IMMUNOHISTOCHEMICAL STUDY OF ACTIN-BINDING PROTEIN (P55) IN THE HUMANKIDNEY

Background. In clinical transplantation, ''passenger'' dendritic cells (DCs) in the allograft have been thought to induce allograft rejectio n. However, the presence of DCs in the normal human kidney is controve rsial. Most reports have relied on the examination of MHC class I and II antigen expression in combination with DC morphology for identifica tion of DCs. Methods. The distribution of the p55 antigen (fascin), wh ich is selectively expressed by human blood and lymphoid DCs, was inve stigated by immunohistochemistry. Results. Our study demonstrates that p55-positive DCs are absent from the normal human kidney and CD1a- an d S100-positive cells are absent or very rare. Furthermore, HLA-DR and factor VIII-related antigen show almost complete colocalization in ca pillaries. In contrast, all 16 kidney biopsies from patients with infl ammatory processes demonstrated p55-positive DCs in the cellular infil trates. Conclusions. These results suggest that DCs are not present or are very rare in normal renal tissues but may migrate into the renal interstitium with inflammatory changes.