Utility of C4d immunostaining in the first year after pediatric and young adult heart transplantation

Acute Cellular Rejection and C4d Positivity in Heart Transplantation : A Manifestation of Asymptomatic Antibody-Mediated Rejection?

OBJECTIVES

The role of routine C4d staining in endomyocardial biopsy specimens is uncertain. The implications of a diagnosis of acute cellular rejection (ACR) with a positive C4d with or without any evidence of antibody-mediated rejection (AMR) are unclear. This study sought to evaluate a distinct phenotype of ACR+/C4d+ in AMR- patients.

METHODS

Data on C4d, ACR, and AMR were collected. Donor-specific antibody (DSA), panel-reactive antibody (PRA), flow crossmatch, and data on ACR and AMR episodes were also reviewed.

RESULTS

Thirty-five patients were followed. Group I with C4d+ biopsy specimens was compared with group II with C4d- biopsy specimens. ACR greater than 1R was higher in group I compared with group II (50% vs 7.4%; P = .01). Clinical suspicion of AMR, positive retrospective crossmatches, and detection of de novo DSA were also higher in group I.

CONCLUSIONS

Our result indicate that C4d and ACR positivity in posttransplant patients may be a harbinger of a subclinical form of asymptomatic AMR.

The state of the art in heart transplantation

Cardiac transplantation is in its fourth decade as a treatment for end-stage cardiomyopathy and heart failure. It has reached a mature stage in its development as an effective treatment and many issues are settled with respect to best practices. However, there are many areas of ongoing research and significant advances that are continually being recognized. What constitutes 'State of the Art' in heart transplantation? This review focuses on developments in the pretransplant, peritransplant, and posttransplant phases of the care of the potential heart transplant recipient.