A single specificity solid phase assay platform was created utilizing 120 soluble HLA alleles and a large panel of control proteins, all of which were validated by qualified monoclonal antibodies. The assays were optimized in regard to sera incubations, wash steps and PE-detection. In some cases, serological specimens were treated using supplemental techniques to reduce sera complexity or remove interference and background problems.
In several case studies, more distinctive reaction patterns compared to other assay manufacturers could be demonstrated. The insight into isotype distribution provided helpful facts to draw further conclusions regarding the patient¡¯s immunological state. The usage of soluble HLA demonstrated a higher capacity in sera titration experiments while lack of substantial structural disintegration reduced the false positive rate allowing better definition of single cross-reactive patterns.
The complex nature of human sera has set new challenges in the evaluation of the phenotypic and functional traits of antibodies. A large diverse panel of highly purified functionally intact HLA antigens along with a definitive set of control proteins is essential to satisfy the increasing demand for meaningful immunological assessment of transplant patients.