Administration of human protein-based drugs to animals often leads to formation of antidrug antibodies (ADAs) that may form circulating immune complexes (CICs) with the dosed protein. Circulating immune complexes can activate and bind complement (cCICs), and if large amount of CICs or cCICs is formed, the clearance mechanism potentially becomes saturated, which can lead to immune complex (IC) deposition and inflammation. To obtain a better understanding of the underlying factors, including the relationship between different dose regimes on IC formation and deposition and identification of possible biomarkers of IC deposition and IC-related pathological changes in kidneys, BALB/c and C57BL/6J mice were administered with human anti-tumor necrosis factor α (aTNFα, adalimumab) or a humanized anti-TNP (aTNP) antibody for 13 weeks. Particularly, ADA, CIC, cCIC formation, IC deposition, and glomerulonephritis were observed in C57BL/6J administered with aTNFα, whereas the immunologic response was minor in BALB/c mice administered with aTNFα and in BALB/c and C57BL/6J mice administered aTNP. Changing dose levels or increasing dosing frequency of aTNFα on top of an already-established CIC and cCIC response did not lead to substantial changes in CIC, cCIC formation, or IC deposition. Finally, no association between the presence of CICs or cCIC in plasma and glomerular IC deposition and/or glomerulonephritis was observed.
Keywords: complement; glomerulonephritis; immune complex; immunogenicity; monoclonal antibodies; mouse.