Information obtained from noninvasive urine testing can distinguish between common causes of renal dysfunction in kidney graft recipients, investigators reported in Journal of the American Society of Nephrology.
The method described could reduce the number of biopsies performed in patients with acute dysfunction of the kidney allograft.
As Thangamani Muthukumar, MD, of Weill Medical College of Cornell University in New York, and associates noted in their paper, noninvasive tests to differentiate the basis for acute dysfunction of the kidney allograft are preferable to invasive allograft biopsies. The group sought to determine whether the differential diagnosis of acute graft dysfunction is feasible using urinary cell messenger RNA (mRNA) profiles.
To accomplish this, Dr. Muthukumar’s team measured absolute levels of 26 pre-specified mRNAs in urine samples collected from persons who had received a kidney. Profiled were 52 urine samples from 52 patients with biopsy specimens indicating acute rejection and 32 urine samples from 32 patients with acute tubular injury without acute rejection.
“Using statistical methods, we have combined the mRNAs to yield a diagnostic signature,” Dr. Muthukumar said in a statement issued by the American Society of Nephrology. “Our study shows that when the creatinine level is elevated in the blood of a kidney transplant recipient, use of our urine test would differentiate the common causes of kidney dysfunction that led to the elevation in creatinine, hence benefiting many patients by allowing them to avoid the need for an invasive needle biopsy.”