Mast cell activation syndrome (MCAS): what is it?

Role of mast cells in allergy had remained undetermined until the discovery of IgE in 1966. Then, IgE purified from many Liters of plasma, which had been donated from a patient with fatal myeloma, was distributed to researchers all over the world (http://buff.ly/12sD3cO).

The term mast cell activation syndrome (MCAS) is finding increasing use as a diagnosis for subjects who present with signs and symptoms involving:

- skin
- gastrointestinal tract
- cardiovascular system
- neurologic complaints

Such patients often have undergone multiple extensive medical evaluations by different physicians in varied disciplines without a definitive medical diagnosis until the diagnosis of MCAS is applied.

Mast cells are traditionally viewed only as IgE-activated histamine-providing effector cells of allergic inflammation.


Mast cells. Image source: Wikipedia, public domain.

MCAS as a distinct clinical entity has not been generally accepted, and there are no definitive criteria for diagnosis.

The authors discuss proposed criteria in the context of other disorders involving mast cells.

Blood cell lineage. Image source: Wikipedia.


Mast cells (mind map).

References:
Mast cell activation syndrome: Proposed diagnostic criteria. Akin C, Valent P, Metcalfe DD. J Allergy Clin Immunol. 2010 Oct 27.

Mast Cells and Basophils

Mast cell activation syndromes: definition and classification http://buff.ly/XlrDje
Mast Cell Activation Disorders - 2014 free full text review http://buff.ly/1kPDdzo

Mast Cell Disorders - figures: