Andreas Lutterotti

Complement activating antibodies to myelin oligodendrocyte glycoprotein in neuromyelitis optica and related disorders

BackgroundSerum autoantibodies against the water channel aquaporin-4 (AQP4) are important diagnostic biomarkers and pathogenic factors for neuromyelitis optica (NMO). However, AQP4-IgG are absent in 5-40% of all NMO patients and the target of the autoimmune response in these patients is unknown. Since recent studies indicate that autoimmune responses to myelin oligodendrocyte glycoprotein (MOG) can induce an NMO-like disease in experimental animal models, we speculate that MOG might be an autoantigen in AQP4-IgG seronegative NMO. Although high-titer autoantibodies to human native MOG were mainly detected in a subgroup of pediatric acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) patients, their role in NMO and High-risk NMO (HR-NMO; recurrent optic neuritis-rON or longitudinally extensive transverse myelitis-LETM) remains unresolved.ResultsWe analyzed patients with definite NMO (n = 45), HR-NMO (n = 53), ADEM (n = 33), clinically isolated syndromes presenting with myelitis or optic neuritis (CIS, n = 32), MS (n = 71) and controls (n = 101; 24 other neurological diseases-OND, 27 systemic lupus erythematosus-SLE and 50 healthy subjects) for serum IgG to MOG and AQP4. Furthermore, we investigated whether these antibodies can mediate complement dependent cytotoxicity (CDC). AQP4-IgG was found in patients with NMO (n = 43, 96%), HR-NMO (n = 32, 60%) and in one CIS patient (3%), but was absent in ADEM, MS and controls. High-titer MOG-IgG was found in patients with ADEM (n = 14, 42%), NMO (n = 3, 7%), HR-NMO (n = 7, 13%, 5 rON and 2 LETM), CIS (n = 2, 6%), MS (n = 2, 3%) and controls (n = 3, 3%, two SLE and one OND). Two of the three MOG-IgG positive NMO patients and all seven MOG-IgG positive HR-NMO patients were negative for AQP4-IgG. Thus, MOG-IgG were found in both AQP4-IgG seronegative NMO patients and seven of 21 (33%) AQP4-IgG negative HR-NMO patients. Antibodies to MOG and AQP4 were predominantly of the IgG1 subtype, and were able to mediate CDC at high-titer levels.ConclusionsWe could show for the first time that a subset of AQP4-IgG seronegative patients with NMO and HR-NMO exhibit a MOG-IgG mediated immune response, whereas MOG is not a target antigen in cases with an AQP4-directed humoral immune response.

EBNA1-specific T cells from patients with multiple sclerosis cross react with myelin antigens and co-produce IFN-γ and IL-2

Symptomatic primary Epstein-Barr virus (EBV) infection and elevated humoral immune responses to EBV are associated with an increased risk of developing multiple sclerosis (MS). We explored mechanisms leading to this change in EBV-specific immunity in untreated patients with MS and healthy virus carriers matched for MS-associated HLA alleles. MS patients showed selective increase of T cell responses to the EBV nuclear antigen 1 (EBNA1), the most consistently recognized EBV-derived CD4+ T cell antigen in healthy virus carriers, but not to other EBV-encoded proteins. In contrast, influenza and human cytomegalovirus–specific immune control was unchanged in MS. The enhanced response to EBNA1 was mediated by an expanded reservoir of EBNA1-specific central memory CD4+ T helper 1 (Th1) precursors and Th1 (but not Th17) polarized effector memory cells. In addition, EBNA1-specific T cells recognized myelin antigens more frequently than other autoantigens that are not associated with MS. Myelin cross-reactive T cells produced IFN-γ, but differed from EBNA1-monospecific cells in their capability to produce interleukin-2, indicative of a polyfunctional phenotype as found in controlled chronic viral infections. Our data support the concept that clonally expanded EBNA1-specific CD4+ T cells potentially contribute to the development of MS by cross-recognition of myelin antigens.

Antigen-Specific Tolerance by Autologous Myelin Peptide–Coupled Cells: A Phase 1 Trial in Multiple Sclerosis

Antigen-coupled cells result in antigen-specific tolerization for treatment of multiple sclerosis. Multiple Sclerosis Therapy Attached at the Hip In multiple sclerosis (MS), a patient’s own immune cells are thought to attack antigens in the brain and spinal cord. One approach to prevent this attack is through tolerization: harnessing one way the body itself attempts to prevent autoimmunity. Ideally, this would happen in an antigen-specific way so that autoimmunity is blocked, while the protective functions of the immune system remain intact. There has been considerable success inducing antigen-specific tolerance in mouse models of MS by chemically coupling the antigen of choice to carrier cells. Now, Lutterotti et al. take this approach into human patients. The authors coupled peripheral blood mononuclear cells from MS patients with seven different myelin peptides thought to be potentially antigenic in MS. Patients who had T cell responses restricted to at least one of the peptides tested were selected. Indeed, patients who received the highest doses of antigen-coupled cells demonstrated decreases in antigen-specific T cell responses after therapy. Although the patient numbers are small in this first-in-human study, the safety, feasibility, and early results suggest that this approach may provide a promising avenue for future trials. Multiple sclerosis (MS) is a devastating inflammatory disease of the brain and spinal cord that is thought to result from an autoimmune attack directed against antigens in the central nervous system. The aim of this first-in-man trial was to assess the feasibility, safety, and tolerability of a tolerization regimen in MS patients that uses a single infusion of autologous peripheral blood mononuclear cells chemically coupled with seven myelin peptides (MOG1–20, MOG35–55, MBP13–32, MBP83–99, MBP111–129, MBP146–170, and PLP139–154). An open-label, single-center, dose-escalation study was performed in seven relapsing-remitting and two secondary progressive MS patients who were off-treatment for standard therapies. All patients had to show T cell reactivity against at least one of the myelin peptides used in the trial. Neurological, magnetic resonance imaging, laboratory, and immunological examinations were performed to assess the safety, tolerability, and in vivo mechanisms of action of this regimen. Administration of antigen-coupled cells was feasible, had a favorable safety profile, and was well tolerated in MS patients. Patients receiving the higher doses (>1 × 109) of peptide-coupled cells had a decrease in antigen-specific T cell responses after peptide-coupled cell therapy. In summary, this first-in-man clinical trial of autologous peptide-coupled cells in MS patients establishes the feasibility and indicates good tolerability and safety of this therapeutic approach.

Patterns of antibody binding to aquaporin-4 isoforms in neuromyelitis optica.

Background Neuromyelitis optica (NMO), a severe demyelinating disease, represents itself with optic neuritis and longitudinally extensive transverse myelitis. Serum NMO-IgG autoantibodies (Abs), a specific finding in NMO patients, target the water channel protein aquaporin-4 (AQP4), which is expressed as a long (M-1) or a short (M-23) isoform. Methodology/Principal Findings The aim of this study was to analyze serum samples from patients with NMO and controls for the presence and epitope specificity of IgG and IgM anti-AQP4 Abs using an immunofluorescence assay with HEK293 cells expressing M-1 or M-23 human AQP4. We included 56 patients with definite NMO (n = 30) and high risk NMO (n = 26), 101 patients with multiple sclerosis, 27 patients with clinically isolated syndromes (CIS), 30 patients with systemic lupus erythematosus (SLE) or Sjögrens syndrome, 29 patients with other neurological diseases and 47 healthy controls. Serum anti-AQP4 M-23 IgG Abs were specifically detected in 29 NMO patients, 17 patients with high risk NMO and two patients with myelitis due to demyelination (CIS) and SLE. In contrast, IgM anti-AQP4 Abs were not only found in some NMO and high risk patients, but also in controls. The sensitivity of the M-23 AQP4 IgG assay was 97% for NMO and 65% for high risk NMO, with a specificity of 100% compared to the controls. Sensitivity with M-1 AQP4 transfected cells was lower for NMO (70%) and high risk NMO (39%). The conformational epitopes of M-23 AQP4 are the primary targets of NMO-IgG Abs, whereas M-1 AQP4 Abs are developed with increasing disease duration and number of relapses. Conclusions Our results confirm M-23 AQP4-IgG Abs as reliable biomarkers in patients with NMO and high risk syndromes. M-1 and M-23 AQP4-IgG Abs are significantly associated with a higher number of relapses and longer disease duration.

Smoking is a risk factor for early conversion to clinically definite multiple sclerosis.

Background Cigarette smoking increases the risk for development of multiple sclerosis and modifies the clinical course of the disease. In this study, we determined whether smoking is a risk factor for early conversion to clinically definite multiple sclerosis after a clinically isolated syndrome. Methods We included 129 patients with a clinically isolated syndrome, disseminated white-matter lesions on brain magnetic resonance imaging, and positive oligoclonal bands in the cerebrospinal fluid. The patients’ smoking status was obtained at the time of the clinically isolated syndrome. Results During a follow-up time of 36 months, 75% of smokers but only 51% of non-smokers developed clinically definite multiple sclerosis, and smokers had a significantly shorter time interval to their first relapse. The hazard ratio for progression to clinically definite multiple sclerosis was 1.8 (95% confidence interval, 1.2–2.8) for smokers compared with non-smokers (P = 0.008). Conclusions Smoking is associated with an increased risk for early conversion to clinically definite multiple sclerosis after a clinically isolated syndrome, and our results suggest that smoking is an independent but modifiable risk factor for disease progression of multiple sclerosis. Therefore, it should be considered in the counseling of patients with a clinically isolated syndrome.

Cerebrospinal fluid B cells correlate with early brain inflammation in multiple sclerosis.

Background There is accumulating evidence from immunological, pathological and therapeutic studies that B cells are key components in the pathophysiology of multiple sclerosis (MS). Methodology/Principal Findings In this prospective study we have for the first time investigated the differences in the inflammatory response between relapsing and progressive MS by comparing cerebrospinal fluid (CSF) cell profiles from patients at the onset of the disease (clinically isolated syndrome, CIS), relapsing-remitting (RR) and chronic progressive (CP) MS by flow cytometry. As controls we have used patients with other neurological diseases. We have found a statistically significant accumulation of CSF mature B cells (CD19+CD138−) and plasma blasts (CD19+CD138+) in CIS and RRMS. Both B cell populations were, however, not significantly increased in CPMS. Further, this accumulation of B cells correlated with acute brain inflammation measured by magnetic resonance imaging and with inflammatory CSF parameters such as the number of CSF leukocytes, intrathecal immunoglobulin M and G synthesis and intrathecal production of matrix metalloproteinase (MMP)-9 and the B cell chemokine CxCL-13. Conclusions Our data support an important role of CSF B cells in acute brain inflammation in CIS and RRMS.

Interferon-beta: the neutralizing antibody (NAb) titre predicts reversion to NAb negativity

Background: It has been reported that in some patients with MS who develop neutralizing antibodies (NAbs) against interferon beta (IFNb), antibody levels can initially increase and then decrease thereafter even when treatment is continued. Objective: To determine whether NAb titre correlates with time to reversion to NAb negativity in patients with multiple sclerosis (MS). Methods: Twenty-eight patients with MS who were NAb-positive during treatment with one of the currently available IFNbs were included in this retrospective study. NAb titres were determined by the myxovirus resistance protein A induction assay. Patients were considered NAb-positive if they had at least two consecutive samples with titres of]/20 neutralizing units (NU). Reversion to NAb-negative status was defined as two consecutive negative samples (NAb titre of B/20 NU) after NAb positivity. Results: When measured two years after treatment initiation, a NAb titre of B/75 NU had a 91.7% sensitivity and a 87.5% specificity for reversion to NAb negativity in the following two years (after a total of four years of treatment). In addition, somewhat surprisingly, patients whose serum converted to NAb-negative generally developed peak NAb titres earlier than patients who remained NAb-positive (mean time of first detection was 21 versus 38 months, respectively). Conclusion: The NAb titre might support treatment decisions in patients with MS whose test results are positive for NAbs.

Increased frequencies of serum antibodies to neurofilament light in patients with primary chronic progressive multiple sclerosis

We investigated whether serum and cerebrospinal fluid (CSF) antibodies to the light subunit of the NF protein (NF-L), a main component of the axonal cytoskeleton, may serve as biological markers for axonal pathology and/or disease progression in multiple sclerosis (MS). IgG to NF-L was measured in sera and CSF of MS patients, patients with inflammatory demyelinating diseases of the PNS, with acute inflammatory neurological diseases (including bacterial and viral meningitis), with neurodegenerative diseases, with acute noninflammatory neurological diseases (including stroke, headache and backache) and healthy controls by enzyme-linked immunosorbent assay. We found that serum anti-NF-L IgG antibodies were significantly elevated in MS patients with primary progressive disease course and we provide evidence for an intrathecal production of these antibodies. Our findings support the use of serum antibodies to NF-L as a marker for axonal destruction.

Plasma levels of soluble adhesion molecules sPECAM-1, sP-selectin and sE-selectin are associated with relapsing-remitting disease course of multiple sclerosis

Adhesion molecule mediated leukocyte migration into the central nervous system is considered to be a critical step in the pathogenesis of multiple sclerosis (MS). We measured plasma levels of the soluble adhesion molecules sPECAM-1, sP-selectin and sE-selectin in 166 MS patients and in 36 healthy blood donors with ELISA. sPECAM-1, sP-selectin and sE-selectin plasma concentrations showed a significant increase in the relapsing-remitting disease course of MS and were elevated during relapse. These findings indicate that sPECAM-1, sP-selectin and sE-selectin might be implemented as paraclinical markers of disease activity in MS with restriction to the clinical course of the disease.

Olfactory threshold is impaired in early, active multiple sclerosis

Background: Olfactory dysfunction has been reported in multiple sclerosis (MS). However, to date no data are available on different qualities of olfactory function, namely odour identification, odour discrimination and odour perception threshold. Objective: To assess different qualities of olfactory function in patients with MS and correlate these with demographic data, clinical data, depression, quality of life and cognitive functions. Methods: In this cross-sectional study, 50 patients with MS or clinically isolated syndrome and 30 healthy controls were included. Olfactory function was measured using the Sniffin’ Sticks test. Results: The scores for odour identification (p = 0.001), odour perception threshold (p = 0.037) and the combined score of odour identification, discrimination and perception threshold (TDI, p = 0.002) were significantly lower in MS. Hyposmia for identification (p = 0.0017), threshold (p = 0.017) and TDI score (p = 0.0014) was more frequent in MS. Olfactory threshold was impaired in patients who were clinically active in the previous year (p = 0.026) and in patients with a disease duration less than 2 years (p = 0.0093). Identification score was negatively correlated with disease duration (p = 0.0017). Olfactory function was not associated with disability, depression or quality of life. Conclusions: We report evidence for qualitatively distinct hyposmia in MS, with increased smell threshold in the early inflammatory phases of the disease and impaired identification with a more widespread chronic disease.