In - house preparation and evaluation of Tc-99m-HIG kit for detection of infection in AIDS patients

99mTc-HIG can be used for early detection of inflammation and infection foci especially in immunodeficiency patients. The present study involves in-house preparation and evaluation of human immunoglobulin-hydrazinonicotinic acid (HIG-HYNIC) kit to be labeled with 99mTc. In this indirect labeling method, the structure and biological activity of the protein can be maintained. The kit consists of two vials A and B, the vial A contains 2 mg of HIG-HYNIC, and the vial B contains 10 mg of tricine and 1 mg of stannous chloride dihydrate (SnCl2.2H2O). The results revealed that the lyophilized kits were stable for at least 10 months, and showed a high quality from the points of physical, chemical, radiochemical and biological purities, and its validity for human injection. The labeling yield of HIG-HYNIC compound exceeded 98%. The application of the prepared kit was experimentally illustrated in animal models with artificially induced inflammatory lesions after E. coli injection into rat leg muscle. The biodistribution and imaging studies in rats have shown good localization in infected muscle (T) in comparison to the normal muscle (M) 4 and 24 h after injection. Ratios of 17 and 18 were achieved 4 and 24 h post injection, respectively. The results of biodistribution of 99mTc-HIG in human and initial clinical evaluation show that this agent is a good radiopharmaceutical for infection imaging.