Lack of Impact of Presence of Positive C4d Staining in Capillaries in Myocardial Biopsies on Long-term Survival of Heart Transplant Patients

Background. The long-term survival of 209 consecutive patients (mean age, 46 +/- 15 years) from a single center with >= 1 diagnostic myocardial biopsy after heart transplantation was analyzed. Methods. Patients were considered as C4d positive if a capillary staining (immunohistochemistry in paraffin samples) was observed in >= 1 myocardial biopsy. Data were analyzed according to pathologic consensus of antibody mediated rejection definition of C4d+ positivity: 2004 definition in group A and the 2013 definition in group B and compared with their respective controls, composed of patients who do not meet those criteria. Age, follow-up time, and number of biopsies were comparable between patients with C4d+ and controls in both groups. Follow-up was 100% complete with mean of observation time 2143 days. Results. During the follow-up period, 62 patients died (group A: C4d+ 32% vs controls 29%; group B: C4d+ 36% vs controls 29% [P = NS]). There were no differences in survival between patients with positive staining and without C4d+ staining when Kaplan-Meier survival curves were compared. Conclusions. The presence of C4d positive staining in myocardial capillaries of heart biopsies of patients after heart transplantation, as an isolated finding, was not related to worse long-term survival.