Alpha 1-antitrypsin - Therapeutic Use

Therapeutic Use

Recombinant alpha 1-antitrypsin is not yet commercially available, but is under investigation as a therapy for alpha 1-antitrypsin deficiency.

Therapeutic concentrates are prepared from the blood plasma of blood donors. The US FDA has approved the use of three alpha 1-antitrypsin products derived from a human plasma: Prolastin, Zemaira, and Aralast. These products for intravenous augmention A1AT therapy can cost up to $100,000 per year per patient. They are administered intravenously at a dose of 60 mg/kg once a week.

A recent study analyzed and compared the three FDA-approved products in terms of their primary structure and glycosylation. All three products showed minor differences compared to the normal human plasma A1AT, and are introduced during the specific purifications procedures. However, these detected differences are not believed to have any negative implications to the patients.

Aerosolized-augmented A1AT therapy is under study. This involves inhaling purified human A1AT into the lungs and trapping the A1AT into the lower respiratory tract. This method proves more successful than intravenous-augmented A1AT therapy because intravenous use of A1AT results in only 10%-15% of the A1AT reaching the lower respiratory tract, whereas 25%-45% of A1AT can reach the lower respiratory tract through inhalation. However, inhaled A1AT may not reach the elastin fibers in the lung where elastase injury actually occurs. Further study is currently underway.