Background

Background: Multiple Sclerosis (MS) is an immune mediated disease of the central nervous system (CNS). Epstein-Barr virus (EBV) is among the most well-established environmental risk factors in MS. MS patients also make low affinity antibodies against neurotrophic viruses such as measles (M), rubella (R), and zoster (Z), and they make these intrathecally. This phenomenon is quite specific for MS and it is called MRZ reaction. The pathophysiological role of MRZ reaction currently remains unclear.

Objectives

Objectives: Because EBV induces differentiation of infected B cells in antigen-nonspecific manner, the aim of this project is to test the hypothesis that the extent of MRZ reaction correlates with the amount of EBV infected B cells in the intrathecal compartment of MS patients and with the MS severity.

Methods

Methods: In a pilot cohort of 80 patients with broad range of MS severity, we blindly analyzed MRZ reaction by enzyme-linked immunosorbent assay (ELISA) applied to matched cerebrospinal fluid (CSF) and serum samples. To derive a single measure of the extent of MRZ reaction, we summed antibody indexes (AI) for each reaction component (M, R and Z) to MRZ score.

Results

Results: Upon unblinding the MS severity outcomes and diagnostic subgroups, the MRZ scores did not significantly correlate with B cell/plasma cell biomarkers known to be increased in MS CSF (i.e., B-cell maturation antigen/BCMA and IgG index) and were not significantly different between relapsing remitting, primary progressive and secondary progressive MS. Finally, the MRZ scores did not correlate with clinical outcomes of MS severity (MS disease severity scale: MS-DSS and brain damage severity: principal component of brain parenchymal fraction and the symbol digit modalities test normalized for patient’s age).

Conclusions

Conclusions: The study proved null hypothesis (i.e., MRZ reaction is not associated with intrathecal biomarkers of B cell/plasma cell expansion and with MS severity). The association between MRZ reaction and MS remains a mystery.

Acknowledgments: The research was supported by the Intramural Research Program of the NIH, NIAID.

Notice: This study involved patients and it was approved by NIAID IRB.

Background

Quantifying cell subpopulations in biological fluids aids in diagnosis and understanding of the mechanisms of injury. Although much has been learned from cerebrospinal fluid (CSF) flow cytometry in multiple sclerosis (MS), previous studies did not contain enough healthy donors (HD) to derive age- and gender-related normative data and sufficient heterogeneity of other inflammatory neurological diseases (OIND) controls to identify MS-specific changes.

Objectives

1. To define physiological age/gender-related changes in blood and CSF cells. 2) To define/validate cellular abnormalities in blood and CSF of untreated MS. 3. To compare the effects of low-efficacy and high-efficacy drugs on MS-related cellular abnormalities.

Methods

1240 prospectively acquired paired CSF/blood samples were collected from 588 subjects, representing HDs, MS patients, and various controls. Samples were blinded during processing, stained with a 12-color antibody panel, and run by flow cytometry. All p-values were adjusted for multiple comparisons. HDs and untreated MS patients were compared in independent training and validation cohorts. Propensity score matching was completed between untreated and treated MS patients to account for differences in age, gender, and disability.

Results

Both CSF and blood of HDs have changes in immune cell populations with age, although the changes are more pronounced in blood than CSF. Different MS subtypes have similar immunological changes, where immune cell populations are constantly recruited to the CSF from the periphery. All MS drugs decrease CSF inflammation; low efficacy drugs tend to normalize it, meanwhile, high efficacy drugs overshoot CSF HD range.

Conclusions

Age-related changes suggest decreased immunosurveillance of CNS by activated, HLA-DR+ T cells associated with natural aging. MS is an immunologically single disease evolving in time. At early stage of the disease, peripherally activated innate and adaptive immune cells migrate into CSF to form MS lesions. T cells and NK cells are depleted from blood as they accumulate, together with B cells, in the CSF. Eventually, these immune cells remain in CNS tissue as compartmentalized inflammation. High efficacy treatments exert a stronger inhibitory effect on recently activated HLA-DR+ T cells, which may underlie their greater efficacy. High efficacy treatments also overshoot CSF immune cell depletion beyond physiological levels, likely disrupting natural immune surveillance of CNS tissue.

Background

Background: Multiple Sclerosis (MS) is an immune mediated disease of the central nervous system (CNS). Epstein-Barr virus (EBV) is among the most well-established environmental risk factors in MS. MS patients also make low affinity antibodies against neurotrophic viruses such as measles (M), rubella (R), and zoster (Z), and they make these intrathecally. This phenomenon is quite specific for MS and it is called MRZ reaction. The pathophysiological role of MRZ reaction currently remains unclear.

Objectives

Objectives: Because EBV induces differentiation of infected B cells in antigen-nonspecific manner, the aim of this project is to test the hypothesis that the extent of MRZ reaction correlates with the amount of EBV infected B cells in the intrathecal compartment of MS patients and with the MS severity.

Methods

Methods: In a pilot cohort of 80 patients with broad range of MS severity, we blindly analyzed MRZ reaction by enzyme-linked immunosorbent assay (ELISA) applied to matched cerebrospinal fluid (CSF) and serum samples. To derive a single measure of the extent of MRZ reaction, we summed antibody indexes (AI) for each reaction component (M, R and Z) to MRZ score.

Results

Results: Upon unblinding the MS severity outcomes and diagnostic subgroups, the MRZ scores did not significantly correlate with B cell/plasma cell biomarkers known to be increased in MS CSF (i.e., B-cell maturation antigen/BCMA and IgG index) and were not significantly different between relapsing remitting, primary progressive and secondary progressive MS. Finally, the MRZ scores did not correlate with clinical outcomes of MS severity (MS disease severity scale: MS-DSS and brain damage severity: principal component of brain parenchymal fraction and the symbol digit modalities test normalized for patient’s age).

Conclusions

Conclusions: The study proved null hypothesis (i.e., MRZ reaction is not associated with intrathecal biomarkers of B cell/plasma cell expansion and with MS severity). The association between MRZ reaction and MS remains a mystery.

Acknowledgments: The research was supported by the Intramural Research Program of the NIH, NIAID.

Notice: This study involved patients and it was approved by NIAID IRB.