Clinical Significance Of Complement Split Product C4d Deposition In Peritubular Capillaries In Acute Renal Allograft Rejection

Objective: To explore the significance of peritubular capillary C4ddeposition in the diagnosis, treatment and prognosis of the patients withacute renal allograft rejection.Methods: 86 allograft biopsies obtained from 78 kidney transplants wereexamined by immunohistochemistry on routine paraffin sections usinganti-C4d polyclonal antibody. We analyzed the relationship of C4d andfunctions, histomorphologic features, therapies and prognoses ofallografts.Results: There were 32 allograft biopsies with Banff typeⅠrejection,51with Banff typeⅡrejection and 3 with Banff type Ⅲrejection.30biopsies were positive in C4d deposition. For 28 patients, at least onebiopsy exhibited peritubular C4d deposition. Evaluating peritubular C4ddeposition, we found no significant differences between typeⅠand typeⅡrejection types. The C4d+ group had proportionately more patients withhigh pane-reactive antibody levels, more patients with pregnant history,and more retransplanted patients. we found an association ofgranulocytes in PTC, glomeruli and interstitial hemorrhage with C4ddepsition, but not tubulitis, interstitial cell infiltration andendarteritis. Mean serum creatinine was significantly higher in C4dpositive patients than in negative patients(312.56±196.26μmol/L vs210.97±136.59μmol/L P=0.0115).Patients with C4d deposition weremore commonly resistant to antirejection therapy with bolus steroids andATG. More patients with peritubular C4d deposition lost their graftsduring the study period(64.3% vs 90.0% p=0.006).Conclusions: That 34.3% biopsies of acute rejection were found C4ddepositions in peritubular capillary, none were found in controls. Ourdata indicate that peritubular C4d deposition is associated withinferior graft outcome. Acute rejection with C4d deposition wereresistant to antirejection therapy with steroids and/or ATG. Acuterejection with C4d deposition are associated with granulocytes in PTC,glomeruli and interstitial hemorrhage with C4d deposition, but nottubulitis, interstitial cell infiltration and endarteritis. We found nosignificant differences between typeⅠand typeⅡrejection types.