Test Code ALLOS AlloSure
Performing Laboratory
Care Dx
Useful For
AlloSure is a donor-derived cell-free DNA (dd-cfDNA) test for noninvasive transplant surveillance, providing a direct measure of organ injury. Cell-free DNA is fragmented DNA originating from cells and continuously released into the bloodstream. AlloSure Kidney measures cfDNA, and uses single nucleotide polymorphisms (SNPs) to distinguish between donor and recipient. AlloSure can quantify increasing levels of dd-cfDNA, serving as a leading indicator of graft injury
Method Name
Cell free DNA
Reference Values
Establishing a baseline AlloSure reading allows comparison against subsequent tests. The study conducted by Bromberg, et al. established a 61% reference value (RCV) for AlloSure8
- A serial increase in AlloSure up to 61% may be attributed to normal biological variation
- A serial increase in AlloSure greater than 61% exceeds expected biological variation
Preferred Container
Kit collection, tiger top STRECK tubes
Minimum Volume
10 ML
Specimen Collection and Handling
- Collect 10 mL of blood into each of the Streck tubes. The minimum blood volume for the tube is 10 mL. Tubes containing less than 10 mL of blood are not acceptable for AlloSure testing and will not be processed.
- Gently invert the tube at least 10 times to fully mix the blood with anticoagulant.
Specimen Stability Information
Ship the specimen as soon as possible following the Specimen Shipping Procedure. If you cannot ship the specimens immediately, hold specimens between 6 °C and 37 °C. Do not refrigerate or freeze. Specimens must arrive at CareDx with 7 days of drawing
Performing Laboratory Location
CareDx, Inc.
3260 Bayshore Boulevard
Brisbane, CA 94005, USA
Tel 415 287 2401
Fax415 287 2456
www.caredx.com
Clinical Significance
The AlloSure test is intended to assess the probability of allograft rejection in kidney transplant recipients with clinical suspicion of rejection and to inform clinical decision-making about the necessity of renal biopsy in such patients at least two weeks post-transplant in conjunction with standard clinical assessment.AlloSure is indicated for use in renal transplant patients who are 18 years of age or older and at least 2 weeks (14 days) post-transplant. Clinical validity of the AlloSure test was established in single-kidney transplant recipients who were 18 years of age or older and at least two weeks post-transplant.The AlloSure test is a clinical-grade, targeted, next generation sequencing (NGS) assay that measures single-nucleotide polymorphisms (SNPs) to accurately quantify donor-derived cell-free DNA (dd-cfDNA) in renal transplant recipients without separate genotyping of either the donor or the recipient. The assay quantifies the fraction of dd-cfDNA in both unrelated and related donor-recipient pairs. Blood is collected from the patient, packaged, and shipped at ambient temperature to CareDx for testing. dd-cfDNA is measured via targeted amplification and sequencing of a set of carefully selected and validated SNPs. The AlloSure bioinformatics software calculates the percent dd-cfDNA in the sample tested and applies the QC cut-off values. Most AlloSure test results are reported to the ordering physician within 3 days from blood specimen collection.
CPT
81479