AUTHOR=Rodriguez Stéphane , Couloume Laura , Ferrant Juliette , Vince Nicolas , Mandon Marion , Jean Rachel , Monvoisin Celine , Leonard Simon , Le Gallou Simon , Silva Nayane S. B. , Bourguiba-Hachemi Sonia , Laplaud David , Garcia Alexandra , Casey Romain , Zephir Helene , Kerbrat Anne , Edan Gilles , Lepage Emmanuelle , Thouvenot Eric , Ruet Aurelie , Mathey Guillaume , Gourraud Pierre-Antoine , Tarte Karin , Delaloy Celine , Amé Patricia , Roussel Mikael , Michel Laure 

TITLE=Blood immunophenotyping of multiple sclerosis patients at diagnosis identifies a classical monocyte subset associated to disease evolution

JOURNAL=Frontiers in Immunology

VOLUME=Volume 15 - 2024

YEAR=2025

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1494842

DOI=10.3389/fimmu.2024.1494842

ISSN=1664-3224

ABSTRACT=IntroductionMyeloid cells trafficking from the periphery to the central nervous system are key players in multiple sclerosis (MS) through antigen presentation, cytokine secretion and repair processes.MethodsCombination of mass cytometry on blood cells from 60 MS patients at diagnosis and 29 healthy controls, along with single cell RNA sequencing on paired blood and cerebrospinal fluid (CSF) samples from 5 MS patients were used for myeloid cells detailing.ResultsMyeloid compartment study demonstrated an enrichment of a peculiar classical monocyte population in 22% of MS patients at the time of diagnosis. Notably, this patients’ subgroup exhibited a more aggressive disease phenotype two years post-diagnosis. This monocytic population, detected in both the CSF and blood, was characterized by CD206, CD209, CCR5 and CCR2 expression, and was found to be more frequent in MS patients carrying the HLA-DRB1*15:01 allele. Furthermore, pathways analysis predicted that these cells had antigen presentation capabilities coupled with pro-inflammatory phenotype.DiscussionAltogether, these results point toward the amplification of a specific and pathogenic myeloid cell subset in MS patients with genetic susceptibilities.