CELLULAR INFLAMMATORY INFILTRATES AND RENAL-CELL TURNOVER IN KIDNEY ALLOGRAFTS - A STUDY USING INSITU HYBRIDIZATION AND COMBINED INSITU HYBRIDIZATION AND IMMUNOHISTOCHEMISTRY WITH A Y-CHROMOSOME-SPECIFIC DNA PROBE AND MONOCLONAL-ANTIBODIES

The generation and targeting of inflammatory cells in acutely rejecting kidney allografts are only partly understood. In order to investigate the origin of infiltrating mononuclear cells and the renal cell turnover, percutaneous renal biopsies (45) and lost renal allografts (4) from 40 sex-mismatched transplant patients clinically suspected of developing acute rejection were analysed by in situ hybridization (ISH) and combined ISH and immunohistochemistry (IMH). A biotinylated Y-chromosome-specific DNA probe was used for ISH. Monoclonal antibodies against leukocytes (leukocyte common antigen (CD45), T lymphocytes (CD43), B lymphocytes (L26) and myeloid/histiocytic cells (mac 387)) were employed using a three-stage immunoperoxidase technique followed by ISH on the same specimens. The ISH method was very sensitive when differentiating male from female cells (p < 0,01). Posttransplant mononuclear infiltrates were shown to be of recipient origin and dominated by T lymphocytes and myeloid/histiocytic cells. Tubular and glomerular cells remained of donor origin even after 10 months. There was no evidence of revascularization by recipient endothelial cells.