Approximately 90% of 1000 recipients available for a pre-screening will be eligible for HLA antibody testing. In at least 10% (n≥90) of tested patients DSA detection can be expected (Lachmann, N et al. 2009). We estimate biopsy-based late AMR features in at least 60% of the DSA-positive patients (Hidalgo, LG et al. 2009). Hence, at least 50 patients will be eligible for inclusion into Part B, the randomized controlled trial.