ABSTRACT
Cyclosporine (CsA) therapeutic drug monitoring has become an essential component of successful CsA therapy. Many clinical laboratories utilize radioimmunoassay (RIA) for CsA measurements because of its adaptability on a large number of samples. Two commercial RIA kits use a monoclonal antibody that is selective for parent CsA molecule. Sandimmun kit involves H-labeled tracer, while the CYCLO-Trac-SP involves a I-labeled-CsA ligand. This chapter aims to compare whole-blood CsA concentrations from transplant patients measured by both kits. In order to assess the difference in concentrations attributed to standards, it utilizes the CYCLO-Trac-SP with two different standard calibration curves. The chapter also utilizes four separate control samples: two blood controls prepared and provided in the Sandimmun kit, and two sample pools from renal transplant patients receiving CsA. Recoveries were studied by adding different standard concentrations to a patient sample and ranged from 94 to 106%.
