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.

LOINCActiveObservation

LOINC Code 53991-6: Nucleolar nuclear Ab pattern IF (S) [Titer]

Name: LOINC Code 53991-6: Nucleolar nuclear Ab pattern IF (S) [Titer]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:36.582Z

53991-6 is a LOINC code used to identify Nucleolar nuclear Ab pattern IF (S) [Titer] 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 Nuclear Ab pattern.nucleolar. 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 Nuclear Ab pattern.nucleolar. 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: ACTIVE
Order vs observation: Observation
Method: IF

What it does not mean

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

Key facts

Nucleolar nuclear Ab pattern [Titer] in Serum by Immunofluorescence
Nuclear Ab pattern.nucleolar
ACIF; ANA; ANA nucleolar; ANA Pat; ANF; Anticomplement Immunofluorescence; Antinuclear antibody; Dilution factor; Dilution Factor (Titer); FA; FANA; Fluorescent antibody; Fluoresent; IFA; Immune fluorescence; Immunoflour; Immunofluor; Immunofluorescence; NA; Nuc; Point in time; Random; Serology; Serum; SmQn; SR; Time Resolved Fluorescence; Titer; Titered; Titre; TRF; Ttr

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

Nucleolar nuclear Ab pattern IF (S) [Titer]Nucleolar nuclear Ab pattern [Titer] in Serum by ImmunofluorescenceANA nucleolar Titr Ser IFNuclear Ab pattern.nucleolarSERONucleolar nuclear Ab pattern, BloodTitr

Frequently asked questions

Code details

Code53991-6

SystemLOINC

Display nameNucleolar nuclear Ab pattern IF (S) [Titer]

DescriptionNuclear Ab pattern.nucleolar

Short nameANA nucleolar Titr Ser IF

ComponentNuclear Ab pattern.nucleolar

PropertyTitr

TimingPt

System (specimen)Ser

ScaleSemiQn

MethodIF

ClassSERO

Example unitstiter

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.26

Last changed2.75

Consumer names

Nucleolar nuclear Ab pattern, Blood

Part names

Nuclear Ab pattern.nucleolarTitrPtSerSemiQnIFNucleolar nuclear Ab patternTiterPoint in time (spot)SerumImmunofluorescence (IF)

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.