Laboratory monitoring of therapy with OKT3 and other murine monoclonal antibodies.

The first monoclonal antibody (MAb) approved by the Food and Drug Administration (FDA) for therapeutic use, OKT3, is now a standard treatment for organ allograft rejection. This article reviews the interpretation of laboratory tests used to manage patients treated with MAb. Emphasis is placed on OKT3, with which the experience is also the greatest, although comparisons with other MAbs in clinical trials is also discussed.