498 Mastocytosis and IgE-dependent Sensitization: Report of 2 Cases

BACKGROUND: Mastocytosis is a heterogeneous disease, with abnormal accumulation of mast cells in one or more organs. Hyperplasia is often found in the bone marrow and peripheral sites such as skin, gastrointestinal mucosa, liver and spleen. The clinical manifestations are due to release of mast cell mediators and tissue infiltration; however, there is no direct relationship between total mast cell mass and symptoms of liberation. METHODS: Describe 2 cases of mastocytosis that manifest with anaphylactic shock and also have IgE-dependent allergy. RESULTS: Case1: Man of 62 years consulting for intraoperative anaphylaxis with an expected elevated serum tryptase (54 mg/L) during episode. The skin test were positive to vecuronium, rocuronium and Izofran and the other drugs and latex were negative. Specific IgE to quaternary ammonium latex and beta-lactams were negative. The tryptase remains elevated (23 mg/L) 6 weeks after surgery. Bone marrow biopsy showed mast cell infiltration of 10% CD 34 staining less than 1% and 10% CD117. Co-CD25 and CD117 were 25% compatible with mastocytosis. CT neck, thorax, abdomen and pelvis were normal. The upper and lower endoscopy revealed polyps in gastric antrum, the histology was nodular foveolar hyperplasia. Case 2: Female, 38 years consulted for 3 episodes of anaphylaxis following the ingestion of fish, shellfish and quinoa. The skin prick test was positive to white fish and shrimp, specific IgE were positive to white and blue fish and shrimp. The initial serum tryptase was 11 mg/L, 3 months was 14 mg/L. Later, patient had a new anaphylaxis episode, after unnoticed consumption of fish. Bone marrow biopsy compatible with mastocytosis. The study with lower and upper endoscopy with chest and abdominal CT scan ruled out visceral involvement. CONCLUSIONS: Both cases of systemic mastocytosis show an IgE sensitization to drugs and to food whose main manifestation was anaphylactic shock. In the literature, anaphylaxis was reported in up to 22% of mastocytosis, mostly men, associated with different triggering stimuli such as muscle relaxants, but not food. Therefore it is essential to rule out the presence of mastocytosis in patients complaining of anaphylaxis even in those with allergy study showing IgE-dependent sensitization.