Diagnose This! (April 17, 2017)
What is this stain and what does this finding mean in a transplant patient (Hint: It’s not a vascular marker).
This is a C4d immunoperoxidase stain showing diffuse positivity within the peritubular capillaries. While this can be a non-specific finding in ABO incompatible transplants, in ABO compatible transplants (the vast majority of transplants in the US) it suggests antibody-mediated rejection, especially when found in concert with other antibody-mediated changes such as microcirculation inflammation (glomerulitis, peritubular capillaritis), transplant glomerulopathy, peritubular capillary multilayering, and transplant arteriopathy.
Quick note: This post is to be used for informational purposes only and does not constitute medical or health advice. Each person should consult their own doctor with respect to matters referenced. Arkana Laboratories assumes no liability for actions taken in reliance upon the information contained herein.