Work

Altered B-cell, plasma cell, and antibody immune profiles in blood of patients with systemic mastocytosis

Year: 2024

Type: article

Abstract: BACKGROUND: Systemic mastocytosis (SM) is a heterogeneous disease characterized by an expansion of KIT-mutated constitutively activated mast cells (MCs) that release MC mediators, which might act on the tumor microenvironment including other immune cells. OBJECTIVE: To investigate the blood distribution of B-cell, plasma cell (PC), and antibody isotype compartments in patients with SM. METHODS: We used spectral flow cytometry and the EuroFlow Immunomonitoring panel and Lymphocyte Screening Tube to quantify B cells, PCs, and their subsets in blood of 108 patients with SM (35 bone marrow mastocytosis [BMM] cases, 64 indolent SM [ISM] cases, 9 aggressive SM [ASM] cases) versus 117 age-matched healthy donors and paired bone marrow samples of 31 patients with SM versus 17 controls, respectively. In parallel, IgM, IgD, IgG, IgA, and IgE plasma levels were measured. RESULTS: memory B cells (P ≤ .032) and elevated IgM (P = .017) plasma levels in cases of ASM, increased IgM (P = .001) and IgD (P = .001) plasma levels in ISM cases, and exacerbated IgE (P < .001) with decreased IgG (P = .008) plasma levels in BMM cases. CONCLUSIONS: Our results reveal a significant dysregulation of the B-cell and PC compartments in blood of patients with SM, consistent with distinctly altered antibody isotype profiles in plasma of patients with BMM versus ISM versus ASM.

Source: Journal of Allergy and Clinical Immunology

DOI: 10.1016/j.jaci.2024.10.005