title: Objective evaluation of local xenogeneic graft-versus-host reaction by computerized radioisotope imaging (CRI).
abstract: The local xenogeneic graft-versus-host reaction (GVHR) assay has been used clinically to evaluate cellular immune competence and experimentally to monitor the immunomodulatory effects of several drugs. By employing a computerized radioisotope imaging (CRI) technique, we were able to perform the assay with smaller numbers of mononuclear cells (MNC) and to rid it entirely of any bias. Measuring the local GVHR by CRI compares well with the conventional measurement of the volume (correlation coefficient r = 0.619; P less than 0.001). A clear-cut distinction was documented between normal donors and cancer patients (P less than 0.001) when 10 X 10(6) or more MNC were used in the assay. This is an improvement over the previous, conventional testing of local GVHR which required injection of 20 X 10(6) MNC in order to achieve a similar resolution. The indications for the presence of immune competence have therefore been redefined using the local GVHR index as determined by CRI according to the scale of MNC injected. Thus, immunocompetence is considered present if the CRI index is greater than or equal to 1.2 for 10 X 10(6) MNC, greater than or equal to 2.0 for 15 X 10(6) MNC and greater than or equal to 2.6 for 20 X 10(6) MNC.
mesh_terms: D000818:Animals; D004306:Dose-Response Relationship, Immunologic; D006087:Graft vs Host Reaction; D006801:Humans; D007121:Immunocompetence; D017710:Lymphocyte Transfusion; D009369:Neoplasms / Q000276:immunology; D011877:Radionuclide Imaging; D051381:Rats; D012867:Skin / Q000000981:diagnostic imaging / Q000276:immunology*; D014183:Transplantation, Heterologous