[Production of highly purified therapeutic immunoglobulins (HPTI): analysis of a purification process]

Heterologous immunoglobulins have been used for more than a century for human therapeutic use. Introduction of fractionation and purification steps for the production of these heterologous immunoglobulins has allowed an improvement in their tolerance. Historically, the fractionation and purification steps consisted in one precipitation with 30% of ammonium sulfate followed by a hydrolysis with pepsin at acid pH. More recently, the addition of purification steps like ion-exchange chromatography and the addition of viral safety steps like pasteurization have allowed to improve the purity of these products and to reduce the risk of adverse events. Today, the more efficient processes are able to reach a proportion of about 95% in F(ab')(2) fragments with less than 0.5% of aggregates and polymers ensuring an optimal safety profile of these products.