Immunohistochemical study of actin binding protein (p55) in the human kidney.

Background. In clinical transplantation, passenger dendritic cells (DCs) in the allograft have been thought to induce allograft rejection. However, the presence of DCs in the normal human kidney is controversial. Most reports have relied on the examination of MHC class I and II antigen expression in combination with DC morphology for identification of DCs. Methods. The distribution of the p55 antigen (fascin), which is selectively expressed by human blood and lymphoid DCs, was investigated by immunohistochemistry. Results. Our study demonstrates that p55-positive DCs are absent from the normal human kidney and CDla- and S100-positive cells are absent or very rare. Furthermore, HLA-DR and factor VIII-related antigen show almost complete colocalization in capillaries. In contrast, all 16 kidney biopsies from patients with inflammatory processes demonstrated p55-positive DCs in the cellular infiltrates. 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.