Allograft rejection: The role played by adhesion molecules

The role of fcgamma receptor gene polymorphism in pediatric renal transplant rejections

The aim of the study reported herein was to determine whether panel-reactive antibody (PRA) and FcgammaR gene polymorphism act in the same way on acute rejection (AR) and chronic rejection (CR) in children who have undergone renal transplantation. The study evaluated 56 children who underwent transplantation and 115 healthy subjects. AR was observed in 13 cases; CR was observed in 7 patients. The assessment for FcgammaR of the groups in which AR was present showed statistical significance only for the FcgammaIIA genotype. There was no statistical significance for either the FcgammaIIIA or FcgammaIIIB genotypes. Assessment of the FcgammaIIA, IIIA, and IIIB genotypes of the groups in whom CR was present did not show statistical significance. As a result, the prediction of graft survival among transplant recipients is possible using molecular biology. The results of our study showed that individuals of the FcgammaRIIA genotype seemed to have a poorer prognosis similar to some autoimmune diseases. These individuals constitute a risk group for AR. If other studies are conducted with more patients to demonstrate the relationship of other FcgammaRs to rejection, the resultant predictive knowledge about the value of genotypes may lead to improved outcomes following renal transplantation.

Hepatic allograft rejection: regulation of the immunogenicity of human intrahepatic biliary epithelial cells

Intrahepatic biliary epithelial cells were immunomagnetically purified from specimens of disaggregated human liver and were propagated in vitro. After three passes in culture, the cells were shown to be over 85% pure with contaminating leukocytes and endothelial cells constituting less than 2% of the population. Sensitive flow microfluorimetric analysis was performed after immunofluorescence labeling to quantify expression of both class 1 and class II major histocompatibility (MHC) antigens and the adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and lymphocyte function-associated antigen-3 (LFA-3). It was shown that resting human intrahepatic biliary epithelial cells (HIBEC) expressed class 1 MHC antigens, ICAM-1, and relatively low levels of LFA-3. Stimulation with tumour necrosis factor-alpha (TNF-alpha) upregulated expression of ICAM-1, whereas Interferon-gamma (IFN-gamma) and a combination of IFN-gamma and TNF-alpha upregulated class I MHC antigens and ICAM-1 and induced class II MHC molecules. The level of expression of MHC antigens and of ICAM-1 and LFA-3 after stimulation of HIBEC with combined IFN-gamma and TNF-alpha was comparable with the expression of these antigens by an Epstein-Barr virus-transformed B-cell line. The phenotypic similarity between cytokine-stimulated HIBEC and a known antigen presenting cell is consistent with a potential role for biliary epithelial cells in antigen presentation.