LOINC

LOINC Code 4515-3: Complement factor B (P) [Mass/Vol]

4515-3 is a LOINC code used to identify Complement factor B (P) [Mass/Vol] 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 Complement factor B. It is commonly used with the system or sample type Plas.

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 Complement factor B. It is commonly used with the system or sample type 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: DEPRECATED

What it does not mean

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

Key facts

  • Deprecated Complement factor B [Mass/volume] in Serum or Plasma
  • Complement factor B
  • C3 proactivator; C3-5 Converting Enzyme; C3PA; Comp; Comp Fact B; Complement c3 proactivator+activator; Complement Protein B; Complmt; CVFBb; Fac; Fact; Factor B; Glycine rich beta glycoprotein; Heat labile factor; HEMATOLOGY/CELL COUNTS; Level; Mass concentration; Pl; Plasma; Plsm; Point in time; Properdin Factor B; QNT; Quan; Quant; Quantitative; Random

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

Complement factor B (P) [Mass/Vol]Deprecated Complement factor B [Mass/volume] in Serum or PlasmaDeprecated Comp Fact B Plas-mCncComplement factor BHEM/BCComplement Factor B, BloodMCnc

Frequently asked questions

Code details

Code4515-3
SystemLOINC
Display nameComplement factor B (P) [Mass/Vol]
DescriptionComplement factor B
Short nameDeprecated Comp Fact B Plas-mCnc
ComponentComplement factor B
PropertyMCnc
TimingPt
System (specimen)Plas
ScaleQn
ClassHEM/BC
StatusDEPRECATED

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.36

Consumer names

Complement Factor B, Blood

Part names

Complement factor BMCncPtPlasQnMass ConcentrationPoint in time (spot)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 4515-3 | HealthAssure