Finally a blood-based alternative to surveillance biopsies for kidney transplant recipients
The Facts About Silent Subclinical Rejection
~25% of stable kidney transplant patients are silently rejecting(1)
~35% of patients experienced silent rejection in the first 2 years(2)
On surveillance biopsy, graft tissue from ~80% of stable patients with silent rejection is classified as “borderline”(1)
What is Silent Subclinical Rejection?
After kidney transplant, clinically unsuspected subclinical acute rejection or (subAR), defined as the presence of histological lesions, indistinguishable from acute rejection in stable transplanted kidneys, occurs in 20% to 25% of patients in the first 12 to 24 months.
Subclinical Acute Rejection is associated with post-transplant complications such as:
- de novo donor specific antibody (dnDSA) formation
- interstitial fibrosis/tubular atrophy (IFTA)
- chronic rejection
- graft loss
Serum creatinine and immunosuppression levels, used almost exclusively to monitor kidney transplant recipients, are both insensitive and nonspecific. Surveillance biopsies can be used to monitor patients with stable renal function, but biopsies are invasive and associated with sampling error and there is a lack of consensus around both histologic interpretation (especially for “borderline changes”) and the effectiveness of treatment. Moreover, the vast majority (75%‐80%) of surveillance biopsy specimens show normal histology (ie, the absence of subAR) and, therefore, expose patients to unnecessary biopsy risks. As a result, the current standard of care in monitoring patients after kidney transplant ranges from not using surveillance biopsies at all, to using them selectively in “high–immunologic risk” patients, to routine use in all patients.
Subclinical Acute Rejection Is Not Clinical Acute Rejection.
After a patient received a transplanted kidney and begins immunosuppressive therapy, their clinician quickly begins to try to reduce immunosuppressive dosing in an effort to enable the patient to remain on the lowest dosage possible, without rejection. However, rejection is a common occurrence in kidney transplant recipients occurring in two types:
- Clinical Acute Rejection (cAR) occurs in 10%-15% of kidney transplant recipients in the first year post transplant. Usually indicated by a rise in serum creatine over baseline and determined by a for-cause biopsy. It is usually alleviated with a change in immunosuppressive therapy.
- Subclinical Acute Rejection (subAR) occurs in 25% of patients with stable serum creatine in the first 2 years post- transplant. It can be referred to as silent rejection because it often goes undetected. The only way to identify subAR is through a surveillance biopsy. However only 22% of transplant center in the U.S. employ a surveillance biopsy program. Recent publications have demonstrated that if untreated, subAR can lead to interstitial fibrosis/tubular atrophy (IFTA), chronic rejection and loss of graft.
What is TruGraf®?
The TruGraf® test is intended for use in kidney transplant recipients with stable renal function as an alternative to surveillance biopsies to rule out “silent” subclinical rejection. It is the only test reimbursed as an alternative to a surveillance biopsy and the only test clinically validated with histologically confirmed samples to rule out subAR. TruGraf has a proven clinical performance demonstrating greater than 91% Negative Predictive value for ruling out subAR.
It is a minimally invasive blood-based test that by measure RNA gene expression in a patients sample, can determine if a patient is adequately immunosuppressed, ruling out subclinical acute rejection.
Unlike tests that confirm rejection or active rejection in patient with elevated serum creatinine, damage has already occurred to the transplanted kidney. TruGraf® is used on patient with stable, renal function, before graft damage occurs.
Speak to your clinician about TruGraf® testing.
Your doctor can contact Transplant Genomics- Eurofins and complete a patient requisition form. A TruGraf® blood collection kit and completed requisition form will be mailed to your home or you can pick one up at your transplant center. You can then go to your transplant center or a Quest or LabCorp patient service center near you, just as you do for all your other routine blood work. After your blood is drawn the kit is mailed to TGI’s certified lab, the sample is analyzed, and a report sent to your doctor for review.
How Does TruGraf® Work?
The TruGraf® test is a minimally-invasive test that measures differentially expressed genes in the blood of kidney transplant recipients to identify patients who are likely to be adequately immunosuppressed. TruGraf® uses RNA microarray technology to determine whether a patient’s blood gene expression profile is more similar to that obtained from a reference population classified by simultaneous histological analysis of a biopsy as Transplant eXcellence (TX), and likely adequately immunosuppressed, or not-TX, and likely to be inadequately immunosuppressed.
How Does TruGraf® Benefit You?
Patients benefit by gaining peace of mind in the knowledge that their graft is doing well, or that their physician has been able to intervene earlier, and without having to perform a painful invasive biopsy, to make a more fully informed treatment decision. Serial monitoring with TruGraf® could also results in a patient’s ability to keep their graft longer while utilizing lower and safer doses of immunosuppressive therapy.
How Does TruGraf® Help My Doctor Make Better Decisions?
TruGraf® results inform a clinician if a patient with stable renal function (normal serum creatinine results) is adequately immunosuppressed (classified as TX for Transplant eXcellence) or inadequately immunosuppressed (classified as Not-TX). Considered in the context of the other clinical information available, a TruGraf® result may be critical in supporting a physician decision regarding:
- As an alternative or complement to surveillance biopsies to rule-out presence of subAR
- Serially monitoring patients with any desired frequency, 24/7/365 to get more information regarding the health of your graft
- Provide support for decisions to minimize immunosuppression
- Revealing whether treatment for rejection has been successful without performing a biopsy
- Enabling early intervention, possibly improve long term patient outcomes
Is TruGraf® Covered by Insurance?
TruGraf® CPT Code: 81479 will be reimbursed for kidney transplant patients covered by Medicare across the United States starting November 25, 2019.