LOINCActiveObservation

LOINC Code 55337-0: P1 Ab [Titer]

55337-0 is a LOINC code used to identify P1 Ab [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 P1 Ab. It is commonly used with the system or sample type Ser/Plas.

Reviewed by HealthAssure Clinical TeamUpdated 25 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 P1 Ab. It is commonly used with the system or sample type Ser/Plas.

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

What it does not mean

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

Key facts

  • P1 Ab [Titer] in Serum or Plasma
  • P1 Ab
  • ABS; Aby; Antby; Anti; Antibodies; Antibody; Autoantibodies; Autoantibody; BLOOD BANK; Dilution factor; Dilution Factor (Titer); Pl; Plasma; Plsm; Point in time; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SmQn; SR; Titer; Titered; Titre; 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

P1 Ab [Titer]P1 Ab [Titer] in Serum or PlasmaP1 Ab Titr SerPlP1 AbBLDBKP1 antibody, BloodTitr

Frequently asked questions

Code details

Code55337-0
SystemLOINC
Display nameP1 Ab [Titer]
DescriptionP1 Ab
Short nameP1 Ab Titr SerPl
ComponentP1 Ab
PropertyTitr
TimingPt
System (specimen)Ser/Plas
ScaleSemiQn
ClassBLDBK
Example unitstiter
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.27
Last changed2.75

Consumer names

P1 antibody, Blood

Part names

P1 AbTitrPtSer/PlasSemiQnTiterPoint in time (spot)Serum or Plasma

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 55337-0 | HealthAssure