Fecal elastase

Elastases—1, 2, 3A, 3B (protease E), medullasin Hepatocyte growth factor activator Glandular kallikreins—EGF-binding protein A-C, NGF-y, renin-y, prostate-specific antigen (PSA), and tonin Mite fecal allergen Der pill... 

Quantitative fecal fat excretion was markedly increased (28 g/day normal is <7 g/day), and fecal elastase 1 concentration was reduced to 24 pg/g (lower level of normal is 200 pg/g).The patient was diagnosed with severe pancreatic exocrine (but not endocrine) insufficiency due to alcoholic chronic calcifying pancreatitis and advised to stop alcohol and cigarette consumption. 

Fecal elastase 1 concentration can be measured by an ELISA test kit using an antibody specific for the human enzyme pancreatin supplements do not interfere with this pancreatic function test and need not be discontinued. Although measurement of fecal elastase 1 excretion appears to be somewhat more sensitive than fecal chymotrypsin, its specificity and positive predictive value are similarly low, and falsepositive results can be expected in patients with intestinal diseases. Conversely, mild-to-moderate stages of pancreatic exocrine insufficiency cannot be diagnosed reliably. 

Direct tests of secretory function such as fecal chymotrypsin and elastase 1 are the tests of first choice if the main diagnostic goal consists of noninvasive confirmation of chronic pancreatitis. Indirect tests may be preferred, however, if the main goal is to verify maldigestion (which needs not be due to loss of pancreatic secretory capacity) or to optimize enzyme treatment. For patients for whom noninvasive direct or indirect tests are negative or equivocal and diagnosis or exclusion of pancreatic exocrine insufficiency appears relevant, the invasive secretin-cerulein (SC) test should be considered. 

Dominici R, Franzini C. Fecal elastase-1 as a test for pancreatic function a review. Clin Chem Lab Med 2002 40 325-32. 

Fecal elastase-1 has been extensively evaluated both in cystic fibrosis and in adult pancreatic insufficiency. In children with cystic fibrosis, the test discriminates between those with and without pancreatic insufficiency. Very low elastase-1 is seen in a wide range of CFTR genotypes with undetectable enzyme (<15 pg/g of stool) in most AF508 homozygotes. Low fecal elastase (<200 pg/g) after 4... 

Figure 48-8 Fecal excretion (mean and SD) of chymotrypsin, fat, and immunoreactive elastase during a 24-hour collection period in 12 patients with cystic fibrosis and steatorrhea with and without enzyme replacement therapy. (From Stein JJung M, Sziegoleit A, Zeuzem S, Caspary WF, Lembcke B. immunoreactive elastase / c//njco/ eva/uat/on of a new non-invasive test of pancreatic function, din Cbem 1996 42 222 6.)...

The specificity of the test was significantly improved by abandoning the nonspecific colorimetric procedures in favor of high-performance liquid chromatography (HPLC)." NBT-PABA has advantages over the pancreolauryl test in that the patient procedure can be completed in a single day but the synthetic peptide is not now easily available, and the test has a lower diagnostic sensitivity and specificity for pancreatic insufficiency than does fecal elastase (see Table 48-8). 

Fecal elastase (measured by the monoclonal antibody method) remains the test of choice as a noninvasive test for assessing pancreatic insufficiency from the perspectives of both diagnostic accuracy and patient convenience. A negative test does not exclude mild disease, and false positives in some nonpancreatic diseases and in very watery samples limit... 

Cade A, Walters MP, McGinley N, Firth J, Brownlee KG, Conway SP, Littlewood JM. Evaluation of fecal pancreatic elastase-1 as a measure of pancreatic exocrine function in children with cystic fibrosis. Pediatr Puhnonol 2000 29 172-6. 

Carroccio A, Verghi F, Santini B, Lucidi V, lacono G, Cavataio F, et al. Diagnostic accuracy of fecal elastase 1 assay in patients with pancreatic maldigestion or intestinal malabsorption. Dig Dis Sci 2001 46 1335-42. 

Dominguez-Munoz J, Hieronymus C, Sauerbruch T, Malfertheiner P. Fecal elastase test evaluation of a new non-invasive pancreatic function test. Am J Gastroenterol 1995 90 1834-7. 

Gullo L, Graziano L, Babbini S, Battistini A, Lazzari R, Pezzilli R. Fecal elastase 1 in children with cystic fibrosis. Eur J Pediatr 1997 156 770-2. 

GuUo L, Ventrucci M, Tomassetti P, Migliori M, Pezzilli R. Fecal elastase 1 determination in chronic pancreatitis. Dig Dis Sci 1999 44 210-3. 

Masoero G, Zaffino C, Laudi C, Lombardo L, Rocca R, GaUo L, et al. Fecal pancreatic elastase 1 in the work up of patients with chronic diarrhea. Int J Pan-creatol 2000 28 175-9. 

Enzyme replacement for exocrine pancreas insufficiency must be adjusted on an individual basis considering age, body weight, weight for height, growth rate, fat intake, supplementary energy needs (particularly for pulmonary function), and clinical as well as laboratory evidence of malabsorption. Clinical symptoms include abdominal pain, distension, intolerance of fatty foods, and character of stools (consistency, number, odor). A more objective assessment involves microscopic examination of stool for neutral and split fats, measurement of fecal chymotrypsin or elastase [96]. 

Three emerging fecal tests are for elastase, calprotectin, and adipsin, but these have yet to be tested widely in toxicology studies. The fecal elastase test has been developed as a noninvasive measurement of exocrine insufficiency, and fecal elastase does not appear to be increased in dogs with intestinal inflammation (Dommguez-Munoz et al. 1995 Stein et al. 1996 Goldberg 2000 Battersby et al. 2005 Schneider et al. 

Schneider, A., B. Funk, W. Caspary, and J. Stein. 2005. Monoclonal versus polyclonal ELISA for assessment of fecal elastase concentration Pitfalls of a new assay. Clinical Chemistry 51 1052-1054. 

---