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

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

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 ¼ 0.68), regions (p ¼ 0.96) or countries (p ¼ 0.50). Conclusions: Our analyses did not discover any difference in mean MSSS among patients from different regions, hemispheres or countries

Number of males and female PPMS patients who provided at least one valid EDSS measurement in each 5 year period.

<p>Number of males and female PPMS patients who provided at least one valid EDSS measurement in each 5 year period.</p

Number of males and female PPMS patients who provided at least one valid EDSS measurement in each 5 year period.

<p>Number of males and female PPMS patients who provided at least one valid EDSS measurement in each 5 year period.</p

Demographics of patients with relapsing- remitting (RR) / secondary progressive (SP) and primary progressive (PP) MS at the initial visit recorded to the MSBase Registry.

<p>Data are shown as mean (+/- SD)</p><p>Demographics of patients with relapsing- remitting (RR) / secondary progressive (SP) and primary progressive (PP) MS at the initial visit recorded to the MSBase Registry.</p

Mean value of EDSS for men and women with primary progressive MS by number of years since initial EDSS.

<p>EDSS is shown as mean value ± SD. Disease duration was derived as the date of the visit at which the EDSS was determined minus the date of onset of MS symptoms. Red squares = females, blue circles = males.</p

Number of male and female RRMS/SPMS patients who provided at least one valid EDSS measurement in each 5 year period.

<p>Number of male and female RRMS/SPMS patients who provided at least one valid EDSS measurement in each 5 year period.</p

Kaplan-Meier estimates of time to secondary progressive MS by sex.

<p>Kaplan-Meier estimates of time to secondary progressive MS by sex.</p