Mast Cell Activation Syndrome (MCAS) can be challenging to diagnose because the symptoms can overlap with many other medical conditions.
Laboratory tests:
Tryptase: Tryptase is an enzyme released by mast cells during activation. Elevated serum tryptase levels suggest mast cell activation. Elevated plasma tryptase levels may also be considered.
Plasma Histamine: Direct measurement of histamine levels in plasma can be performed. Elevated plasma histamine, especially during symptom flare-ups, support a diagnosis of MCAS.
Histamine Metabolites: Histamine is broken down in the body, and measuring its metabolites, such as N-methylhistamine, in urine provide an indication of mast cell activity.
Prostaglandin D2 (PGD2): Prostaglandin D2 is another mediator released by mast cells. Elevated levels in urine or blood suggest mast cell activation.
Plasma Chromogranin A: Chromogranin A is a protein released by neuroendocrine cells, including mast cells. Elevated levels may be associated with mast cell activation.
Cytokine Panel: Measurement of cytokines, such as interleukins and tumor necrosis factor (TNF), can provide insights into the inflammatory response associated with MCAS.
Comprehensive Allergy Testing: Allergy tests, including skin prick tests and specific IgE blood tests, may help identify specific allergens triggering mast cell activation.
Genetic Testing: Some individuals with MCAS may have genetic predispositions that affect their ability to regulate mast cell activity. Genetic testing for mutations may be considered.