B cell expression of the inhibitory Fcγ receptor is unchanged in early MS

Multimodal peripheral fluid biomarker analysis in clinically isolated syndrome and early multiple sclerosis

BACKGROUND

Increasing evidence suggests that various inflammatory, immunological and metabolic pathways are altered in the clinically isolated syndrome (CIS) of multiple sclerosis (MS). Moreover, recent diagnostic criteria have made possible the very early diagnosis of MS. We evaluated multiple fluid biomarkers in people with early MS and CIS.

METHODS

We measured blood levels of cytokines, matrix metalloproteinases (MMPs), serum metabolomics and immune cell immunophenotyping in participants in the Trial of Minocycline in a Clinically Isolated Syndrome of Multiple Sclerosis.

RESULTS

When compared with healthy controls, people with early MS/CIS had higher levels of eotaxin, MCP-3, IL-1 receptor antagonist, IL-1β, IL-9 and IP-10, as well as MMPs 1, 8 and 9. In metabolomics analysis, the alanine, aspartate and glutamate metabolism and the synthesis and degradation of ketone bodies pathways were altered compared to healthy controls. There were no differences in lymphocyte subpopulation numbers. Out of all these biomarkers, only MMP-1 was able to differentiate between early MS and CIS, and was found to correlate with lesion volume and gadolinium enhancing lesions on MRI.

CONCLUSION

The immunological and metabolic profile of CIS and early MS is remarkably similar, supporting that these are a continuum of a common underlying pathophysiological process.

FcγRIIb Expression Is Decreased on Naive and Marginal Zone-Like B Cells From Females With Multiple Sclerosis

B cells are critical to the development of multiple sclerosis (MS), but the mechanisms by which they contribute to the disease are poorly defined. We hypothesised that the expression of CD32b (FcγRIIb), a receptor for the Fc region of IgG with inhibitory activities in B cells, is lower on B cell subsets from people with clinically isolated syndrome (CIS) or MS. CD32b expression was highest on post-naive IgM⁺ B cell subsets in healthy controls. For females with MS or CIS, significantly lower CD32b expression was identified on IgM⁺ B cell subsets, including naive and IgM^hi MZ-like B cells, when compared with control females. Lower CD32b expression on these B cell subsets was associated with detectable anti-Epstein Barr Virus viral capsid antigen IgM antibodies, and higher serum levels of B cell activating factor. To investigate the effects of lower CD32b expression, B cells were polyclonally activated in the presence of IgG immune complexes, with or without a CD32b blocking antibody, and the expression of TNF and IL-10 in B cell subsets was assessed. The reduction of TNF but not IL-10 expression in controls mediated by IgG immune complexes was reversed by CD32b blockade in naive and IgM^hi MZ-like B cells only. However, no consequence of lower CD32b expression on these cells from females with CIS or MS was detected. Our findings highlight a potential role for naive and marginal zone-like B cells in the immunopathogenesis of MS in females, which requires further investigation.

Fcγ receptors in Norwegian multiple sclerosis patients and healthy controls

BACKGROUND

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system in genetically susceptible persons. Fcγ receptors (FcγR) are involved in autoimmune diseases.

PATIENTS AND METHODS

Sixteen Norwegian patients with relapsing-remitting MS (RRMS) were studied to see whether treatment with either interferon-beta (INF-β) or glatiramer acetate (GA) influenced the proportion of FcγR1a, FcγR2a, and FcγR3b positive monocytes, granulocytes, or lymphocytes or FcγR1a, FcγR2a, and FcγR2b mRNA levels in leukocytes. One hundred and twenty-seven patients with RRMS and 54 Norwegian healthy blood donors were also analyzed for FcγR2b polymorphisms.

RESULTS

Interferon-beta or GA treatment initiated an increase in the proportion of FcγR positive lymphocytes, but did not cause major influence of the long-term proportion of FcγR positive leukocytes or their FcγR mRNA levels. No significant differences were observed between RRMS patients and healthy controls for the genotype and allele frequencies of FcγR2b polymorphisms.

DISCUSSION

INF-β or GA treatment probably has no major role in the regulation of FcγRs on immune cells in RRMS. Furthermore, polymorphisms of the inhibitory FcγR2b do not seem to influence the susceptibility for MS.

Cytometric profiling in various clinical forms of multiple sclerosis with respect to CD21+, CD32+, and CD35+ B and T cells

Background

We aimed to evaluate the frequency of various types of B and T cells expressing CD21, CD32, and CD35 in multiple sclerosis (MS) clinical courses.

Methods

Peripheral blood mononuclear cell from 30 MS patients (17 relapsing remitting [RRMS], six secondary progressive [SPMS], and seven primary progressive MS [PPMS]) and 18 healthy subjects were analyzed. All patients were in acute attack. Healthy controls were matched for age and gender ratio. The frequencies of various subsets of B and T cells were determined using flow cytometry.

Results

The frequency of CD4⁺T cells was lower in MS patients compared to control subjects (41.14 ± 9.45% vs. 46.88 ± 6.98%, respectively, P < 0.05). The CD32⁺ fraction of CD4⁺T cells and the CD21⁺ fraction of CD8⁺T cells were higher in MS patients (2.85 ± 3.72% vs. 1.06 ± 0.62% for CD32⁺CD4⁺T cells, 2.71 ± 1.86% vs. 1.16 ± 0.99% for CD21⁺CD8⁺T cells in MS patients and control subjects, respectively, P < 0.05). After dividing subjects by type of MS course, higher values of these two T cell subsets were found in SPMS patients compared to control subjects (P < 0.05). Further, RRMS patients had lower levels of CD32⁺CD4⁺T cells than SPMS patients and also they had lower levels of CD32⁺CD8⁺T cells than PPMS patients (P < 0.05). However, neither the expression of CD35 on T cells nor the various B cell subsets were statistically different between the compared groups.

Conclusions

Our findings demonstrate that T cell subsets expressing CD21 and CD32 may differ with respect to the presence or clinical forms of MS disease. By contrast, CD35⁺T cells and different subsets of B cells are not altered in various MS clinical courses.

Increased plasma 8,12-iso-iPF2alpha- VI levels in relapsing multiple sclerosis patients are not predictive of disease progression

Background:

Oxidative stress plays an important role in multiple sclerosis (MS). Isoprostanes are biomarkers for oxidative stress and have been related to neurological disease progression.

Objective:

To study whether plasma isoprostane levels were related to disease progression in MS.

Methods:

Plasma levels of 8,12-iso-iPF2alpha-VI were determined in 17 patients with clinically isolated syndrome (CIS), 41 relapsing–remitting MS (RRMS) patients and 5 primary progressive MS (PPMS) patients and related to MRI and clinical disease parameters.

Results:

Isoprostane levels were similar in CIS (60.9, interquartile range (IQR): 47.7–77.7 pg/ml) and RRMS patients (65.3, IQR: 51.9–82.8 pg/ml). The plasma levels were lower in PPMS patients (42.5, IQR: 37.1–49.9) pg/ml, p<0.05) compared to CIS and RRMS patients in this cohort, which was not confirmed in a second cohort. Baseline isoprostane levels were not related to clinical progression defined by conversion form CIS to RRMS or change in Expanded Disability Status Scale (EDSS) or MS Functional Composite (MSFC) scores during six years of follow-up (CIS + RRMS), nor to change in volume of gadolinium enhancing lesions, T2 lesion load or T1 hypointense lesion load during 2.8 years of follow-up (CIS + RRMS).

Conclusion:

These results do not support a strong role of 8,12-iso-iPF2alpha-VI in the prediction of disease progression in MS.