[Preparation and radioimmunoimaging of a monoclonal antibody against human granulocytes].

The aim of this research is to prepare a novel monoclonal antibody against granulocytes by the intraperitional routine procedure and evaluate the usefulness of (99)Tc(m) labelled anti-granulocyte monoclonal antibody (McAb) SZ-102 for the detection of experimental inflammatory areas in rabbits. It was characterized as IgG1 subclass by the double immunodiffusion analysis. The flow cytometry demonstrated that SZ-102 reacted selectively with human granulocytes, monocytes, and with their bone marrow precursors, while human lymphocytes, red blood cells and platelets remained negative. In addition, SZ-102 antigen was expressed on the macrophages of liver, lung, thymus, spleen and lymph node by immunohistochemical SP methods. It is suggested that McAb SZ-102 is mainly against granulocytes. SZ-102 was labelled with (99)Tc(m) using 2-iminothiolane modification McAb and (99)Tc(m) -glucoheptonate (GH) transchelation method. The experimental rabbit model of inflammatory areas was prepared,through injecting with (99)Tc(m)-SZ-102 by ear-edge vein, and then imaged by SPECT. (99)Tc(m) labelled murine IgG was used as a negative control. The inflammatory areas in rabbits were clearly imaged at 2 to 4 hour after injection of (99)Tc(m)-SZ-102, while the control group after injection of (99)Tc(m)-labeled murine IgG was negative. In conclusion, the McAb SZ-102 may be a potential agent for the diagnosis and localization of inflammatory areas of carcinomas and clinically concealed infectious diseases.