Interactions between immunoglobulin G molecules

Cross-reactive and pre-existing antibodies to therapeutic antibodies—Effects on treatment and immunogenicity

“…However, immunoglobulins can also associate in a variety of other ways. 98 Depending on the type of immunoassay that is carried out, such non-specific associations may result in a positive signal, which will often reflect limitations of the assay format rather than a genuine interaction that may also take place in vivo. It is important to keep in mind that for some of the aforementioned examples of pre-existing antibodies, assays used to measure them can also suffer from these limitations, direct ELISAs in particular, as will be elaborated below.…”

“…108,109 These lowaffinity interactions will not result in association between monomeric IgG molecules, but may be responsible for the fact that IgG Fc fragments readily crystallize, and possibly facilitate PEGinduced immune complex precipitation reactions. 98 Interference from these non-specific, low-affinity interactions in immunoassays may be minimized by ensuring that reagents, including drug molecules that are tagged (e.g., with biotin), are aggregate-free.…”

Behavior of Monoclonal Antibodies: Relation Between the Second Virial Coefficient (B 2) at Low Concentrations and Aggregation Propensity and Viscosity at High Concentrations

“…As for the relationship between self-association and aggregation, Wu et al reported that hydrophobic patches on the surface of monoclonal antibody (MAb) molecules cause low solubility and induce aggregation due to self-association (21). Primary and higher-order structures of MAbs are also important factors, and different types of self-association have been reported such as Fab-Fab and Fc-Fc interactions (22). Kanai et al reported that self-association between Fab fragments is responsible for high viscosity at high concentrations where electrostatic interactions are a major driving force for self-association (11).…”

Anticomplementary activity of horse IgG and F(ab′)2 antivenoms

“…13,32 IgG aggregates can be formed by F(ab)-F(ab) or Fc-Fc interactions and occur after prolonged storage times, increasing the immunogenicity and modifying the physical properties of antivenoms. 33 Low-molecular mass proteins were also detected in reduced samples, but they did not correspond to Ig degradation products, which was shown by the Western blot reactions; thus, they were considered protein contaminants.…”