Aspirin provocation of patients with Systemic Mastocytosis

Systemic mastocytosis (SM) is a myeloproliferative disease in which aberrant
mast cells accumulate. Patients with SM experience more anaphylaxis than
healthy persons because of the large amount of mast cells. For this reason, the
use of certain medications that could theoretically trigger mast cell
degranulation is discouraged in SM patients. Among these medications are
radiologic contrast media, anaesthetics, opioid analgesics and nonsteroidal
anti-inflammatory drugs (NSAID*s). However, SM patients could benefit from some
of these drugs in their daily life. Acetylsalicyl acid (ASA) is a widely-used
remedy for flushing in some patients. Moreover, since osteoporosis is a
frequent complication of SM with up to 50% having reduced bone density[5], they
are more often in need of analgesics due to fractures etc. Lastly, SM patients
are at increased risk for cardiovascular morbidity and of course, aspirin is
the cornerstone of (secondary) prophylaxis for these diseases.
For these reasons, it would be of great importance to explore the real
prevalence and severity of aspirin-induced anaphylaxis in SM patients. Aspirin
can be used as a model for all NSAID*s.

To determine the prevalence and severity of aspirin-related allergic reactions
in SM patients.

Double-blind, placebo-controlled, crossover study.

Double blind, placebo controlled provocation with aspirin.

Patients will have to spend 2 half days of approximately 4 hours in the
hospital in which they will be asked to take three tablets (either placebo or
ASA). During these days, we will collect blood and urine samples on two
occasions. Questionnaires and minor physical examination will be performed
every hour to screen for anaphylactic symptoms.
We do not expect the patients to experience any other discomfort. We expect a
low incidence and minor severity of allergic symptoms.