Algorithmic approach to finding people with multiple sclerosis using routine healthcare data in Wales.

BACKGROUND: Identification of multiple sclerosis (MS) cases in routine healthcare data repositories remains challenging. MS can have a protracted diagnostic process and is rarely identified as a primary reason for admission to the hospital. Difficulties in identification are compounded in systems that do not include insurance or payer information concerning drug treatments or non-notifiable disease. AIM: To develop an algorithm to reliably identify MS cases within a national health data bank. METHOD: Retrospective analysis of the Secure Anonymised Information Linkage (SAIL) databank was used to identify MS cases using a novel algorithm. Sensitivity and specificity were tested using two existing independent MS datasets, one clinically validated and population-based and a second from a self-registered MS national registry. RESULTS: From 4 757 428 records, the algorithm identified 6194 living cases of MS within Wales on 31 December 2020 (prevalence 221.65 (95% CI 216.17 to 227.24) per 100 000). Case-finding sensitivity and specificity were 96.8% and 99.9% for the clinically validated population-based cohort and sensitivity was 96.7% for the self-declared registry population. DISCUSSION: The algorithm successfully identified MS cases within the SAIL databank with high sensitivity and specificity, verified by two independent populations and has important utility in large-scale epidemiological studies of MS.

Real-world persistence of multiple sclerosis disease-modifying therapies.

BACKGROUND AND PURPOSE: Treatment persistence is the continuation of therapy over time. It reflects a combination of treatment efficacy and tolerability. We aimed to describe real-world rates of persistence on disease-modifying therapies (DMTs) for people with multiple sclerosis (pwMS) and reasons for DMT discontinuation. METHODS: Treatment data on 4366 consecutive people with relapse-onset multiple sclerosis (MS) were pooled from 13 UK specialist centres during 2021. Inclusion criteria were exposure to at least one MS DMT and a complete history of DMT prescribing. PwMS in blinded clinical trials were excluded. Data collected included sex, age at MS onset, age at DMT initiation, DMT treatment dates, and reasons for stopping or switching DMT. For pwMS who had received immune reconstituting therapies (cladribine/alemtuzumab), discontinuation date was defined as starting an alternative DMT. Kaplan-Meier survival analyses were used to express DMT persistence. RESULTS: In 6997 treatment events (1.6 per person with MS), median time spent on any single maintenance DMT was 4.3 years (95% confidence interval = 4.1-4.5 years). The commonest overall reasons for DMT discontinuation were adverse events (35.0%) and lack of efficacy (30.3%). After 10 years, 20% of people treated with alemtuzumab had received another subsequent DMT, compared to 82% of people treated with interferon or glatiramer acetate. CONCLUSIONS: Immune reconstituting DMTs may have the highest potential to offer a single treatment for relapsing MS. Comparative data on DMT persistence and reasons for discontinuation are valuable to inform treatment decisions and in personalizing treatment in MS.

COVID-19 Vaccine Response in People with Multiple Sclerosis.

OBJECTIVE: The purpose of this study was to investigate the effect of disease modifying therapies on immune response to severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) vaccines in people with multiple sclerosis (MS). METHODS: Four hundred seventy-three people with MS provided one or more dried blood spot samples. Information about coronavirus disease 2019 (COVID-19) and vaccine history, medical, and drug history were extracted from questionnaires and medical records. Dried blood spots were eluted and tested for antibodies to SARS-CoV-2. Antibody titers were partitioned into tertiles with people on no disease modifying therapy as a reference. We calculated the odds ratio of seroconversion (univariate logistic regression) and compared quantitative vaccine response (Kruskal Wallis) following the SARS-CoV-2 vaccine according to disease modifying therapy. We used regression modeling to explore the effect of vaccine timing, treatment duration, age, vaccine type, and lymphocyte count on vaccine response. RESULTS: Compared to no disease modifying therapy, the use of anti-CD20 monoclonal antibodies (odds ratio = 0.03, 95% confidence interval [CI] = 0.01-0.06, p < 0.001) and fingolimod (odds ratio = 0.04; 95% CI = 0.01-0.12) were associated with lower seroconversion following the SARS-CoV-2 vaccine. All other drugs did not differ significantly from the untreated cohort. Both time since last anti-CD20 treatment and total time on treatment were significantly associated with the response to the vaccination. The vaccine type significantly predicted seroconversion, but not in those on anti-CD20 medications. Preliminary data on cellular T-cell immunity showed 40% of seronegative subjects had measurable anti-SARS-CoV-2 T cell responses. INTERPRETATION: Some disease modifying therapies convey risk of attenuated serological response to SARS-CoV-2 vaccination in people with MS. We provide recommendations for the practical management of this patient group. ANN NEUROL 20219999:n/a-n/a.

Contemporary study of multiple sclerosis disability in South East Wales.

BACKGROUND: A contemporary understanding of disability evolution in multiple sclerosis (MS) is an essential tool for individual disease management and planning of interventional studies. We have used prospectively collected longitudinal data to analyse disability progression and variation in a British MS cohort. METHODS: Cox proportional hazards regression was used to estimate hazard of Expanded Disability Status Scale (EDSS) 4.0 and 6.0. A continuous Markov model was used to estimate transitional probabilities for individual EDSS scores. Models were adjusted for age at MS onset, sex and disease-modifying treatments (DMTs) exposure. RESULTS: 2135 patients were included (1487 (70%) female, 1922 (89%) relapsing onset). 865 (41%) had used DMTs. Median time to EDSS 4.0 and 6.0 was 18.2 years (95% CI 16.3 to 20.2) and 22.1 years (95% CI 20.5 to 24.5). In the Markov model, the median time spent at EDSS scores of <6 (0.40-0.98 year) was shorter than the time spent at EDSS scores of ≥6 (0.87-4.11 year). Hazard of change in EDSS was greatest at EDSS scores <6 (HR for increasing EDSS: 1.02-1.33; decreasing EDSS: 0.34-1.27) compared with EDSS scores ≥6 (HR for increasing EDSS: 0.08-0.61; decreasing EDSS: 0.18-0.54). CONCLUSIONS: These data provide a detailed contemporary model of disability outcomes in a representative population-based MS cohort. They support a trend of increasing time to disability milestones compared with historical reference populations, and document disability variation with the use of transitional matrices. In addition, they provide essential information for patient counselling, clinical trial design, service planning and offer a comparative baseline for assessment of therapeutic interventions.

Risk of COVID-19 in people with multiple sclerosis who are seronegative following vaccination.

BACKGROUND: People with multiple sclerosis (pwMS) treated with certain disease-modifying therapies (DMTs) have attenuated IgG response following COVID-19 vaccination; however, the clinical consequences remain unclear. OBJECTIVE: To report COVID-19 rates in pwMS according to vaccine serology. METHODS: PwMS with available (1) serology 2-12 weeks following COVID-19 vaccine 2 and/or vaccine 3 and (2) clinical data on COVID-19 infection/hospitalisation were included. Logistic regression was performed to examine whether seroconversion following vaccination predicted risk of subsequent COVID-19 infection after adjusting for potential confounders. Rates of severe COVID-19 (requiring hospitalisation) were also calculated. RESULTS: A total of 647 pwMS were included (mean age 48 years, 500 (77%) female, median Expanded Disability Status Scale (EDSS) 3.5% and 524 (81%) exposed to DMT at the time of vaccine 1). Overall, 472 out of 588 (73%) were seropositive after vaccines 1 and 2 and 222 out of 305 (73%) after vaccine 3. Seronegative status after vaccine 2 was associated with significantly higher odds of subsequent COVID-19 infection (odds ratio (OR): 2.35, 95% confidence interval (CI): 1.34-4.12, p = 0.0029), whereas seronegative status after vaccine 3 was not (OR: 1.05, 95% CI: 0.57-1.91). Five people (0.8%) experienced severe COVID-19, all of whom were seronegative after most recent vaccination. CONCLUSION: Attenuated humoral response to initial COVID-19 vaccination predicts increased risk of COVID-19 in pwMS, but overall low rates of severe COVID-19 were seen.

Real-world annualized relapse rates from contemporary multiple sclerosis clinics in the UK: a retrospective multicentre cohort study.

BACKGROUND: Annualized relapse rate (ARR) is used as an outcome measure in multiple sclerosis (MS) clinical trials. Previous studies demonstrated that ARR has reduced in placebo groups between 1990 and 2012. This study aimed to estimate real-world ARRs from contemporary MS clinics in the UK, in order to improve the feasibility estimations for clinical trials and facilitate MS service planning. METHODS: A multicentre observational, retrospective study of patients with MS from 5 tertiary neuroscience centres in the UK. We included all adult patients with a diagnosis of MS that had a relapse between 01/04/2020 and 30/06/2020. RESULTS: One hundred thirteen out of 8783 patients had a relapse during the 3-month study period. Seventy-nine percent of the patients with a relapse were female, the mean age was 39 years, and the median disease duration was 4.5 years; 36% of the patients that had a relapse were on disease-modifying treatment. The ARR from all study sites was estimated at 0.05. The ARR for relapsing remitting MS (RRMS) was estimated at 0.08, while the ARR for secondary progressive MS (SPMS) was 0.01. CONCLUSIONS: We report a lower ARR compared to previously reported rates in MS.

A Rapid Electronic Cognitive Assessment Measure for Multiple Sclerosis: Validation of Cognitive Reaction, an Electronic Version of the Symbol Digit Modalities Test.

BACKGROUND: Incorporating cognitive testing into routine clinical practice is a challenge in multiple sclerosis (MS), given the wide spectrum of both cognitive and physical impairments people can have and the time that testing requires. Shortened paper and verbal assessments predominate but still are not used routinely. Computer-based tests are becoming more widespread; however, changes in how a paper test is implemented can impact what exactly is being assessed in an individual. The Symbol Digit Modalities Test (SDMT) is one validated test that forms part of the cognitive batteries used in MS and has some computer-based versions. We developed a tablet-based SDMT variant that has the potential to be ultimately deployed to patients' own devices. OBJECTIVE: This paper aims to develop, validate, and deploy a computer-based SDMT variant, the Cognition Reaction (CoRe) test, that can reliably replicate the characteristics of the paper-based SDMT. METHODS: We carried out analysis using Pearson and intraclass correlations, as well as a Bland-Altman comparison, to examine consistency between the SDMT and CoRe tests and for test-retest reliability. The SDMT and CoRe tests were evaluated for sensitivity to disability levels and age. A novel metric in CoRe was found: question answering velocity could be calculated. This was evaluated in relation to disability levels and age for people with MS and compared with a group of healthy control volunteers. RESULTS: SDMT and CoRe test scores were highly correlated and consistent with 1-month retest values. Lower scores were seen in patients with higher age and some effect was seen with increasing disability. There was no learning effect evident. Question answering velocity demonstrated a small increase in speed over the 90-second duration of the test in people with MS and healthy controls. CONCLUSIONS: This study validates a computer-based alternative to the SDMT that can be used in clinics and beyond. It enables accurate recording of elements of cognition relevant in MS but offers additional metrics that may offer further value to clinicians and people with MS.

Cannabis and multiple sclerosis.

Patients with multiple sclerosis have long turned to complementary therapies to manage symptoms that licensed products can only partially control. Around half of patients with multiple sclerosis admit to previous or current cannabis use for medicinal purposes and would endorse legalisation. Despite many governments worldwide relaxing regulations around medicinal cannabis, there remain many unanswered questions as to how clinicians should prescribe or recommend products, and access to pharmaceutical-grade products remains highly restricted. Here we address what adult neurologists need to know about cannabis and its use in multiple sclerosis.

Distal hereditary motor neuropathy with vocal cord paresis: from difficulty in choral singing to a molecular genetic diagnosis.

Patients presenting with distal weakness can be a diagnostic challenge; the eventual diagnosis often depends upon accurate clinical phenotyping. We present a mother and daughter with a rare form of distal hereditary motor neuropathy type 7 in whom the diagnosis became apparent by initial difficulty in singing, from early vocal cord dysfunction. This rare neuropathy has now been identified in two apparently unrelated families in Wales. This family's clinical presentation is typical of distal hereditary motor neuropathy type 7, and they have the common truncating mutation in the SLC5A7 gene. Advances in genetic analysis of these rare conditions broaden our understanding of their potential molecular mechanisms and may allow more directed therapy.

Long-term outcome of paediatric-onset multiple sclerosis: a population-based study.

BACKGROUND: Age of onset of multiple sclerosis (MS) peaks in the 3rd and 4th decades and is rarely less than 18. Robust longitudinal studies in paediatric-onset MS (POMS) are limited, and a clearer understanding of outcome could optimise management strategies. METHODS: Patients with disease onset <18 years were identified from a prospective population-based register. Clinical features including presenting symptoms, time to Expanded Disability Status Scale (EDSS) 4.0, 6.0 and 8.0 and onset of secondary progression were compared with patients with adult-onset MS (AOMS). RESULTS: 111 POMS patients were identified from a cohort of 2068. No significant differences in sex ratio, familial recurrence, relapse rate, ethnicity or clinical symptoms at presentation were identified between POMS and AOMS. However, interval to second relapse was longer (5 vs 2.6 years, p=0.04) and primary progressive disease was less common (0.9% vs 8.5%, p=0.003) in POMS than in AOMS. POMS patients also took longer to develop secondary progressive disease (32 vs 18 years, p=0.0001) and to reach disability milestones (EDSS 4.0, 23.8 vs 15.5 years, p<0.0001; EDSS 6.0, 30.8 vs 20.4 years, p<0.0001; EDSS 8.0, 44.7 vs 39 years, p=0.02), but did so between 7.0 and 12 years younger than in AOMS. CONCLUSIONS: 5.4% of patients with MS have POMS (2.7% <16 years; 0.3% <10 years) and have distinct phenotypic characteristics in early disease. Furthermore, while patients with POMS take longer to reach disability milestones, they do so at a younger age than their adult counterparts and could be considered to have a poorer prognosis. Management strategies for these patients should take account of these data.

Temporal evolution of remission following multiple sclerosis relapse and predictors of outcome.

BACKGROUND: Relapse is a characteristic clinical feature of multiple sclerosis (MS) and is commonly employed as a measure of efficacy following therapeutic intervention. However, less is known about the temporal evolution of subsequent disability or factors predicting recovery. OBJECTIVES: The objective of this study was to assess the pattern of recovery following relapse and identify factors which predict recovery and residual disability following relapse. METHODS: A total of 226 relapses were studied prospectively in a cohort of 144 patients with standardised clinical assessments of physical disability including Expanded Disability Status Scale (EDSS), 10-m timed walk, 9-hole peg test and Multiple Sclerosis Impact Scale (MSIS-29) at 0, 2, 6 and 12 months. A total of 82 patients completed 12 months of follow up without further relapse. RESULTS: Thirty per cent of relapses were severe (change in EDSS >2.0) of which 11% failed to recover. All measures showed significant improvement at 2 months but additional improvement was also observed in 9-hole peg test and MSIS-29 up to 12 months following initial assessment. Mean time to second relapse was 382 days. The only predictor of relapse severity in the model tested was younger age; however, increasing age and initial relapse severity were also predictors of poor outcome. CONCLUSIONS: This study shows that the majority of improvement in physical disability following relapse occurs by 2 months but that more subtle recovery can take place over 12 months in a small sub-group of patients. These data will aid in patient counselling and will also inform the timing of therapeutic intervention and physical support.

Response to COVID-19 booster vaccinations in seronegative people with multiple sclerosis.

BACKGROUND: People with MS treated with anti-CD20 therapies and fingolimod often have attenuated responses to initial COVID-19 vaccination. However, uncertainties remain about the benefit of a 3rd (booster) COVID-19 vaccine in this group. METHODS: PwMS without a detectable IgG response following COVID-19 vaccines 1&2 were invited to participate. Participants provided a dried blood spot +/- venous blood sample 2-12 weeks following COVID-19 vaccine 3. Humoral and T cell responses to SARS-CoV-2 spike protein and nucleocapsid antigen were measured. RESULTS: Of 81 participants, 79 provided a dried blood spot sample, of whom 38 also provided a whole blood sample; 2 provided only whole blood. Anti-SARS-CoV-2-spike IgG seroconversion post-COVID-19 vaccine 3 occurred in 26/79 (33%) participants; 26/40 (65%) had positive T-cell responses. Overall, 31/40 (78%) demonstrated either humoral or cellular immune response post-COVID-19 vaccine 3. There was no association between laboratory evidence of prior COVID-19 and seroconversion following vaccine 3. CONCLUSIONS: Approximately one third of pwMS who were seronegative after initial COVID-19 vaccination seroconverted after booster (third) vaccination, supporting the use of boosters in this group. Almost 8 out of 10 had a measurable immune response following 3rd COVID-19 vaccine.

Complement regulator factor H in multiple sclerosis.

A recent proteomic study published in this journal demonstrated lower cerebrospinal fluid (CSF) expression of factor H (fH), an important complement regulator, along with two other complement proteins, in active multiple sclerosis (MS) patients. We have previously demonstrated raised serum fH levels in MS and here, an extended analysis, quantifying fH in CSF, demonstrates no change in fH levels in active disease, but significantly raised levels in progressive disease. These findings support our previous work showing raised serum fH in patients with progressive MS, and our results predict that CSF fH levels will be raised rather than reduced in active disease.

Complement regulator factor H as a serum biomarker of multiple sclerosis disease state.

Multiple sclerosis has a variable phenotypic presentation and subsequent disease course that, although unpredictable at disease onset, is of crucial importance in guiding interventions. Effective and accessible biomarkers are required in order to stratify patients and inform treatment. We examined whether the complement regulator factor H and its Tyr402His polymorphism, recently implicated as biomarkers in other chronic inflammatory central nervous system conditions, might identify or predict specific pathological processes and outcomes in multiple sclerosis. Employing novel assays, we measured factor H and its His402 variant in serum from 350 patients with multiple sclerosis classified according to disease course and relapse status. Serum factor H levels were significantly higher in progressive disease (P < 0.001) compared to controls and relapsing patients, after controlling for variables including disease duration, age, gender, disability and treatment. Serum factor H levels were capable of distinguishing secondary progressive from relapsing remitting disease (excluding patients in clinical relapse) with a sensitivity of 89.41%, specificity of 69.47% and a positive predictive value of 72.38%. Acute relapse was also associated with transiently increased factor H levels (P = 0.009) compared to stable relapsing disease. In clinically stable patients, factor H levels remained constant over 1 year (coefficient of variation percentage = 6.8), however, in patients in transition from relapsing to progressive disease, factor H levels significantly increased over a period of 2 years (P = 0.007). Concentration of the His402 variant in heterozytgotes was significantly higher in secondary progressive (P < 0.01) and primary progressive (P < 0.05) disease, suggesting altered expression or consumption of variants when factor H is upregulated. Serum factor H may be an effective indicator of progression and a practical and accessible biomarker and stratifying tool in determining disease course, providing objective evidence to help guide therapeutic decisions.

Very long chain fatty acid levels in patients diagnosed with multiple sclerosis.

In clinical practice it is not uncommon for patients with adrenomyeloneuropathy or female carriers of adrenoleucodystrophy to have a presenting history and examination compatible with multiple sclerosis. This suggests that there may be an under-diagnosis of adrenoleucodystrophy and its variants in the multiple sclerosis population. We measured levels of very long chain fatty acids, which are typically elevated in the plasma of patients with adrenoleucodystrophy, in a large cohort of patients diagnosed clinically with multiple sclerosis. We tested serum samples from patients with either a first degree relative with multiple sclerosis or those with a primary progressive phenotype. No elevations in very long chain fatty acids were found in the cohort. This study suggests that the number of cases of adrenomyeloneuropathy or adrenoleucodystrophy amongst patients diagnosed clinically with multiple sclerosis is likely to be extremely low. This has important diagnostic implications.

Contribution of relapses to disability in multiple sclerosis.

The impact of relapses on long-term disability in multiple sclerosis remains unclear; however some evidence suggests that relapses play an important role in determining subsequent prognosis. We report on outcome, prognostic factors for recovery and the contribution of relapses to the accumulation of fixed disability in a large series of patients with documented relapses. Two hundred and seventy-nine relapses in 182 patients were assessed before, during and after relapse by expanded disability status scale and data analysed to assess degree of recovery. Factors affecting outcome were considered including sex, age and site of relapse. Mean EDSS prior to relapse was 3.73, during relapse 5.18 and post relapse 4.23. Mean interval to post relapse assessment was 127 days post relapse. Mean residual change in EDSS score (pre to post relapse) was 0.50 points. Overall 49.4 % of patients had a residual increase in disability post relapse of at least 0.5 EDSS points and 32.7 % had an increase of at least 1 point. No significant difference was observed in mean residual EDSS for sex, site of relapse or age at relapse or in the proportion of patients with a residual increase in disability of > or = 1 EDSS point post relapse. 14.4 % of patients had no increase in EDSS score during relapse compared to pre relapse. These results suggest that acute relapses are commonly associated with an objective worsening of disability in the majority of patients with MS and that recovery is incomplete in approximately half and not influenced by gender, age or site of lesion. Therapies which reduce relapse frequency and/or severity might therefore be expected to slow or prevent worsening of disability if initiated prior to the onset of more permanent damage.

Seasonal variation in multiple sclerosis relapse.

Relapses are a characteristic clinical feature of multiple sclerosis (MS), but an appreciation of factors that cause them remains elusive. In this study, we have examined seasonal variation of relapse in a large population-based MS cohort and correlated observed patterns with age, sex, disease course, and climatic factors. Relapse data were recorded prospectively in 2076 patients between 2005 and 2014. 3902 events were recorded in 1158 patients (range 0-24). There was significant seasonal variation in relapse rates (p < 0.0001) and this was associated with monthly hours of sunshine (odds ratio OR 1.08, p = 0.02). Relapse rates were highest in patients under the age of 30 (OR 1.42, p = 0.0005) and decreased with age. There was no evidence of different relapse rates for males compared to females (OR 0.90, p = 0.19). Identification of potentially modifiable environmental factors associated with temporal variation in relapse rates may allow alteration of risk on a population basis and alteration of outcome of established disease once established. Future epidemiological studies should examine dynamic environmental factors with serial prospective measurements and biological sampling. Significant seasonal differences in relapse rates highlight the importance of environmental factors in disease expression and should be taken into account when planning clinical trials in which relapse frequency is an outcome. In addition, identification of potentially modifiable factors associated with this variation may offer unique opportunities for alteration of risk of relapse and long-term outcome on a population level, and suggest putative biological mechanisms for relapse initiation.

Complement activation in multiple sclerosis plaques: an immunohistochemical analysis.

INTRODUCTION: Inflammation and complement activation are firmly implicated in the pathology of multiple sclerosis; however, the extent and nature of their involvement in specific pathological processes such as axonal damage, myelin loss and disease progression remains uncertain. This study aims to bring clarity to these questions. RESULTS: We describe a detailed immunohistochemical study to localise a strategically selected set of complement proteins, activation products and regulators in brain and spinal cord tissue of 17 patients with progressive multiple sclerosis and 16 control donors, including 9 with central nervous system disease. Active, chronic active and chronic inactive multiple sclerosis plaques (35 in total) and non-plaque areas were examined.Multiple sclerosis plaques were consistently positive for complement proteins (C3, factor B, C1q), activation products (C3b, iC3b, C4d, terminal complement complex) and regulators (factor H, C1-inhibitor, clusterin), suggesting continuing local complement synthesis, activation and regulation despite the absence of other evidence of ongoing inflammation. Complement staining was most apparent in plaque and peri-plaque but also present in normal appearing white matter and cortical areas to a greater extent than in control tissue. C1q staining was present in all plaques suggesting a dominant role for the classical pathway. Cellular staining for complement components was largely restricted to reactive astrocytes, often adjacent to clusters of microglia in close apposition to complement opsonised myelin and damaged axons. CONCLUSIONS: The findings demonstrate the ubiquity of complement involvement in multiple sclerosis, suggest a pathogenic role for complement contributing to cell, axon and myelin damage and make the case for targeting complement for multiple sclerosis monitoring and therapy.

Clinical relevance of differential lymphocyte recovery after alemtuzumab therapy for multiple sclerosis.

OBJECTIVE: Alemtuzumab is potentially a highly effective treatment for relapsing multiple sclerosis (MS) acting via complement-mediated lysis of circulating lymphocytes. Variability in posttreatment lymphocyte recovery time is observed, with some patients showing striking durability in the efficacy of treatment. This study aims to establish whether this observed variation affects clinical and imaging parameters of disease activity. METHODS: A total of 56 patients were followed for a median of 39.5 months post alemtuzumab treatment with interval clinical assessments, lymphocyte immunophenotyping, and MRI. Timing and degree of CD4+, CD8+, and CD19+ recovery were correlated with the re-emergence of disease activity defined as clinical relapse, increasing disability, and new T2/enhancing lesions on MRI. RESULTS: New disease activity was recorded in 14% of patients. Mean time to CD19+, CD8+, and CD4+ reconstitution was 6, 10, and 36 months. No differences were observed in CD8+ and CD19+ reconstitution between patients with active disease and those in remission. Patients with active disease showed an accelerated recovery of CD4+ cells (p = 0.001) with a difference in absolute CD4+ counts at 24 months (p = 0.009). CD4+ counts <388.5 × 10(6) cells/mL predicted MRI stability. CONCLUSIONS: Differential lymphocyte recovery in MS following alemtuzumab may be a biomarker for relapse and also inform monitoring and treatment protocols. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that differential lymphocyte reconstitution after alemtuzumab treatment may be a biomarker for relapse.

Genotype-phenotype correlation for non-HLA disease associated risk alleles in multiple sclerosis.

BACKGROUND: Recent advances in MS genetics have led to the successful identification of a number of novel disease associated non-HLA genes. It is now becoming possible to begin to analyse the possible effects of these genes on aspects of disease phenotype where longitudinal clinical data is available. OBJECTIVE: We examined phenotypic impact of 10 non-HLA disease associated single nucleotide polymorphisms (SNPs) in 1003 patients with MS followed for an average of 14.1 years. METHODS: Association of SNPs with time to established disability milestones (Expanded Disability Status Scale (EDSS) 4.0, 6.0, 8.0), onset of secondary progression and cross-sectional aspects of early phenotype were tested using survival analysis. RESULTS: No SNP was associated with systematic deflection in time to disability milestones, age at onset or time to secondary progression. CONCLUSIONS: Genotypic information from non-HLA associated SNPs is unlikely to inform individual patient prognosis in the clinical setting although minor phenotypic effects operative at specific phases of disease cannot be excluded. This preliminary study provides a framework for future genotype-phenotype analysis in MS and will need to be replicated in independent patient cohorts.