Study On The Types Of Immunocytes Infiltrated In Intimal Arteritis In Rejected Kidney Allograft

Background. Acute allograft kidney rejection was consisted of T-cell mediated rejection and antibody mediated rejection. People know T-cell mediated rejection much better than antibody mediated rejection because that antibody mediated rejection accounts for only 0~8% of the total recipients population after kidney transplantation. Antibody mediated rejection showed diversify histological features contained Intimal arteritis, glomerulitis and peritubular capillaritis. But the immunophenotype of the cells which infiltrated in the Intimal arteritis and glomerulitis was still not been clarified. Then we take use of four excised kidney allograft which suffered acute rejection. to identify the cellular infiltrates in intimal arteritis and glomerulitis.Methods. We obtained four allografts removed from renal transplant recipients who had been diagnosed by clinical criteria and/or biopsy as having acute allograft rejection before their transplants were resected. Then the specimens were performed HE staining and detected C4d deposition by immunohistochemistry, for the aim of diagnosis. Based on the diagnosis of antibody mediated rejection we clarified the immunophenotype of the cells in the intimal arteritis and glomerulitis by immunohistochemistry in serial sections of the resected kidney. Moreover, in aim to clarify the relationship of position between the immunocytes and endothelial cells, double staining of immunohistochemistry was performed with the antibodies of lysozyme(macrophages) and CD34(endothelial cells).Results. These four kidney allografts showed classical pathological features of antibody-mediated rejection,we found infarction at different extension, and we can see intimal arteritis, glomerulitis, and peritubular capillaritis beside the infarction area. Immunohistochemistry for C4d showed that all of these four cases were positive fpr C4d staining according to the latest diagnose standard, finally all these cases were diagnosed as suffered acute antibody mediated rejection. The result of immunohistochemistry for the immunocytes showed that in the intimal arteritis, the most important cellular infiltration came from macrophages and T-lymphocytes which took percentage of 39.8±10.5% and 32.3±14.4% respectively. There was no significant difference between the two kinds of cells, but their percentages were higher than those of B cells, plasma cells and neutrophils. Even the T cells took a huge percentage for the cellular infiltration in the intimal arteritis, the CD8 positive cells did not account most of them, the CD8 positive rate was only 14.9±8.3% and was much lower than that of CD3 positive cells. At the same time, the NK cell can appear in the intimal arteritis too. At last, result of double staining of immunochemistry showed that the infiltrated cells were indeed under the endothelial cells, not in the lumens. The cells which infiltrated in the glomerulitis were macrophages and neutrophils.Conclusion. All these four cases were diagnosed as suffered acute antibody mediated rejection. Both macrophages and T-lymphocytes take part in the intimal arteritis of antibody-mediated rejection and accounted a highest percentage. But the T-lymphocytes which infiltrated under the endothelial cells were not only Cytotoxic T cell. NK cells can appear in the intimal arteritis of antibody mediated rejection. There was no similar report about these before. In glomerulitis, immunocytes infiltrated in the capillary were macrophages and neutrophil, this result was same to other people's ideas.