Background Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system (CNS). In Hong Kong, the prevalence rates of MS is 4.8/100,000. First line disease modifying agent (DMA) type 1 interferon β (IFN-β) is the most commonly use therapy for relapsing and remitting MS(RRMS). Depending on the administration type and route of IFN-β, up to 80% of patients develop harmless binding antibody (BAb),which binds to IFN molecules but not necessary interfere its bioactivity. When IFN-β therapy continues, maturation of BAb response can lead to the formation of high affinity neutralizing antibody (NAb). About 45% of MS patients develop NAb against IFN-β in one year of IFN-β treatment. NAb shows a loss of IFN-β clinical effect by increasing MRI activity and disease progression. As the clinical effect of NAb is lagging behind the initial appearance of NAb in the body, it is suggested to develop a NAb assay to predict treatment failure and advice switching therapy for patients when NAb is present. Aim The aim of this study was: I. To develop and evaluate a qPCR-based method for the measurement of NAb to IFN-β in MS patient. II. To establish the normal reference range of NAb in Chinese population. III. To seek the possibility of using anti-IFN-β BAb assay and in vivo MxA gene expression assay as a screening test for NAb IV. To compare the performance between MxA induction qPCR, ELISA, WB assay and luciferase IFN-β reporter gene assay Materials and methods23Chinese RRMS patients who treated with IFN-β-1a therapy for a minimum of12 months were recruited in this study. Serum and PBMC were collected12 hours after the IFN-β-1a injection. MxA, IFNAR1 and IFNAR2 mRNA from PBMC were tested byin vivo MxA gene expression assay. NAb containing serum was tested by anti-IFN-β BAb assay, IFN-β reporter gene assay, in vitro MxA induction WB, ELISA and qPCR assay. In addition, blood samples from 3 Chinese volunteers without any known autoimmune disease history were collected to evaluate the baseline of NAb titer and MxA expression. Result The experimental condition of MxA induction qPCR assay was optimized by using 2.5×105A549 cells plating density, 10% FCS concentration,5 hours IFN-β stimulation time and GAPDH normalization. Assay accuracy was validated by reference anti-IFN-β antibody. Starting from 2.5 TRU, linear relationship could be observed (r2= 0.9873). The lower limit of quantification (LLOQ) was 0.02 LU/mL, the upper limit of quantification (ULOQ) was 16LU/mL and the limit of detection (LOD) was 0.002 LU/mL. The reproducibility of the assay was measured, the intra-and inter-assay imprecision(%CV)for high value were 5.95% and 7.17% respectively, while the intra-and inter-assay impression were8.31% and 15.95%respectively.Results of the qPCR-based method were concurring with that of luciferase IFN-β reporter gene assay. The upper limit of the NAb reference range in Chinese population was 40.3 TRU (n=3, 95% CI = 31.7-48.8). The performance observed in MxA induction ELISA assay swas unsatisfactory. The correlation of anti-IFN-β BAb assay and in vivoMxA gene expression assay results with NAb status indicated both tests were sensitive enough for NAb screening. Conclusion A normal range of NAb titer in Chinese population was established in this study. Anti-IFN-β BAb assay and in vivo MxA gene expression assay were proved suitable for NAb screening. The performance of the developed MxA induction qPCR assay was superior to MxA induction ELISA, WB assay and comparable to luciferase IFN-β reporter gene assay. By using MxA induction qPCR assay, actual efficacy of IFN-β therapy could be measured and monitored. Any treatment failure could be predicted earlier. / published_or_final_version / Pathology / Master / Master of Medical Sciences

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In order to assess cognitive function in multiple sclerosis (MS) and the effect of cholinergic modulation, experiments were conducted using functional magnetic resonance imaging (fMRI) to assess the brain activation during cognitive tasks. A study comparing the processing of verbal working memory with an N-back task found that patients showed smaller increase in activation than healthy controls with greater task difficulty, suggesting a reduced functional reserve. Controls and patients showed differences of correlations between brain regions activated. Interactions between prefrontal regions may provide an adaptive mechanism that could limit clinical expression of the disease distinct from recruitment of novel processing regions. The effect of Rivastigmine on the cognitive processing in MS patients was tested in a longitudinal study, involving serial fMRI scans. Changes in the brain activation patterns were demonstrated with drug administration, without any changes in behavioural measures. Rivastigmine may act to increase the functioning of the normal neural network reducing the need for previously recruited compensatory mechanisms in MS patients. A study on healthy subjects examined the effect of cholinergic inhibition on cognitive processing and brain activation. Changes in functional activation due to Hyoscine during verbal working memory were found analogous to that in MS patients without any changes in behavioural measures. Processes that potentially impair brain cognitive function may recruit similar compensatory functional adaptive mechanisms. Studies on rats and MS patients explored the effect of Rivastigmine on the relationship of the BOLD fMRI signal with the underlying neural activity. Rivastigmine may be influencing the cortical excitability after direct cortical stimulation but showed only a small effect on the BOLD signal under more physiological neural activity. The neural activity in response to visual stimulation is slightly increased with Rivastigmine in MS patients, a change not detected with functional imaging. These studies suggest that changes in BOLD signal do represent sufficiently large changes of underlying neural activity in the presence of Rivastigmine. The relationship of damage in MS to measures of connectivity was studied using diffusion tensor imaging (DTI). Correlation was found between measures of connectivity and callosal size, a measure of fibre loss. The distribution of lesions was spatially correlated with changes in connectivity due to MS. Thus DTI could be utilized to explore the connectivity changes associated with MS, and the relationship with changes in functional activation.

Background The monoclonal antibody natalizumab (NAT) inhibits the migration of lymphocytes throughout the blood–brain barrier by blocking very late antigen (VLA)-4 interactions, thereby reducing inflammatory central nervous system (CNS) activity in patients with multiple sclerosis (MS). We evaluated the effects of different NAT treatment regimens. Methods We developed and optimised a NAT assay to measure free NAT, cell-bound NAT and VLA-4 expression levels in blood and cerebrospinal fluid (CSF) of patients using standard and prolonged treatment intervals and after the cessation of therapy. Results In paired CSF and blood samples of NAT-treated MS patients, NAT concentrations in CSF were approximately 100-fold lower than those in serum. Cell-bound NAT and mean VLA-4 expression levels in CSF were comparable with those in blood. After the cessation of therapy, the kinetics of free NAT, cell-bound NAT and VLA-4 expression levels differed. Prolonged intervals greater than 4 weeks between infusions caused a gradual reduction of free and cell-bound NAT concentrations. Sera from patients with and without NAT-neutralising antibodies could be identified in a blinded assessment. The NAT-neutralising antibodies removed NAT from the cell surface in vivo and in vitro. Intercellular NAT exchange was detected in vitro. Conclusions Incorporating assays to measure free and cell-bound NAT into clinical practice can help to determine the optimal individual NAT dosing regimen for patients with MS.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Radiography in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology Supervisor: Ms. Ferial Isaacs Co-supervisor: Prof. Susan J. Van Rensburg Bellville September 2013 / Multiple Sclerosis (MS) is characterised by demyelination within the central nervous system (CNS), which may result in neurological disabilities over time, causing considerable hardship to patients and their families, in addition to being costly to treat. Recent studies have linked MS to impaired cerebral blood flow, called chronic cerebrospinal venous insufficiency (CCSVI). Anecdotal evidence has suggested that surgical correction thereof results in improvement of symptoms experienced by MS patients. To my knowledge, no information is available in the literature on carotid artery disease in MS. The USA National MS Society has therefore called for more research to be done in this area. This cross-sectional observational sub-study will determine, by ultrasound (B-Mode, Colour and Pulsed-wave Doppler), the prevalence of chronic venous insufficiency (CCSVI) and carotid artery disease in the selected sample of MS patients within the region of the Western Cape, South Africa. Biochemical data; lifestyle factors such as physical activity and smoking; and nutritional status of MS patients were determined from the main study entitled: “The development of a comprehensive gene-based, pathology supported intervention program for improved quality of life in patients diagnosed with multiple sclerosis” (Division of Chemical Pathology, NHLS, Tygerberg Hospital, and University of Stellenbosch). Twenty-nine (29) patients were aged between 28-64years and they suffered from MS for 0.83-27years. A larger proximal and mid cross-sectional diameter (CSD) of the right IJV compared to the left (differences significant, P= 0.026 and P=0.023) was demonstrated. Increased intima media thickness (IMT) was present in 13.33% of the non-smoking MS group and 20% in the smoking MS group. IJV reflux was evident in 13.33% of the MS group. A significant reduction of cross-sectional diameters of the IJV’s was evident in smoking MS patients; suggesting that smoking is not only a risk factor for atherosclerotic disease but could also be related to narrowing of the major neck veins. This study also supports findings of other studies viz that there’s no significant correlation between extracranial venous abnormalities and MS. Early carotid artery disease was noted in smoking and non-smoking MS patients, however the findings were non-significant.