What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveBoth

LOINC Code 97102-8: Phosphorylated tau 181/Amyloid beta 42 peptide (CSF) [Ratio]

Name: LOINC Code 97102-8: Phosphorylated tau 181/Amyloid beta 42 peptide (CSF) [Ratio]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:29.655Z

97102-8 is a LOINC code used to identify Phosphorylated tau 181/Amyloid beta 42 peptide (CSF) [Ratio] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Tau protein.phosphorylated 181/Amyloid beta 42 peptide. It is commonly used with the system or sample type CSF.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Tau protein.phosphorylated 181/Amyloid beta 42 peptide. It is commonly used with the system or sample type CSF.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Both

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Phosphorylated tau 181/Amyloid beta 42 peptide [Ratio] in Cerebral spinal fluid

Tau protein.phosphorylated 181/Amyloid beta 42 peptide

The ratio of phosphorylated tau-181 (p-tau(181)) to beta-amyloid 42 (Abeta42). To report the ratio of total tau (t-tau) to Abeta42 in cerebral spinal fluid, use Tau protein/Amyloid beta 42 peptide [Ratio] in CSF [LOINC41027-4].

181P; Ab42 peptide; Abeta; Abeta 42; AL beta42; Alzheimer disease; Alzheimer's disease; B; Beta-amyloid; Cerebral spinal fluid; Cerebrospinal Fl; Chemistry; Neuro; Neurology; Pept; phospho T181; Point in time; PR; Prot; p-tau181; pThr181; QNT; Quan; Quant; Quantitative; Random; Ratios; Rto; Spinal Fl; Spinal Fld; Spinal Flu; Spinal Fluid; Thr181; threonine 181

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Phosphorylated tau 181/Amyloid beta 42 peptide (CSF) [Ratio]Phosphorylated tau 181/Amyloid beta 42 peptide [Ratio] in Cerebral spinal fluidp-tau181/AL beta42 CSF-RtoTau protein.phosphorylated 181/Amyloid beta 42 peptideCHEMPhosphorylated tau 181/Amyloid Beta 42 Peptide, Spinal fluidRatio

Frequently asked questions

Code details

Code97102-8

SystemLOINC

Display namePhosphorylated tau 181/Amyloid beta 42 peptide (CSF) [Ratio]

DescriptionTau protein.phosphorylated 181/Amyloid beta 42 peptide

Short namep-tau181/AL beta42 CSF-Rto

ComponentTau protein.phosphorylated 181/Amyloid beta 42 peptide

PropertyRatio

TimingPt

System (specimen)CSF

ScaleQn

ClassCHEM

Example unitsratio

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.70

Last changed2.70

Consumer names

Phosphorylated tau 181/Amyloid Beta 42 Peptide, Spinal fluid

Part names

Tau protein.phosphorylated 181/Amyloid beta 42 peptideRatioPtCSFQnPoint in time (spot)Cerebral spinal fluid

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.