Is there an immunological cross-reactivity of antibodies to the myelin oligodendrocyte glycoprotein and coronaviruses?

Recent reports indicated that myelin oligodendrocyte glycoprotein antibody-associated disease might be a rare complication after severe acute respiratory syndrome coronavirus 2 infection or vaccination. It is unclear whether this is an unspecific sequel of infection or vaccination or caused by possible immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 proteins and myelin oligodendrocyte glycoprotein. The aim of this study was therefore to elucidate whether there is an immunological cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike or nucleocapsid proteins and myelin oligodendrocyte glycoprotein and to explore the relation of antibody responses against myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 and other coronaviruses. We analysed serum samples from patients with severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 12) or without myelin oligodendrocyte glycoprotein-antibodies (n = 10); severe acute respiratory syndrome coronavirus 2 infection without neurological symptoms (n = 32); vaccinated patients with no history of severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 10) or without myelin oligodendrocyte glycoprotein-antibodies (n = 9); and severe acute respiratory syndrome coronavirus 2 negative/naïve unvaccinated patients with neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 47) or without myelin oligodendrocyte glycoprotein-antibodies (n = 20). All samples were analysed for serum antibody responses to myelin oligodendrocyte glycoprotein, severe acute respiratory syndrome coronavirus 2, and other common coronaviruses (CoV-229E, CoV-HKU1, CoV-NL63 and CoV-OC43). Based on sample amount and antibody titres, 21 samples were selected for analysis of antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 spike and nucleocapsid proteins using affinity purification and pre-absorption. Whereas we found no association of immunoglobulin G and A myelin oligodendrocyte glycoprotein antibodies with coronavirus antibodies, infections with severe acute respiratory syndrome coronavirus 2 correlated with an increased immunoglobulin M myelin oligodendrocyte glycoprotein antibody response. Purified antibodies showed no cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike protein and myelin oligodendrocyte glycoprotein. However, one sample of a patient with myelin oligodendrocyte glycoprotein antibody-associated disease following severe acute respiratory syndrome coronavirus 2 infection showed a clear immunoglobulin G antibody cross-reactivity to severe acute respiratory syndrome coronavirus 2 nucleocapsid protein and myelin oligodendrocyte glycoprotein. This patient was also seropositive for other coronaviruses and showed immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 and CoV-229E nucleocapsid proteins. Overall, our results indicate that an immunoglobulin G antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 proteins is rare. The presence of increased myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies after severe acute respiratory syndrome coronavirus 2 infection may either be a consequence of a previous infection with other coronaviruses or arise as an unspecific sequel after viral infection. Furthermore, our data indicate that myelin oligodendrocyte glycoprotein-immunoglobulin A and particularly myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies are a rather unspecific sequel of viral infections. Finally, our findings do not support a causative role of coronavirus infections for the presence of myelin oligodendrocyte glycoprotein-immunoglobulin G antibodies.

Immune profiling in multiple sclerosis: a single-center study of 65 cytokines, chemokines, and related molecules in cerebrospinal fluid and serum.

Introduction: The understanding of the pathophysiology of multiple sclerosis (MS) has evolved alongside the characterization of cytokines and chemokines in cerebrospinal fluid (CSF) and serum. However, the complex interplay of pro- and anti-inflammatory cytokines and chemokines in different body fluids in people with MS (pwMS) and their association with disease progression is still not well understood and needs further investigation. Therefore, the aim of this study was to profile a total of 65 cytokines, chemokines, and related molecules in paired serum and CSF samples of pwMS at disease onset. Methods: Multiplex bead-based assays were performed and baseline routine laboratory diagnostics, magnetic resonance imaging (MRI), and clinical characteristics were assessed. Of 44 participants included, 40 had a relapsing-remitting disease course and four a primary progressive MS. Results: There were 29 cytokines and chemokines that were significantly higher in CSF and 15 in serum. Statistically significant associations with moderate effect sizes were found for 34 of 65 analytes with sex, age, CSF, and MRI parameters and disease progression. Discussion: In conclusion, this study provides data on the distribution of 65 different cytokines, chemokines, and related molecules in CSF and serum in newly diagnosed pwMS.

Increased peripheral inflammatory responses in myelin oligodendrocyte glycoprotein associated disease and aquaporin-4 antibody positive neuromyelitis optica spectrum disorder.

Autoantibody-associated demyelinating diseases of the central nervous system such as myelin oligodendrocyte glycoprotein-antibody associated disease (MOGAD) and aquaporin 4-antibody positive neuromyelitis optica spectrum disorders (AQP4+ NMOSD) are rare diseases but can cause severe disability. In both diseases, associated neuroinflammation is accompanied by blood and cerebrospinal fluid cytokine and chemokine signatures, which were shown to be distinct from those observed in patients with multiple sclerosis (MS). In this study, we aimed to confirm and extend these findings by analyzing a larger number of serum cytokines, chemokines and related molecules in patients with MOGAD or AQP4+ NMOSD in comparison to MS, to better understand the pathophysiology and to identify biomarkers potentially useful in clinical practice for diagnostic and treatment purposes. A total of 65 serum cytokines, chemokines and related molecules like growth factors and soluble receptors were measured by Procartaplex multiplex immunoassays in 40 MOGAD, 40 AQP4+ NMOSD and 54 MS patients at baseline. Furthermore, follow-up samples of 25 AQP4+ NMOSD and 40 MOGAD patients were measured after 6-12 months. Selected analytes were validated in a subgroup of samples using other bead-based assays and ELISA. At baseline, 36 analytes in MOGAD and 30 in AQP4+ NMOSD were significantly increased compared to MS. K-means cluster analysis of all significantly altered molecules revealed three distinct groups: Cluster I, including 12 MOGAD, 2 AQP4+ NMOSD and 3 MS patients, had a specific association with 11 IL-6/IL-17A associated cytokines. In this cluster, 9/17 (53%) patients were children. Cluster II with 13 MOGAD, 24 AQP4+ NMOSD and 1 MS patient was associated with 31 upregulated analytes. Cluster III contained 15 MOGAD, 14 AQP4+ NMOSD and 50 MS patients. In cluster II and III the majority were adults (82% and 92%). Most measured analytes remained stable over time. Validation of selected cytokines and chemokines using other analytical methods revealed moderate to high correlation coefficients, but absolute values differed between assays. In conclusion, these results obtained by bead-based multiplex assays highlight a significant association of biomarkers of peripheral inflammation in patients with antibody-associated demyelinating diseases in comparison with MS.

Soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) and Natalizumab Serum Concentration as Potential Biomarkers for Pharmacodynamics and Treatment Response of Patients with Multiple Sclerosis Receiving Natalizumab.

BACKGROUND: Natalizumab (NTZ) is an established treatment for highly active, relapsing-remitting multiple sclerosis. In the context of rare progressive multifocal leukoencephalopathy and extended interval dosing as a treatment option, biomarkers for treatment monitoring are required. Natalizumab serum concentration (NTZ SC) and soluble vascular cell adhesion molecule 1 (sVCAM-1) concentration were shown to change on treatment with NTZ. We aimed to investigate whether NTZ SC and sVCAM-1 could be suitable pharmacodynamic markers and whether they could predict disease activity on NTZ, improving the concept of personalized multiple sclerosis treatment. METHODS: In a retrospective study at the Medical University of Innsbruck, Austria, we identified patients treated with NTZ and chose samples longitudinally collected during routine follow-ups for the measurement of NTZ SC and sVCAM-1 by an enzyme-linked immunosorbent assay. We correlated these with clinical and demographic variables and clinical outcomes. Furthermore, we analyzed the stability of NTZ SC and sVCAM-1 during treatment. RESULTS: One hundred and thirty-seven patients were included. We found a strong negative correlation between NTZ SC and sVCAM-1. Both showed significant associations with body mass index, infusion interval, sample age, and anti-drug-antibodies. Natalizumab serum concentration was reduced in extended interval dosing, but not sVCAM-1. Only sVCAM-1 showed a weak association with relapses during treatment, while there was no association with disease progression. Both NTZ SC and sVCAM-1 showed a wide inter-individual distribution while levels in single patients were stable on treatment. CONCLUSIONS: Soluble vascular cell adhesion molecule 1 is a suitable pharmacodynamic marker during treatment with NTZ, which is significantly reduced already after the first dose, remains stable in individual patients even on extended interval dosing, and strongly correlates with NTZ SC. Because of the high inter-individual range, absolute levels of sVCAM-1 and NTZ SC are difficult to introduce as treatment monitoring biomarkers in order to predict disease activity in single patients.

12-month SARS-CoV-2 antibody persistency in a Tyrolean COVID-19 cohort.

BACKGROUND: Short-term antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been shown previously. The further development remains to be determined. METHODS: We prospectively followed 29 coronavirus disease 2019 cases, mean age 44 ± 13.2 years. Except for one participant in whom rheumatoid arthritis existed, all other cases were previously healthy. We determined anti-viral binding antibodies at 2-10 weeks, 3 months, 6 months, and 12 months after disease onset as well as neutralizing antibodies (NAb) against wild type at 6 and 12 months and the B.1.1.7 and B.1.351 variants at month 12. Three binding antibody assays were used, targeting the nucleocapsid protein (NCP), the S1 subunit of the spike protein, and the receptor binding domain (RBD). RESULTS: Antibodies to the RBD persisted for 12 months in all cases with increasing concentrations, whereas antibodies to S1 dropped below cut-off point in 7 participants and NCP antibodies were above cut-off point in only 5 subjects at month 12. The NAb against wild type were detected in all but 2 samples at 12 months of follow-up but clearly less frequently when targeting the variants. In 5 participants who were vaccinated against COVID-19 there was a strong increase of antibodies against S1 and RBD as well as an increase of NAb titres against wild type and the variants. CONCLUSION: There was a persisting antibody response against SARS-CoV­2 up to 12 months after COVID-19 with declining concentrations except for RBD and a strong increase of all antibody concentrations after vaccination.

Signs of sympathetic and endothelial cell activation in the skin of patients with restless legs syndrome.

OBJECTIVES: To evaluate skin biopsies of patients with early- and late onset restless legs syndrome (RLS) for concomitant small fiber neuropathy (SFN) and to determine cutaneous sympathetic innervation and microvascularization in comparison to healthy individuals. METHODS: Density of intraepidermal nerve fibers (IENFD), adrenergic nerve fibers and dermal capillaries was analyzed by immunofluorescence for PGP9.5, tyrosine hydroxylase and endothelial markers CD31 and CD105 in skin biopsies of 11 individuals with RLS and 8 age- and sex-matched controls. RESULTS: IENFD did not differ between RLS and controls, but two RLS patients with comorbid impaired glucose metabolism fulfilled morphometric criteria of SFN according to published normative values. In contrast, dermal nerve bundles of RLS patients showed an increased density of tyrosine hydroxylase+ adrenergic nerve fibers (p < 0.005). Moreover, an increased ratio between immature CD105+ and mature CD31+ endothelial cells within dermal capillaries was observed in RLS (p < 0.02). CONCLUSIONS: SFN, as a potential contributing factor for RLS, should be considered in patients with predisposing comorbidities presenting with burning or shooting pain, dysesthesias and impaired sensory and temperature perception. Evidence of an increased adrenergic innervation of the skin in RLS patients is in accordance with sympathetic hyperactivity while signs of endothelial cell activation may reflect an adaptive response to tissue hypoxia.

6-month SARS-CoV-2 antibody persistency in a Tyrolian COVID-19 cohort.

BACKGROUND: As coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 evolved only recently, the persistency of the anti-viral antibody response remains to be determined. METHODS: We prospectively followed 29 coronavirus disease 2019 cases, mean age 44 ± 13.2 years. Except for one participant with a pre-existing diagnosis of rheumatoid arthritis, all other participants were previously healthy. We determined anti-viral binding antibodies at 2-10 weeks, 3 months, and 6 months after disease onset as well as neutralizing antibodies at 6 months. Two binding antibody assays were used, targeting the S1 subunit of the spike protein, and the receptor binding domain. RESULTS: All participants fully recovered spontaneously except for one who had persisting hyposmia. Antibodies to the receptor binding domain persisted for 6 months in all cases with a slight increase of titers, whereas antibodies to S1 dropped below the cut-off point in 2 participants and showed a minimal decrease on average, mainly at month 3 of follow-up in males; however, neutralizing antibodies were detected in all samples at 6 months of follow-up. CONCLUSION: There is a stable and persisting antibody response against acute respiratory syndrome coronavirus 2 at 6 months after infection. Neutralizing antibodies confirm virus specificity. As the number of coronavirus disease 2019 convalescent cases is increasing sharply, antibody testing should be implemented to identify immunized individuals. This information can be helpful in various settings of professional and private life.

Intraepidermal Nerve Fiber Density in Friedreich's Ataxia.

Friedreich's Ataxia (FRDA) is caused by a homozygous intronic GAA expansion in the FXN gene. FRDA affects primarily the peripheral nervous system (PNS) with cumulative evidence from postmortem studies and in vitro models suggesting a developmental component of its pathology. In the present study, we aimed at gaining further insight in the PNS involvement in FRDA by investigating small nerve fibers in vivo. For this purpose, we evaluated the intraepidermal nerve fiber (IENF) density in skin-biopsies of the lower leg and applied clinical assessments of small fiber function (painDETECT, quantitative sensory testing) in 17 FRDAs. Mean IENF density was significantly lower in FRDAs compared to controls (5.77 ± 4.68 vs 9.33 ± 1.41, p = 0.013). Clinically, cold detection threshold was decreased in FRDAs (FRDA = -3.47(-6.64; -3.14), controls = -1.71 (-3.43; -1.23), p = 0.001) while other measures of small fiber function such as warm and pain sensation thresholds did not differ from controls. Five patients had sensory complaints, but none was diagnosed with neuropathic pain at painDETECT. The degree of small fiber loss was markedly variable in our cohort and showed an inverse correlation with the GAA repeat length (R2 = 0.573, p = 0.001). Our findings support a genetically determined small fiber loss in FRDA.

Utility of Two-Dimensional Difference Gel Electrophoresis in Diagnosis of Multiple Sclerosis.

Two-dimensional difference gel electrophoresis (2D-DIGE) has been used for identification of possible biomarkers in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients. However, in different studies inconsistent results have been obtained. We wanted to analyze the diagnostic value of 2D-DIGE in early MS patients by comparing protein patterns between single and pooled samples of MS patients and controls. CSF samples of 20 MS patients and 10 control subjects were processed with 2D-DIGE. The so obtained protein patterns were analyzed with DeCyder 6.5 software, whereby we described variation of patterns presented in one gel as well as between different gels. Even when running single samples of patients of the same group in one gel, variation of protein patterns was high. The number of identified spots with different protein level varied between 4 and 30, depending on which sample batches were compared. We did not find a consistent pattern throughout all possible batch combinations. The inter-individual variation of protein expression as well as the susceptibility of 2D-DIGE for methodological variations makes use of 2D-DIGE as a diagnostic tool for MS and for detection of possible candidate biomarkers difficult, since detected proteins vary depending on which samples are compared.

Cytokine profiles show heterogeneity of interferon-ß response in multiple sclerosis patients.

OBJECTIVE: To evaluate serum cytokine profiles for their utility to determine the heterogeneous responses to interferon (IFN)-ß treatment in patients with multiple sclerosis (MS). METHODS: Patients with relapsing-remitting MS (RRMS) or clinically isolated syndrome receiving de novo IFN-ß treatment were included in this prospective, observational study. Number of relapses and changes in disability were assessed 2 years prior to and 2 years after initiation of treatment. Sera were collected at baseline and after 3 months on therapy. Cytokine levels in sera were assessed by Luminex multiplex assays. Baseline cytokine profiles were grouped by hierarchical clustering analysis. Demographic features, changes in cytokines, and clinical outcome were then assessed in the clustered patient groups. RESULTS: A total of 157 patients were included in the study and clustered into 6 distinct subsets by baseline cytokine profiles. These subsets differed significantly in their clinical and biological response to IFN-ß therapy. Two subsets were associated with patients who responded poorly to therapy. Two other subsets, associated with a good response to therapy, showed a significant reduction in relapse rates and no worsening of disability. Each subset also had differential changes in cytokine levels after 3 months of IFN-ß treatment. CONCLUSIONS: There is heterogeneity in the immunologic pathways of the RRMS population, which correlates with IFN-ß response.

Natalizumab treatment reduces endothelial activity in MS patients.

Vascular cell adhesion molecule-1 a ligand for leukocyte very late activating antigen-4 is a key player in leukocyte extravasation in MS lesions. Natalizumab a monoclonal antibody against VLA-4 blocks this interaction. VCAM-1 and its soluble form are up-regulated during endothelial activation in MS. We investigated the effect of Natalizumab on sVCAM-1 and VLA-4 on circulating leukocytes in MS patients. Natalizumab reduced levels of sVCAM-1 compared to controls (256 vs. 597 ng/mL). This effect was sustained and only reversed in patients with neutralizing antibodies against Natalizumab. Correspondingly Natalizumab diminished VLA-4 on leukocyte subsets. Our findings indicate that Natalizumab reduces transmigration not only by blocking VLA-4 but also by down-regulating VCAM-1.