# K252163: Elecsys Phospho-Tau (181P) Plasma

- Pathway: 510(k) (Traditional)
- Applicant: Roche Diagnostics
- Decided: Oct 8, 2025 after 90 days
- Product code: SET (Immunoassay Blood Test For Amyloid Pathology Assessment)
- Device class: 2
- Regulation: 21 CFR 866.5840
- Recalls of this device: none
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 2 generations back to DEN200072 (2022). 2 ancestors in all.
No later device cites it as a predicate yet.
0 of 3 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K221842: Elecsys B-Amyloid (1-42) CSF II, Elecsys Phospho-Tau (181P) CSF, Roche Diagnostics (2022) Summary page 5.

## Indications for use
Elecsys Phospho-Tau (181P) Plasma is an in vitro electrochemiluminescence immunoassay (ECLIA) intended for the measurement of the phosphorylated Tau 181 protein in human plasma on cobas e immunoassay analyzers. The Elecsys Phospho-Tau (181P) Plasma assay result is intended to be used as an aid in the initial assessment for Alzheimer’s disease and other causes of cognitive decline in adult patients aged 55 years and older, presenting with signs, symptoms, or complaints of cognitive decline. The result should be interpreted in conjunction with other clinical information. A negative test result is consistent with a negative amyloid positron emission tomography (PET) scan result and reduced likelihood that a patient's cognitive impairment is due to amyloid pathology. These patients should be investigated for other causes of cognitive decline. A positive test result may not be consistent with a positive amyloid PET scan result. Patients with an initial positive result should be further investigated to determine whether the amyloid pathology can be a cause of cognitive impairment. Limitations of use The Elecsys Phospho-Tau (181P) Plasma assay is not recommended for patients with signs, symptoms, or complaints of cognitive decline, who are already referred to the specialist. The performance of Elecsys Phospho-Tau (181P) Plasma has not been established for: ▪ Predicting development of dementia or other neurologic conditions. ▪ Monitoring responses to therapies.

Source page: https://510kreport.com/device/K252163
Methodology: https://510kreport.com/methodology