Neurofilament Light Chain ,Chitinase-3 Like-1 Proteins and Plasmacytoid Dendritic Cells in Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune neurodegenerative disease characterized by demyelination and neurodegeneration of the central nervous system (CNS) . Current diagnostic criteria and management depend on MRI, clinical status, and oligoclonal immunoglobulin g bands . These markers often fail to predict relapse, progression and therapy response .There is an increased need to identify biomarkers for clinical endpoints . One of the hallmark features of MS is axonal damage which associated with brain and cervical atrophy.Nf levels indicate the extent of axonal damage. Neurofilaments are composed of four subunits: neurofilament light polypeptides (NfL) is the most abundant and soluble and it is highly sensitive to neurodegenerative processes . Chitinase 3-like 1 (CHI3L1) is expressed in astrocytes in the brain tissue of MS patients . CHI3L1 plays a role as prognostic biomarker in patients with MS. CHI3L1 cerebrospinal fluid levels were associated correlated with disease activity and neurological disability. Dendritic cells (DCs) are highly specialized antigen-presenting cells with a key role in activating and preventing CNS immune-mediated damage in MS . Dendritic cells express Human Leukocyte Antigen-antigen D Related (HLA-DR) . Plasmacytoid dendritic cells characterized by the expression of blood dendritic cells antigen-2 (BDCA-2) .Plasmacytoid dendritic cells are present in the cerebrospinal fluid (CSF), leptomeninges and demyelinating lesions of patients with MS . Plasmacytoid dendritic cells also exhibit up-regulation of chemokine (CCR7C) expression. It was demonstrated increased amounts of chemokine CCR7 in the CSF from MS patients during relapses .CCR7 controls migration and functional activity of regulatory T cells and plays an important role in the establishment of tolerance . Tolerogenic DCs (TolDCs) present an intermediate phenotype between immature dendritic cells (iDCs) and mature dendritic cells (mDCs) regarding costimulatory molecules, a pronounced shift toward anti-inflammatory . TolDCs exhibit tolerogenic molecules such as HLA-G and CD274 \[programmed death-ligand 1 (PD-L1)\] either in peripheral blood or in CSF. These characteristics lead to T cell clonal anergy and T cell unresponsiveness due to Ag presentation in the presence of low co-stimulation .We aim to investigate the role of NfL,(CHI3L1) and markers of plasmacytoid dendritic cells in MS.