Kidney transplants are followed by a challenging, lifelong regimen of medications to offset rejection and the damage that those immunosuppressive drugs cause the body. The only way to assess organ rejection is with invasive procedures such as biopsies.
Invitrogen, part of Life Technologies (Carlsbad, California), has launched a new biomarker tool for use in preclinical research into kidney function. The PlexMark 3 Renal Biomarker Panel Assay provides a non-invasive mechanism to assess kidney function post-transplantation.
"Biopsy is performed to provide a pathological confirmation when injury is suspected," Beth Button, director of Transplantation Diagnostics at Life Technologies (Carlsbad, California), told Medical Device Daily. "Many centers do not routinely perform biopsies and will only perform them when current tests indicate an issue. Currently there is no good test available to provide this indication. Serum creatine is performed but lacks sensitivity and specificity. What this means is a patient's serum creatinine can increase for many reasons and not specific to the kidney transplant. Also, serum creatinine will show a delayed increase or decrease in relation to the kidney injury process or treatment regimen effects."
Invitrogen's new assay is expected to assist in the development of studies which may lead to more effective methods used to monitor kidney health in transplant research.
The assay is designed to help researchers in the development of studies using urine biomarkers and tracking therapies early in the course of rejection to understand mechanisms to improve renal graft mortality.
Button said, "Transplant researchers are currently conducting studies and preliminary data shows IP-10 and MIG sheds and can be identified in the urine, early in the injury process and specific to the kidney damage. The potential is a physician will have an early indicator to intervene and conduct appropriate viral assays and biopsy to confirm rejection."
She added that the new assay is more sensitive and specific than serum creatinine. "It's equivalent to Cylex, which is an immunotherapy level test, but far less than a biopsy."
The assay measures levels of cytokines, chemokines and receptor levels in urine, which enable researchers to better understand immune function and response.
Button said the assay uses Luminex xMAP, multiplexing technology for bioassay analysis, in a standard immunoassay.
The biomarkers in the PlexMark panel assay are licensed from Renovar (Appleton, Wisconsin).
Button said that Life Technologies will begin a clinical trial by the end of 2009 in an effort to obtain in vitro diagnostic approval from the FDA. For now, it's available globally for research use only.
"Researchers are currently gathering data to support the specificity and early indications," she said.
"Development of a non-invasive test that could help differentiate between acute renal injury, rejection and infection would satisfy a critical unmet need in transplantation," said Brian Shames, MD, assistant professor of surgery, Division of Transplant Surgery, Medical College of Wisconsin (Milwaukee). "A biomarker test that can accomplish this would be of extreme importance in pre-clinical kidney transplantation research." n
Lynn Yoffee, 770-361-4789; lynn.yoffee@ahcmedia.com