How do you test for alpha-1?
Point of care test: there is an innovative point of care test to screen COPD patients for alpha-1-antitrypsin (A1AT) deficiency (also known as alpha-1) that allows the identification of the Z-AAT protein in the blood, doing it in a fast, quick, and accurate way. If the test result is positive, diagnostic testing is recommended for clarification.
Alpha-1 cannot be diagnosed by symptoms or by medical examination alone.1
Diagnostic testing includes:
- Quantitative tests for serum A1AT levels2
- Qualitative tests for the identification of A1AT genetic variants2
- Serum A1AT levels2-4
- Determined by rocket immunoelectropheresis, radial immunodiffusion, or nephelometry
- Because A1AT is an acute phase reactant, levels can be misleading
A genotype/phenotype is recommended along with a serum level test
- Genotyping by PCR 2,3
- Identifies the most common abnormal alleles (Z or S)
- Genotyping by direct sequencing 2,3
- Identifies null or rare alleles
- Phenotyping 3
- Identifies A1AT variants through isoelectric focusing
A decrease in A1AT serum levels increases the risk of emphysema2, 5-7*
Although the maintenance of blood serum levels of alpha-1 proteinase inhibitor (PI) (antigenically measured) above 11 μM (or 80 mg/dL [RID]) has been historically postulated to provide therapeutically relevant antineutrophil elastase protection, this has not been proven.