The enzyme tryptase is released from mast cells along with histamine during a normal immune response as well as in allergic (hypersensitivity) reaction.
What might a low result mean?
Although normal tryptase results may indicate that symptoms are not due to mast cell activation, with anaphylaxis, tryptase concentrations usually peak around 1 to 2 hours after the symptoms begin so if a sample is drawn too early or late, the results may be normal.
What might a high result mean?
Anaphylaxis symptoms along with an elevated tryptase result, indicate anaphylaxis as the likely diagnosis.
Persistently elevated tryptase concentrations along with symptoms of mast cell activation suggest mastocytosis is likely.