Seasonal variation of relapse rate in multiple sclerosis is latitude dependent.

OBJECTIVE: Previous studies assessing seasonal variation of relapse onset in multiple sclerosis have had conflicting results. Small relapse numbers, differing diagnostic criteria, and single region studies limit the generalizability of prior results. The aim of this study was to determine whether there is a temporal variation in onset of relapses in both hemispheres and to determine whether seasonal peak relapse probability varies with latitude. METHODS: The international MSBase Registry was utilized to analyze seasonal relapse onset distribution by hemisphere and latitudinal location. All analyses were weighted for the patient number contributed by each center. A sine regression model was used to model relapse onset and ultraviolet radiation (UVR) seasonality. Linear regression was used to investigate associations of latitude and lag between UVR trough and subsequent relapse peak. RESULTS: A total of 32,762 relapses from 9,811 patients across 30 countries were analyzed. Relapse onset followed an annual cyclical sinusoidal pattern with peaks in early spring and troughs in autumn in both hemispheres. Every 10° of latitude away from the equator was associated with a mean decrease in UVR trough to subsequent relapse peak lag of 28.5 days (95% confidence interval = 3.29-53.71, p = 0.028). INTERPRETATION: We demonstrate for the first time that there is a latitude-dependent relationship between seasonal UVR trough and relapse onset probability peak independent of location-specific UVR levels, with more distal latitude associated with shorter gaps. We confirm prior meta-analyses showing a strong seasonal relapse onset probability variation in the northern hemisphere, and extend this observation to the southern hemisphere.

Predictors and dynamics of postpartum relapses in women with multiple sclerosis.

BACKGROUND: Several studies have shown that pregnancy reduces multiple sclerosis (MS) relapses, which increase in the early postpartum period. Postpartum relapse risk has been predicted by pre-pregnancy disease activity in some studies. OBJECTIVE: To re-examine effect of pregnancy on relapses using the large international MSBase Registry, examining predictors of early postpartum relapse. METHODS: An observational case-control study was performed including pregnancies post-MS onset. Annualised relapse rate (ARR) and median Expanded Disability Status Scale (EDSS) scores were compared for the 24 months pre-conception, pregnancy and 24 months postpartum periods. Clustered logistic regression was used to investigate predictors of early postpartum relapses. RESULTS: The study included 893 pregnancies in 674 females with MS. ARR (standard error) pre-pregnancy was 0.32 (0.02), which fell to 0.13 (0.03) in the third trimester and rose to 0.61 (0.06) in the first three months postpartum. Median EDSS remained unchanged. Pre-conception ARR and disease-modifying treatment (DMT) predicted early postpartum relapse in a multivariable model. CONCLUSION: Results confirm a favourable effect on relapses as pregnancy proceeds, and an early postpartum peak. Pre-conception DMT exposure and low ARR were independently protective against postpartum relapse. This novel finding could provide clinicians with a strategy to minimise postpartum relapse risk in women with MS planning pregnancy.

Risk of relapse phenotype recurrence in multiple sclerosis.

OBJECTIVES: The aim was to analyse risk of relapse phenotype recurrence in multiple sclerosis and to characterise the effect of demographic and clinical features on this phenotype. METHODS: Information about relapses was collected using MSBase, an international observational registry. Associations between relapse phenotypes and history of similar relapses or patient characteristics were tested with multivariable logistic regression models. Tendency of relapse phenotypes to recur sequentially was assessed with principal component analysis. RESULTS: Among 14,969 eligible patients (89,949 patient-years), 49,279 phenotypically characterised relapses were recorded. Visual and brainstem relapses occurred more frequently in early disease and in younger patients. Sensory relapses were more frequent in early or non-progressive disease. Pyramidal, sphincter and cerebellar relapses were more common in older patients and in progressive disease. Women presented more often with sensory or visual symptoms. Men were more prone to pyramidal, brainstem and cerebellar relapses. Importantly, relapse phenotype was predicted by the phenotypes of previous relapses. (OR = 1.8-5, p = 10(-14)). Sensory, visual and brainstem relapses showed better recovery than other relapse phenotypes. Relapse severity increased and the ability to recover decreased with age or more advanced disease. CONCLUSION: Relapse phenotype was associated with demographic and clinical characteristics, with phenotypic recurrence significantly more common than expected by chance.

Sex as a determinant of relapse incidence and progressive course of multiple sclerosis.

The aim of this work was to evaluate sex differences in the incidence of multiple sclerosis relapses; assess the relationship between sex and primary progressive disease course; and compare effects of age and disease duration on relapse incidence. Annualized relapse rates were calculated using the MSBase registry. Patients with incomplete data or <1 year of follow-up were excluded. Patients with primary progressive multiple sclerosis were only included in the sex ratio analysis. Relapse incidences over 40 years of multiple sclerosis or 70 years of age were compared between females and males with Andersen-Gill and Tweedie models. Female-to-male ratios stratified by annual relapse count were evaluated across disease duration and patient age and compared between relapse-onset and primary progressive multiple sclerosis. The study cohort consisted of 11 570 eligible patients with relapse-onset and 881 patients with primary progressive multiple sclerosis. Among the relapse-onset patients (82 552 patient-years), 48,362 relapses were recorded. Relapse frequency was 17.7% higher in females compared with males. Within the initial 5 years, the female-to-male ratio increased from 2.3:1 to 3.3:1 in patients with 0 versus ≥4 relapses per year, respectively. The magnitude of this sex effect increased at longer disease duration and older age (P < 10(-12)). However, the female-to-male ratio in patients with relapse-onset multiple sclerosis and zero relapses in any given year was double that of the patients with primary progressive multiple sclerosis. Patient age was a more important determinant of decline in relapse incidence than disease duration (P < 10(-12)). Females are predisposed to higher relapse activity than males. However, this difference does not explain the markedly lower female-to-male sex ratio in primary progressive multiple sclerosis. Decline in relapse activity over time is more closely related to patient age than disease duration.

The Kurtzke EDSS rank stability increases 4 years after the onset of multiple sclerosis: results from the MSBase Registry.

BACKGROUND: The Expanded Disability Status Scale (EDSS) is widely used to rate multiple sclerosis (MS) disability, but lack of disease duration information limits utility in assessing severity. EDSS ranking at specific disease durations was used to devise the MS Severity Score, which is gaining popularity for predicting outcomes. As this requires validation in longitudinal cohorts, we aimed to assess the utility of EDSS ranking as a predictor of 5-year outcome in the MSBase Registry. METHODS: Rank stability of EDSS over time was examined in the MSBase Registry, a large multicentre MS cohort. Scores were ranked for 5-year intervals, and correlation of rank across intervals was assessed using Spearman's rank correlation. EDSS progression outcomes at 10 years were disaggregated by 5-year EDSS scores. RESULTS: Correlation coefficients for EDSS rank over 5-year intervals increased with MS duration: years 1-6=0.55, years 4-9=0.74, years 7-12=0.80 and years 10-15=0.83. EDSS progression risk at 10 years after onset was highly dependent on EDSS at 5 years; one-point progression risk was greater for EDSS score of >2 than ≤2. Two-point progression was uncommon for EDSS score of <2 and more common at EDSS score of 4. CONCLUSIONS: EDSS rank stability increases with disease duration, probably due to reduced relapses and less random variation in later disease. After 4 years duration, EDSS rank was highly predictive of EDSS rank 5 years later. Risk of progression by 10 years was highly dependent on EDSS score at 5 years duration. We confirm the utility of EDSS ranking to predict 5-year outcome in individuals 4 years after disease onset.

Natalizumab for relapsing remitting multiple sclerosis.

BACKGROUND: Natalizumab (NTZ) (Tysabri(®)) is a monoclonal antibody that inhibits leukocyte migration across the blood-brain barrier, thus reducing inflammation in central nervous system, and has been approved worldwide for the treatment of relapsing-remitting multiple sclerosis (RRMS). OBJECTIVES: To evaluate the efficacy, tolerability and safety of NTZ in the treatment of patients with RRMS. SEARCH STRATEGY: We searched the Cochrane Multiple Sclerosis Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2010, Issue 1), MEDLINE (PubMed) and EMBASE, all up to 19 February 2010, and bibliographies of papers. Handsearching was carried out. Trialists and pharmaceutical companies were contacted. Furthermore, the websites of US Food and Drug Administration (FDA), the European Medicines Evaluation Agency (EMA) and the National Institute for health and Clinical Excellence (NICE) were also checked. SELECTION CRITERIA: All double-blind, randomised, controlled trials analysing more than a single infusion of NTZ (dosage > 3 mg/kg intravenous infusion every 4 weeks), also including its use as add-on treatment, versus placebo or other drugs in patients with RRMS. No restrictions on the basis of duration of treatment or length of follow up. DATA COLLECTION AND ANALYSIS: Three reviewers independently selected articles which met the inclusion criteria. Disagreements were solved by discussion. Two reviewers independently extracted the data and assessed the methodological quality of each trial. Missing data was sought by contacting principal authors and Biogen Idec, through Biogen-Dompé Italia. MAIN RESULTS: Three studies met the inclusion criteria. These included one placebo-controlled trial (942 patients) and two add-on placebo-controlled trials, i.e. one plus glatiramer acetate (110 patients) and the second plus interferon beta-1a (1171 patients).This review assessed the efficacy, tolerability and safety of NTZ in patients with RRMS. Data was conclusive with respect to efficacy and tolerability, but not safety. As far as efficacy is concerned, the results showed statistically significant evidence in favour of NTZ for all the primary outcomes and for the secondary ones where data was available. NTZ reduced the risk of experiencing at least one new exacerbation at 2 years by about 40% and of experiencing progression at 2 years by about 25% as compared to a control group. MRI parameters showed statistical evidence in favour of participants receiving NTZ. Infusion reactions, anxiety, sinus congestion, lower limb swelling, rigors, vaginitis and menstrual disorders were reported as adverse events (AEs) more frequently after NTZ treatment. In this review NTZ was found to be well tolerated over a follow-up period of two years: the number of patients experiencing at least one AE (including severe and serious AEs) during this period did not differ between NTZ-treated patients and controls. Safety concerns have been raised about Progressive Multifocal Leukoencephalopathy (PML). In the trials included in this review, two cases of PML were encountered: one in a patient who had received 29 doses of NTZ and a second fatal case of PML in another patient after 37 doses of NTZ. Our protocol was insufficient to evaluate PML risk as well as other rare and long-term adverse events such as cancers and other opportunistic infections, which are very important issues in considering the risk/benefit ratio of NTZ. AUTHORS' CONCLUSIONS: Although one trial did not contribute to efficacy results due to its duration, we found robust evidence in favour of a reduction in relapses and disability at 2 years in RRMS patients treated with NTZ. The drug was well tolerated. There are current significant safety concerns due to reporting of an increasing number of PML cases in patients treated with NTZ. This review was unable to provide an up-to-date systematic assessment of the risk due to the maximum 2 year-duration of the trials included. An independent systematic review of the safety profile of NTZ is warranted. NTZ should be used only by skilled neurologists in MS centres under surveillance programs.All the data in this review came from trials supported by the Pharmaceutical Industry. In agreement with the Cochrane Collaboration policy, this may be considered a potential source of bias.

The OPTimization of interferon for MS study: 375 microg interferon beta-1b in suboptimal responders.

We aimed to evaluate the safety and MRI efficacy of interferon beta-1b (IFNbeta-1b) 375 microg (subcutaneously [sc] every other day [eod]) in relapsing-remitting multiple sclerosis (RRMS) patients with a suboptimal response to IFNbeta-1b 250 microg, i.e., with MRI activity or relapses. The OPTimization of Interferon for MS (OPTIMS) study was a prospective multicenter randomized phase 2 trial comprising a 6-month run-in phase (to identify suboptimal responders) and a 6-month randomized phase of open-label clinical and blinded MRI follow-up. During run-in all patients were treated with IFNbeta-1b 250 microg sc eod; during the study phase suboptimal treatment responders were randomized either to IFNbeta-1b 250 or 375 microg sc eod. Primary outcome was the proportion of patients without MRI activity during study Months 9-12 according to the intention-to-treat principle. 216 RRMS patients entered the study: 83 suboptimal responders were identified and randomized, 7 refused to continue treatment, 76 were included in the analysis. More patients treated with 375 microg had no MRI activity at Months 9-12 (30/36 vs.16/40; relative risk, 0.28; 95 % confidence interval, 0.08-0.47; p = 0.0001). Sensitivity analysis ("worst case scenario") confirmed the results. No new or unexpected adverse events were observed, but there was a trend towards more withdrawals in the 375 microg group. Increasing the dose of IFNbeta-1b from 250 microg to 375 microg is a successful strategy for reducing subclinical signs of disease activity in RRMS patients. Further studies are needed to show whether this dose may also improve clinical efficacy.

A rare case of parotid gland lipoma arising from the deep lobe of the parotid gland.

Lipomas are the most commonly encountered benign mesenchymal tumors, but their occurrence in the head and neck is rare, even more at the level of the parotid region where they can be found nearby the parotid capsule, inside the capsule, or within the gland. In addition, lipomas involving the deep parotid lobe are extremely unusual. That is why lipomas are not often considered for differential diagnosis of parotid lumps. Concerning diagnostic tools, magnetic resonance imaging (MRI) is nowadays considered as the main imaging examination for parotid lipomas due to a characteristic signal intensity on T1- and T2-weighted images. Furthermore, even if the cost of MRI is nearly three times that of computed tomography, MRI is accurate, safe, and has few biological costs for the patient. In this reported case, MRI provided all information for either diagnosis or preoperative planning being the best diagnostic tool regarding tumor margin characteristics and surrounding tissues' involvement. Concerning treatment, surgical excision of parotid masses is always mandatory for definitive diagnosis, but it is challenging because of the facial nerve. For this reason, a well-established surgical technique is mandatory for success. The authors present a rare case of parotid gland lipoma arising from the deep lobe and discuss diagnostic tools and surgical technique.

Comparative efficacy of first-line natalizumab vs IFN-ß or glatiramer acetate in relapsing MS.

BACKGROUND: We compared efficacy and treatment persistence in treatment-naive patients with relapsing-remitting multiple sclerosis (RRMS) initiating natalizumab compared with interferon-ß (IFN-ß)/glatiramer acetate (GA) therapies, using propensity score-matched cohorts from observational multiple sclerosis registries. METHODS: The study population initiated IFN-ß/GA in the MSBase Registry or natalizumab in the Tysabri Observational Program, had ≥3 months of on-treatment follow-up, and had active RRMS, defined as ≥1 gadolinium-enhancing lesion on cerebral MRI at baseline or ≥1 relapse within the 12 months prior to baseline. Baseline demographics and disease characteristics were balanced between propensity-matched groups. Annualized relapse rate (ARR), time to first relapse, treatment persistence, and disability outcomes were compared between matched treatment arms in the total population (n = 366/group) and subgroups with higher baseline disease activity. RESULTS: First-line natalizumab was associated with a 68% relative reduction in ARR from a mean (SD) of 0.63 (0.92) on IFN-ß/GA to 0.20 (0.63) (p [signed-rank] < 0.0001), a 64% reduction in the rate of first relapse (hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.28-0.47; p < 0.001), and a 27% reduction in the rate of discontinuation (HR 0.73, 95% CI 0.58-0.93; p = 0.01), compared with first-line IFN-ß/GA therapy. Confirmed disability progression and area under the Expanded Disability Status Scale-time curve analyses were not significant. Similar relapse and treatment persistence results were observed in each of the higher disease activity subgroups. CONCLUSIONS: This study provides Class IV evidence that first-line natalizumab for RRMS improves relapse and treatment persistence outcomes compared to first-line IFN-ß/GA. This needs to be balanced against the risk of progressive multifocal leukoencephalopathy in natalizumab-treated patients. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that first-line natalizumab for RRMS improves relapse rates and treatment persistence outcomes compared to first-line IFN-ß/GA.

Predictors of disability worsening in clinically isolated syndrome.

OBJECTIVE: To assess demographic, clinical, magnetic resonance imaging, and treatment exposure predictors of time to 3 or 12-month confirmed disability worsening in clinically isolated syndrome (CIS) and early multiple sclerosis (MS). METHODS: We utilized the MSBase Incident Study (MSBasis), a prospective cohort study of outcome after CIS. Predictors of time to first 3 and 12-month confirmed expanded disability status scale worsening were analyzed using Cox proportional hazards regression. RESULTS: About 1989 patients were analyzed, the largest seen-from-onset cohort reported to-date. A total of 391 patients had a first 3-month confirmed disability worsening event, of which 307 were sustained for 12 months. Older age at CIS onset (adjusted hazard ratio: aHR 1.17, 95% 1.06, 1.30), pyramidal (aHR 1.45, 95% CI 1.13, 1.89) and ambulation (HR 1.60, 95% CI 1.09, 2.34) system dysfunction, annualized relapse rate (aHR 1.20, 95% CI 1.18, 1.22), and lower proportion of observation time on treatment were associated with 3-month confirmed worsening. Predictors of time to 12-month sustained worsening included pyramidal system dysfunction (Hazard ratio: aHR 1.38, 95% CI 1.05, 1.83), and older age at CIS onset (aHR 1.17, 95% CI 1.04, 1.31). Greater proportion of follow-up time exposed to treatment was associated with greater reductions in the rate of worsening. INTERPRETATION: This study provides class IV evidence for a strong protective effect of disease-modifying treatment to reduce disability worsening events in patients with CIS and early MS, and confirms age and pyramidal dysfunction at onset as risk factors.

Male Sex Is Independently Associated with Faster Disability Accumulation in Relapse-Onset MS but Not in Primary Progressive MS.

BACKGROUND: Multiple Sclerosis is more common in women than men and females have more relapses than men. In a large international cohort we have evaluated the effect of gender on disability accumulation and disease progression to determine if male MS patients have a worse clinical outcome than females. METHODS: Using the MSBase Registry, data from 15,826 MS patients from 25 countries was analysed. Changes in the severity of MS (EDSS) were compared between sexes using a repeated measures analysis in generalised linear mixed models. Kaplan-Meier analysis was used to test for sex difference in the time to reach EDSS milestones 3 and 6 and the secondary progressive MS. RESULTS: In relapse onset MS patients (n = 14,453), males progressed significantly faster in their EDSS than females (0.133 vs 0.112 per year, P<0.001,). Females had a reduced risk of secondary progressive MS (HR (95% CI) = 0.77 (0.67 to 0.90) P = 0.001). In primary progressive MS (n = 1,373), there was a significant increase in EDSS over time in males and females (P<0.001) but there was no significant sex effect on the annualized rate of EDSS change. CONCLUSION: Among registrants of MSBase, male relapse-onset patients accumulate disability faster than female patients. In contrast, the rate of disability accumulation between male and female patients with primary progressive MS is similar.

Multiple sclerosis in Latin America: A different disease course severity? A collaborative study from the MSBase Registry.

Limited data suggest that multiple sclerosis (MS) in Latin America (LA) could be less severe than in the rest of the world. The objective was to compare the course of MS between LA and other regions. METHODS: Centers from 18 countries with >20 cases enrolled in the MSBase Registry participated. Patients with MS with a disease duration of >1 year and <30 years at time of EDSS measurement were evaluated. The MS Severity Score (MSSS) was used as a measure of disease progression. Comparisons among regions (North America, Europe, Australia and LA), hemispheres and countries were performed. RESULTS: A total of 9610 patients were included. Patients were from: Europe, 6290 (65.6%); North America, 1609 (16.7%); Australia, 1119 (11.6%); and LA, 592 (6.1%). The mean MSSS in patients from LA was 4.47 ± 2.8, 4.53 ± 2.8 in North America, 4.51 ± 2.8 in Europe and 4.49 ± 2.7 in Australia. Mean MSSS in the northern hemisphere was 4.51 ± 1.6 compared to 4.48 ± 1.9 in the southern hemisphere. No differences were found for MSSS among hemispheres (p = 0.68), regions (p = 0.96) or countries (p = 0.50). CONCLUSIONS: Our analyses did not discover any difference in mean MSSS among patients from different regions, hemispheres or countries.

Fingolimod after natalizumab and the risk of short-term relapse.

OBJECTIVE: To determine early risk of relapse after switch from natalizumab to fingolimod; to compare the switch experience to that in patients switching from interferon-ß/glatiramer acetate (IFN-ß/GA) and those previously treatment naive; and to determine predictors of time to first relapse on fingolimod. METHODS: Data were obtained from the MSBase Registry. Relapse rates (RRs) for each patient group were compared using adjusted negative binomial regression. Survival analyses coupled with adjusted Cox regression were used to model predictors of time to first relapse on fingolimod. RESULTS: A total of 536 patients (natalizumab-fingolimod [n = 89]; IFN-ß/GA-fingolimod [n = 350]; naive-fingolimod [n = 97]) were followed up for a median 10 months. In the natalizumab-fingolimod group, there was a small increase in RR on fingolimod (annualized RR [ARR] 0.38) relative to natalizumab (ARR 0.26; p = 0.002). RRs were generally low across all patient groups in the first 9 months on fingolimod (RR 0.001-0.13). However, 30% of patients with disease activity on natalizumab relapsed within the first 6 months on fingolimod. Independent predictors of time to first relapse on fingolimod were the number of relapses in the prior 6 months (hazard ratio [HR] 1.59 per relapse; p = 0.002) and a gap in treatment of 2-4 months compared to no gap (HR 2.10; p = 0.041). CONCLUSIONS: RRs after switch to fingolimod were low in all patient groups. The strongest predictor of relapse on fingolimod was prior relapse activity. Based on our data, we recommend a maximum 2-month treatment gap for switches to fingolimod to decrease the hazard of relapse. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that RRs are not higher in patients with multiple sclerosis switching to fingolimod from natalizumab compared to those patients switching to fingolimod from other therapies.

Persistence on therapy and propensity matched outcome comparison of two subcutaneous interferon beta 1a dosages for multiple sclerosis.

OBJECTIVES: To compare treatment persistence between two dosages of interferon ß-1a in a large observational multiple sclerosis registry and assess disease outcomes of first line MS treatment at these dosages using propensity scoring to adjust for baseline imbalance in disease characteristics. METHODS: Treatment discontinuations were evaluated in all patients within the MSBase registry who commenced interferon ß-1a SC thrice weekly (n = 4678). Furthermore, we assessed 2-year clinical outcomes in 1220 patients treated with interferon ß-1a in either dosage (22 µg or 44 µg) as their first disease modifying agent, matched on propensity score calculated from pre-treatment demographic and clinical variables. A subgroup analysis was performed on 456 matched patients who also had baseline MRI variables recorded. RESULTS: Overall, 4054 treatment discontinuations were recorded in 3059 patients. The patients receiving the lower interferon dosage were more likely to discontinue treatment than those with the higher dosage (25% vs. 20% annual probability of discontinuation, respectively). This was seen in discontinuations with reasons recorded as "lack of efficacy" (3.3% vs. 1.7%), "scheduled stop" (2.2% vs. 1.3%) or without the reason recorded (16.7% vs. 13.3% annual discontinuation rate, 22 µg vs. 44 µg dosage, respectively). Propensity score was determined by treating centre and disability (score without MRI parameters) or centre, sex and number of contrast-enhancing lesions (score including MRI parameters). No differences in clinical outcomes at two years (relapse rate, time relapse-free and disability) were observed between the matched patients treated with either of the interferon dosages. CONCLUSIONS: Treatment discontinuations were more common in interferon ß-1a 22 µg SC thrice weekly. However, 2-year clinical outcomes did not differ between patients receiving the different dosages, thus replicating in a registry dataset derived from "real-world" database the results of the pivotal randomised trial. Propensity score matching effectively minimised baseline covariate imbalance between two directly compared sub-populations from a large observational registry.

Geographical variations in sex ratio trends over time in multiple sclerosis.

BACKGROUND: A female/male (F/M) ratio increase over time in multiple sclerosis (MS) patients was demonstrated in many countries around the world. So far, a direct comparison of sex ratio time-trends among MS populations from different geographical areas was not carried out. OBJECTIVE: In this paper we assessed and compared sex ratio trends, over a 60-year span, in MS populations belonging to different latitudinal areas. METHODS: Data of a cohort of 15,996 (F = 11,290; M = 4,706) definite MS with birth years ranging from 1930 to 1989 were extracted from the international MSBase registry and the New Zealand MS database. Gender ratios were calculated by six decades based on year of birth and were adjusted for the F/M born-alive ratio derived from the respective national registries of births. RESULTS: Adjusted sex ratios showed a significant increase from the first to the last decade in the whole MS sample (from 2.35 to 2.73; p = 0.03) and in the subgroups belonging to the areas between 83° N and 45° N (from 1.93 to 4.55; p<0.0001) and between 45° N to 35° N (from 1.46 to 2.30; p<0.05) latitude, while a sex ratio stability over time was found in the subgroup from areas between 12° S and 55° S latitude. The sex ratio increase mainly affected relapsing-remitting (RR) MS. CONCLUSIONS: Our results confirm a general sex ratio increase over time in RRMS and also demonstrate a latitudinal gradient of this increase. These findings add useful information for planning case-control studies aimed to explore sex-related factors responsible for MS development.

Increasing age at disability milestones among MS patients in the MSBase Registry.

OBJECTIVE: To analyze time-trends in age at disability milestones among MS patients who were enrolled into the MSBase International Registry during 1996-2010 period. METHODS: We used linear regression to describe the relationship between mean age at major EDSS benchmarks and calendar time. We then assessed time-trend in age at initial EDSS rating with a three level linear growth model specifying that patients were nested within each of 20 participating countries. The model estimated the average of time-trends in mean age at initial clinical assessment within each country while controlling for patients' EDSS and sex in each country. Analyses were repeated in subsamples of patients diagnosed according to Poser or McDonald criteria. RESULTS: The MSBase Registry contained data on 11,108 MS patients enrolled between 1996 and 2010 who fulfilled our inclusion criteria. During the 1996-2010 period, enrollment age for patients with EDSS 4/4.5 increased by 7.9 years, from 43 to 51 years (p<0.001), and for EDSS 6/6.5 - by 4.9 years, from 48 to 53 year (p<0.001). These trends were consistent across 20 investigator countries and were observed in Poser-diagnosed as well as McDonald-diagnosed patient subsets. CONCLUSIONS: The more recent MSBase enrollees in each of the mild-to-moderate disability strata were significantly older than earlier enrollees. Possible explanations for this phenomenon are discussed.

Country, sex, EDSS change and therapy choice independently predict treatment discontinuation in multiple sclerosis and clinically isolated syndrome.

OBJECTIVES: We conducted a prospective study, MSBASIS, to assess factors leading to first treatment discontinuation in patients with a clinically isolated syndrome (CIS) and early relapsing-remitting multiple sclerosis (RRMS). METHODS: The MSBASIS Study, conducted by MSBase Study Group members, enrols patients seen from CIS onset, reporting baseline demographics, cerebral magnetic resonance imaging (MRI) features and Expanded Disability Status Scale (EDSS) scores. Follow-up visits report relapses, EDSS scores, and the start and end dates of MS-specific therapies. We performed a multivariable survival analysis to determine factors within this dataset that predict first treatment discontinuation. RESULTS: A total of 2314 CIS patients from 44 centres were followed for a median of 2.7 years, during which time 1247 commenced immunomodulatory drug (IMD) treatment. Ninety percent initiated IMD after a diagnosis of MS was confirmed, and 10% while still in CIS status. Over 40% of these patients stopped their first IMD during the observation period. Females were more likely to cease medication than males (HR 1.36, p = 0.003). Patients treated in Australia were twice as likely to cease their first IMD than patients treated in Spain (HR 1.98, p = 0.001). Increasing EDSS was associated with higher rate of IMD cessation (HR 1.21 per EDSS unit, p<0.001), and intramuscular interferon-ß-1a (HR 1.38, p = 0.028) and subcutaneous interferon-ß-1a (HR 1.45, p = 0.012) had higher rates of discontinuation than glatiramer acetate, although this varied widely in different countries. Onset cerebral MRI features, age, time to treatment initiation or relapse on treatment were not associated with IMD cessation. CONCLUSION: In this multivariable survival analysis, female sex, country of residence, EDSS change and IMD choice independently predicted time to first IMD cessation.