exocrine pancreatic function have been devised over the years, but the search for a simple and yet sensitive and specific test has been elusive until recently. We will discuss the evidence that determination of the faecal concentration of pancreatic elastase 1 with an enzyme-linked immunosorbent assay method fulfils these criteria and thus provides an ideal tool to assess exocrine pancreatic function.Approximately 90% of the pancreas is made up of exocrine tissue comprising acinar cells, which secrete pancreatic enzymes, and ductal cells, which secrete bicarbonate rich fluid. About 1% of the pancreas is endocrine tissue, the remainder being stromal tissue. The exocrine pancreas has a large functional capacity. More than 98% of function is usually lost before symptoms and signs of fat malabsorption are manifest.The most common disease causing exocrine pancreatic insufficiency in children is cystic fibrosis (CF). Other conditions are rare but include chronic and familial pancreatitis, Shwachman–Diamond syndrome, Johanson–Blizzard syndrome, Pearson syndrome and isolated specific enzyme deficiencies—for example, lipase. A secondary pancreatic insufficiency may be seen in small bowel enteropathies, significant protein-energy malnutrition or short gut syndrome.1 There is increasing recognition of exocrine pancreatic dysfunction in children with diabetes.2The clinical consequences of inadequate exocrine pancreatic output are mainly due to maldigestion of protein and fat rather than carbohydrate. With protein maldigestion, hypoproteinaemia and oedema may occur, and in fat maldigestion, overt malnutrition with steatorrhoea and wasting is more prominent. In practice, both tend to occur together and the signs and symptoms associated with the fat maldigestion are more obvious. Fat-soluble vitamin deficiencies also develop quickly. Previously available pancreatic function tests Direct tests These tests measure the enzyme activities, the bicarbonate levels and the pancreatic juice flow rates in the duodenal juice after exogenous hormonal stimulation of the pancreas, usually with secretin and cholecystokinin or, occasionally, after … ER -