LOINCActiveBoth

LOINC Code 51803-5: Fibrillarin Ab IF (S) [Titer]

51803-5 is a LOINC code used to identify Fibrillarin Ab 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 Fibrillarin Ab. 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 Fibrillarin Ab. 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: Both
  • Method: IF

What it does not mean

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

Key facts

  • Fibrillarin Ab [Titer] in Serum by Immunofluorescence
  • Fibrillarin Ab
  • ABS; Aby; ACIF; Antby; Anti; Antibodies; Antibody; Anticomplement Immunofluorescence; Autoantibodies; Autoantibody; Dilution factor; Dilution Factor (Titer); FA; Fluorescent antibody; Fluoresent; IFA; Immune fluorescence; Immunoflour; Immunofluor; Immunofluorescence; 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

Fibrillarin Ab IF (S) [Titer]Fibrillarin Ab [Titer] in Serum by ImmunofluorescenceFibrillarin Ab Titr Ser IFFibrillarin AbSEROFibrillarin antibody, BloodTitr

Frequently asked questions

Code details

Code51803-5
SystemLOINC
Display nameFibrillarin Ab IF (S) [Titer]
DescriptionFibrillarin Ab
Short nameFibrillarin Ab Titr Ser IF
ComponentFibrillarin Ab
PropertyTitr
TimingPt
System (specimen)Ser
ScaleSemiQn
MethodIF
ClassSERO
Example unitstiter
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.24
Last changed2.75

Consumer names

Fibrillarin antibody, Blood

Part names

Fibrillarin AbTitrPtSerSemiQnIFTiterPoint 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.

LOINC Code 51803-5 | HealthAssure