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 66764-2: Nucleated RBC/Leukocytes (BldCo) [Ratio]

Name: LOINC Code 66764-2: Nucleated RBC/Leukocytes (BldCo) [Ratio]
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

66764-2 is a LOINC code used to identify Nucleated RBC/Leukocytes (BldCo) [Ratio] 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 Erythrocytes.nucleated/Leukocytes. It is commonly used with the system or sample type BldCo.

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 Erythrocytes.nucleated/Leukocytes. It is commonly used with the system or sample type BldCo.

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

Nucleated erythrocytes/Leukocytes [Ratio] in Cord blood
Erythrocytes.nucleated/Leukocytes
Blood - (umbilical) cord; Cord (umbilical) blood; Cord bld; Cord blood; Discocytes; Erthrocyte; Erythroblasts; Erythrocyte; HEMATOLOGY/CELL COUNTS; Leuc; Leuk; Leukocyte; Lkcs; Normoblasts; nRBC; nRBCs; Nuc; Point in time; QNT; Quan; Quant; Quantitative; Random; Ratios; RBC; RBCS; Red blood cell; Red blood cells; Red blood corpuscle; Red blood corpusles; Red cell; Red cells; Rto; WBC; WBCs; White blood cell; White blood cells

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.

Related SNOMED CT concepts

705114005SNOMED CT mapping for Nucleated RBC/Leukocytes (BldCo) [Ratio] (66764-2)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

Nucleated RBC/Leukocytes (BldCo) [Ratio]Nucleated erythrocytes/Leukocytes [Ratio] in Cord bloodnRBC BldCo-RtoErythrocytes.nucleated/LeukocytesHEM/BCNucleated red blood cells/White Blood Cells, Cord bloodRatio

Frequently asked questions

Code details

Code66764-2

SystemLOINC

Display nameNucleated RBC/Leukocytes (BldCo) [Ratio]

DescriptionErythrocytes.nucleated/Leukocytes

Short namenRBC BldCo-Rto

ComponentErythrocytes.nucleated/Leukocytes

PropertyRatio

TimingPt

System (specimen)BldCo

ScaleQn

ClassHEM/BC

Example units/100 WBC

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.38

Last changed2.79

Consumer names

Nucleated red blood cells/White Blood Cells, Cord blood

Part names

Erythrocytes.nucleated/LeukocytesRatioPtBldCoQnPoint in time (spot)Blood cord

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.