Allina Health Laboratory a part of Abbott Northwestern Hospital



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Test Name:Alpha 1 antitrypsin by IHC
Test Number:12376 - Technical only; 12379 - Technical & interpretation
Collect:Formalin-fixed, paraffin embedded (FFPE) tissue block.
Container:FFPE tisue block
Processing:Submit processed tissue block or tissue section mounted on a charged, unstained slide.
Transport/Stability:Ambient (preferred)
Alternate Names:AAT
Performing Lab:AHL - Immunohistochemistry
Days Set Up:Mo - Fr
Expected TAT:1 - 2 days
Ref. Ranges:If requested, an interpretive report will be provided
All IHC stains will include a positive control tissue
Processing Details:

  • AAT is a glycoprotein that represents a major component of the alpha-1-globulin serum fraction (90%)
  • AAT is found in serum, as well as in other bodily fluids such as lymphatics, mucus, saliva, synovial fluid, GI secretions, semen, amniotic fluid and colostrum
  • The embryonal yolk sac is the initial site of AAT production
  • Although AAT is predominately made in the liver, it is also produced in histiocytes and monocytes
Staining patterns:
  • Granular based cytoplasmic activity
  • In alpha-1-antitrypsin deficiency, the staining appears as large globules, particularly around the periphery of hepatocytes
  • The primary use for this antibody is in identifying the accumulation of AAT granules in alpha-1-antitrypsin deficiency of the liver
  • AAT is a very useful marker in the work-up of alpha-1-antitrypsin deficiency, since although it is synthesized by the liver in this disease, it is not released into the circulation (thus, the serum is deficient)
  • This antibody is also useful in identifying tumors which can make this protein, such as liver neoplasms, endodermal sinus tumors, and for histiocytic related tumors
  • AAT is expressed in liver related proliferations as follows: focal nodular hyperplasia (56%), liver cell adenoma (68%) and hepatoma (89%)
  1. Palmer, P.E. et al; Am J Surg Pathol 2:275-281, 1978.

Method:Immunohistochemical staining
Microscopic examination
CPT Codes:88342 - 1st stain
88341 - each additional stain
Date Created:03/02/2016
Revised Date:10/17/2018