Call for revolution: a new approach to describing allograft deterioration.

I propose a set of definable entities in the renal transplant course, eliminating the need for the term 'chronic rejection'. The status of a renal transplant can be defined by the presence and extent of rejection (T-cell-mediated or antibody-mediated); allograft nephropathy (parenchymal atrophy, fibrosis, and fibrous intimal thickening in arteries); transplant glomerulopathy; specific diseases; and factors which could accelerate progression. The level of function and the slope of the loss of function should be separately determined. This approach can be applied both in research and in clinical practice, and can be adapted to other organ transplants.