Alpha-1 Antitrypsin (A1AT) proteinase inhibitor is an enzyme biosynthesized in the liver and transported to the lungs through blood. The physiological function of this protein is to protect the lung tissue from damage by an enzyme called neutrophil elastase. Neutrophil elastase is an enzyme produced by the white blood cells in response to infections or to digest away any dying or damaged tissue in the lungs.
A gene called SERPINA1 encodes A1AT . Mutations in this gene result in low or no production of A1AT or may even result in deposition of structurally deformed A1AT in the hepatocytes (liver cells). As a result deficiency in A1AT results in emphysema or Chronic Obstructive Pulmonary disease and even liver cirrhosis from the build-up of A1AT. The patient becomes susceptible to cigarette smoke or other inhalants.
During plasma fractionation A1AT is produced by precipitating the Fraction IV (see fractionation for more details). The purified human plasma derived A1AT is infused into patients with A1AT deficiency as part of the augmentation therapy. However the infusions must be continual in order to maintain the effective levels of A1AT in the patient’s body.
- National Institute of Health (NIH) Genetics Home Reference. Aug 2009.