A robust and scalable immunoadsorbent platform based on the high-affinity M03-IgG antibody for targeted IL-6 Removal in cytokine storm.

The therapeutic removal of interleukin-6 (IL-6) via blood perfusion has demonstrated clinical efficacy in the management of autoimmune diseases and sepsis. However, efficient clearance is hindered by the complexity of blood, which contains over 3,000 plasma proteins, and by the low physiological abundance of IL-6, which ranges from picograms to nanograms per milliliter even during cytokine storms. Existing adsorbents are limited by their specificity, binding capacity, and cost-effectiveness. To address these challenges, we developed an IgG-based immunoadsorbent utilizing M03-IgG, a high-affinity anti-IL-6 antibody with an EC50 of approximately 15 pM. Langmuir isotherm analysis indicated a maximum adsorption capacity of 5.18 mg of IL-6 per gram of microspheres. Dynamic adsorption assays, conducted at an adsorbent-to-serum ratio of 1:25, achieved approximately 93% clearance of IL-6. The adsorbent exhibited excellent blood compatibility and retained 85% of its initial activity following six months of storage. These results underscore the potential of this system as a clinically viable, high-performance platform for IL-6 removal.