Possible alternative to European Pharmacopoeia's method of analysis Test for Fc Function of Immunoglobulin (2.7.9) by using tetanus toxoid as antigen.

Preparations of intravenous immunoglobulins must keep functional integrity throughout the purification process. In order to assess Fc fragment functionality, the European Pharmacopoeia proposes the Test for Fc function of immunoglobulin (2.7.9), which is based on a rubella antigen of high titre. Sometimes, such antigen is difficult to obtain. In the present study, we develop the same assay using tetanus toxoid instead of rubella antigen, adapting the procedure for the use of tetanus toxoid. The comparison between rubella-based and tetanus-based assays showed that the slopes of the haemolysis curves were higher if red blood cells had been sensitised with the rubella antigen than with tetanus toxoid. Nonetheless, the tetanus-based assay gave satisfactory results and it could be a good alternative antigen target.