Blood Test Predicts Signs of Acute Rejection in Kidney Transplants

UCSF News reports on research led by Minnie Sarwal, MD, PhD, Director of the Sarwal Lab, in developing a  test for diagnosing and predicting acute rejection (AR) in kidney transplants, a finding that eventually could replace the need for biopsies and lead to earlier detection of AR and treatment.

'We have found a set of genes in blood that pick up inflammation and acute rejection in different solid organ transplants and thus can replace the need for an invasive biopsy in the future,' said senior author Minnie Sarwal, MD, PhD, Professor of Transplant Surgery at UCSF. 'This assay also predicts the onset of histological rejection by three to four months, meaning graft inflammation can be treated early and proactively, even reversed.'

'This is the first assay of its kind that can provide a sensitive readout of very early rejection and inflammation in the organ, which cannot be picked up by any other blood test on the market,' Sarwal continued. 'The result is improved graft function and survival.'

All organ transplant recipients have some amount of acute rejection (AR). In extreme cases, the donated organ can be injured or even fail, resulting in costly treatments and diminished quality of life.

Occurring in 15-20 percent of kidney transplant recipients, AR is detected by an invasive biopsy after a drift in the patient’s serum creatinine, then treated with immunosuppressive medications. However, this drift is not specific for AR and occurs only after substantial organ damage, and some patients can contract AR without a drift.

To improve disease diagnosis and patient monitoring, scientists are working on noninvasive molecular assays in several clinical areas. In this PLOS Medicine study, Sarwal and her international study team sought to create a 'kidney solid organ response test' (kSORT) using a simple blood gene expression assay that would detect patients at risk for AR.

Other UCSF Department of Surgery contributors to the study were Silke Roedder, Pharm.D., PhD (former Assistant Research Scientist in the Sarwal Lab), Tara Sigdel, PhD of the Sarwal Lab (pictured below), Flavio Vincenti, MD, and Nancy Ascher, MD, PhD.