Scintigraphic Detection Of Inflammation/Infection With Technetium-99m-Labeled Human Polyclonal Immunoglobulin G(～(99m)Tc-HIG)

Rapid and accurate detection and localization of occult foci of inflammation/ infection in the body are important in many clinical conditions. Nuclear medicine imaging seems to be a non - invasive and effective method for this purpose. In the past decades although there were several radiopharmaceuticals used for infection imaging, none of them was ideal. In recent 5 to 6 years, a new infection imaging agent, technetium -99m- labeled human polyclonal immunoglobulin G (^99mTc-HIG) has been developed and used successfully. Since there are very few institutes performing infection imaging study in China, it is extremely important to prepare an instant ^99mTc-HIG kit and evaluate its clinical usefulness.The present study consists of two parts:1. Experimental studyA rapid one-step kit for labeling HIG with ^99mTc was developed by the following procedure: Commercial HIG was modified with 2 -iminothiolane for creating extra S -H bonds and adequate SnCI₂· H₂O tartrate was added for transchelation. The mixture was dispensed into small sterile vials and lyophilized and sealed under the presence of nitrogen gas. Preparation of ^99mTc-HIG can be easily achieved by reconstituting HIG kit with desirable dose of fresh ^99mTcO₄^- elute. The in vitro and in vivo characteristics of ^99mTc - HIG, including radiochemical purity, stability, biodistribution and safety were assessed. The radiochemical purity of ^99mTc-HIG remains >95% from 5 min to 4h post labeling. No significant changes were observed within 4 months post preparation of HIG kit. After reconstitution, the ^99mTc-HIG is a...