A team of researchers from two Flemish institutions have developed a simple urine test that can predict the possibility that a kidney transplant recipient might reject their new organ.
The development involved researchers from the university of Leuven and the Flemish Institute for Technological Research (VITO).
Around 500 Belgians every year undergo a kidney transplant because of kidney failure. The transplant is one of the most successful carried out anywhere, and can even be carried out in a chain. For example, a wife receives a kidney from her husband, who then gets a donor kidney from someone else to supplement the one he has left.
Nonetheless, in fewer than one in three patients, the host body rejects the transplant. The most usual cause is ABMR – antibody-mediated rejection – where the immune system of the recipient refuses to accept the graft.
Normally, if the patient develops symptoms of rejection, the situation can only be monitored by taking a kidney biopsy – a sample of renal cells – which is an invasive procedure involving discomfort and inconvenience.
Most new transplant patients have to undergo the procedure two or three times a year, and the risk is that they may have to go back onto dialysis, with all of the change of lifestyle that entails.
But now the VITO/KULeuven team – working together with three other European teams – have developed a simple urine test that allows them to measure the presence in the urine of certain biomarkers which give an early and non-invasive indication of the likelihood of rejection.
“In recent years, thousands of proteins were screened in this way,” said Inge Mertens of VITO. “We did this both for transplant patients without complaints and for patients with complaints, distinguishing three types of rejection.”
The researchers were able to identify ten proteins that together provide a good indication of whether a kidney is being rejected – and at an early phase.
“This set of proteins gives us clear biomarkers for rejection, allowing us to detect this at an early stage by means of a simple urine test,” she said.
The hope now is that a test can be developed that will eventually be as quick and simple as a pregnancy test, and tests in the field could begin soon at the Gasthuisberg hospital in Leuven.
“It’s now a matter of making this urine test clinically available as soon as possible,” said Inge Mertens. "We want to be able to quickly convert the scientific results into a usable test. After that, we can get to the market introduction.”
The teams results are published in the journal Kidney International Reports.