Diagnosis of Acute Rejection in Renal Transplant Patients by Urine Mass Spectrometry

Reliable and timely detection of acute rejections in renal transplant patients is important to preserve the graft function and to prevent premature graft failure. The current gold standard for the rejection diagnosis is a renal biopsy which is usually performed upon an unexplained decline in the graft function (determined by serum creatinine or clearance). Because of the insensitivity of creatinine determinations and the invasiveness of renal biopsies, non-invasive tests have been suggested to diagnose acute rejection including mass spectrometry (MS) analysis of urine samples.

The ability of MS analysis to detect acute rejection has been demonstrated in small studies on selected patients but evidence is lacking that this test is efficacious in the routine setting of the post-transplant patient care. Based on our previous work that established urine peptide sets for acute rejection by MS, a prospective, multicentre diagnostic phase III study will be executed.

The aim of the study is to prove that this test is as equally effective as the allograft biopsy to detect acute rejection in patients that undergo a biopsy for unexplained renal dysfunction. The perspective of this approach is that the test could be used either in place of the biopsy or as decision guidance whether a biopsy is necessary to confirm the presence of rejection. Another perspective is that the MS test (respectively, a simplified test system derived from this method) could be used in the regular post-transplant surveillance for acute rejection, in place of the relatively insensitive procedure with periodic monitoring of the graft function by creatinine determinations.