There is diffuse tubular dilatation, suggestive of acute tubular injury. Given the positive C4d stain in the peritubular capillaries, this may result from acute antibody-mediated rejection (type 1).  What about patient's donor specific antibody (DSA)?

There is also tubulitis along with interstitial mononuclear cell infiltration in photo 5-7). So concurrent acute T-cell mediated rejection is likely.

Photo 2 shows isometric vacuolization of tubular epithelium, suggestive of acute drug toxicity.

Thank you for posting this interesting case. The C4d stain is so impressive.