A1ALC [A Test in Focus]

David Murray, M.D., Ph.D., provides a brief overview of the new Alpha-1-Antitrypsin Proteotype S/Z by LC-MS/MS, Serum test now available from Mayo Medical Laboratories. This test should be ordered for individuals suspected of A1A deficiency and can be used for diagnosis and identification of a specific proteotype to determine prognosis.

  • Determining the specific proteotype for prognosis and genetic counseling for patients with alpha-1-antitrypsin deficiency
  • Alpha-1-antitrypsin (A1A) inhibits the enzyme neutrophil elastase. This function is especially important in the lungs because it protects against excess tissue degradation.
  • Patients with AIA deficiency may be misdiagnosed as having asthma because the symptoms (cough, wheezing, and dyspnea with exertion) are similar.
  • A1A deficiency is a relatively common disorder in Northern European Caucasians.
  • A1A is produced by the liver and mutations in the protein can cause defective transport out of the liver resulting in liver cell destruction and elevated liver enzymes.
  • The combination of quantitation of the serum A1A and A1A proteotype determination by mass spectrometry is Mayo Clinic’s preferred approach to diagnose A1A deficiency.
  • When the serum level differs from what is expected for that proteotype, additional studies are performed that may include A1A phenotyping by isoelectric focusing and DNA sequencing.

When should I order this test?

This test should be ordered for individuals suspected of A1A deficiency. The test can be used for diagnosis and to identify a specific proteotype to determine prognosis.

  • A1ALC: Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
  • AATP: Nephelometry


  • Day(s) and Time(s) Test Performed: Monday and Thursday; 12:00 p.m.
  • Test reported Tuesday and Friday; 11:00 a.m.
  • Analytic Time: 4 days
Andy Tofilon

Andy Tofilon

Andy Tofilon is a Marketing Segment Manager at Mayo Clinic Laboratories.