The significance of renal C4d staining in patients with BK viruria, viremia, and nephropathy.

Peritubular capillary C4d staining in allograft kidney is an important criterion for antibody-mediated rejection. Whether BK virus infection can result in complement activation is not known. We studied 113 renal allograft biopsies from 52 recipients with a history of BK virus activation.

Clinical significance of the distribution of C4d deposits in different anatomic compartments of the allograft kidney.

Diffuse C4d deposition in peritubular capillaries is a well-recognized marker of antibody-mediated rejection. The significance of staining patterns that are focal or affect non-peritubular capillary compartments is less well defined. Paired frozen section and paraffin-embedded tissue stains were performed in 52 kidney allograft biopsies, and correlated with clinicopathologic parameters.