Increased group 2 innate lymphoid cells in peripheral blood of adults with mastocytosis

BackgroundSystemic mastocytosis is a hematological disease in which aberrant mast cells accumulate because of gain-of-function mutations the KIT receptor. Group 2 innate lymphoid (ILC2s) are effector type immune responses that also express and colocalize with at barrier tissue sites. In mouse models, cell-ILC2 crosstalk can drive local inflammation. However, possible role for ILC2s pathophysiology remains unexplored.ObjectiveWe sought to characterize circulating clinically diverse cohort patients mastocytosis.MethodsWe included 21 adults systemic 18 healthy controls. Peripheral blood ILC2 abundance phenotype were analyzed by flow cytometry correlated clinical characteristics, including presence D816V mutation.ResultsILC2 levels significantly higher D816V+ compared D816V− or We observed increased proportions KIT+ among mastocytosis, regardless status. Patients skin involvement itch showed highest ILC2s, was independent from atopy serum tryptase levels. Allele-specific quantitative PCR vast majority did not carry mutation.ConclusionsOur findings suggest pathogenic ILC2-mast cell mastocytosis. hypothesize high cutaneous burden alters microenvironment induce chronic activation their dissemination into circulation. Activated could contribute symptoms producing inflammatory mediators further augmenting mediator release. Systemic unexplored. mutation. Our