Avidity Of Anti-Naja Haje Antivenin In Relation To In Vivo And In Vitro Activity

Avidity, which is a measure of the bonding strength between antigens and antibodies, becomes an important medical parameter in many aspects of therapeutic and diagnostic purposes. In the present investigation, we studied the relationship between the avidity and the in vivo and in vitro activity of 18 samples of anti-Naja haje antivenins collected randomly from various horses at different immunization intervals. Although the avidity indices of the antivenins varied within a very narrow range, we found that the avidity was closely associated to the neutralizing potency but independent of the ELISA titer. The results obtained highlights the value of avidity assays in amplifying the sensitivity of the in vitro immunoassays and suggested the use of avidity tests for evaluation and standardization of antivenins in some antivenin production steps