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Published on: September 10, 2018
Molecular evidence of transient therapeutic effectiveness of natalizumab despite high-titre neutralizing antibodies
G Pilz1, A Harrer, K Oppermann
1Paracelsus Medical University, Salzburger Landeskliniken, Christian-Doppler-Klinik, Department of Neurology, Salzburg, Austria. georg.pilz@salk.at
Natalizumab is a humanized monoclonal antibody directed against the alpha-4 integrin subunit of very late activation antigen-4 (VLA-4). Natalizumab neutralizing antibodies (NAB) have been found to significantly reduce beneficial effects of natalizumab treatment in multiple sclerosis. We investigated interactions of NAB with natalizumab by serial measurements of alpha-4 integrin levels on peripheral blood mononuclear cells using flow cytometry. In addition, serum concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1), the endothelial ligand of VLA-4, and serum NAB were serially determined. Natalizumab infusion led to a transient reduction in alpha-4 integrin levels on immune cells and serum sVCAM-1 levels along with serum negativity of NAB lasting for a few days post-infusion. Apparently, the high-dose effect of freshly infused natalizumab resulted in a transient neutralization of NAB possibly involving a transient therapeutic effectiveness.
Natalizumab is a humanized monoclonal antibody directed against the alpha-4 integrin subunit of very late activation antigen-4 (VLA-4). Natalizumab neutralizing antibodies (NAB) have been found to significantly reduce beneficial effects of natalizumab treatment in multiple sclerosis. We investigated interactions of NAB with natalizumab by serial measurements of alpha-4 integrin levels on peripheral blood mononuclear cells using flow cytometry. In addition, serum concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1), the endothelial ligand of VLA-4, and serum NAB were serially determined. Natalizumab infusion led to a transient reduction in alpha-4 integrin levels on immune cells and serum sVCAM-1 levels along with serum negativity of NAB lasting for a few days post-infusion. Apparently, the high-dose effect of freshly infused natalizumab resulted in a transient neutralization of NAB possibly involving a transient therapeutic effectiveness.
