title: Clearance of C4d deposition after successful treatment of acute humoral rejection in follow-up biopsies: a report of three cases.
abstract: Acute humoral rejection (AHR) is currently perceived as an immunological reaction against donor antigens mediated by complement-binding antibodies. C4d, a split product of complement activation and bound to endothelial cells of the peritubular capillaries, is used as a diagnostic marker for AHR. We report on three patients with biopsy-proven acute humoral rejection who were treated initially with plasmapheresis (PS). As two of the patients did not recover renal function, and biopsy showed persistent C4d staining after PS, immunoadsorption (IAS) was additionally performed on them. In all patients, renal function recovered, and follow-up biopsies in two patients showed complete disappearance of C4d, 29 days and 58 days after transplantation and only minimal residual C4d deposits in one patient 48 days after transplantation. We conclude that successful treatment of AHR is followed by complete resolution of serological and histological markers of AHR, displayed by the disappearance of C4d.
authors.affiliation: Department of Nephrology, University Hospital of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Koller
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Steurer
authors.forename: Walter
authors.initials: W
authors.lastname: Mark
authors.forename: Raimund
authors.initials: R
authors.lastname: Margreiter
authors.forename: Karl
authors.initials: K
authors.lastname: Lhotta
authors.forename: Gert
authors.initials: G
authors.lastname: Mayer
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Rosenkranz
mesh_terms: D000328:Adult; D001706:Biopsy; D015935:Complement C4b / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000276:immunology*; D006801:Humans; D007163:Immunosorbent Techniques; D016030:Kidney Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000378:metabolism*; D010956:Plasmapheresis
chemical_list: D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d