Test Catalog

Test ID: AATRP    
Alpha-1-Antitrypsin Immunostain, Technical Component Only

Useful For Suggests clinical disorders or settings where the test may be helpful

Identification of abnormal accumulation of alpha-1-antitrypsin

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

For the initial technical component only immunohistochemical (IHC) stain performed, the appropriate bill-only test ID will be reflexed and charged (IHTOI). For each additional technical component only IHC stain performed, an additional bill-only test ID will be reflexed and charged (IHTOA).

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Alpha-1-antitrypsin (AAT) is a plasma protein synthesized in the liver and is present in serum and tissue fluids where it acts as an inhibitor of proteases, especially elastase. AAT deficiency is associated with development of emphysema and liver disease. In liver disease, abnormal accumulation of AAT is seen as cytoplasmic globules in hepatocytes.

Interpretation Provides information to assist in interpretation of the test results

The positive and negative controls are verified as showing appropriate immunoreactivity. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request, call 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen dependent. Best practice is for paraffin sections to be cut within 6 weeks.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Callea F, Fevery J, Massi G, Lievens C, de Groote J, Desmet VJ: Alpha-1-antitrypsin (AAT) and its stimulation in the liver of PiMZ phenotype individuals. A "recruitment-secretory block" ("R-SB") phenomenon. Liver. 1984:4(5):325-337

2. Lam M, Torbenson M, Yeh MM, Vivekanandan P, Ferrell L: HFE mutations in alpha-1-antitrypsin deficiency: an examination of cirrhotic explants. Mod Pathol. 2010;23:637-643

3. Theaker JM, Fleming KA: Alpha-1-antitrypsin and the liver: a routine immunohistological screen. J Clin Pathol. 1986;39(1):58-62