Light microscopy showing antibody-mediated rejection in kidney transplant biopsy, ATN, and polymorphonuclear leukocytes

Numerous interstitial polymorphonuclear leukocytes (PMNs) and extensive acute tubular necrosis are evident in this kidney transplant biopsy. Histologic findings in antibody-mediated rejection may include PMN infiltration. This specimen also demonstrated positive C4d staining on immunofluorescence.