Alpha-1-Antitrypsin

Alternate Name: A1 Antitrypsin Serum

  | Alpha1-Protease Inhibitor; Acute Phase Proteins

SAL Code:

501

CPT:

82103

Loinc:

1825-9

Turn Around Time:

1-2 days

Setup:

Daily

Units:

mg/dL

Department:

Special Chemistry

Methodology:

Immunologic

Specimen Requirements:

Primary Tube:

SST

Primary Substance:

Serum

Alternate Sample Info:

Lavender-top (EDTA) tube, or green-top (heparin) tube

Temperature

Period

Stable Ambient:

14 days

Stable Fridge:

14 days

Stable Frozen:

14 days

Rejection Criteria:

Chylous serum

Clinical Info:

Detection of hereditary decreases in the production of a1-antitrypsin (a1AT). Decreased or nearly absent levels of a1AT can be a factor in chronic obstructive lung disease and liver disease. An increased prevalence of non-MM phenotypes is found with cryptogenic cirrhosis and with CAH. Cirrhosis in a child should raise consideration of a1AT deficiency or Wilson's disease. Diagnosis of inflammatory states, if elevated (eg, rheumatoid arthritis, bacterial infection, vasculitis, neoplasia).

Additional Information:

Should be run when a1-globulin in serum protein electrophoresis is low or when two bands are seen in the a1-region. Heterozygous patients exhibit AAT levels which are commonly about 60% of normal. Homozygous recessive a1AT patients exhibit levels at about 10% of normal. Phenotyping is desirable on patients with low values and on all patients being worked up for AAT-deficient liver disease. Most pathologic is homozygous state ZZ. An M null genotype will have phenotype as MM but low serum level. AAT is one of the alpha-globulins, which together are called “acute phase reactants.” These rise rapidly, but nonspecifically, in response to inflammatory insults.

Contraindications: If CRP is positive, retest a1AT in 10-14 days.

Sample Collection:

Overnight fasting is preferred. Collect patient samples using standard phlebotomy techniques. Click here for additional collection instructions.

Test Limitations:

a1AT may be elevated into normal range in heterozygous deficient patients during concurrent infection, pregnancy, estrogen therapy, steroid therapy, cancer, and during postoperative periods. Homozygous deficient patients will not show such elevation. Normal a1AT levels may occur in patients with liver disease who are heterozygotes. In normals, pregnancy and contraceptive medication may elevate levels. Levels are normally low at birth but rise soon thereafter.

Specimen Handling Instructions:

Maintain at room temperatrure.

Test Information:

Components: