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.

LOINC

LOINC Code 18346-7: S. pneumoniae 18c IgG Qn (S)

Name: LOINC Code 18346-7: S. pneumoniae 18c IgG Qn (S)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:27.587Z

18346-7 is a LOINC code used to identify S. pneumoniae 18c IgG Qn (S) 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 Streptococcus pneumoniae 18c Ab.IgG. It is commonly used with the system or sample type Ser.

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 Streptococcus pneumoniae 18c Ab.IgG. It is commonly used with the system or sample type Ser.

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: DEPRECATED

What it does not mean

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

Key facts

Deprecated Streptococcus pneumoniae 56 IgG Ab [Units/volume] in Serum
Streptococcus pneumoniae 18c Ab.IgG
ABS; Aby; Antby; Anti; Antibodies; Antibody; Arbitrary concentration; Autoantibodies; Autoantibody; ID; Immune globulin G; Immunoglobulin G; Infectious Disease; InfectiousDisease; Microbiology; Pneu; pneum; Pneumo; Pneumococ; Pneumococcal; Pneumococcal pneumonia; Pneumococcus; Pneumon; Pneumonia; Point in time; QNT; Quan; Quant; Quantitative; Random; S pneumo; S pneumoniae; Serum; Spn; SR; Strep; Strept

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

S. pneumoniae 18c IgG Qn (S)Deprecated Streptococcus pneumoniae 56 IgG Ab [Units/volume] in SerumDeprecated S pneum18c IgG Ser-aCncStreptococcus pneumoniae 18c Ab.IgGMICROStreptococcus pneumoniae 18c IgG antibody, BloodACnc

Frequently asked questions

Code details

Code18346-7

SystemLOINC

Display nameS. pneumoniae 18c IgG Qn (S)

DescriptionStreptococcus pneumoniae 18c Ab.IgG

Short nameDeprecated S pneum18c IgG Ser-aCnc

ComponentStreptococcus pneumoniae 18c Ab.IgG

PropertyACnc

TimingPt

System (specimen)Ser

ScaleQn

ClassMICRO

StatusDEPRECATED

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0l

Last changed2.69

Consumer names

Streptococcus pneumoniae 18c IgG antibody, Blood

Part names

Streptococcus pneumoniae 18c Ab.IgGACncPtSerQnStreptococcus pneumoniae 18c IgGArbitrary ConcentrationPoint in time (spot)Serum

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.