The development and clinical validation of the test used patient samples and clinical data obtained during the Cardiac Allograft Rejection Gene Expression Observational (CARGO) Study. From 2001 to 2005, 737 patients from nine U.S. transplant centers enrolled in the Study and contributed 5,834 blood samples and associated clinical data.<ref name="Deng"/> Initial clinical experience at three medical centers was published in 2006, confirming the efficacy and performance of the test.<ref name="Starling"/>
== Indications for use ==
The test is currently indicated for use in heart transplant recipients 15 years of age or older, and at least 2 months (≥55 days) post-transplant.
== Method of use ==
The test is based on standard quantitative [[real-time polymerase chain reaction]] technology (qRT-PCR) using RNA isolated from peripheral blood mononuclear cells (PBMC). A blood sample is collected, PBMC are isolated, lysed and the released RNA stabilized and frozen (PBMC lysate). RNA is then purified from the PBMC lysate, converted into complementary DNA (cDNA), and mixed with gene-specific primers and probes. The expression of each gene is measured by amplification and fluorescence detection using a qRT-PCR instrument. A mathematical classifier combines the measured expression values for each gene into a single value reported as a score between 0 and 40.
Each score is associated with a [[negative predictive value]] (NPV) and a [[positive predictive value]] (PPV). The test is characterized by high negative predictive values and is therefore a test used to help identify patients at low probability of rejection. The test has a relatively low positive predictive value, meaning that even when the score is relatively high, the risk of rejection may still be low.
== References==
Line 31 ⟶ 23:
== External links ==
* [http://www.allomap.com/ Official Product Website]
