Process optimization to remove immunoglobulin A, immunoglobulin M and prekallikrein activator for intravenous immunoglobulin G production

BACKGROUND AND OBJECTIVES: The demand for intravenous immunoglobulin (IVIG) is increasing, but supply is limited. Some residual protein contaminants such as prekallikrein activator (PKA) and immunoglobulin A (IgA) can cause severe adverse effects, necessitating a more efficient purification process with high recovery and fewer impurities. MATERIALS AND METHODS: We used IVIG intermediate from caprylic acid precipitation as the starting material. Diatomite adsorption and two-step anion exchange chromatography (AEX) were employed to remove PKA, Factor XII, prekallikrein and kallikrein. Three resins for the second-step flow-through mode AEX were evaluated, and the loading conditions were optimized by Design of Experiments (DoE) and high-throughput screening experiments to better remove IgA and immunoglobulin M (IgM). Pilot-scale experiments validated the feasibility of the optimized process. RESULTS: Diatomite adsorption (300 g/kg, 1 h) and two-step AEX could remove PKA, Factor XII, prekallikrein and kallikrein to below the limit of detection. The best AEX resin and optimal loading condition (pH 6.0 with 3.0 mS/cm conductivity) to remove IgA and IgM were obtained. As a result, IgA and IgM could be reduced to 3.83 and 10.70 μg/mL, respectively, with the immunoglobulin G (IgG) recovery over 86.9%. The 800-L pilot-scale results demonstrated successful process scale-up, achieving robust IgG recovery and effective impurity removal for IVIG production. CONCLUSION: The combination of diatomite absorption and optimized two-step AEX resulted in IVIG preparation with enhanced purity and high recovery.