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Test Name

AlloSure® Donor-Derived Cell-Free DNA Test CPT code: 81479

Intended Use

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.

Indications for Use

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.

Summary and Explanation of the Test

Principle of the Test

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.