| Development of graft-versus-host disease and leukemia relapse remain serious complication following bone marrow transplantation. This study revolved mainly around the two problems. 1. Selective radiation of hematolymphoid tissue delivered by 131I-Anti-CD45 McAbObjective: To obtain the tissue distribution data and dosimetry of 131l-labelled anti-CD45 monoclonal antibody (McAb) in both target and nontarget organs.Methods: Antibodies were iodinated with Na131I or Na125I, using the Chloramine T-labeling method. The double isotope labeling method of pressman was used to determine the biodistribution of two kinds of antibodies in mice. According to formula, the data of mice change into the data of 10yr-old-child model. Microsoft Origin 50 was used to calculate residence time. The absorbed doses (mGy/MBq) to each organ were estimated using the MIRDOSE 3.1 procedure.Results: 131I-labelled anti-CD45 McAb were cleared more quickly than 125I-labelled IgG from blood. The biodistribution studies showed rapid specific uptake and persistent uptake of 131I-labelled anti-CD45 McAb in both marrow and spleen. The concentration of 131I-labelled anti-CD45 McAb peaked in spleen and marrow at Ih after infusion. An injection of 125I-labelled IgG resulted in an even distribution over the whole body. The radiation absorbed dose delivered to the spleen, marrow were 0.733, 0.412mGy/MBq respectively. The liver was the normal organ estimated to receive the highest absorbed radiation dose (0.209 mGy/MBq).Conclusions: 131I-labelled anti-CD45 monoclonal antibody has special biodistribution. The radiolabeled monoclonal antibody can deliver radiation to lymphohematopoietic tissues with relative specificity, while sparing the normal organs. This radiolabeled anti-CD45 monoclonal antibody is promising for adjuvant conditioning radioimmunotherapy of hematolymphoid tissue before bone marrow transplantation, with no readily appreciable increased risk of regimen-related toxicity.
|
PDF Full Text Request