The Utility of Measuring Urinary Metabolites of Mast Cell Mediators in Systemic Mastocytosis and Mast Cell Activation Syndrome

• Published in: The journal of allergy and clinical immunology in practice (Cambridge, MA) Vol. 8; no. 8; p. 2533
• Main Authors: Butterfield, Joseph, Weiler, Catherine R
• Format: Journal Article
• Language: English
• Published: United States 01.09.2020
• Subjects: Humans; Leukotriene E4; Mast Cells; Mastocytosis - diagnosis; Mastocytosis, Systemic - diagnosis; Tryptases; Histamine; 2,3-Dinor-11β-PGF(2α); Mast cell activation syndrome; Leukotriene E; Leukotriene C; Prostaglandin D; N-Methyl histamine; Systemic mastocytosis
• ISSN: 2213-2201
• DOI: 10.1016/j.jaip.2020.02.021

Mast cells (MCs) leave evidence of their presence and activation. Aside from increased numbers of MCs in tissues, this evidence includes detecting elevated serum levels of tryptase and discovering increased excretion of urinary metabolites of prostaglandin (PG) D , leukotriene (LT) C , and/or histamine. The importance of measuring these nontryptase mediator metabolites has largely gone unnoticed. We reviewed the utility of quantitating urinary levels of MC mediator metabolites in systemic mastocytosis (SM) and MC activation disorders and summarized the relative production of these mediators by MCs and other cell types. Quantitation of urinary n-methyl histamine, 2,3-dinor-11βPGF , and LTE offers a simple, noninvasive avenue to monitor their constitutive release as well as contemporaneous discharge during MC activation as well as supporting a diagnosis of SM. These increases can occur independently of or in addition to raised levels of tryptase. Quantitation of these mediator metabolites potentially offers targets for therapeutic intervention. Synthesis of PGD , a product nearly exclusively of MCs, can be controlled with aspirin, histamine increase by H1 and H2 receptor blockade, and LTC by a 5-LO inhibitor or LT receptor antagonist. Although other sources are reported, the increase in MC numbers in SM supports this cell as the predominant origin of all 3 mediators.