Fecal elastase-1 determination in the diagnosis of chronic pancreatitis

Abstract

The diagnosis of chronic pancreatitis is based on morphological and functional data. To evaluate exocrine function, the secretin-cholecystokinin test is the gold standard but this is invasive and frequently unavailable. Recently, fecal elastase-1 determination has been investigated as an indirect test of pancreatic function. To evaluate the diagnostic value of fecal elastase-1 in chronic pancreatitis by comparing it with other indirect methods of evaluating pancreatic function such as the urine pancreolauryl test and fecal chymotrypsin determination. To do this, we analyzed the three diagnostic methods in four groups of patients: group I (14 patients with confirmed chronic pancreatitis); group II (5 patients with recurrent episodes of acute alcoholic pancreatitis; group III (9 patients with non-pancreatic diarrhea); group IV (8 patients with other gastrointestinal diseases). Compared with the control groups (groups III and IV), patients in groups I and II presented lower levels of fecal elastase-1 (groups I-II: 88 mcg/g, groups III-IV: 635 mcg/g, p < 0.0001), fecal chymotrypsin (4.3 U/g and 29.3 U/g, respectively, p < 0.0001), and pancreolauryl (14% and 54%, respectively, p < 0,001). In the diagnosis of confirmed chronic pancreatitis (group I) the fecal elastase-1 and pancreolauryl tests showed a sensitivity of 85.6% and 78.5%, respectively. However, in group II, the most sensitive test was the pancreolauryl test (80% versus 60% for the chymotrypsin test and only 40% for the fecal elastase-1 test). In contrast, the fecal elastase-1 test showed the highest specificity (94.1% versus 88.2% for the fecal chymotrypsin test and 81.3% for the pancreolauryl test). Fecal elastase-1 determination is an effective indirect method in the diagnosis of patients with advanced chronic pancreatitis. However, when the disease is in the early stages, its sensitivity is no greater than that of other indirect tests. The greatest advantage of this test is its high specificity.