Mast Cell Activation Disorder As A Presentation Of Primary Immunodeficiencies
Saturday, March 3, 2018
South Hall A2 (Convention Center)
Anne L. Maitland, MD PhD, Sydney Littlejohn, Gigia Roizen
RATIONALE: Mannose-binding lectin (MBL) is a protein that participates in innate immunity by targeting microbes for opsonization. MBL deficiency is present in 7% of the population and has been implicated in increased susceptiblity to infections. The purpose of this study was to characterize Mast cell activation disorder (MCAD) as presenting manifestations of a primary immune deficiency (PID).

METHODS: This was a retrospective study of patients referred to a community based allergy/immunology practice for evaluation of possible MCAD. Immunological test results included mast cells (MC) activation markers (tryptase, histamine, prostaglandin metabolites) and an analyses of immuneglobulins, complement and MBL. Past medical histories and laboratory findings were analyzed.

RESULTS: Data from 14 patients (10 females), average age 40 years old, was analyzed. All patients presented MCAD symptoms: 92.8% presented immediate hypersensitivity manifestations: asthma, rhinitis and/or hives and 15.3% among them presented anaphylaxis. 100% of patients had other MCAD symptoms; headache, flushing, itching, neurocognitive symptoms and/or irritable bowel disease. Serum histamine and tryptase levels were within normal range.

MBL levels were deficient in all patients. 12/14 had past medical histories worrisome for possible PID, including recurrent sinopulmonary infections. Pneumococcal immunity was depressed in in 71.4% of them.

CONCLUSIONS: This study highlights the presence of MCAD in patients with PID, indicating the need to screen for PID in patients presenting with immediate hypersensitivity disorders.