Abstract 12356: The Effect of Mechanical Circulatory Support on Cardiac Antibody-Mediated Rejection With Regard to C3d and C4d Depositions
Introduction: Due to the shortage of donor organs, mechanical circulatory support systems (MCS) are now widely used as a treatment option to bridge the failing heart to transplantation. It has been observed that MCS patients show a higher frequency of antibody-mediated rejection (AMR) episodes. These are thought to represent an immune reaction directed against the device in terms of allosensitation.
Hypothesis: Capillary C4d depositions are required to diagnose AMR in cardiac allografts. In this regard the role of C3d is still being considered.
We aimed to analyze the effects of MCS on cardiac AMR with regards to capillary C3d and C4d depositions.
Methods: We evaluated all consecutive right ventricular endomyocardial biopsies (EMBs) of cardiac allografts taken between 01/2011 and 12/2012 (254 patients). With regard to pre-transplant MCS treatment, patients were divided into two groups (MCS group n=82 patients, non-MCS group n=138 patients). Patients were excluded from the analysis if they had an MCS system that was used in fewer than five of the study population patients.
Conventional histology (hematoxylin-eosin stained slides) and immunohistochemical stains were used on formalin-fixed paraffin-embedded tissue sections (FFPE) to evaluate the EMBs regarding AMR (complements C3d and C4d). Fisher’s exact test was performed to analyze the relationship between C4d and C3d in both patient groups. The Cochran-Mantel-Haenzsel test was applied to assess significance of the differences in interactions between groups.
Results: In the study population as a whole there is a positive correlation between C3d and C4d (p=0.007), with 64% concordant cases (107 negative and 33 positive out of 220 in total). Analyzing the two groups separately a significant C3d/C4d correlation was found only for the MCS group (p=0.002, odds ratio=4.185, non-MCS group p=0.418, odds ratio=1.392).
Conclusion: Only in patients with pre-transplant MCS does C3d correlate with capillary C4d depositions. This circumstance may beneficially complement existing diagnostic criteria for AMR.
Author Disclosures: K. Wassilew: None. E. Potapov: None. D. Kemper: None. R. Hetzer: None.
- © 2014 by American Heart Association, Inc.