Category:

Turnaround Time: 1 - 2 days
CPT Code:

82103

Test Type: 1 mL Serum (preferred) or plasma
Stability Time:

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3

Reference Range:

Age

Male

mg/dL

Female

mg/dL

0 to 7 d

102–186

102–186

8 to 30 d

73–187

73–187

31 d to 5 y

86–173

86–173

6 to 12 y

99–156

99–156

13 to 40 y

95–164

100–188

>40 y

101–187

101–187

Overview:

Detection of hereditary decreases in the production of α1-antitrypsin (α1AT). Decreased or nearly absent levels of α1AT 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 α1AT deficiency or Wilson's disease. Diagnosis of inflammatory states, if elevated (eg, rheumatoid arthritis, bacterial infection, vasculitis, neoplasia).

α1AT 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 α1AT 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.

If CRP is positive, retest α1AT in 10 to 14 days.

Should be run when α1-globulin in serum protein electrophoresis is low or when two bands are seen in the α1-region. Heterozygous patients exhibit AAT levels which are commonly about 60% of normal. Homozygous recessive α1AT 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.

Collection Details:

Patient Preparation:

Overnight fasting is preferred.

Collection Instructions:

Red-top tube, gel-barrier tube, lavender-top (EDTA) tube, or green-top (heparin) tube.

Separate serum or plasma from cells.

Maintain specimen at room temperature.