Cellular inflammatory infiltrates and renal cell turnover in kidney allografts: a study using in situ hybridization and combined in situ 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 less than 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.