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 33640-4: Lymphocyte proliferation stimulated by tetanus toxoid Qn (Bld)

Name: LOINC Code 33640-4: Lymphocyte proliferation stimulated by tetanus toxoid Qn (Bld)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:21.183Z

33640-4 is a LOINC code used to identify Lymphocyte proliferation stimulated by tetanus toxoid Qn (Bld) 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 Lymphocyte proliferation.tetanus toxoid stimulation. It is commonly used with the system or sample type Bld.

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 Lymphocyte proliferation.tetanus toxoid stimulation. It is commonly used with the system or sample type Bld.

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

Lymphocyte proliferation stimulated by tetanus toxoid [Units/volume] in Blood
Lymphocyte proliferation.tetanus toxoid stimulation
Arbitrary concentration; Blood; LPA; LPT; LPT TT; LST; Lymphocyte antigen proliferation; Lymphocyte antigen stimulation; Microbiology; PHA; Point in time; QNT; Quan; Quant; Quantitative; Random; Stim; WB; Whole blood

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

Lymphocyte proliferation stimulated by tetanus toxoid Qn (Bld)Lymphocyte proliferation stimulated by tetanus toxoid [Units/volume] in BloodLPT TT Bld-aCncLymphocyte proliferation.tetanus toxoid stimulationMICROLymphocyte proliferation stimulated by tetanus toxoid, BloodACnc

Frequently asked questions

Code details

Code33640-4

SystemLOINC

Display nameLymphocyte proliferation stimulated by tetanus toxoid Qn (Bld)

DescriptionLymphocyte proliferation.tetanus toxoid stimulation

Short nameLPT TT Bld-aCnc

ComponentLymphocyte proliferation.tetanus toxoid stimulation

PropertyACnc

TimingPt

System (specimen)Bld

ScaleQn

ClassMICRO

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.09

Last changed2.73

Consumer names

Lymphocyte proliferation stimulated by tetanus toxoid, Blood

Part names

Lymphocyte proliferation.tetanus toxoid stimulationACncPtBldQnLymphocyte proliferation tetanus toxoid stimulationArbitrary ConcentrationPoint in time (spot)Blood

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.