NfL and GFAP in serum are associated with microstructural brain damage in progressive multiple sclerosis.

BACKGROUND: The potential of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) as biomarkers of disease activity and severity in progressive forms of multiple sclerosis (MS) is unclear. OBJECTIVE: To investigate the relationship between serum concentrations of NfL, GFAP, and magnetic resonance imaging (MRI) in progressive MS. METHODS: Serum concentrations of NfL and GFAP were measured in 32 healthy controls and 32 patients with progressive MS from whom clinical and MRI data including diffusion tensor imaging (DTI) were obtained during three years of follow-up. RESULTS: Serum concentrations of NfL and GFAP at follow-up were higher in progressive MS patients than in healthy controls and serum NfL correlated with the EDSS score. Decreasing fractional anisotropy (FA) in normal-appearing white matter (NAWM) correlated with worsening EDSS scores and higher serum NfL. Higher serum NfL and increasing T2 lesion volume correlated with worsening paced autitory serial addition test scores. In multivariable regression analyses with serum GFAP and NfL as independent factors and DTI measures of NAWM as dependent factors, we showed that high serum NfL at follow-up was independently associated with decreasing FA and increasing MD in NAWM. Moreover, we found that high serum GFAP was independently associated with decreasing MD in NAWM and with decreasing MD and increasing FA in cortical gray matter. CONCLUSION: Serum concentrations of NfL and GFAP are increased in progressive MS and are associated with distinct microstructural changes in NAWM and CGM.

Expression of melanoma cell adhesion molecule-1 (MCAM-1) in natalizumab-treated multiple sclerosis.

The objectives were to study the expression of very late antigen (VLA)-4, melanoma cell adhesion molecule-1 (MCAM-1) and activated leukocyte cell adhesion molecule (ALCAM) on CD4+ T cells during natalizumab treatment and to investigate the association with disease activity. We find that subgroups of autoreactive T cells are retained in peripheral blood, in particular MOG-reactive CD4+ T cells expressing MCAM-1. The expression of MCAM-1 or ALCAM on CD4+ T cells was, however, not clearly associated with disease activity (clinical or MRI) during natalizumab treatment. We confirm upregulation of MCAM-1 on CD4+ T cells during natalizumab treatment while VLA-4 is downregulated.

Soluble serum VCAM-1, whole blood mRNA expression and treatment response in natalizumab-treated multiple sclerosis.

BACKGROUND: Natalizumab reduces disease activity in multiple sclerosis (MS). Natalizumab binds to the very late antigen-4 and inhibits vascular cell adhesion molecule-1 (VCAM-1)-mediated transmigration of immune cells across the blood-brain-barrier. This is associated with decreased serum concentrations of soluble (s)VCAM-1 and an altered composition of immune cell-subsets in the blood. OBJECTIVE: We aimed to examine if sVCAM-1 serum concentrations and whole blood mRNA expression levels of immune activation biomarkers is associated with disease activity in natalizumab-treated MS-patients. METHODS: sVCAM-1 serum concentrations and whole blood mRNA expression were measured in blood samples from untreated RRMS-patients and from two independent groups of natalizumab-treated patients. RESULTS: sVCAM-1 serum concentrations and whole blood expression of HLX1 and IL1B mRNA were lower, whereas expression of EBI3 mRNA was higher in natalizumab-treated MS-patients. Five genes were differentially expressed in clinically unstable natalizumab-treated MS-patients in the discovery but not in the validation group. CONCLUSION: Decreased serum concentrations of sVCAM-1 and altered whole blood mRNA expression levels of a panel of immunomarkers, associated with natalizumab-treatment, are not sensitive markers of MS disease activity. However, decreased expression of pro-inflammatory HLX1 and IL1B and increased expression of immunoregulatory EBI3 may indicate a less pathogenic immune activation status in natalizumab-treated MS.

Identification of Suitable Reference Genes for Peripheral Blood Mononuclear Cell Subset Studies in Multiple Sclerosis.

Quantitative real-time PCR (qPCR) involves the need of a proper standard for normalizing the gene expression data. Different studies have shown the validity of reference genes to vary greatly depending on tissue, cell subsets and experimental context. This study aimed at the identification of suitable reference genes for qPCR studies using different peripheral blood cell subsets (whole blood (WB) cells, peripheral blood mononuclear cells (PBMCs) and PBMC subsets (CD4(+) T cells, CD8(+) T cells, NK cells, monocytes, B cells and dendritic cells) from healthy controls (HC), patients with relapsing-remitting multiple sclerosis (RRMS) and interferon-ß-treated patients with RRMS (RRMS-IFN-ß). Eight candidate reference genes (CASC3, EEF1A1, GAPDH, HPRT1, RPLP0, UBC, UBE2D2 and YWHAZ) were analysed using normfinder and genorm algorithms to identify the most stably expressed genes. We found reference gene expression varied most across cell subsets, and less variation between the donor groups. UBE2D2 was the most stably expressed gene across both HC and RRMS patients and across cell subsets, while UBC was the most stably expressed gene between HC, RRMS and RRMS-IFN-ß patients. UBE2D2 and HPRT1 was the most stable combination for analyses of cell subsets between HC and RRMS patients, while the combination of UBC and YWHAZ was superior for analysis of cell subsets between HC, RRMS and RRMS-IFN-ß groups. GAPDH was generally unsuitable for blood cell subset studies in multiple sclerosis. In conclusion, we found that blood cell subsets result in marked variation in reference gene expression, and we identified suitable reference genes for studies involving PBMC subsets, RRMS patients and interferon-ß treatment.

Immunological effects of methylprednisolone pulse treatment in progressive multiple sclerosis.

OBJECTIVE: To investigate the effect of monthly oral methylprednisolone pulse treatment in progressive MS. METHODS: 30 progressive MS patients were treated with oral methylprednisolone every month. Peripheral blood mononuclear cells were analyzed by flow cytometry. RESULTS: Out of 102 leukocyte phenotypes investigated, 25 changed at nominal significance from baseline to week 12 (p<0.05). After correction for multiple comparisons, we found 5 subpopulations that changed compared to baseline. No pattern were suggesting modulation of Th17 or TFH cells. CONCLUSION: Methylprednisolone pulse treatment has some effects on circulating immune cells but does not modulate markers of Th17 and TFH cell activity in progressive MS.

Gene expression analysis of relapsing-remitting, primary progressive and secondary progressive multiple sclerosis.

BACKGROUND: Previous studies of multiple sclerosis (MS) have indicated differences in the pathogenesis in relapsing-remitting (RRMS), secondary progressive (SPMS) and primary progressive (PPMS) disease. OBJECTIVE: We hypothesized that different MS subtypes would show differences in gene expression that could be traced to specific subsets of peripheral blood mononuclear cells (PBMCs). METHODS: Gene expression in RRMS, SPMS, PPMS and healthy control (HC) PBMCs was analyzed on Affymetrix arrays. In addition, we studied gene expression in pools of purified PBMC subsets. RESULTS: We found 380 genes that were differentially expressed in RRMS, PPMS, SPMS and HCs (false discovery rate < 5%). There were no major differences between the subtypes of MS. The genes showing most prominent expression changes in RRMS were associated with adaptive immune pathways, while genes in PPMS were associated with innate immune system pathways. SPMS patients shared pathways with RRMS and PPMS patients. Gene expression changes were most prominent in B cells, CD8+ T cells and monocytes. CONCLUSION: Differences in gene expression, which could be traced to B cells, CD8+ T cells and monocytes, were found between MS patients and HCs but only minor differences were observed between MS subgroups.

Increased cerebrospinal fluid concentrations of the chemokine CXCL13 in active MS.

BACKGROUND: Accumulating evidence supports a major role of B cells in multiple sclerosis (MS) pathogenesis. How B cells are recruited to the CNS is incompletely understood. Our objective was to study B-cell chemokine concentrations in MS, their relationship with disease activity, and how treatment with methylprednisolone and natalizumab affected the concentration in CSF. METHODS: Using a cross-sectional design, CSF and blood samples were obtained from cohorts of patients with clinically isolated syndromes (CIS), relapsing-remitting MS (RRMS), primary progressive MS (PPMS), or secondary progressive MS (SPMS), and noninflammatory neurologic disease control subjects. Some patients with RRMS were studied before and after treatment with methylprednisolone or natalizumab. RESULTS: In CSF, concentrations of CXCL13, but not CXCL12, were higher in patients with CIS, RRMS, SPMS, and PPMS than in controls. CSF concentrations of CXCL13 correlated with the CSF B-cell count, with markers of immune activation, and with disease activity in patients with CIS and RRMS. CSF concentrations of CXCL13 decreased after treatment with high-dose methylprednisolone and natalizumab. High CSF concentrations of CXCL13 correlated with low expression of messenger RNA encoding the immunoregulatory cytokines interleukin 10 and transforming growth factor beta1, but not with the expression of T-helper type 1 (Th1) and Th17 factors. CONCLUSION: The chemokine CXCL13 may play a major role in recruitment of B cells and T-cell subsets expressing the chemokine receptor CXCR5 to the CNS in multiple sclerosis (MS), and may be a useful biomarker for treatment effects in MS. Furthermore, CXCL13 or its receptor CXCR5 should be considered as therapeutic targets in MS.

The effects of natalizumab on inflammatory mediators in multiple sclerosis: prospects for treatment-sensitive biomarkers.

BACKGROUND: Natalizumab affects systemic cytokine expressions and clinical course in relapsing-remitting multiple sclerosis (RRMS). We analyzed levels of inflammatory cytokines in cerebrospinal fluid (CSF) cells and peripheral blood mononuclear cells (PBMCs), levels of matrix metalloproteinase (MMP)-9 and osteopontin (OPN) in CSF, and clinical outcome measures in 22 natalizumab-treated RRMS patients. METHODS: mRNA levels of cytokines in cells were detected with real-time RT-PCR. Protein levels of OPN and MMP-9 were measured by ELISA. RESULTS: Natalizumab reduced CSF cell counts (P < 0.0001). Tumor necrosis factor (TNF) and interferon-gamma (IFN-gamma) mRNAs were significantly increased in PBMCs. In contrast, expressions of IFN-gamma and interleukin (IL)-23 were decreased but IL-10 increased in the CSF cells. OPN and MMP-9 were reduced in the CSF. Patients being in remission at baseline showed the same deviations of mediators as those in relapse after natalizumab treatment. The open label clinical outcome measures were either stable or improved during therapy. CONCLUSIONS: Natalizumab attenuates pro-inflammatory mediators intrathecally and the reduced pro-inflammatory milieu may allow increased production of the anti-inflammatory mediator IL-10. The increased systemic cytokines may impede the improvement of certain clinical measures like fatigue. The affected mediators seem to be sensitive to an immune-modifying treatment which could be used as biomarkers for this therapy.