Analytical and Clinical Validation of a Molecular Diagnostic Signature in Kidney Transplant Recipients

Autor: Terri Gelbart, Michael Abecassis, John J. Friedewald, Deirdre Pierry, Martin Roy First, Sunil M. Kurian, Thomas Whisenant, Nadia Bayat, Stan Rose, Michael McNulty, Darren Lee, April Venzon, Peter Lewis
Rok vydání: 2017
Předmět:
Zdroj: Journal of Transplantation Technologies & Research.
ISSN: 2161-0991
Popis: Context: The TruGraf test is a blood-based assay that provides non-invasive, accurate assessment of adequacy of immunosuppression in kidney transplant recipients. TruGraf relies on gene-expression “signatures” that differentiate a state of Transplant eXcellence (TX, indicating adequately immunosuppressed) from not-TX. Objective: To evaluate the performance of the TruGraf test. Design: Analytical performance studies to characterize stability of RNA in blood during collection and shipment, analytical sensitivity (input RNA concentration), analytical specificity (interfering substances) and assay performance (clinical validity, and intra-assay, inter-assay, inter-laboratory reproducibility). Results: Total RNA extracted from whole blood specimens collected in PAXgene Blood RNA tubes was stable up to 3 days at room temperature (stable RNA yield). Under routine ambient shipping conditions, storage and shipping temperatures did not affect results. However, specimen shipments exposed to temperatures >400°C or to ambient temperatures for >3 days were unacceptable for processing. Analytical sensitivity studies demonstrated tolerance to variation in RNA input (50 to 400 ng per 3’ IVT (in vitro transcript] labeling reaction). Specificity studies using genomic DNA spiked into 3 ’IVT reactions at 10-20% demonstrated negligible assay interference. The test was reproducible across operators, runs, reagent lots, and laboratories. External validation demonstrated that the TruGraf blood test accurately classified patients in 72% of 295 samples. Conclusions: Analytical sensitivity, analytical specificity, robustness, quality control, and clinical validity of the TruGraf blood test were successfully verified, indicating its suitability for clinical use.
Databáze: OpenAIRE