A breakthrough non-invasive test can detect whether transplanted kidneys are in the process of being rejected, as well as identify patients at risk for rejection weeks to months before they show symptoms, according to a study published in The New England Journal of Medicine.
By measuring just three genetic molecules in a urine sample, the test accurately diagnoses acute rejection of kidney transplants, according to the study's lead author, Manikkam Suthanthiran, MD, Stanton Griffis Distinguished Professor of Medicine at Weill Cornell Medical College.
He and his colleagues found that increased expression of three mRNAs can determine if an organ will be, or is being, rejected. The mRNAs (18S ribosomal (rRNA)–normalized CD3e mRNA, 18S rRNA–normalized interferon-inducible protein 10 [IP-10] mRNA, and 18S rRNA) indicate that killer T immune cells are being recruited to the kidney in order to destroy what the body has come to recognize as alien tissue.
The signature test consists of adding levels of the three mRNAs in urine into a composite score. Tracked over time, a rising score can indicate heightened immune system activity against a transplanted kidney, Dr. Suthanthiran says. A score that stays the same suggests that the patient is not at risk for rejection.
The test may help physicians fine-tune the amount of powerful immunosuppressive drugs that organ transplant patients must take for the rest of their lives, says Dr. Suthanthiran, whose laboratory developed what he calls the “three-gene signature” of the health of transplanted kidney organs. Read the article preview.