Identification of Immunophenotypic Signatures in the Innate Immune System of MS Patients by Multiparametric Flow Cytometry (P02.098)

Abstract

Objective: Identification of cell surface markers in peripheral blood to distinguish patients from controls. Background MS patients by multiparametric flow cytometry Background: MS is a chronic inflammatory and demyelinating disease of the CNS with unknown etiology until now. CD4+ T helper (Th) 1 cells, proinflammatory Th17 cells, CD8+ T cells, B cells, natural killer (NK) cells and denritic cells (DC) are accepted to play in important role in pathogenesis of disease. Lymphocytes of the peripheral blood from multiple sclerosis (MS) patients are characterized by proinflammatory function but robust cell surface markers to distinguish patients from controls are not available until now. Design/Methods: In this pilot study we analysed phenotypes and their frequencies of peripheral blood cell subsets by multicolour flow cytometry in a limited set of MS patients. The combination of 50 different monoclonal antibodies allowed the detection of nearly 1000 immunophenotypic parameters per sample. Relative and, absolute cell numbers including relative fluorescence intensities of all fluorochromes were compared between 10 patients with early relapsing-remitting MS (RRMS) and 10 healthy age- and sex-matched controls. Results: Immunophenotypic signatures have been identified that allowed a clear classification of MS-patients if compared to healthy controls. These signatures were composed of parameters, which predominantly describe changes in the cells of the innate immune system, such as NK cells, monocytes and neutrophils. For example, in MS IFNg receptor on NK cells, CD62L on granulocytes and CCR2 on neutrophiles was upregulated in MS compared to controls. Conclusions: Our innovative approach identified for the first time MS-specific immunophenotypic signatures of peripheral blood leukocytes by multiparametric flow cytometry. Expression receptors involved in function and activation of innate immune cells showed a significant increase in MS patients compared to controls. Thus, large–scale immunophenotyping is an encouraging tool to identify new disease relevant leukocyte subtypes in a hypothesis-based and hypothesis-generating manner. Supported by: Parts of the study were supported by Merck Serono. Disclosure: Dr. Schulte-Wrede has nothing to disclose. Dr. Grun has nothing to disclose. Dr. Scholz has nothing to disclose. Dr. Harms has received personal compensation for activities with Biomarin, Biogen, Bayer Health Care, Talecris, Merck-Serono as scientific advisory board member and/or speaker. Dr. Grutzkau has nothing to disclose. Dr. Rosche has received personal compensation for activities with Biogen Idec, Bayer-Schering, Teva, and Merck-Serono as a speaker.