Classical, intermediate and non-classical monocytes:
Monocytes can be classified as classical, intermediate and non-classical, based on expression of CD14 and CD16; there is a continuum between the three subtypes.
- Classical: CD14+ CD16-
- Non-classical: CD14dim CD16+
- Intermediate: CD14+ CD16+
In normal circumstances, the classical subtype is dominant.
The proportions can be skewed in certain disease states, for example in inflammatory states.
- It is important to recognize those subtypes to avoid overdiagnosing malignancy.
The following plots are from the peripheral blood of a patient with arthritis. There was monocytosis with a subset of non-classical monocytes with dim CD14 and gain of CD16 (note our panels do not contain CD14 and CD16 in the same tubes).
Reference: Mukherjee et al. Non-classical monocytes display inflammatory features: Validation in Sepsis and Systemic Lupus Erythematous. Sci. Rep. 5, 13886 (2015).
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