A preserved native kidney alters acute renal allograft rejection in the rat

In this study the effect of a native recipient kidney on acute rat renal allograft rejection is analysed. The authors performed a sequential daily analysis of allograft morphology and infiltration by macrophages and T cells in the presence and the absence of a recipient kidney. Several differences among both experimental groups were observed. Infiltrating macrophages and T cells in the allograft interstitium were more numerous in the presence than in the absence of a recipient kidney. The ratio of macrophages to T cells was 2:1 in the presence and 1:1 in the absence of a recipient kidney. Interstitial allograft infiltration started 1 day earlier in the presence of a contralateral kidney than in its absence. Graft necrosis occurred on day 6 and was complete in the presence of a native kidney. After total nephrectomy a patchy pattern of necrotic and viable tubules was observed from day 5 until the death of the animal. The diameter of monocytes in graft vessels increased only moderately in the presence of a recipient kidney but duplicated in its absence. The authors propose that in experimental renal transplantation contralateral nephrectomy should be performed according to a standardized schedule.