26498-6

Myelocytes/Leukocytes in Blood

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Part Descriptions

LP15077-8   Myelocytes
The identification of mature and immature granulocytes, including myelocytes and metamyelocytes, in blood and bone marrow is fundamental to the diagnosis of haematological disorders. A myelocyte is a young cell of the granulocytic series, occurring normally in bone marrow, but not in circulating blood (except when caused by certain diseases). Myelocytes are derived from promyelocytes and give rise to metamyelocytes. When stained with the usual dyes, the cytoplasm in myelocytes is distinctly basophilic and relatively more abundant than in myeloblasts or promyelocytes. Numerous cytoplasmic granules are present in the more mature forms of myelocytes. Neutrophilic and eosinophilic granules are peroxidase-positive, while basophilic granules are not. The nucleus of a myelocyte is fairly regular in contour (not indented), and seems to be 'buried' beneath the numerous cytoplasmic granules. If the nucleus were indented, it is likely be a metamyelocyte. Copyright Text is available under the Creative Commons Attribution/Share-Alike License. See http://creativecommons.org/licenses/by-sa/3.0/ for details. Source: Wikipedia , Wikipedia (Myelocyte and Metamyelocyte)

LP157588-7   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

Reference Information

Fully-Specified Name

Component

Myelocytes/Leukocytes

Property

NFr

Time

Pt

System

Bld

Scale

Qn

Method

Additional Names

Long Common Name

Myelocytes/Leukocytes in Blood

Short Name

Myelocytes NFr Bld

Display Name

Myelocytes/Leukocytes (Bld)

Consumer Name Alpha Get Info

Myelocytes/White Blood Cells, Blood

Basic Attributes

Class

HEM/BC

Type

Laboratory

First Released

Version 2.00

Last Updated

Version 2.79 (NAM)

Change Reason

Release 2.79: COMPONENT: Triggered by Coll w SCT: This is a specific fraction case where the denominator is percentage or /100. Because the logic is that the percentage piece is captured by Property: NFr (Numeric Fraction), and by Unit: %, therefore, it is redundant to include "100" in the component;

Order vs. Observation

Observation

Common Test Rank Get Info

335

Member of these Panels

Language Variants Get Info

Related Names

• Blood
• Hematology
• HEMATOLOGY/CELL COUNTS
• Heme
• Leuc
• Leuk
• Leukocyte
• Lkcs
• Myel
• Myelo
• Myelocyte
• Number fraction
• Percent
• Point in time
• QNT
• Quan
• Quant
• Quantitative
• Random
• WB
• WBC
• WBCs
• White blood cell
• White blood cells
• Whole blood

Example Units

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CodeSystem lookup

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LOINC Copyright

Copyright © 2025 Regenstrief Institute, Inc. All Rights Reserved. To the extent included herein, the LOINC table and LOINC codes are copyright © Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. See https://loinc.org/license for the full LOINC copyright and license.