Multiplexing analysis of the polyspecific intrathecal immune response in multiple sclerosis

Clinical significance of fluid biomarkers in Alzheimer's Disease

The number of patients with Alzheimer's Disease (AD) and other types of dementia disorders has drastically increased over the last decades. AD is a complex progressive neurodegenerative disease affecting about 14 million patients in Europe and the United States. The hallmarks of this disease are neurotic plaques consist of the Amyloid-β peptide (Aβ) and neurofibrillary tangles (NFTs) formed of hyperphosphorylated Tau protein (pTau). Currently, four CSF biomarkers: Amyloid beta 42 (Aβ42), Aβ42/40 ratio, Tau protein, and Tau phosphorylated at threonine 181 (pTau181) have been indicated as core neurochemical AD biomarkers. However, the identification of additional fluid biomarkers, useful in the prognosis, risk stratification, and monitoring of drug response is sorely needed to better understand the complex heterogeneity of AD pathology as well as to improve diagnosis of patients with the disease. Several novel biomarkers have been extensively investigated, and their utility must be proved and eventually integrated into guidelines for use in clinical practice. This paper presents the research and development of CSF and blood biomarkers for AD as well as their potential clinical significance. Upper panel: Aβ peptides are released from transmembrane Amyloid Precursor Protein (APP) under physiological conditions (blue arrow). In AD, however, pathologic accumulation of Aβ monomers leads to their accumulation in plaques (red arrow). This is reflected in decreased concentration of Aβ1-42 and decreased Aβ42/40 concentration ratio in the CSF. Lower panel: Phosphorylated Tau molecules maintain axonal structures; hyperphosphorylation of Tau (red arrow) in AD leads to degeneration of axons, and release of pTau molecules, which then accumulate in neurofibrillary tangles. This process is reflected by increased concentrations of Tau and pTau in the CSF.

G1m1 predominance of intrathecal virus-specific antibodies in multiple sclerosis

We have previously shown that plasmablasts of the G1m1 allotype of IgG1 are selectively enriched in the cerebrospinal fluid of G1m1/G1m3 heterozygous patients with multiple sclerosis, whereas both allotypes are equally used in neuroborreliosis. Here, we demonstrate a strong preference for the G1m1 allotype in the intrathecal humoral immune responses against measles, rubella, and varicella zoster virus in G1m1/G1m3 heterozygous multiple sclerosis patients. Conversely, intrathecally synthesized varicella zoster virus‐specific IgG1 in varicella zoster virus meningoencephalitis comprised both allotypes. This implies that G1m1 B cells are selected to the central nervous system of multiple sclerosis patients regardless of specificity and suggests that an antigen‐independent mechanism could drive the intrathecal humoral immune response.

The MRZ reaction helps to distinguish rheumatologic disorders with central nervous involvement from multiple sclerosis

BACKGROUND

Some rheumatologic disorders may initially manifest with central nervous system (CNS) affection, mimicking the clinical, magnetic resonance imaging, and cerebrospinal fluid findings of multiple sclerosis (MS). The MRZ reaction (MRZR), composed of the three respective antibody indices (AIs) against measles, rubella, and varicella zoster virus, has been found positive frequently in MS patients. However, it is unclear whether the MRZR is helpful to distinguish rheumatologic disorders with CNS involvement (RDwCNS) from MS.

METHODS

The MRZR was evaluated in patients with RDwCNS (n = 23), MS (n = 46; age and sex matched to patients with RDwCNS), and other inflammatory autoimmune neurological diseases affecting the CNS (OIND; n = 48). Both the stringency levels that have been used in previous MRZR studies, MRZR-1 (≥ 1 of 3 AIs positive) and MRZR-2 (≥ 2 of 3 AIs positive), were applied.

RESULTS

There was no statistically significant difference in the prevalence of positive MRZR between patients with RDwCNS (MRZR-1: 13.0% and MRZR-2: 8.7%, respectively) and OIND (MRZR-1: 22.9% and MRZR-2: 8.3%, respectively). Compared to these two study cohorts, the MS group exhibited significantly higher prevalences of positive MRZR (MRZR-1: 82.6%, MRZR-2: 63.0%; p < 0.005 each).

CONCLUSIONS

Considering the high specificity of MRZR-2 for MS found in this study, MRZR-2 can be a useful diagnostic tool for distinguishing MS from RDwCNS or OIND.

The MRZ reaction in primary progressive multiple sclerosis

Background

The MRZ reaction (MRZR), composed of the three antibody indices (AI) against measles, rubella and varicella zoster virus and found positive in the majority of relapsing-remitting multiple sclerosis (RRMS) patients, is absent in other inflammatory neurological diseases (OIND). So far, it has been uncertain whether its differential diagnostic promise extends to patients with primary-progressive multiple sclerosis (PPMS).

Objective

To investigate the prevalence of MRZR in PPMS compared to RRMS and OIND patients.

Methods

MRZR was assessed in patients with PPMS (n = 103), RRMS (n = 100) and OIND (n = 48). Both stringency levels for MRZR testing, MRZR-1 (≥1 AI positive) and MRZR-2 (≥2 AI positive), were applied.

Results

Prevalence of positive MRZR-1 was 83.5% in PPMS and 67.8% in RRMS (p < 0.05). A positive MRZR-2 was found in 54.4% of PPMS and in 43.0% of RRMS patients (not significant). Compared to both MS subgroups, OIND patients exhibit lower frequencies of positive MRZR (MRZR-1: 22.9%, MRZR-2: 8.3%; p < 0.0001 each).

Conclusion

Positive MRZR was at least as frequent in PPMS as in RRMS and much less frequent in OIND, confirming its promise as a potentially useful diagnostic tool for distinguishing both MS course types from OIND.

Validation of a multiplexing technique to determine the intrathecal, polyspecific antiviral immune response in multiple sclerosis

BACKGROUND

Beside the determination of oligoclonal bands (OCBs) as a diagnostic biomarker in multiple sclerosis (MS), the presence of an intrathecal production of antibodies against the neurotropic viruses measles (M), rubella (R) and Varicella-Zoster (Z), the so called MRZ reaction (MRZR) is an even more specific diagnostic biomarker in MS.

METHODS

We compared and validated the determination of the MRZR in 97 cerebrospinal fluid (CSF) and serum sample pairs of a bead-based multiplexing technique and a classical enzyme-linked immunosorbent assay (ELISA).

RESULTS

Conformity of 94% (M), 94% (R), 94% (Z), 96% (H) and 97% for the interpretation of the MRZR was obtained.

CONCLUSION

Based on our findings of high conformity between the multiplex technique and classical ELISA, as well as the time and cost savings multiplexing allows, we conclude that the multiplexing technique is applicable as a diagnostic tool for the determination of the MRZR.

Elevated antibody reactivity to measles virus NCORE protein among patients with multiple sclerosis and their healthy siblings with intrathecal oligoclonal immunoglobulin G production

BACKGROUND

Patients with multiple sclerosis (MS) and their healthy siblings with the MS oligoclonal bands (OCB) trait, (a hyperimmune condition in form of two or more CSF enriched OCBs) harbor in cerebrospinal fluid (CSF) and serum elevated immunoglobulin G (IgG) titers against measles crude whole-cell antigen. The underlying mechanism resulting in the increased IgG antibody reactivity to measles remains unclear. The response may represent specific IgG reactivity to measles antigens or unspecific auto-antibodies targeting cellular components in the crude whole virus antigens commonly used in detection assays.

OBJECTIVE

To determine the specificity of the measles IgG antibody reactivity by using a purified single nucleoprotein as antigen, thereby minimizing the contribution from auto-antibodies.

STUDY DESIGN

The conserved N-terminal portion of the measles nucleocapsid protein (NCORE) was expressed as a specific antigen devoid of human or primate components. Serological analyses were performed on CSF and sera from MS patients, their clinically healthy siblings and healthy unrelated controls.

RESULTS

MS patients demonstrated higher IgG reactivity compared to healthy controls in both CSF (P<0.001) and serum (P<0.001), and compared to siblings in CSF (P<0.001) and serum (P=0.2). Siblings with MS OCB trait showed higher IgG reactivity than healthy controls in CSF (P=0.002) and serum (P=0.01). Comparison between siblings with MS OCB trait and siblings without MS OCB trait showed (P=0.04) for CSF and (P=0.08) for serum.

CONCLUSION

These findings suggest a measles-specific component in the antibody reactivity demonstrated by MS patients and their siblings with the MS OCB trait.

The participation of varicella zoster virus in relapses of multiple sclerosis

OBJECTIVE

Recent studies have documented the apparent participation of varicella zoster virus (VZV) in the etiopathogenesis of multiple sclerosis (MS). The present study aimed to corroborate the possible presence of VZV during exacerbations of MS.

DESIGN

Fifty-three patients with definite MS were included; of them, 31 were studied during the first week of a clinical relapse, whereas 16 were studied during remission; 6 patients with progressive MS were also studied. Genes from 5 herpes viruses: varicella zoster, herpes simplex 1 and 2, Epstein-Barr and herpes 6 were studied by polymerase chain reaction in cerebrospinal fluid and in peripheral blood mononuclear cells (PBMC). As controls 21 patients with inflammatory or functional neurological disorders were included.

RESULTS

DNA from varicella zoster virus was found in the CSF from all MS patients studied during relapse (100%) and in the PBMC from 28 of them (90%). However, VZV DNA was found in the CSF only in 5 MS patients studied during remission (31%) and in the PBMC from 3 of them (19%). VZV DNA was also found, but in lower amounts, in the CSF (83%) and PBMC (33%) from patients with progressive MS. In contrast, VZV was not found either in CSF or in PBMC from controls. Results from the other herpes viruses tested were similar in MS patients and in controls.

CONCLUSIONS

Our results corroborate the conspicuous, but ephemeral presence of VZV during relapses of MS and support the idea of VZV involvement in the etiopathogenesis of MS. Recent epidemiological and molecular studies as well as reports of severe VZV infections triggered by specifically induced immunosuppression during therapy of MS give additional support to this potential association.