Structural changes in the tubular epithelium of allografted human kidneys after transplantation

Abstract

The structure of allografted cadaveric human kidneys (AK) was studied between 4 months and 6 years after transplantation. In AK which kept on functioning well until death of the patients from causes unconnected with failure of the grafts, a weak cellular immune response and moderate sclerosis of the intertubular connective tissue were observed. Cytological reconstruction of the epithelium of the proximal tubules consisted of the formation of numerous polykaryocytes with a hypertrophied brush border. This phenomenon (“proximal polykaryocytosis”) is interpreted as a manifestation of the regenerative powers of the epithelium of the proximal tubules of AK in the late stages after transplantation. Chronic moderate hypoxia of AK is a favorable factor for reconstruction of the epithelium of the proximal portion of the nephron. In AK with unsatisfactory function associated with the development of chronic rejection, not responding to treatment, an intensive cellular immune response was observed, with the development of coarse sclerosis, resulting in atrophy of most of the tubules of AK.