Correlation of Donor-Specific Antibodies, Complement and Its Regulators with Graft Dysfunction in Cardiac Antibody-Mediated Rejection

Abstract

Antibody-mediated rejection (AMR) is an immunopathologic process in which activation of complement often results in allograft injury. This study correlates C4d and C3d with HLA serology and graft function as diagnostic criteria for AMR. Immunofluorescence staining for C4d and C3d was performed on 1511 biopsies from 330 patients as part of routine diagnostic work-up of rejection. Donor-specific antibodies were detected in 95% of those with C4d+C3d+ biopsies versus 35% in the C4d+C3d-group (p = 0.002). Allograft dysfunction was present in 84% in the C4d+ C3d+ group versus 5% in the C4d+C3d− group (p < 0.0001). Combined C4d and C3d positivity had a sensitivity of 100% and specificity of 99% for the pathologic diagnosis of AMR and a mortality of 37%. Since activation of complement does not always result in allograft dysfunction, we correlated the expression pattern of the complement regulators CD55 and CD59 in patients with and without complement deposition. The proportion of patients with CD55 and/or CD59 staining was highest in C4d+C3d− patients without allograft dysfunction (p = 0.03). We conclude that a panel of C4d and C3d is diagnostically more useful than C4d alone in the evaluation of AMR. CD55 and CD59 may play a protective role in patients with evidence of complement activation.

Antibody-Mediated Rejection in Cardiac Transplantation: Emerging Knowledge in Diagnosis and Management

“…35 The combination of C4d and C3d detected by immunofluorescence predicts graft dysfunction and mortality better than C4d alone. 47 Because C3d staining of arterioles may be seen in Immunoglobulin binding and complement activation are regulated in vivo by complement inhibitors. Two such regulators, CD59 and CD55 (decay accelerating factor), are used in conjunction with C4d and C3d to indicate aborted complement activation.…”

Inflammation in Myocardial Diseases

“…187 A more recent study has also shown that immunofluorescence staining of C3 days, together with C4 days, can strongly and positively correlate with the presence of donor-specific alloantibodies, as well as allograft dysfunction in transplant recipients. 188 Clinically, the presence and accumulation of C4 days in the allograft vasculature has been adopted as a key criteria to support the diagnosis of AMR. 159 …”

Pathologic diagnosis of antibody-mediated rejection in endomyocardial biopsy after heart transplantation based on renewed International Society for Heart and Lung Transplantation criteria

“…Primary antibody panel for frozen section IF comprises C4d and, C3d and anti-HLA-DR while optional panel includes fibrin, immunoglobulin G and M and others depending on individual centers' preferences [9]. Long-lasting complement split product C3d has been well reported in frozen IF studies [31,32] but experience in paraffin IHC has been limited and further studies are needed. Therefore, it was proposed as optional staining in paraffin section IHC and primary staining in frozen section IF.…”