Test Details
Methodology
Quantitative enzyme-linked immunosorbent assay (ELISA)
Result Turnaround Time
4 - 8 days
Use
This α1-antitrypsin ELISA test is intended for the quantitative determination of α1-antitrypsin in stool samples.
Specimen Requirements
Limitations
Results of this test are labeled for research purposes only by the assay's manufacturer. The performance characteristics of this assay have not been established by the manufacturer. The result should not be used for treatment or for diagnostic purposes without confirmation of the diagnosis by another medically established diagnostic product or procedure. The performance characteristics were determined by LabCorp.
Custom Additional Information
Intestinal protein loss is a serious consequence of various systemic or local gastrointestinal diseases (eg, allergies, chronic inflammation; malignancies). These pathologies damage the mucosal integrity and/or cause lymphostasis, thereby leading to an increased transfer of plasma proteins into the bowel lumen. Subsequently, hypoproteinemia accompanied with edema may develop. This condition is diagnosed by exclusion of other sources of protein loss and by proof of an elevated α1-antitrypsin concentration in stool.
In serum, α1-antitrypsin represents the majority of serine protease inhibitors and protects tissues from protease damages during inflammation. The protein is synthesized primarily in the liver, but also to a small extent in intestinal macrophages, monocytes, and intestinal epithelial cells. Since α1-antitrypsin is relatively resistant against enzymatic digestion, the secreted amount in stool reflects the internal concentration of the protein. An elevated α1-antitrypsin stool concentration is, therefore, a widely recognized marker for intestinal protein loss and for an increased mucosal permeability.
Specimen
Stool, frozen (unpreserved, random)
Volume
1 g
Minimum Volume
0.5 g
Container
Clean, screw-capped, plastic vial with no preservatives
Storage Instructions
Freeze.
Causes for Rejection
Nonfecal sample received (eg, serum, plasma, urine); sample taken from diaper unless portion taken has not been in contact with diaper material; preserved stool received (eg, 10% Formalin, Merthiolate Formalin, Sodium Acetate Formalin, or Polyvinyl Alcohol)
Collection Instructions
Do not contaminate outside of container with specimen; do not overfill container. Loose/watery stools are acceptable. Ensure that no toilet tissue/sanitary materials are present in the submitted specimen.
Stability Requirements
Temperature | Period |
---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Reference Range
See table.
Age | Male (mg/g) | Female (mg/g) |
---|---|---|
0 to 30 d | Not established | Not established |
31 d to 6 m | 0.074–0.776 | 0.081–0.561 |
7 m to 17 y | 0.064–0.406 | 0.064–0.406 |
18 to 30 y | 0.064–0.319 | 0.069–0.271 |
31 to 40 y | 0.052–0.353 | 0.066–0.401 |
41 to 50 y | 0.061–0.387 | 0.060–0.277 |
51 to 60 y | 0.037–0.319 | 0.051–0.313 |
61–70 y | 0.042–0.309 | 0.041–0.336 |
>70 y | 0.048–0.298 | 0.047–0.361 |
LOINC® Map
Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
---|---|---|---|---|---|---|
123010 | Alpha-1-Antitrypsin, Fecal, Qn | 25303-9 | 123011 | Alpha-1-Antitrypsin, Fecal, Qn | mg/g | 25303-9 |
Order Code | 123010 | |||||
Order Code Name | Alpha-1-Antitrypsin, Fecal, Qn | |||||
Order Loinc | 25303-9 | |||||
Result Code | 123011 | |||||
Result Code Name | Alpha-1-Antitrypsin, Fecal, Qn | |||||
UofM | mg/g | |||||
Result LOINC | 25303-9 |