Cell-free DNA and genetic testing company Natera Inc (NASDAQ: NTRA) announced on Monday that it has introduced the Prospera Heart test with Donor Quantity Score (DQS), improving the detection of rejection in heart transplant patients. This new feature enhances the ability to detect both acute cellular rejection (ACR) and antibody-mediated rejection (AMR).

Traditional donor-derived cell-free DNA (dd-cfDNA) tests rely on the percentage of dd-cfDNA in the blood, which can be affected by unrelated factors like infection or chemotherapy. The new DQS technique normalises these fluctuations by incorporating a second metric. Prospera Heart with DQS combines the traditional donor fraction and the DQS into a two-threshold algorithm, providing a more accurate risk assessment.

A study conducted at the University of Utah and the University of California San Diego demonstrated that incorporating DQS improves the performance of Prospera Heart in screening for biopsy-proven active rejection. In an analysis of 703 plasma samples, the sensitivity increased from 80.0% to 88.2%, specificity from 76.1% to 84.2%, and the negative predictive value (NPV) from 97.4% to 98.6%, reducing false positives by 37.5%.

These findings were presented at the International Society for Heart and Lung Transplantation's annual meeting in April 2024 and will be submitted for peer-reviewed publication.

The company has successfully applied a similar two-threshold approach in kidney transplant rejection tests with Prospera Kidney, published in the Journal of the American Society of Nephrology. The Prospera tests use single-nucleotide (SNP)-based massively multiplexed PCR (mmPCR) technology to identify allograft rejection non-invasively, without needing prior donor or recipient genotyping.

Natera focuses on oncology, women's health and organ health. The company operates ISO 13485-certified and CAP-accredited laboratories in Austin, Texas and San Carlos, California.