Gamma scintigraphic localization of platelets labeled with indium 111 in a focus of infection.

To determine if autologous platelets would localize in a focus of infection, a pyogenic abscess was created in the left hind limb of dogs, using previously processed human stool, while an identical surgical procedure without bacterial inoculation was performed on the right hind limb. Autologous platelets labeled with indium 111 (500 microCi) were administered intravenously to five control dogs that had not undergone surgery, to eight dogs two hours following stool inoculation, and to five dogs 24 hours after stool inoculation. A statistically significant scintigraphic increase in tracer activity was apparent within 24 hours in each animal at the site of abscess creation. Tissue samples, obtained at 48 hours after the administration of labeled platelets, revealed a significant increase in percent dose of 111In per gram of infected muscle compared with control muscle. These studies show that platelets localize at the site of bacterial infection.