Inactivation of viruses during a new manufacturing process of α2‐macroglobulin from Cohn Fraction IV by dry‐heat treatment

BACKGROUND α2‐Macroglobulin (α2‐M) has a curative effect on radiation injury. Virus transmission through plasma derivatives is still not risk‐free. Effect of dry heat on α2‐M activity and virus inactivation by dry heat in a new manufacturing process of α2‐M were studied. STUDY DESIGN AND METHODS Effects of 100°C for 30 minutes, 80°C for 72 hours, and lyophilization on α2‐M activity were detected, and stabilizing agents were optimized. Effect of a treatment at 100°C for 30 minutes has been tested on a range of viruses and characteristics change of α2‐M was investigated. RESULTS More than 90 and 80% α2‐M activity recovery were reserved after treatment at 100°C for 30 minutes and 80°C for 72 hours, respectively. A concentration of 0.05 mol/L histidine presented a better protecting effect for α‐M activity. No substantial changes were observed in the characteristics of α2‐M compared with the untreated. By lyophilization and dry‐heat treatment at 100°C for 30 minutes, murine encephalomyocarditis virus and pseudorabies virus (PRV) were inactivated below detectable level within 5 minutes (virus titers reduction ≥ 5.75 log) and 30 minutes (virus titers reduction ≥ 6.00 log), respectively. Bovine viral diarrhea virus and porcine parvovirus were inactivated by 4.29 and 2.46 log reduction, respectively. CONCLUSION Treatment at 100°C for 30 minutes could improve the virus safety of α2‐M with a slight activity loss.