Monocytes/macrophages in renal allograft rejection

Monocytes/macrophages (MO) have long been recognized to be involved in renal allograft rejection. Monocytes/macrophages have been detected in the glomerular, vascular, and tubulointerstitial compartments during rejection. The recent demonstration that peritubular capillary deposition of complement split factor C4d, a marker for antibody-mediated rejection, is associated with relatively marked MO infiltration of the allograft during acute rejection is a significant development in our understanding of the role of the MO in rejection. High levels of MO in rejecting allografts have been associated with severe rejection, and glomerular MO infiltration in particular has been shown to be an indicator of poor graft outcome.