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| Clinical Indications |
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Inflammatory
bowel conditions can lead to a protein-losing enteropathy in
which there is increased loss of plasma proteins into the gut.
Alpha-1 antitrypsin, a protease inhibitor, is relatively
resistant to breakdown by proteolytic enzymes found in the gut
and may pass relatively unchanged into the faeces.
Levels of alpha-1 antitrypsin in faeces may be used as a guide
to the extent of protein loss into the gut, although some
studies have show a high frequency of false negative results.
Nevertheless, a positive finding may be useful in confirming a
diagnosis of protein-losing enteropathy and monitoring
progress of the disease. A negative result does not exclude
protein-losing enteropathy.
It is recommended that a serum
alpha-1 antitrypsin is measured to ensure normal serum
levels. |
Request Form |
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Combined Pathology Blood form (Yellow/Black) |
Availability |
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Analysed by referral laboratory
if specific criteria met. |
Specific Criteria |
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Requested by Consultant
Gastroenterologist or if agreed with Consultant Biochemist. |
Turnaround Time |
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2 weeks |
Specimen |
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Faeces |
Volume |
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10 gram
minimum |
Container |
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Plastic
universal (blue-topped) |
| Collection |
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Samples must be transported to
laboratory immediately. |
Lab. Handling |
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Freeze
immediately and store at –20°C. Samples must be sent
frozen to referral laboratory. |
Causes for Rejection |
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Delay
in sample reaching laboratory. Not meeting specific criteria
for analysis. |
Reference Range |
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Less
than 5 mg/g dry weight faeces.
This range assumes normal serum alpha-1 antitrypsin levels and
will apply to the PI M phenotype only. |
| Interpretation |
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False
negative results may occur from protein degradation due to
incorrect collection or alpha-1 antitrypsin deficiency. False
positive results may occur in G.I. bleeding. |
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