Secaucus, New Jersey, August 24, 2026
Quest Diagnostics announced new developments in its Quest AD-Detect® blood-testing portfolio, expanding access to blood-based biomarker testing for symptomatic patients being evaluated for Alzheimer’s disease pathology. The company plans to offer an AD-Detect-branded laboratory testing service based on Roche’s FDA-cleared Elecsys® pTau217 Plasma blood test to physicians and clinical-trial collaborators nationwide in the fourth quarter of 2026. The move strengthens Quest Diagnostics’ position in the rapidly developing field of blood-based Alzheimer’s diagnostics, where laboratory testing is increasingly being explored as a more accessible approach to evaluating underlying disease pathology. Quest also plans to incorporate the Roche pTau217 assay into future AD-Detect testing panels beginning in 2027, potentially giving clinicians additional options for biomarker-based assessment across primary and specialty care settings..
Roche pTau217 Test Strengthens Quest AD-Detect Portfolio
The addition of the Roche Elecsys pTau217 test represents a significant expansion of Quest’s Alzheimer’s testing capabilities. The FDA-cleared assay is designed to support rule-in and rule-out assessment of amyloid pathology using validated clinical cutoffs and represents the first FDA-cleared single-assay, single-biomarker blood test with this capability, according to the companies. Quest intends to make the test available through its national laboratory infrastructure, extending access beyond highly specialized centers. The development is particularly relevant because established approaches such as amyloid PET imaging and cerebrospinal fluid testing can be costly, invasive or difficult to access in some clinical settings. By adding an FDA-cleared pTau217-based option to AD-Detect, Quest is positioning blood-based biomarker testing as an increasingly practical component of Alzheimer’s disease evaluation.
New Multi-Biomarker Test Targets Lower Indeterminate Results
Alongside the Roche test offering, Quest Diagnostics is launching AD-Detect® ABeta 42/40, p-tau217, and ApoE Evaluation, a laboratory-developed test designed to combine multiple biological signals associated with Alzheimer’s disease pathology. The test uses pTau217, amyloid beta 42/40 and the APOE isoform, a genetic risk marker, to generate a score estimating the likelihood of Alzheimer’s pathology. Quest reported that research published in Neurology Clinical Practice showed the test achieved an indeterminate rate of approximately 10%, compared with the 15%–20% rate referenced by the Global CEO Initiative on Alzheimer’s Disease for a typical clinical population. The company said its research supports the potential value of combining biomarkers rather than relying on individual measurements alone. The new multi-biomarker test is expected to become available nationwide to physicians and clinical-trial collaborators at the end of August 2026.
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Quest Diagnostics Expands Access Through Nationwide Testing Network
The developments reinforce Quest Diagnostics’ broader strategy of making Alzheimer’s blood biomarker testing more accessible through routine laboratory infrastructure. With a physician’s order, patients can provide blood samples for AD-Detect testing through Quest’s network of approximately 2,000 U.S. patient service locations, as well as physician offices and mobile phlebotomy services. For the diagnostics industry, the expansion is important because blood-based biomarkers could help address accessibility limitations associated with conventional Alzheimer’s pathology assessments while supporting clinical decision-making and research. Quest also cited research indicating that blood-based biomarker testing may offer a more efficient and cost-effective approach to assessing Alzheimer’s pathology in patients experiencing cognitive decline compared with amyloid PET imaging. The company’s planned rollout of the FDA-cleared Roche pTau217 assay, combined with its own multi-biomarker testing capabilities, could further expand the role of laboratory-based diagnostics in Alzheimer’s disease evaluation.
Source:Quest Diagnostics press relese
