is a relatively mast-cell-specific protease that is released
upon mast-cell degranulation; its plasma level peaks at 1
hour post event and may be detectable for up to 6 hours.
The finding an elevated serum tryptase level compared with a baseline level obtained when the patient is
asymptomatic may confirm that symptoms were due to an
anaphylactic /anaphylactoid reaction.
For use of plasma
tryptase levels used in investigation of suspected adverse
drug reaction there is a specific
adverse drug reaction protocol.
Plasma tryptase levels
are also useful in diagnosis and monitoring of urticaria
pigmentosa (cutaneous mastocytosis) and systemic mastocytosis.
Recent evidence suggests that tryptase may also be useful in
management of asthma patients with moderate to severe Type 1
(anaphylactic) allergy reactions.