Thank you, Frankbj. The case you posted is great. The immunohistochemical stain for C4d is not easy to interpret. If your interpretation is "positive in peritubular capillaries", I favor the diagnosis of "suggestive of acute antibody-mediated rejection, type 2 or 3 (?).  There is early endoarteritis, not a true v3 lesion. I don't see thrombosis (what about in the #1 photo?). Please let us know your final diagnosis and your patient's response to the treatment.

移植肾急性抗体介导性排斥反应II级（血管内皮炎性细胞淤积，微血栓栓塞，C4d+）,伴肾组织内局灶性出血，较多肾小管坏死。

学习了