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Uses: Preferred test to identify alpha-1-antitrypsin deficiency and causative DNA and protein variants. Congenital deficiency of Alpha-1-Antitrypsin is associated with early lung disease, Neonatal hepatitis and Infantile cirrhosis
Method: Nephelometry, Immunoturbidimetry, Polymerase Chain Reaction, Fluorescence Monitoring, Isoelectric Focusing, ELISA
Category: Genetic Disorders
Reference: Alpha-1-Antitrypsin Stool-Clearance: 1 – 49 mL/24h
Alpha-1-Antitrypsin, Quantitative by ELISA, Random Stool: 0.00 – 0.50 mg/g
Alpha-1-Antitrypsin: 90-200 mg/dL
Pre-test Information: No special preparation required
Specimen Collection: 2 mL (0.5 mL min.) serum from 1 Red tube. Do not use SST gel barrier tubes. Separate serum from cells immediately. Ship refrigerated or frozen or lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B) tube.
Alpha-1-Antitrypsin Clearance, Quantitative by ELISA, Timed Stool: Entire 24-, 48-, or 72-hour stool collection. Refrigerate during collection. Collect blood during the stool collection time interval. Allow serum to clot completely at room temperature. Separate from cells ASAP or within 2 hours of collection
Storage: Frozen
Stability: Serum: Ambient: 1 week; Refrigerated: 3 months; Frozen: 3 months (avoid repeat freeze/thaw cycles)
Whole Blood: Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month
Report Availability: Same day-10 days
More Details: Alpha-1-Antitrypsin (AAT) is a protease inhibitor which has the capacity to combine with and inactivate trypsin. It also neutralizes the activity of other proteases like elastase and hence is an intrinsic factor in the homeostatic mechanism modulating endogenous proteolysis. Deficiency of AAT is seen in Pulmonary emphysema and in children with Cirrhosis. At least 75 different alleles exist for AAT of which about 17 alleles are associated with pulmonary disease and only a few are responsible for liver disease. Elevated AAT levels are due to acute-phase reaction to inflammation and infections which is not linked to genetic defects. High values are also seen during pregnancy and on oral contraceptives