Preparation and properties of alpha 1-proteinase inhibitor concentrate from human plasma.

Alpha 1-proteinase inhibitor (alpha 1-PI) has been prepared as a concentrate in quantities large enough for clinical testing of its safety and efficacy in the treatment of emphysema and other disorders. The alpha 1-PI was purified from Cohn fraction IV-1 paste by polyethylene glycol precipitation and DEAE-Sepharose chromatography. The methods used in the purification are gentle and the resulting product behaves almost identically to the alpha 1-PI from plasma. The protein has been heat treated (60 degrees C, 10 h) to lower the risk of transmission of plasma-borne diseases. This resulted in some aggregation of the protein, but did not cause the generation of new antigenic sites. Half-life studies in animals showed that the protein behaved normally (catabolic t1/2 of 68 h).