Fig. 1
From: Developing renal allograft surveillance strategies – urinary biomarkers of cellular rejection

Non-invasive screening for subclinical rejection. Ideally, when a non-invasive biomarker is negative, we can exclude an inflammatory process with high confidence and a surveillance biopsy can be safely omitted. Alternatively, if the non-invasive screening biomarker is positive, an allograft biopsy can be performed to confirm rejection