Influence of histocompatibility genes on disease susceptibility and treatment response in patients with relapsing-remitting multiple sclerosis treated with interferon β-1a

Multiple sclerosis (MS) is the most common, non-traumatic cause of neurological disability in young adults. The aim of this study was to investigate the influence of HLA class II alleles DRB1* and DQB1* on susceptibility to relapsing-remitting (RR) MS and response to interferon (IFN) β-1a treatment. A prospective observational study was conducted. Seventeen patients with clinically definite RRMS, attending a tertiary referral center for multiple sclerosis in Israel and receiving treatment with subcutaneous IFN β-1a, 22 mcg three times weekly were recruited between December 1998 and February 2000 and observed for 12 months. HLA genotyping was performed and clinical characteristics (relapse rate and disability progression) assessed at baseline and after 12 months. HLA data for a healthy control group were also used for comparison. HLA and the success of treatment with IFN β-1a in this group of RRMS patients were assessed. The frequency of DRB1*03 was six times higher in patients treated with IFN β-1a than in the healthy control group (n=100): 29% (5/17) versus 5% (5/100), respectively. Additionally, DQB1*03 and DQB1*02 were present in 82% (14/17) and 41% (7/17) of RRMS patients, but in only 33% (33/100) and 18% (18/100) of control patients, respectively. A better response to IFN β-1a treatment was seen in patients carrying these alleles than in patients without these alleles. Our results indicated that DRB1*03, DQB1*03 and DQB1*02 alleles may contribute to MS susceptibility and IFN β-1a responsiveness, and warrant further verification in a larger population

Comparative effectiveness of glatiramer acetate and interferon beta formulations in relapsing-remitting multiple sclerosis

Background: The results of head-to-head comparisons of injectable immunomodulators (interferon β, glatiramer acetate) have been inconclusive and a comprehensive analysis of their effectiveness is needed. Objective: We aimed to compare, in a real-world setting, relapse and disability outcomes among patients with multiple sclerosis (MS) treated with injectable immunomodulators. Methods: Pairwise analysis of the international MSBase registry data was conducted using propensity-score matching. The four injectable immunomodulators were compared in six head-to-head analyses of relapse and disability outcomes using paired mixed models or frailty proportional hazards models adjusted for magnetic resonance imaging variables. Sensitivity and power analyses were conducted. Results: Of the 3326 included patients, 345–1199 patients per therapy were matched (median pairwise-censored follow-up was 3.7 years). Propensity matching eliminated >95% of the identified indication bias. Slightly lower relapse incidence was found among patients treated with glatiramer acetate or subcutaneous interferon β-1a relative to intramuscular interferon β-1a and interferon β-1b (p≤0.001). No differences in 12-month confirmed progression of disability were observed. Conclusion: Small but statistically significant differences in relapse outcomes exist among the injectable immunomodulators. MSBase is sufficiently powered to identify these differences and reflects practice in tertiary MS centres. While the present study controlled indication, selection and attrition bias, centre-dependent variance in data quality was likely

Highly active immunomodulatory therapy ameliorates accumulation of disability in moderately advanced and advanced multiple sclerosis.

OBJECTIVE: To evaluate variability and predictability of disability trajectories in moderately advanced and advanced multiple sclerosis (MS), and their modifiability with immunomodulatory therapy. METHODS: The epochs between Expanded Disability Status Scale (EDSS) steps 3-6, 4-6 and 6-6.5 were analysed. Patients with relapse-onset MS and having reached 6-month confirmed baseline EDSS step (3/4/6) were identified in MSBase, a global observational MS cohort study. We used multivariable survival models to examine the impact of disease-modifying therapy, clinical and demographic factors on progression to the outcome EDSS step (6/6.5). Sensitivity analyses with varying outcome definitions and inclusion criteria were conducted. RESULTS: For the EDSS 3-6, 4-6 and 6-6.5 epochs, 1560, 1504 and 1231 patients were identified, respectively. Disability trajectories showed large coefficients of variance prebaseline (0.92-1.11) and postbaseline (2.15-2.50), with no significant correlations. The probability of reaching the outcome step was not associated with prebaseline variables, but was increased by higher relapse rates during each epoch (HRs 1.58-3.07; p<0.001). A greater proportion of each epoch treated with higher efficacy therapies was associated with lower risk of reaching the outcome disability step (HRs 0.72-0.91 per 25%; p≤0.02). 3 sensitivity analyses confirmed these results. CONCLUSIONS: Disease progression during moderately advanced and advanced MS is highly variable and amnesic to prior disease activity. Lower relapse rates and greater time on higher efficacy immunomodulatory therapy after reaching EDSS steps 3, 4 and 6 are associated with a decreased risk of accumulating further disability. Highly effective immunomodulatory therapy ameliorates accumulation of disability in moderately advanced and advanced relapse-onset MS

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

Towards personalized therapy for multiple sclerosis: prediction of individual treatment response.

Timely initiation of effective therapy is crucial for preventing disability in multiple sclerosis; however, treatment response varies greatly among patients. Comprehensive predictive models of individual treatment response are lacking. Our aims were: (i) to develop predictive algorithms for individual treatment response using demographic, clinical and paraclinical predictors in patients with multiple sclerosis; and (ii) to evaluate accuracy, and internal and external validity of these algorithms. This study evaluated 27 demographic, clinical and paraclinical predictors of individual response to seven disease-modifying therapies in MSBase, a large global cohort study. Treatment response was analysed separately for disability progression, disability regression, relapse frequency, conversion to secondary progressive disease, change in the cumulative disease burden, and the probability of treatment discontinuation. Multivariable survival and generalized linear models were used, together with the principal component analysis to reduce model dimensionality and prevent overparameterization. Accuracy of the individual prediction was tested and its internal validity was evaluated in a separate, non-overlapping cohort. External validity was evaluated in a geographically distinct cohort, the Swedish Multiple Sclerosis Registry. In the training cohort (n = 8513), the most prominent modifiers of treatment response comprised age, disease duration, disease course, previous relapse activity, disability, predominant relapse phenotype and previous therapy. Importantly, the magnitude and direction of the associations varied among therapies and disease outcomes. Higher probability of disability progression during treatment with injectable therapies was predominantly associated with a greater disability at treatment start and the previous therapy. For fingolimod, natalizumab or mitoxantrone, it was mainly associated with lower pretreatment relapse activity. The probability of disability regression was predominantly associated with pre-baseline disability, therapy and relapse activity. Relapse incidence was associated with pretreatment relapse activity, age and relapsing disease course, with the strength of these associations varying among therapies. Accuracy and internal validity (n = 1196) of the resulting predictive models was high (>80%) for relapse incidence during the first year and for disability outcomes, moderate for relapse incidence in Years 2-4 and for the change in the cumulative disease burden, and low for conversion to secondary progressive disease and treatment discontinuation. External validation showed similar results, demonstrating high external validity for disability and relapse outcomes, moderate external validity for cumulative disease burden and low external validity for conversion to secondary progressive disease and treatment discontinuation. We conclude that demographic, clinical and paraclinical information helps predict individual response to disease-modifying therapies at the time of their commencement