Saturday, February 9, 2008

Fecal Elastase Testing

From a flyer I picked up at a GI conference --it is from Genova Diagnostics

The Stool test

*Abdominal pain
*Malassimilation, is the pancreas involved?
*Diagnosis or exclusion of exocrine pancreatic insufficiency
*The gold standard for non-evasive exocrine pancreatic function testing

Main indications for stool test: Diagnosis or exclusion of pancreatic involvement in case of abdominal pain, malassimilation, post-traumatic injuries, other digestive symptoms, follow-up study of patients with mild or moderate exocrine pancreatic insufficiency.

Stool test Diagnosis: Diagnosis or exclusion of exocrine pancreatic insufficiency caused by e.g. chronic pancreatitis, cholelithiasis, cystic fibrosis, diabetes mellitus, papillary stenosis, pancreatic cancer

Diagnostics-main advantages (stool test)- Pancreatic Elastase 1 is absolutely pancreas-specific, intra-individual variation of pancreatic Elastase 1 concentration is low. Digestive enzyme substitution therapy has no influence on the determination of pancreatic Elastase 1. High stability of pancreatic Elastase 1 allows time for conventional mailing of samples. Specificity: 93% Sensitivity: 93%

Method of detection: Sandwich ELISA with two monoclonal antibodies highly specific for human pancreatic Elastase 1. The ELISA kit is based on a microtiter plate (96 well format) with 12 single strips x 8 wells suitable for up to 41 samples in duplicate

Sample material: Single spot stool sample (about 100mg) is sufficient. Samples are stable for convenient mailing and may be stored in the laboratory for up to 3 days at 4 degrees- 8 degrees C or for up to a year at -20 degrees C. Undiluted stool extracts are stable for 1 day at 4 degrees to 8 degrees C.

Reference concentration (for adults and children after the first month of life):

Values >200 ug Elastase/g stool indicate normal exocrine pancreatic function.
Values <200ug Elastase/g stool indicate exocrine pancreatic insufficiency

The serum test

*Diagnosis or exclusion of acute pancreatitis
*Diagnosis of ERCP-or gallstone – induced pancreatitis
*Follow-up study of acute pancreatitis

Main Indications: Diagnosis or exclusion of acute pancreatitis, Diagnosis of ERCP or gallstone-induced pancreatitis, follow-up study of acute pancreatitis.

Diagnosis: Diagnosis or exclusion of acute pancreatitis e.g. ERCP-induced pancreatitis, gallstone-induced pancreatitis

Main advantages E1 is absolutely pancreas specific. Like other pancreatic enzymes, E1is released into the blood circulation during an inflammatory episode. Due to its longer half-life, compared to amylase and lipase, its concentration remains elevated longer, and enables detection of an acute pancreatitis even three or four days after onset of the disease. In contrast to amylase and lipase, the serum E1 concentration is only marginally increased in patients with renal insufficiency. Specificity: 96% Sensitivity: 96%

Method of detection: Sandwich ELISA with two monoclonal antibodies highly specific for human pancreatic Elastase 1. The ELISA kit is based on a microtiter plate (96 well format) with 12 single strips x 8 wells suitable for up to 41 samples in duplicate.

Sample material and sample stability: 1 ml serum. Undiluted serum samples may be stored for up to five days at 4-8 degrees C or up to one year at -20 degrees C

Reference concentration: <3,5 ng/ml serum

Human pancreatic Elastase 1 (E1) remains undegraded during intestinal transit. Therefore, its concentration in feces reflects exocrine pancreatic function. The diagnostic efficiency of pancreatic Elastase 1 determination in stool has been evaluated in several clinical studies. Stein et al (1993,1996 & 1997) and Loser et al (1995 & 1996) compared the E1 determination with evasive intubation tests, the secretin-pancreozymin test and the secretin-caerulein test, respectively. Both authors report a sensitivity greater than 90% for the diagnosis of exocrine pancreatic insufficiency. In contrast to the fecal chymotrypsin assay, even a moderate pancreatic insufficiency can be detected by E1 determination (Loser et al 1995 & 1996, Gullo et al 1999)

In addition, studies by Terbrack et al (1996), Soldan et al (1996), Gullo et al (1997), Wallis et al (1997) and Walkowiak et al (1999) and Cade et al (2000) showed an excellent sensitivity and specificity for the diagtmosis of cystic fibrosis with pancreatic involvement.

Human pancreatic Elastase 1 (E1) is synthesized from acinar cells of the pancreas. During an inflammation of the pancreas, E1 is released into blood circulation. Thus the quanification of pancreatic Elastase in the serum allows diagnosis or exclusion of acute pancreatitis.