Macrophages and HLA-DR(+) cells in acutely rejecting kidney transplants, predict subsequent graft survival, even after reversal of the acute episode

Renal graft biopsies from 19 selected patients with acute cellular rejection (ACR) were analysed using a panel of monoclonal antibodies. All patients had only one episode of ACR, which was completely reversible. In 11 patients (group 1) graft function slowly deteriorated over a period of 14 (+/-17) months after the episode. In the remaining eight (group 2) graft function remained stable over a similar period of observation. In group 1 there was a significantly increased infiltrate of glomerular and interstitial monocytes/ macrophages (MM) when compared with group 2. Also, the expression of HLA-DR antigen by the tubular cells were stronger in group 1, while T-cells in the glomeruli and the interstitium were equally distributed in both groups. We conclude that large numbers of MM and HLA-DR expressing cells (glomerular, interstitial and tubular) in rejecting kidneys predict a more rapid decline of follow-up renal function despite reversal of the acute episode. This may suggest that subclinical ongoing injury continues in some patients and perhaps more intense immunosuppression is necessary to prevent graft loss.