After renal transplantation, allograft rejection is a major risk factor for the development of chronic allograft deterioration and reduction in long-term graft survival. Up to 50% of all rejection episodes occur subclinically without changes in standard parameters such as creatinine or blood urea nitrogen. Some authors suggest protocol biopsies at fixed time points after transplantation to diagnose AR, to improve transplant outcomes. However, core needle biopsies are invasive and may be associated with severe complications. Moreover, sampling errors and variability in biopsy analysis confound conclusions about graft health. Finally, repeated biopsies are cumbersome for the patient and cause considerable expense. Thus, noninvasive screening methods might be superior. We develop different strategies for evaluation of transplant vasculitis as a surrogate of renal allograft rejection.

We aim to non-invasively specifically and early a) diagnose acute transplant rejection, to b) evaluate graft prognosis, and to c) assess graft function.