Thank you for posting this interesting case.

The tubules shows diffuse simplification, suggesting acute injury. There are intratubular calcifications (photo 1, 2, 8) and tubular isometric vacuolization (photo 6).  These changes are highly suggestive of acute drug toxicity.

The photo 7 demonstrates interstitial mononuclear cell infiltration and tubulitis. These changes are not specific for the rejection. The degree of infiltration and tubulitis is important. Sometimes it is difficult to interpret because any of tubulointerstitial processes, such as acute drug toxicity or interstitial nephritis, may have the similar morphology.

The artery and glomerulus appear unremarkable.

 考虑为:

1移植肾轻度急性药物毒性损伤（mild acute drug nephrotoxicity injury）;

2疑为急性排斥反应（suspicious of acute rejection, Banff 2005 Schema, i1,t1,v0,g0,ah0,mm0）（C4d免疫组织化学染色呈阴性。）