Version 2.71

49498-9Leukocytes [#/volume] in Blood by EstimateActive

Term Description

In the Hematology world estimated cell counts have existed for many moons and they are reported either qualitatively or quantitatively and done strictly by blood smear review.

Smear Estimated WBC and Platelet counts that aren't just reported as reduced/adequate/many that are actually estimated as a numeric result like an estimate of 4 K/cumm for WBC or 400 K/cumm for platelets. Like doing a retic count by counting so many fields on the smear type of estimate.

This WBC estimate count is a manual quantitative count. We report a number.
See laboratory procedure:

A. WBC Count Smear Estimate:

1. Use the 50X oil immersion objective.
2. Count the number of both intact and disrupted WBCs in each of 10 microscopic fields in different areas of the slide where RBCs slightly overlap. Divide the total number by 10 to establish the mean number of WBCs/field and multiply this mean by 3,000 to get the estimated WBC count/mm³. Do not round off the mean, e.g., if the mean is 5.7 do not round off to 6 but leave the figure at one place past the decimal point for greater accuracy.
3. If the quantitative WBC count is <25,000, the estimated smear count should be within 1,500 cells of this figure. Estimate counts are less reliable at >25,000 cells/mm³.


A. A Color Atlas and Instruction Manual of Peripheral Blood Cells Morphology, by Barbara H. O'Connor, 1984, p. 20.
B. Principles and Procedures, Barbara A. Brown, 6th Edition, 1993, p. 104.
Source: Regenstrief LOINC

Part Description

LP14419-3   Leukocytes
Leukocytes or white blood cells (WBCs) are immune cells that fight infection, neoplasms and other inflammatory conditions, and mediate allergic responses. There are five types of WBCs normally present in the circulation that are all derived from a similar stem cell in the bone marrow. The five type of WBCs are divided into two groups based on the presence or absence of granules in the cytoplasm. The granulocytes include the neutrophils, basophils and eosinophils. The non-granulocytes include the lymphocytes and the monocytes. The neutrophils fight infection by ingesting and digesting bacteria. Eosinophils and basophils respond to allergic reactions and are capable of ingesting antigen-antibody complexes. Monocytes phagocytose bacteria and release interferon to stimulate the immune system. Lymphocytes are divided into T-cells and B-cells. T-cell immunity is cellular and involves the activation of phagocytes and B-cell immunity uses antibodies to fight infection. Both elevated and low leukocyte counts can be markers of infection and malignancy, and low leukocyte counts are associated with a variety of primary and secondary immunodeficiencies, depending on the WBC type(s) that are out of range. (Mosby's manual of diagnostic and laboratory tests, Kathleen Deska Pagana; Timothy James Pagana, Elsevier St. Louis, Mo ©2010) Source: Regenstrief LOINC

Fully-Specified Name


Additional Names

Short Name
WBC # Bld Est
Display Name
WBC Estimate (Bld) [#/Vol]
Consumer Name Alpha
White blood cell (WBC) count, Blood

Basic Attributes

First Released
Version 2.22
Last Updated
Version 2.70
Order vs. Observation

Reference Information

Type Source Reference
Webcontent Lab Tests Online®Copyright Copyright © 2021 Lab Tests Online. All rights reserved. White Blood Cell Count (WBC)

Member of these Groups

LG32857-1 Leukocytes|NCnc|Pt|Bld

Language Variants Get Info

zh-CNChinese (China)
nl-NLDutch (Netherlands)
fr-BEFrench (Belgium)
Leucocytes:Concentration numérique:Temps ponctuel:Sang:Quantitatif:Estimation
fr-CAFrench (Canada)
Leucocytes:Concentration numérique:Temps ponctuel:Sang:Quantitatif:Estimé
fr-FRFrench (France)
it-ITItalian (Italy)
pt-BRPortuguese (Brazil)
es-ESSpanish (Spain)
Leucocitos:Concentración de número:Punto temporal:Sangre:Qn:Estimación
tr-TRTurkish (Turkey)

Example Units

Unit Source
10*3/uL Example UCUM Units

LOINC FHIR® API Example - CodeSystem Request Get Info