ACUTE KIDNEY GRAFT-REJECTION - A MORPHOLOGICAL AND IMMUNOHISTOLOGICAL STUDY ON ZERO-HOUR AND FOLLOW-UP BIOPSIES WITH SPECIAL EMPHASIS ON CELLULAR INFILTRATES AND ADHESION MOLECULES

Serial biopsies from 41 consecutive renal allotransplanted patients were evaluated in order to obtain pretransplant data as well as information on well-functioning and acutely rejecting grafts. Each patient served as his own control. Thirty-five patients were followed according to the schedule which included biopsy prior to transplantation, shortly after opening of reanastomosis, at least once postoperatively (days 7-10), and furthermore whenever clinically indicated. The morphological evaluation was in each case combined with immunofluorescence (to detect immunoglobulins and complement fractions) and immunohistochemistry with a wide panel of monoclonal antibodies for T cells (CD2, CD3, CD4, CD8, gamma delta), B cells (CD20, CD22), macrophages (CD68, MAC387) NK cells (leu-7, CD16), activation markers (IL-2-R, Ki-67, transferrin-R), MHC antigens (HLA-ABC, HLA-DR), adhesion molecules (ICAM-1, VCAM-1, ELAM-1, PADGEM, VLA-4, LFA-1 alpha/beta), and growth factors (EGF, TGF-alpha EGF-R). When 132 biopsies and 10 failed allografts were examined, no specific morphological or immunohistological parameter predictive of rejection or graft outcome could be found. Morphology in follow-up biopsies from non-rejecting and rejecting patients revealed a continuum of inflammatory changes, and several non-rejecting cases demonstrated cellular inflammatory infiltrates which could not be discriminated from those seen in acute rejection. Of the patients 44% had acute rejection accompanied by increased infiltration of T cells and macrophages showing enhanced IL-2-R expression, increased tubular and endothelial staining for MHC class II, ICAM-1, and VCAM-1, and strong leukocytic expression of VLA-4 and LFA-1 alpha/beta.