Comparative study for the detection of C4d in paraffin-embedded renal allograft biopsies by immunohistochemical techniques.

Background: Peritubular capillary complement C4d deposition is one of the criteria for diagnosis of acute humoral rejection in kidney allografts. Little information is provided for the effective technique to stain C4d protein.

Objective: To compare C4d staining results by using indirect immunofluorescence detection (IF) with immunoperoxidase methods (IP) in formalin-fixed, paraffin-embedded renal allograft tissue.