Clinical characteristics and dynamics of disability progression in a cohort of patients with multiple sclerosis in Latvians.

There is wide variation in the time from the onset to secondary progressive multiple sclerosis (MS) and some controversy regarding the clinical characteristics of the courses (phenotypes) of MS. The present study aimed to characterize demographic and clinical factors that potentially influence long-term disability progression in the cohort of Latvian MS patients. A descriptive longitudinal incidence study was conducted using a cohort of 288 MS patients beginning in 2011 (disease duration from 1 to 51 years). Socio-demographic and clinical information from the first visit to 15/20 years was analysed in groups stratified by gender and visits at five-time points (the first visit; after a year or 2; after 5 ± 1 year; after 10 ± 2 years; after 15-20 years). Our study was dominated by patients from urban areas and non-smokers. The female/male ratio was 2.4:1; the distribution of clinical courses at the first visit was consistent with most European studies. The most common symptom at presentation in our study was optic manifestations, followed by sensory disturbances and motor deficits. In the Latvian study, gender was not a significant influencing factor on the rate of disease progression; however, patient age was statistically significantly associated with EDSS (Expanded Disability Status Scale) value at the first visit. Early clinical features of MS are important in predicting the disability accumulation of patients. Despite the small differences regarding the first MS symptoms, the disability outcomes in the cohort of Latvian patients are similar to other regions of the world.

Nitrosative stress parameters and the level of oxidized DNA bases in patients with multiple sclerosis.

Multiple sclerosis (MS) is a neurodegenerative disease with various factors affecting its etiology. Overproduction of nitric oxide and subsequent lesions of biopolymers are some of the possible causes of the disease. This study aimed to measure the most relevant nitrosative and oxidative stress biomarkers and the level of modified DNA bases in patients with MS. Each parameter was assayed in 25 patients with MS and 25 healthy controls. This study involved detecting blood plasma and serum nitric oxide metabolites by chemiluminescence detector Sievers NOA-280i, malondialdehyde (MDA) measurements with thiobarbituric acid reactive substance (TBARS) assay, detection of oxidized purines and pyrimidines with the enzyme-modified comet assay. Statistical analysis of the results was performed by one-way analysis of variance (ANOVA) and unpaired t test for the comparison of less than three data sets. DNA single-strand breaks, levels of modified purines and pyrimidines, as well as nitrite and nitrate levels in plasma and serum samples, were significantly higher in patients with MS than in healthy controls. On the contrary, MDA levels appeared to be lower in patients with MS.

An Intergenic rs9275596 Polymorphism on Chr. 6p21 Is Associated with Multiple Sclerosis in Latvians.

Background and objectives: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system, leading to demyelination of neurons and potentially debilitating physical and mental symptoms. The disease is more prevalent in women than in men. The major histocompatibility complex (MHC) region has been identified as a major genetic determinant for autoimmune diseases, and its role in some neurological disorders including MS was evaluated. An intergenic single-nucleotide polymorphism (SNP), rs9275596, located between the HLA-DQB1 and HLA-DQA2 genes, is in significant association with various autoimmune diseases according to genome-wide association studies (GWASs). A cumulative effect of this SNP with other polymorphisms from this region was revealed. The aim of the study was to verify the data on rs9275596 association in multiple sclerosis in a case/control study of the Latvian population and to evaluate eventual functional significance of allele substitutions. Materials and Methods: rs9275596 (chr6:32713854; GRCh38.p12) was genotyped in 273 MS patients and 208 controls on main and sex-specific associations. Eventual functional significance of allele substitutions was evaluated in silico using publicly available tools. Results: The rs9275596 rare alleles were identified as a disease susceptibility factor in association with the MS main group and in affected females (p < 0.001 and p < 0.01, respectively). Risk factor genotypes with rare alleles included were associated with the MS common cohort (p < 0.002) and female cohort (odds ratio, OR = 2.24) and were identified as disease susceptible in males (OR = 2.41). It was shown that structural changes of rs9275596 affect the secondary structure of DNA. Functional significance of allele substitutions was evaluated on the eventual sequence affinity to transcription factors (TFs) and splicing signals similarity. A possible impact of the particular polymorphisms on the transcription and splicing efficiency is discussed. Conclusions: Our results suggest susceptibility of rs9275596 to multiple sclerosis in Latvians.

Genetic variations in the PSMA6 and PSMC6 proteasome genes are associated with multiple sclerosis and response to interferon-ß therapy in Latvians.

Several polymorphisms in genes related to the ubiquitin-proteasome system exhibit an association with pathogenesis and prognosis of various human autoimmune diseases. Our previous study reported the association between multiple sclerosis (MS) and the PSMA3-rs2348071 polymorphism in the Latvian population. The current study aimed to evaluate the PSMA6 and PSMC6 genetic variations, their interaction between each other and with the rs2348071, on the susceptibility to MS risk and response to therapy in the Latvian population. PSMA6-rs2277460, -rs1048990 and PSMC6-rs2295826, -rs2295827 were genotyped in the MS case/control study and analysed in terms of genotype-protein correlation network. The possible association with the disease and alleles, single- and multi-locus genotypes and haplotypes of the studied loci was assessed. Response to therapy was evaluated in terms of 'no evidence of disease activity'. To the best of our knowledge, the present study was the first to report that single- and multi-loci variations in the PSMA6, PSMC6 and PSMA3 proteasome genes may have contributed to the risk of MS in the Latvian population. The results of the current study suggested a potential for the PSMA6-rs1048990 to be an independent marker for the prognosis of interferon-ß therapy response. The genotype-phenotype network presented in the current study provided a new insight into the pathogenesis of MS and perspectives for future pharmaceutical interventions.

Approaches and challenges in the diagnosis and management of secondary progressive multiple sclerosis: A Central Eastern European perspective from healthcare professionals.

Secondary progressive multiple sclerosis (SPMS) is a debilitating condition characterized by gradual worsening after an initial relapsing disease course. Despite the recent advances in our understanding of the disease, the diagnosis and treatment of SPMS continue to be challenging in routine clinical practice. The aim of this review article is to present the views of leading MS experts on the challenges in the diagnosis and management of SPMS and clinicians' perspectives in Central and Eastern Europe. This article also provides recommendations of MS experts to improve the situation with diagnosis and management of SPMS. Many countries within Central and Eastern Europe have high prevalence of MS (>100 per 100,000 population). Consistent with the global trend, in the absence of reliable tests or biomarkers, SPMS at early stage remains undiagnosed. Due to diagnostic uncertainty and lack of a universally accepted disease definition, clinicians rely more on retrospective analysis of the clinical symptoms to confirm the diagnosis. With the lack of awareness and poor understanding of the timing of the onset of SPMS, clinicians may tend to direct attention to relapses than the symptoms of progression, which leads to underestimation of SPMS. Although several predictors of progression to SPMS have been identified, their predictive value is highly variable. Therefore, defining the transitioning period as a separate stage of MS is essential. According to experts' opinion, frequent follow-up of patients and periodic assessment of progression are recommended for the timely identification of patients transitioning from RRMS to SPMS. MSProDiscuss Tool is an example of a quick assessment tool for identifying patients progressing from RRMS to SPMS. MS progression is usually assessed by changes in Expanded Disability Status Scale (EDSS) scores. As EDSS scores tend to fluctuate when measured in the short term (3-6 months), a longer period (≥12 months) may be needed to confirm the progression. Assessment of cognitive function is also important for evaluating secondary progression. Compartmentalization of inflammation within the central nervous system is an important reason behind the limited success of disease-modifying therapies (DMTs) for treating SPMS. Most of the DMTs fail to cross the blood-brain barrier; only 38% of the tested DMTs achieved their primary endpoint in SPMS. In Europe, siponimod is the first oral treatment for adults with active SPMS. Particularly, in Central and Eastern Europe, patients with SPMS are still being prescribed less efficacious DMTs and interferons. The absence of alternative treatments in SPMS supports the use of new products (siponimod and others); however the decision to initiate siponimod therapy in more severe patients (EDSS score of 7 or higher) should be individualized in consultation with the payers. The focus should be on early treatment initiation to delay disease progression.

Blood levels of nitric oxide and DNA breaks assayed in whole blood and isolated peripheral blood mononucleated cells in patients with multiple sclerosis.

Oxidative stress, especially overproduction of nitric oxide (NO), is considered to be one of the crucial factors in the pathogenesis of multifactorial multiple sclerosis (MS). DNA breaks could be one of the consequences of oxidative stress; however, data on DNA breakage in MS are very few and contradictory. There are no data on direct measurements of NO production in the blood of MS patients. The goal of this study was to determine the level of single-stranded DNA breaks in whole blood or isolated peripheral blood mononuclear cells (PBMNCs) by means of alkaline single cell gel electrophoresis (comet assay) and to evaluate production of NO in the human blood by applying electron paramagnetic resonance (EPR) spectroscopy. Groups of healthy subjects and MS patients were enrolled in the study. Blood samples were obtained by vein puncture and divided in aliquots for the analysis of the whole blood and isolated PBMNC with comet assay. Alkaline single cell gel electrophoresis was performed on whole blood and isolated PBMNC samples of 28 patients and 15 controls. A separate blood sample was mixed with a spin-trap, frozen in liquid nitrogen and used for NO detection by EPR; 22 MS patients and 22 controls were tested. A statistically significant increase in the level of DNA breakage was observed in specimens taken from MS patients compared to healthy persons. The level of DNA damage in whole blood and PBMNCs of the same group was similar. NO production was significantly higher in the blood of MS patients.