Comparison of biodistribution of 111 I - tropolone leukocytes and 125 I - human nonspecific polyclonal IgG in normal and induced inflammation mice for detection of inflammation.

Human nonspecific polyclonal IgG and granulocytes, which accumulate in inflammation foci, were radiolabeled with 125I and "'In-Tropolone, respectively. Biodistribution of these two radiolabels was assessed in normal and inflammation-induced mice. 125I-IgG showed better localization to the inflammated areas. Blood levels with "'In-Tropolone leukocytes were lower at all time points. In addition, the inflammatory thigh-to-blood ratios showed an improvement, whereas the ratios of inflammatory thigh-to-other normal tissues were higher for 125I-IgG than "'In-Tropolone leukocytes. In conclusion, labeled IgG due to better localization in inflammated sites and higher target-to-background ratios is more suitable agent than labeled leukocytes for immunoscintigraphy of inflammation