Kinetic data of in-vivo labeled granulocytes in humans with a murine Tc-99m-labelled monoclonal antibody

Abstract

Twenty-five patients were examined in vivo with 99mTc labelled monoclonal antibodies; 15 with suspected infections with an antigranulocyte antibody (BW 250/183), 10 with suspected recurrence of a colorectal carcinoma with an anti CEA antibody (BW 431/26). Both antibodies were IgG1 isotypes. In the patients with suspected infections no change of the peripheral leukocyte count could be observed after the antibody injection (1 mg, n = 9; 0.5 mg, n = 1; 0.25 mg, n = 6). In 2 patients examined with the anti CEA antibody (2 mg), a significant decrease of the peripheral leukocyte count could be observed. The recovery rate of the 99mTc antibody labelled granulocytes was calculated to be about 10%. The increase of the antibody-antigen binding was calculated to be 0.2%/min. In vivo the organ distribution curves demonstrated an increase of 99mTc activity over spleen and bone marrow of 1.1%/min, which was interpreted as antigen-antibody reactivity. The organ distribution curves of the anti granulocyte antibody over spleen and bone marrow showed typical binding characteristics to the local granulocyte epitopes. The curves over other organs showed a simple perfusion pattern. The curves of the anti CEA antibody showed a perfusion pattern over all the examined organs. A sham dialysis model in one patient with renal insufficiency undergoing regular dialysis treatment demonstrated the viability of 99mTc antibody labelled granulocytes in vivo. The kinetic patterns of the 99mTc antibody in patients with Crohn's disease were interpreted as CEA binding of the antibody in the bowel wall.

White blood cell scintigraphy with monoclonal antibodies in the study of the infected endoprosthesis

“…The disadvantages of WBC scanning with the labelling of separated granulocytes concern the time-consuming procedure including the risk of cell damage, unsatisfactory labelling results, opportunities for iatrogenic errors and a small risk of human immunodeficiency virus (HIV) infection (Alazraki 1990). The characteristics of WBC scanning with monoclonal antibodies and the diagnostic accuracy in various entities concerning infection and inflammation have been described in many publications (Becker et al 1989a, b;Joseph et al 1988;Lind et al 1990;Locher et al 1986;Reuland et al 1991;Sciuk et al 1991 ;Segarra et al 1991). No side effects have been reported, and the possible induction of human anti-mouse antibodies did not prove to be a problem since only small amounts of protein need to be injected.…”

Experience with the iodine-123 and technetium-99m labelled anti-granulocyte antibody MAb47: a comparison of labelling methods

“…Our experience shows that the diagnostic potential of the labelled preparations is similar, independent of radionuclide and labelling procedure, and that they compare well with 99mTc-labelled BW250/183 [28][29][30], showing similar pharmacological properties. Around 20% of the labelled antibody circulating in blood is bound to granulocytes, which is in accordance with the number of binding sites per cell, number of cells in the blood and the affinity constant of the antibodies for their target antigens [31].…”

Chronic complicated osteomyelitis of the appendicular skeleton: Diagnosis with technetium-99m labelled monoclonal antigranulocyte antibody-immunoscintigraphy

“…However, the examination requires time-consuming ex vivo blood handling techniques and special training, and entails risk of infection for both laboratory personal and patients. 99mTc-MAB binding granulocytes show a quite similar in vivo distribution to that of radiolabelled granulocytes and allow the detection of granulocyte accumulation in the appendicular skeleton [19,20]. The advantage of 99mTc-MAB is the simplicity of the labelling process of Tc with the antibodies and the in vivo labelling of granulocytes.…”