CD16

Summary

The major role for CD16 is to identify and classify LGL disorders, but CD16 may also e used to demonstrate myeloid lineage commitment in MPAL

CD16 the FCRiii receptor is a protein bound to the cell membrane by a gpi-link; the molecule binds the fc region of antibody to mediate antibody-dependent cellular cytotoxicity. In blood CD16 is expressed mainly on NK cells neutrophils and monocytes. In tissues it is expressed by macrophages and natural killer cells.

Background

In normal myeloid cells expression of CD16 is progressively acquired through maturation and is highly expressed by myelocytes and neutrophils, it is also expressed less strogly by eosinophils and monocytes. CD16 is strongly expressed by NK cells.

Diagnostic Use

• CD16 has has value in the assessment of LGL disorders: T-LGL cells have variable or absent expression of CD16, while in LGL proliferations of NK cells CD16 is usually expressed
• As a gpi-linked protein CD16 may be lost from granulocytes in PNH, although it is not generally used in PNH diagnosis

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