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

In the first year after HTx, C4d+ occurred early and only in children and young adults with pre-transplant DSA or with clinical suspicion of AMR. Although our data suggest that assessment limited to the first 90 days post-transplant in patients with pre-transplant DSA≥4,000 MFI may be appropriate in the absence of clinical concern for AMR, further research is needed to determine the optimum strategy for post-transplant surveillance.