Analysis of seroconversion following COVID-19 vaccination among multiple sclerosis patients treated with disease-modifying therapies in Poland.

CLINICAL RATIONALE FOR THE STUDY: The rapid spread of SARS-CoV-2 throughout the world has highlighted the importance of vaccinations to control the pandemic and to protect people at risk for severe disease courses. Disease-modifying therapies (DMT) in multiple sclerosis (MS), whether immunomodulatory or immunosuppressive, may affect the immune response. Therefore, the question arose as to whether these vaccinations would be effective. AIM OF THE STUDY: We planned a study to assess the immune response to SARS-CoV-2 vaccines by type of therapy. MATERIAL AND METHODS: Participants were recruited from 14 Polish MS centres. The data was obtained by neurologists using a questionnaire. We collected data on 353 MS patients (269 females, 84 males) who received complete primary SARS-CoV-2 vaccination. All persons with MS (PwMS) were treated with disease-modifying therapies. RESULTS: 305 out of 353 PwMS (86.4%) were positive for IgG Abs against SARS-CoV-2 S domain S1 Ag after vaccination. A strong immune response was noted in 129 PwMS (36.5%). The rate of seroconversion after SARS-CoV-2 vaccination in PwMS who received immunomodulatory DMTs (interferon beta, glatiramer acetate, teriflunomide, dimethyl fumarate, natalizumab) was 91.5%, in PwMS receiving immune reconstruction therapy (alemtuzumab, cladribine) was 92%, and in immunosuppressive DMTs (fingolimod, ocrelizumab), the seroconversion rate was 59%. CONCLUSIONS AND CLINICAL IMPLICATIONS: Our study shows that, in PwMS receiving immunomodulatory therapy, the immune response to vaccination is generally excellent. Even in immunosuppressive patients, seroconversion is satisfactory.

Value of short exercise and short exercise with cooling tests in diagnosis of recessive form of myotonia congenita (Becker disease) - are sex differences important?

INTRODUCTION: In myotonia congenita (MC), activation with exercise or cooling can induce transient changes in compound motor action potential (CMAP) parameters, thus providing a guide to genetic analysis. MATERIAL AND METHODS: We performed the short exercise test (SET) and the short exercise test with cooling (SETC) in 30 patients with genetically confirmed Becker disease (BMC) to estimate their utility in the diagnosis of BMC. RESULTS: Although we observed a significant decrease in CMAP amplitude immediately after maximal voluntary effort in both tests in the whole BMC group, in men this decline was significantly smaller than in women, especially in SET. Clinical implications/future directions: In men with a clinical suspicion of BMC, a small decrease in CMAP amplitude in SET together with a typical decline in SETC does not exclude the diagnosis of BMC. Our results show a sex-specific difference in chloride channel function in BMC, which needs further investigation.

Analysis of Side Effects Following Vaccination Against COVID-19 Among Individuals With Multiple Sclerosis Treated With DMTs in Poland.

Background and Objectives: Since vaccination against COVID-19 is available for over a year and the population of immunized individuals with autoimmune disorders is higher than several months before, an evaluation of safety and registered adverse events can be made. We conducted a large study of side effects following the COVID-19 vaccine among patients with multiple (MS) sclerosis treated with disease-modifying therapies (DMTs) and analyzed factors predisposing for particular adverse events. Methods: We gathered data of individuals with MS treated with DMTs from 19 Polish MS Centers, who reported at least one adverse event following COVID-19 vaccination. The information was obtained by neurologists using a questionnaire. The same questionnaire was used at all MS Centers. To assess the relevance of reported adverse events, we used Fisher's exact test, t-test, and U-Menn-Whutney test. Results: A total of 1,668 patients with MS and reports of adverse events after COVID-19 vaccination were finally included in the study. Besides one case marked as "red flag", all adverse events were classified as mild. Pain at the injection site was the most common adverse event, with a greater frequency after the first dose. Pain at the injection site was significantly more frequent after the first dose among individuals with a lower disability (EDSS ≤2). The reported adverse events following immunization did not differ over sex. According to age, pain at the injection site was more common among individuals between 30 and 40 years old, only after the first vaccination dose. None of the DMTs predisposed for particular side effects. Conclusions: According to our findings, vaccination against COVID-19 among patients with MS treated with DMTs is safe. Our study can contribute to reducing hesitancy toward vaccination among patients with MS.

Safety of Vaccines against SARS-CoV-2 among Polish Patients with Multiple Sclerosis Treated with Disease-Modifying Therapies.

(1) Background: The present study aims to report the side effects of vaccination against coronavirus disease 2019 (COVID-19) among patients with multiple sclerosis (MS) who were being treated with disease-modifying therapies (DMTs) in Poland. (2) Methods: The study included 2261 patients with MS who were being treated with DMTs, and who were vaccinated against COVID-19 in 16 Polish MS centers. The data collected were demographic information, specific MS characteristics, current DMTs, type of vaccine, side effects after vaccination, time of side-effect symptom onset and resolution, applied treatment, relapse occurrence, and incidence of COVID-19 after vaccination. The results were presented using maximum likelihood estimates of the odds ratio, t-test, Pearson's chi-squared test, Fisher's exact p, and logistic regression. The statistical analyses were performed using STATA 15 software. (3) Of the 2261 sampled patients, 1862 (82.4%) were vaccinated with nucleoside-modified messenger RNA (mRNA) vaccines. Mild symptoms after immunization, often after the first dose, were reported in 70.6% of individuals. Symptoms included arm pain (47.5% after the first dose and 38.7% after the second dose), fever/chills/flu-like symptoms (17.1% after the first dose and 20.5% after the second dose), and fatigue (10.3% after the first dose and 11.3% after the second dose). Only one individual presented with severe side effects (pro-thrombotic complications) after vaccination. None of the DMTs in the presented cohort were predisposed to the development of side effects. Nine patients (0.4%) had a SARS-CoV-2 infection confirmed despite vaccination. (4) Conclusions: Vaccination against SARS-CoV-2 is safe for people with MS who are being treated with DMTs. Most adverse events following vaccination are mild and the acute relapse incidence is low.

Clinical course and outcome of SARS-CoV-2 infection in multiple sclerosis patients treated with disease-modifying therapies - the Polish experience.

INTRODUCTION: The aim of this study was to report the course and outcome of SARS-CoV-2 infection in multiple sclerosis (MS) patients treated with disease-modifying therapies (DMTs) in Poland. A major concern for neurologists worldwide is the course and outcome of SARS-CoV-2 infection in patients with MS treated with different DMTs. Although initial studies do not suggest an unfavourable course of infection in this group of patients, the data is limited. MATERIALS AND METHODS: This study included 396 MS patients treated with DMTs and confirmed SARS-CoV-2 infection from 28 Polish MS centres. Information concerning patient demographics, comorbidities, clinical course of MS, current DMT use, as well as symptoms of SARS-CoV-2 infection, need for pharmacotherapy, oxygen therapy, and/or hospitalisation, and short-term outcomes was collected up to 30 January 2021. Additional data about COVID-19 cases in the general population in Poland was obtained from official reports of the Polish Ministry of Health. RESULTS: There were 114 males (28.8%) and 282 females (71.2%). The median age was 39 years (IQR 13). The great majority of patients with MS exhibited relapsing-remitting course (372 patients; 93.9%). The median EDSS was 2 (SD 1.38), and the mean disease duration was 8.95 (IQR 8) years. Most of the MS patients were treated with dimethyl fumarate (164; 41.41%). Other DMTs were less frequently used: interferon beta (82; 20.70%), glatiramer acetate (42; 10.60%), natalizumab (35;8.84%), teriflunomide (25; 6.31%), ocrelizumab (20; 5.05%), fingolimod (16; 4.04), cladribine (5; 1.26%), mitoxantrone (3; 0.76%), ozanimod (3; 0.76%), and alemtuzumab (1; 0.25%). The overall hospitalisation rate due to COVID-19 in the cohort was 6.81% (27 patients). Only one patient (0.3%) died due to SARS-CoV-2 infection, and three (0.76%) patients were treated with mechanical ventilation; 106 (26.8%) patients had at least one comorbid condition. There were no significant differences in the severity of SARS-CoV-2 infection regarding patient age, duration of the disease, degree of disability (EDSS), lymphocyte count, or type of DMT used. CONCLUSIONS AND CLINICAL IMPLICATIONS: Most MS patients included in this study had a favourable course of SARS-CoV-2 infection. The hospitalisation rate and the mortality rate were not higher in the MS cohort compared to the general Polish population. Continued multicentre data collection is needed to increase the understanding of SARS-CoV-2 infection impact on the course of MS in patients treated with DMTs.

Impact of Immunoablation and Autologous Hematopoietic Stem Cell Transplantation on Treatment Cost of Multiple Sclerosis: Real-World Nationwide Study.

OBJECTIVES: To provide real-world data on the impact of autologous hematopoietic stem cell transplantation (AHSCT) on treatment costs of patients with multiple sclerosis (MS) in Poland. METHODS: Medical data of 105 patients who underwent AHSCT in the years 2011 to 2016 were obtained from the National Health Fund (NHF) database. Treatment costs were calculated from the public payer's perspective per patient-year for the total available period as well as 12 months before and after AHSCT. The statistical analysis was performed using MATLAB 2016b. RESULTS: Mean treatment-related costs covered by the NHF per patient-year before and after the transplantation were €4314.9 and €1188.8 , respectively. The average cost of disease-modifying drugs per patient was reduced from €2497.9/year before to €65.3/year after AHSCT. CONCLUSIONS: Although the initial cost of AHSCT is high, the costs involving AHSCT and post-AHSCT treatment could, according to our analysis, pay off in 3.9 years, when compared to the costs of disease-modifying drug therapy in aggressive MS. The study provides evidence that the AHSCT can lead to significant savings in treatment costs of aggressive MS from the public payer's perspective.

COVID-19 mRNA vaccines (Pfizer-BioNTech and Moderna) in patients with multiple sclerosis: a statement by a working group convened by the Section of Multiple Sclerosis and Neuroimmunology of the Polish Neurological Society.

A working group convened by the Section of Multiple Sclerosis and Neuroimmunology of the Polish Neurological Society has developed a statement with regard to the currently available mRNA vaccines (Pfizer-BioNTech and Moderna) preventing novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) infection, which causes Coronavirus disease 2019 (COVID-19), in patients with multiple sclerosis (MS). This statement has been based on the literature available as of 15 January, 2021. The guidance will be updated as new data emerges. All data regarding the above-mentioned vaccines comes from clinical trials which have been reviewed, published and approved by the regulatory authorities [1, 2]. In the current manuscript, whenever a SARS-CoV-2 vaccine is discussed, it refers to mRNA vaccines only.

The relationship between aquaporin-4 antibody status and visual tract integrity in neuromyelitis optica spectrum disorders: A visual evoked potential study.

BACKGROUND: Optic neuritis (ON) is one of the hallmark symptomatic features of neuromyelitis optica spectrum disorders (NMOSD). The majority of patients with NMOSD present highly specific autoantibodies against aquaporin-4 (AQP4). A number of studies have reported poor visual acuity outcomes in individuals with AQP4 seropositive NMOSD, but no such relationship has been found with regard to visual evoked potentials (VEP) parameters such as the amplitude and latency of the P100 component. In this paper, we aimed (i) to describe VEP responses in patients with NMOSD; (ii) to analyze those results based on a scoring system; and (iii) to investigate the association between the VEPs and AQP4 antibody status. METHODS: We retrospectively analysed the VEP responses of 40 patients with a diagnosis of NMOSD (according to the 2015 IPND criteria), including 16 with AQP4-postive status (AQP4[+]) and 24 with AQP4-negative status (AQP4[-]). In the first step, we measured the P100 peak latency and P100-N2 peak-to-peak amplitude in each patient. In the second, we converted these measures to the VEP score (0-10) using the scoring proposed by Jung et al. (2008). All recordings were performed using the same VEP device and testing protocol. RESULTS: Abnormal VEPs were recorded in 25 of 40 patients (62.6%). Of these, 17 (42.5%) had prolonged P100 latency, and 8 (20%) had no response detected in at least one eye. The patients with ON as the initial relapse symptom had significantly higher median VEP scores than those who experienced the longitudinally extensive transverse myelitis (LETM) at the disease onset (7.0 [in-terquar-tile range (IQR), 2.0-8.0] vs. 0.0 [IQR, 0.0-4.0], p<0.001). A lack of VEP response in at least one eye was detected more frequently in the AQP4[+] group than the AQP4[-] group (7/16 vs. 1/24, p<0.005). Logistic regression model controlling for age, gender, disease duration, and the type of relapse at onset showed an independent impact of AQP4[+] status (OR=35.45, p = 0.018) on the higher rate of absent VEP responses. In the entire group of patients (n = 40), those with AQP4[+] showed a small tendency towards a higher median VEP score (4.0 [IQR, 0.0-7.8] vs. 1.0 [IQR, 0.0-4.0], p = 0.304). Among individuals with abnormal responses (n = 25), the patients with AQP4[+] had significantly higher median VEP scores (7.0 [IQR, 4.0-8.5] vs. 3.0 [IQR, 1.0-7.0], p = 0.034) and more common bilateral involvement of the optic tracts (80% vs. 40%, p = 0.048) than those who were seronegative for anti-AQP4 antibody. A median regression analysis model controlling for age, gender, disease duration, type of onset, and number of relapses in last 12 months showed an independent association between the AQP4-positive status and a higher VEP score in patients with NMOSD (t = 2.882, df=2, p = 0.007). CONCLUSION: VEP study remains a useful tool in the assessment of NMOSD patients. Due to the high prevalence of absent VEPs in NMOSD patients, the scoring system appears to be more applicable for the precise analysis of VEP recordings. There is a positive association between the AQP-positive serostatus and the poorer outcome in VEP responses, especially in patients with severe impairment of the optic nerve(s).

The needle EMG findings in myotonia congenita.

INTRODUCTION: Myotonia congenita (MC) is caused by pathogenic variants in the CLCN1 gene coding the chloride channel protein. METHODS: To test the hypothesis that needle EMG could be helpful in distinguishing between the recessive and dominant MC, we performed EMG examination in 36 patients (23 men) aged 4-61 years with genetically proven MC: in 30 patients with autosomal recessive MC (Becker MC) and in 6 with autosomal dominant MC (Thomsen MC). RESULTS: Myotonic discharges were recorded in 95.8% of examined muscles. For the whole MC group we observed a significant positive correlation between parameters of motor unit activity potentials (MUAPs) in vastus lateralis and tibialis anterior muscles and the duration of the disease. Similar correlation for biceps brachii also was found in Becker MC subgroup only. DISCUSSION: EMG could still be helpful in diagnosis of MC and together with provocative tests might be useful in differentiation between recessive and autosomal MC.

Real-world effectiveness of fingolimod in Polish group of patients with relapsing-remitting multiple sclerosis.

OBJECTIVES: Fingolimod is indicated for the treatment of relapsing-remitting multiple sclerosis (RRMS) patients with highly aggressive disease characterized by frequent relapses and active magnetic resonance imaging. Its efficacy has been demonstrated in three large phase III trials, used in the regulatory submissions throughout the world. Fingolimod in licensed in Europe since 2011 but with a growing number of disease-modifying drugs (DMD) becoming available for RRMS, it is important to gather real-world evidence data regarding long-term effectiveness in treated patients with MS. The aim of this study was to assess fingolimod effectiveness in a real life Polish group of RRMS patients receiving fingolimod as second line treatment. PATIENTS AND METHODS: The observational study with retrospective data collection was performed at 13 sites that were asked to document eligible patients in consecutive chronological order to avoid selection bias. Demographic and clinical data from 253 adult patients with RRMS treated with fingolimod were analyzed. RESULTS: Mean treatment time with fingolimod was 42 months. Relapses reduction during 3 years treatment period was observed (2.0 v 0.2) and majority of patients were free of relapses. Mean EDSS score was stable during the time of observation. The proportion of patients who were free from any clinical disease activity, i.e. without relapses and disability progression, was over 70%. During the first and second year of observation significant reduction of new MRI lesions was observed. CONCLUSION: In the Polish group of patients with RRMS treated with fingolimod, the majority of them showed freedom from relapses, disability progression and reduction of new MRI lesions. Switching from injectable immunomodulatory drugs to fingolimod is associated with fewer relapses and lower disability progression.

Internet Usage by Polish Patients With Multiple Sclerosis: A Multicenter Questionnaire Study.

BACKGROUND: The internet is a source of knowledge and medium widely used in services that facilitate access to information and networking. Multiple sclerosis (MS) patients find the possibility of acquiring information relating to their condition particularly rewarding. OBJECTIVE: We aimed to identify Polish MS patients' preferences by analyzing a percentage of internet users and determining the most common search subjects and patients' approach to information on the internet. Disability connected with the condition, its duration, and other factors that influence patients' internet use were examined along with instances of relations established through the internet and their durability. METHODS: The study examined 1045 patients (731 women, 314 men) treated in 10 Polish MS centers, of whom 932 (89.19%) declared to be internet users. Their average age was 40.65 (SD 11.06) and average MS duration was 9.08 (SD 6.97) years. The study used a proprietary survey on information seeking, the range of searched subjects, and internet usage frequency. RESULTS: The majority of the patients (494/932, 53.0%) used the internet 6-7 times per week and 4.3% (40/932) declared they spent minimum 2 hours per day. The most commonly searched subjects were world news (604/932, 72.9% of patients using the internet); 60.8% (504/932) searched for information on their condition, particularly for new treatment methods (562/932, 67.8%) and the course of illness (520/932, 62.7%). One's sex had no impact on internet usage (female vs male, odds ratio [OR] 1.13, 95% CI 0.72-1.77), although a patient's age might, at varying degrees. We found several significant associations using a .05 significance level: a patient with higher education used the internet 9 times more often than one with primary education (OR 8.64, 95% CI 3.31-22.57); lasting relationships increased chances of internet usage by 10-fold compared to widowers (OR 0.12, 95% CI 0.05-0.31); living in a city with a population over 100,000 increased chances by nearly 6 times compared with the countryside (OR 5.59, 95% CI 2.72-11.48); the relapsing-remitting MS type saw a 2-fold increase compared with the primary progressive MS type (OR 0.47, 95% CI 0.29-0.75); and those needing assistance were 2 times less likely to use the internet than patients who could move independently (OR 0.53, 95% CI 0.31-0.89). More than half of the patients (489/932, 52.5%) did not discuss the information found on the internet with their neurologists; 15.9% (148/932) believed that relationships established through the internet can be stable. CONCLUSIONS: The majority of Polish patients use the internet as a crucial information source on their condition and innovative treatment methods. The internet can be helpful in establishing new relationships, which are usually short-lived. Polish patients do not frequently discuss the information gathered on the internet with their doctors.

Electrophysiological and clinical assessment of dysautonomia in multiple system atrophy (MSA) and progressive supranuclear palsy (PSP): a comparative study.

CLINICAL RATIONALE FOR THE STUDY: Autonomic nervous system (ANS) involvement in different parkinsonian syndromes has been frequently discussed. It is well established in multiple system atrophy (MSA), whereas it is less evident in progressive supranuclear palsy (PSP). AIMS OF THE STUDY: The aims were to assess the presence and pattern of ANS involvement in MSA and PSP using noninvasive tests i.e. the sympathetic skin response (SSR) test and the R-R interval variation (RRIV) test; to analyse the relationship between clinical and electrophysiological abnormalities in both disorders; and to assess whether an autonomic profile might help to differentiate them. MATERIALS AND METHODS: Clinical and electrophysiological assessments of dysautonomia were performed in 59 patients with MSA (24 cases of MSA-C and 35 cases of MSA-P), these 59 cases including 31 females, mean disease duration 4.2 ± 2.7 years, mean age 60.3 ± 8.4 years, and in 37 patients with PSP (12 females, mean disease duration 4.6 ± 3.6 years, mean age 67.5 ± 6.1 years) and the results were compared to the results obtained from 23 healthy controls matched for age and sex. RESULTS: Clinical dysautonomia assessed by an Autonomic Symptoms Questionnaire was observed in 97% of the MSA patients and in 84% of the PSP patients. SSR was abnormal in 64% and RRIV was abnormal in 73% of MSA cases. In PSP cases, these figures were 78% and 81% respectively. Dysautonomia was clinically more pronounced in MSA compared to PSP (p < 0.05), whereas electrophysiological testing revealed frequently subclinical ANS damage in PSP patients. CONCLUSIONS AND CLINICAL IMPLICATIONS: Our results point to the complementary role of electrophysiological tests in the diagnostic work-up of dysautonomia in parkinsonian syndromes.

WITHDRAWN: Evidence for a relatively high proportion of DM2 mutations in a large group of Polish patients.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, 10.1016/j.pjnns.2018.02.008. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Evidence for a relatively high proportion of DM2 mutations in a large group of Polish patients.

INTRODUCTION: Myotonic dystrophies (DMs) type 1 (DM1) and type 2 (DM2) are autosomal dominant, multisystem disorders, considered the most common dystrophies in adults. DM1 and DM2 are caused by dynamic mutations in the DMPK and CNBP genes, respectively. METHODS: Molecular analyses were performed by PCR and the modified RP-PCR in patients, in their at-risk relatives and prenatal cases. RESULTS: The analysis of Polish controls revealed the range of 5-31 CTG repeats for DM1 and 110-228 bp alleles for DM2. Among 318 confirmed probands - 196 (62%) were DM1 and 122 (38%) - DM2. Within DM1families, 10 subjects carried a low expanded CTG tract (< 100 repeats), which resulted in a full mutation in subsequent generations. Two related individuals had unstable alleles-188 bp and 196 bp without common interruptions. CONCLUSION: The relative frequencies of DM1/DM2 among Polish patients were 68% and 32%, respectively, with a relatively high proportion of DM2 mutations (1.6:1).

Electromyographic findings in sporadic inclusion body myositis.

INTRODUCTION: Clinically oriented diagnostic criteria can be as specific for diagnosis of sporadic inclusion body myositis (sIBM) as pathological criteria, especially at the time of presentation. EMG may provide an convincing proof that a muscle biopsy should be performed. AIMS: To compare the EMG results in patients with sIBM divided into subgroups based on the newest ENMC criteria for sIBM and to obtain the utility of EMG in the diagnostic process at the time of presentation. METHODS: We retrospectively analysed 16 patients with sIBM for motor unit action potential (MUAP) morphology as well as occurrence and distribution of abnormal spontaneous activity (SA) in muscles. RESULTS: Abnormal SA was recorded in 62.5% of sIBM patients. We found statistically significant differences between subgroups in the incidence of polyphasic MUAPs and high amplitude outliers which were more commonly seen in the "clinico-pathologically defined sIBM". Duration of MUAP in the tibialis anterior was significantly shorter in "probable sIBM". DISCUSSION: "Pseudo-neurogenic" MUAPs, mainly in lower limb muscles, are more commonly seen in "clinico-pathologically defined sIBM" while myopathic MUAPs with prominent abnormal SA are recorded in patients diagnosed with "probable sIBM". Both EMG patterns may be suggestive of sIBM and be an indication for further diagnosis.

"Cure" for multiple sclerosis (MS)-Evolving views of therapy goals in patients on different stages of the disease: A pilot study in a cohort of Polish MS patients.

INTRODUCTION: New aggressive treatments promise improvement of results in the treatment of multiple sclerosis (MS), however, with high risk of serious complications. In this study, we analyzed patients' acceptance for risks connected with the MS treatment. METHODS: The study was designed as a prospective nonanonymous online questionnaire. Responders were asked about the definition of the "cure" for MS and crucial goals in the treatment. RESULTS: One hundred and eighty patients filled in the questionnaire (129 women and 51 men), and the mean age was 33 years (SD = 10.29). The MS forms were as follows: relapsing-remitting (65%), secondary progressive (14%), primary progressive (10%), and other (11%), with mean EDSS score of 3 points (SD = 2.6). For 50% of the patients, relief of symptoms such as fatigue (72%), paresis (66%), and balance disorders (65%) was synonymous with "cure." The patients with faster progression of the disease were likely to accept risky "curative" treatments-with average 68% accepted mortality risk (p = .003). Over 81% of patients accepted mortality rates over 1% for the treatment that achieves self-defined cure. CONCLUSION: The study shows that the MS patients are likely to accept even very risky treatments as long as they promise patient-defined "cure."

Abnormal spontaneous activity in primary myopathic disorders.

INTRODUCTION: Reproducible non-insertional spontaneous activity (SA), with the exception of endplate activity, is an unequivocal sign of abnormality and is one of the most useful findings obtained on electromyography. METHODS: In this retrospective study we analyzed occurrence and distribution of abnormal SA in 151 patients with genetically confirmed myopathies. RESULTS: Complex repetitive discharges (CRDs) occurred more frequently than fibrillation potentials (fibs) and positive sharp waves (PSWs) in centronuclear myopathy (CNM) and limb-girdle muscular dystrophy type 2A (LGMD-2A), whereas fibs/PSWs were observed more often in desminopathy and facioscapulohumeral dystrophy (FSHD). Abnormal SA was commonly found in CNM (66.7%) and desminopathy (61.5%), occasionally in Duchenne (DMD) and Becker muscular dystrophy (BMD) (45.2% and 27.6%, respectively), but rarely in FSHD (14.9%) and LGMD-2A (12.0%). CONCLUSIONS: Abnormal SA probably occurs more frequently in disorders associated with structural changes in muscle fibers. Screening for SA may be a valuable tool for diagnosis of non-myotonic myopathies. Muscle Nerve 56: 427-432, 2017.

Metagenomic Analysis of Cerebrospinal Fluid from Patients with Multiple Sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of central nervous system of unknown etiology. However, some infectious agents have been suggested to play a significant role in its pathogenesis. Next-generation sequencing (NGS) and metagenomics can be employed to characterize microbiome of MS patients and to identify potential causative pathogens. In this study, 12 patients with idiopathic inflammatory demyelinating disorders (IIDD) of the central nervous system were studied: one patient had clinically isolated syndrome, one patient had recurrent optic neuritis, and ten patients had multiple sclerosis (MS). In addition, there was one patient with other non-inflammatory neurological disease. Cerebrospinal fluid (CSF) was sampled from all patients. RNA was extracted from CSF and subjected to a single-primer isothermal amplification followed by NGS and comprehensive data analysis. Altogether 441,608,474 reads were obtained and mapped using blastn. In a CSF sample from the patient with clinically isolated syndrome, 11 varicella-zoster virus reads were found. Other than that similar bacterial, fungal, parasitic, and protozoan reads were identified in all samples, indicating a common presence of contamination in metagenomics. In conclusion, we identified varicella zoster virus sequences in one out of the 12 patients with IIDD, which suggests that this virus could be occasionally related to the MS pathogenesis. A widespread bacterial contamination seems inherent to NGS and complicates the interpretation of results.

Yeast model analysis of novel polymerase gamma variants found in patients with autosomal recessive mitochondrial disease.

Replication of the mitochondrial genome depends on the single DNA polymerase (pol gamma). Mutations in the POLG gene, encoding the catalytic subunit of the human polymerase gamma, have been linked to a wide variety of mitochondrial disorders that show remarkable heterogeneity, with more than 200 sequence variants, often very rare, found in patients. The pathogenicity and dominance status of many such mutations remain, however, unclear. Remarkable structural and functional conservation of human POLG and its S. cerevisiae ortholog (Mip1p) led to the development of many successful yeast models, enabling to study the phenotype of putative pathogenic mutations. In a group of patients with suspicion of mitochondrial pathology, we identified five novel POLG sequence variants, four of which (p.Arg869Ter, p.Gln968Glu, p.Thr1053Argfs*6, and p.Val1106Ala), together with one previously known but uncharacterised variant (p.Arg309Cys), were amenable to modelling in yeast. Familial analysis indicated causal relationship of these variants with disease, consistent with autosomal recessive inheritance. To investigate the effect of these sequence changes on mtDNA replication, we obtained the corresponding yeast mip1 alleles (Arg265Cys, Arg672Ter, Arg770Glu, Thr809Ter, and Val863Ala, respectively) and tested their effect on mitochondrial genome stability and replication fidelity. For three of them (Arg265Cys, Arg672Ter, and Thr809Ter), we observed a strong, partially dominant phenotype of a complete loss of functional mtDNA, whereas the remaining two led to partial mtDNA depletion and significant increase in point mutation frequencies. These results show good correlation with the severity of symptoms observed in patients and allow to establish these variants as pathogenic mutations.