Immunoaffinity chromatography for the preparation of equine tetanus immunoglobulin F(ab’)2 for enhanced safety and efficacy

Typically, the antigen-specific antibodies constitute a small fraction—often estimated to be around 2–10 %—of the total IgG in the serum after immunization. This low percentage necessitates the use of purification techniques to enrich the antigen-specific antibodies for therapeutic or research purposes. This study introduces an affinity chromatography column using NHS-activated Sepharose as a matrix and the tetanus toxin subunit C, TeNT-Hc-C869A, as a ligand, enabling the purification of polyclonal antibodies with high specificity. This process improves antitoxin purity to over 95 %, effectively neutralizes the tetanus toxin, and removes inactive antibodies and other impurities, thereby reducing the risk of allergic reactions caused by heterologous proteins. This method offers promising advancements for tetanus prevention and treatment. The developed affinity column is applicable for purifying equine plasma, enzymatically digested equine tetanus F(ab’)₂, and human immunoglobulins targeting the tetanus toxin. Following purification, the specific activities of these preparations increased by factors of 5, 5, and 30, respectively, enhancing their clinical safety profiles. The affinity matrix exhibits durability, high loading capacity, and non-toxicity, supporting its scalability. This streamlined, cost-effective preparation process highlights the column's potential for broad applications in the biopharmaceutical field.