Comparison of Leukocytes Labeled with Indium-11 l-2-Mercaptopyridine-7V-Oxide

lndium-111 leukocyte scanning has evolved into a practical and highly accurate method for the identification of infectious and inflammatory processes. The most commonly used agent for labeling leukocytes has been [111ln]oxine.We have investigated a newer agent, 2-mercaptopyndine-A/-oxide(Merc) at our institution which unlike oxine, allows us to label leukocytes in plasma, using a simple kit procedure. Of the 92 consecutive patients referred for detection or localization of an infectious process, autologous leukocytes of 55 patients were labeled with [111ln]Merc,while those of the remaining 37 patients were labeled with [111ln]oxine.The sensitivities for Merc and oxine procedures were 87 % and 92%, respectively, while the respective specificities were 100 % and 92%. We conclude that the[111ln]Merc-labeledleukocytes are equally effective as |1"ln|oxine-labeled leukocytes in detecting infectious processes. The use of [111ln]Mercis advantageous over [111ln]oxinefor white blood cell labeling because of its easier preparation. J NucÃ-Med 28:438-441,1987 rver the past few years, indium-111 ('"In) oxine-labeled leukocytes have been used extensively for the detection and localization of infectious and inflamm