Of the 27 companies in the index, 14 firms' stocks were down, while 13 companies' share prices increased.
CareDx said it will add XynManagement's products to its digital solutions portfolio and integrate them with current offerings including OTTR.
The Medicare contractor has proposed to cover the non-invasive test for certain kidney and heart transplant patients.
The company reported $31.5 million in total revenues for the quarter and said testing services revenues rose 84 percent year over year.
Of the 27 companies in the index, 12 firms' share prices retreated last month, 14 companies' stocks increased, and one firm's share value was flat.
The broader market drove down the stock prices of many diagnostics companies. Natera, Guardant Health, and CareDx paced the gainers.
The company's new KidneyCare test will include AlloSure for rejection, AlloMap for quiescence, and Cibiltech's AI algorithm for graft health information.
The company reported $26 million in total revenues for the quarter and said that testing services revenues more than doubled year over year.
The diagnostic will now be a contracted service with Anthem Blue Cross of California and 10 of its affiliated health plans.
The companies will commercialize Predigraft, a data analysis tool that provides early predictions of risk for allograft rejection and transplant loss.