XExtension Codes
Anatomy and topography
Functional anatomy
Haematopoietic system
XA8EC5Blood
XA8UK8Blood cells
XA32R4Leucocytes
XA8YQ2
category
Lymphocytes
Definition Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity).
Also indexed as
Lymphocytes
International Classification of Diseases, Eleventh Revision (ICD-11), World Health Organization (WHO) 2019/2021, https://icd.who.int/browse11. Licensed under Creative Commons Attribution-NoDerivatives 3.0 IGO (CC BY-ND 3.0 IGO).
Release 2026-01.
View this entity in the official WHO ICD-11 browser .
This page reproduces WHO classification content for reference. It is not
medical advice and must not be used to diagnose or treat. For coding
decisions, consult the official release and your national coding guidelines.
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