Irena Dujmovic

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.

Uric acid levels in sera from patients with multiple sclerosis

Abstract The levels of uric acid (UA), a natural peroxynitrite scavenger, were measured in sera from 240 patients with multiple sclerosis (MS) and 104 sex- and age-matched control patients with other neurological diseases (OND). The mean serum UA concentration was lower in the MS than in the OND group, but the difference did not reach the level of statistical significance (P=0.068). However, the mean serum UA level from patients with active MS (202.6+67.1 μmol/l) was significantly lower than that in inactive MS patients (226.5+78.6 μmol/l; P=0.046) and OND controls (P=0.007). We found a significant inverse correlation of serum UA concentration with female gender (P=0.0001), disease activity (P=0.012) and duration (P=0.017), and a trend towards an inverse correlation with disability as assessed by EDSS score, which did not reach statistical significance (P=0.067). Finally, multivariate linear regression analyses showed that UA concentration was independently correlated with gender (P=0.0001), disease activity (P=0.014) and duration of the disease (P=0.043) in MS patients. These findings suggest that serum UA might serve as a possible marker of disease activity in MS. They also provide support to the potential beneficial therapeutic effect of radical-scavenging substances in MS.

Consensus definitions and application guidelines for control groups in cerebrospinal fluid biomarker studies in multiple sclerosis.

The choice of appropriate control group(s) is critical in cerebrospinal fluid (CSF) biomarker research in multiple sclerosis (MS). There is a lack of definitions and nomenclature of different control groups and a rationalized application of different control groups. We here propose consensus definitions and nomenclature for the following groups: healthy controls (HCs), spinal anesthesia subjects (SASs), inflammatory neurological disease controls (INDCs), peripheral inflammatory neurological disease controls (PINDCs), non-inflammatory neurological controls (NINDCs), symptomatic controls (SCs). Furthermore, we discuss the application of these control groups in specific study designs, such as for diagnostic biomarker studies, prognostic biomarker studies and therapeutic response studies. Application of these uniform definitions will lead to better comparability of biomarker studies and optimal use of available resources. This will lead to improved quality of CSF biomarker research in MS and related disorders.

The analysis of IL-1 beta and its naturally occurring inhibitors in multiple sclerosis: The elevation of IL-1 receptor antagonist and IL-1 receptor type II after steroid therapy

The aim of our investigation was to analyze the pattern of interleukin-1 (IL-1) family compounds: IL-1 beta, IL-1 receptor accessory protein (Acp), IL-1 receptor antagonist (IL-1Ra) and IL-1 receptor type II (IL-1RII) in the serum and cerebrospinal fluid (CSF) from 67 multiple sclerosis (MS) patients and 31 controls. We found significantly elevated CSF levels of IL-1 beta, IL-1Ra and Acp in MS patients compared to controls (p=0.001), while IL-1 beta and Acp were significantly elevated in MS sera (p=0.001). IL-1Ra and/or IL-1 RII increased in sera of all 10 investigated patients after the steroid treatment for relapse. Our findings suggest the important beneficial role of the induction of IL-1 RII and IL-1Ra in MS.

Prognostic factors for survival in multiple sclerosis

In a hospital-based study of 119 patients with definite multiple sclerosis, demographic and clinical factors were analysed with respect to their validity in assessing the long-term prognosis. Over a mean follow-up of 21.7 years, the following factors negatively influenced the prognosis by the univariate analysis: male sex, age at onset over 25, pyramidal involvement or spasticity at onset, 53 functional systems affected at onset or after 5 years, incomplete first remission, length of the first remission 41 year, 45 attacks in the first 10 years, secondary or primary-progressive disease, time to reach secondary progression over 5 years and time to reach EDSS 6 over 7 years. The multivariate model showed that in patients with relapsing-remitting disease, 5 years after onset, pyramidal involvement at onset and shorter time to reach EDSS 6 predicted poor outcome, while after 10 years, higher age at onset and incomplete first remission indicated poor prognosis. Ten years after onset, the predictors of poor outcome in the secondary-progressive group were shorter time to reach EDSS 6 or secondary progression and higher EDSS, while in the primary-progressive group those variables were spasticity or higher number of functional systems affected at onset, and higher EDSS after 5 and 10 years.

Antibodies against myelin oligodendrocyte glycoprotein in the cerebrospinal fluid of multiple sclerosis patients

Antibodies against myelin oligodendrocyte glycoprotein (MOG) mediate demyelination in experimental autoimmune encephalomyelitis (EAE) in different animal species and are implicated in the immunopathogenesis of multiple sclerosis (MS). In order to evaluate the anti-MOG response, we have analyzed the cerebrospinal fluids (CSFs) from 44 MS patients and 51 controls, 11 with other inflammatory neurological disorders (OIND) and 40 with non-inflammatory neurological disorders (NIND). The frequency of anti-MOG antibodies positive patients in the MS group (30%) was significantly higher compared to the NIND (8%, p=0.02), but not compared to the OIND group (55%, p=0.228). Interestingly, all six patients with neurosarcoidosis had MOG-specific antibodies in their CSF. Frequency of anti-MOG antibodies was similar in patients with clinically active and stable MS (32% and 26%, respectively; p=0.921). However, in clinically active MS patients, antibody titers were higher in comparison with patients with stable disease, although the difference did not reach the level of statistical significance (p=0.06). These results further support the potential role of anti-MOG antibodies in the immunopathology of MS in the subset of patients with this disease. Furthermore, our findings suggest for the first time that anti-MOG antibodies could be an accessory diagnostic tool in neurosarcoidosis.

Nitric oxide metabolites and interleukin‐6 in cerebrospinal fluid from multiple sclerosis patients

Interleukin‐6 (IL‐6) and nitric oxide (NO) are implicated in the pathology of multiple sclerosis (MS). We have investigated the levels of these mediators in the cerebrospinal fluid (CSF) from 50 patients with MS and 23 control subjects. Mean CSF IL‐6 level was higher in the total MS group in comparison with controls, but not significantly, whilst the difference between patients with stable MS and controls reached the level of statistical significance. Mean CSF nitrite/nitrate level was significantly higher in the total MS group compared with the control group, as well as in active MS patients versus controls. There was significant difference neither in the mean CSF IL‐6 nor in nitrite/nitrate levels between active and stable MS patients. Interestingly, we observed a significant negative correlation between IL‐6 and nitrite/nitrate levels in the CSF in the total MS group. Such a trend existed in both subgroups with active and stable MS, but without reaching the level of statistical significance. Our data further support the involvement of IL‐6 and NO in ongoing pathological processes in MS, suggesting their potential interplay within the central nervous system in this disease.

Decreased frequency of the tumor necrosis factor α-308 allele in Serbian patients with multiple sclerosis

Tumor necrosis factor (TNF) α has been considered the prototypic cytopathogenic cytokine in multiple sclerosis (MS), but recently this cytokine has been shown to possess significant anti-inflammatory and neuroprotective effects in demyelinating diseases. It has been reported that the TNFα –308 polymorphism influences levels of TNFα production, and that the rare allele, TNF2, is associated with high TNFα production. We investigated the TNFα –308 polymorphism in 143 unrelated Serbian patients with MS and 123 ethnically matched, healthy individuals using the allele-specific restriction fragment length polymorphism polymerase chain reaction technique. The frequency of the TNF2 allele was significantly decreased in MS patients (14%) in comparison with controls (24%; p = 0.044). The TNF2 allele had no influence on disease behavior, since it was not associated with the course and severity of MS in this group of patients. The result suggests that in the Serbian population polymorphism at position –308 of TNFα or at an adjacent locus might have a role in MS susceptibility.

Cerebrospinal fluid and serum uric acid levels in patients with multiple sclerosis

Abstract Background: Peroxynitrite was hypothesized to be involved in the pathogenesis of multiple sclerosis (MS) through its various neurotoxic effects. Uric acid (UA) was shown to be a strong peroxynitrite scavenger. Methods: We analyzed cerebrospinal fluid (CSF) and serum UA concentrations in 30 MS patients and 20 controls with non-inflammatory neurological diseases (NIND) and correlated these findings with demographic and clinical characteristics of MS patients. Disease activity was assessed by brain magnetic resonance imaging (MRI) and the CSF/serum albumin quotient as an indicator of the state of blood-brain-barrier (BBB). Results: Serum UA concentrations were found to be significantly lower in MS patients compared with controls (p=0.019). CSF UA concentrations were lower in MS patients as compared to controls, as well as in patients with active MS (clinical and/or MRI activity) in comparison to patients with inactive MS or controls, but these differences were not statistically significant. Significant correlation was found between CSF and serum UA concentrations (p=0.016) in MS patients, but not in controls; and between CSF UA concentrations and the CSF/serum albumin quotient in MS patients (p=0.043), but not in controls. Conclusions: Our results support the significance of UA in the pathogenesis of MS. Decreased serum UA concentrations in MS patients might be due to both intrinsically reduced antioxidant capacity and increased UA consumption in MS. CSF UA concentrations may not be a reliable marker of disease activity in MS since its concentration is dependent on leakage of UA molecules from serum through the damaged BBB and the balance between consumption/production within the central nervous system (CNS). Clin Chem Lab Med 2009;47:848–53.

Guidelines for uniform reporting of body fluid biomarker studies in neurologic disorders

Objective: The aim of these guidelines is to make the process of reporting body fluid biomarker studies in neurologic disorders more uniform and transparent, in line with existing standards for reporting research in other biomedical areas. Although biomarkers have been around for decades, there are concerns over the high attrition rate of promising candidate biomarkers at later phases of development. Methods: BioMS-eu consortium, a collaborative network working toward improving the quality of biomarker research in neurologic disorders, discussed the merits of standardizing the reporting of body fluid biomarker research. A checklist of items integrating the results of other published guidances, literature, conferences, regulatory opinion, and personal expertise was created to ultimately form a structured summary guidance incorporating the key features. Results: The summary guidance is comprised of a 10-point uniform reporting format ranging from introduction, materials and methods, through to results and discussion. Each item is discussed in detail in the guidance report. Conclusions: To enhance the future development of body fluid biomarkers, it will be important to standardize the reporting of studies. This guideline by the BioMS-eu consortium is aimed at setting a standard for the reporting of future body fluid biomarker research studies in neurologic disorders. We anticipate that following these guidelines will help to accelerate the selection of biomarkers for clinical development.