Genetic burden of common variants in progressive and bout-onset multiple sclerosis

A Whole-Genome Sequencing Study Implicates GRAMD1B in Multiple Sclerosis Susceptibility

While the role of common genetic variants in multiple sclerosis (MS) has been elucidated in large genome-wide association studies, the contribution of rare variants to the disease remains unclear. Herein, a whole-genome sequencing study in four affected and four healthy relatives of a consanguineous Italian family identified a novel missense c.1801T > C (p.S601P) variant in the GRAMD1B gene that is shared within MS cases and resides under a linkage peak (LOD: 2.194). Sequencing GRAMD1B in 91 familial MS cases revealed two additional rare missense and two splice-site variants, two of which (rs755488531 and rs769527838) were not found in 1000 Italian healthy controls. Functional studies demonstrated that GRAMD1B, a gene with unknown function in the central nervous system (CNS), is expressed by several cell types, including astrocytes, microglia and neurons as well as by peripheral monocytes and macrophages. Notably, GRAMD1B was downregulated in vessel-associated astrocytes of active MS lesions in autopsied brains and by inflammatory stimuli in peripheral monocytes, suggesting a possible role in the modulation of inflammatory response and disease pathophysiology.

A multi-step genomic approach prioritized TBKBP1 gene as relevant for multiple sclerosis susceptibility

Background

Over 200 genetic loci have been associated with multiple sclerosis (MS) explaining ~ 50% of its heritability, suggesting that additional mechanisms may account for the “missing heritability” phenomenon.

Objective

To analyze a large cohort of Italian individuals to identify markers associated with MS with potential functional impact in the disease.

Methods

We studied 2571 MS and 3234 healthy controls (HC) of continental Italian origin. Discovery phase included a genome wide association study (1727 MS, 2258 HC), with SNPs selected according to their association in the Italian cohort only or in a meta-analysis of signals with a cohort of European ancestry (4088 MS, 7144 HC). Top associated loci were then tested in two Italian cohorts through array-based genotyping (903 MS, 884 HC) and pool-based target sequencing (588 MS, 408 HC). Finally, functional prioritization through conditional eQTL and mQTL has been performed.

Results

Top associated signals overlap with already known MS loci on chromosomes 3 and 17. Three SNPs (rs4267364, rs8070463, rs67919208), all involved in the regulation of TBKBP1, were prioritized to be functionally relevant.

Conclusions

No evidence of novel signal of association with MS specific for the Italian continental population has been found; nevertheless, two MS loci seems to play a relevant role, raising the interest to further investigations for TBKBP1 gene.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-022-11109-8.

Can inpatient multidisciplinary rehabilitation improve health-related quality of life in MS patients on the long term - The Danish MS Hospitals Rehabilitation Study

Background:

Inpatient multidisciplinary rehabilitation (MDR) can improve health-related quality of life (HRQoL) in multiple sclerosis (MS) patients. However, the evidence of a long-term benefit is limited.

Objectives:

To investigate the long-term effectiveness of inpatient MDR on HRQoL in MS patients.

Methods:

We conducted a randomized controlled partial crossover trial with 427 MS patients.

Results:

Statistical significant long-term improvements in HRQoL were found in three of the six outcome measures at 12-month follow-up. Three in four suggested minimal clinically important differences (MCIDs) were unmet.

Conclusion:

These results indicate that the administration of inpatient MDR may lead to long-lasting improvements in HRQoL in MS patients.

Environmental and genetic risk factors for MS: an integrated review

Recent findings have provided a molecular basis for the combined contributions of multifaceted risk factors for the onset of multiple sclerosis (MS). MS appears to start as a chronic dysregulation of immune homeostasis resulting from complex interactions between genetic predispositions, infectious exposures, and factors that lead to pro-inflammatory states, including smoking, obesity, and low sun exposure. This is supported by the discovery of gene-environment (GxE) interactions and epigenetic alterations triggered by environmental exposures in individuals with particular genetic make-ups. It is notable that several of these pro-inflammatory factors have not emerged as strong prognostic indicators. Biological processes at play during the relapsing phase of the disease may result from initial inflammatory-mediated injury, while risk factors for the later phase of MS, which is weighted toward neurodegeneration, are not yet well defined. This integrated review of current evidence guides recommendations for clinical practice and highlights research gaps.

Impact of alemtuzumab on health-related quality of life over 6 years in CARE-MS II trial extension patients with relapsing-remitting multiple sclerosis

Background:

In CARE-MS II (Comparison of Alemtuzumab and Rebif^® Efficacy in Multiple Sclerosis; NCT00548405), alemtuzumab (12 mg/day; baseline: 5 days; 12 months later: 3 days) significantly improved health-related quality of life (HRQL) outcomes versus subcutaneous interferon beta-1a (SC IFNB-1a) in relapsing-remitting multiple sclerosis (RRMS) patients over 2 years. Patients completing CARE-MS II could enter a 4-year extension study (NCT00930553).

Objective:

The aim of this study is to assess 6-year HRQL outcomes in alemtuzumab-treated CARE-MS II patients, including those with highly active disease (HAD).

Methods:

During extension, patients could receive additional alemtuzumab for clinical/magnetic resonance imaging (MRI) activity or other disease-modifying therapies per investigator’s discretion. Assessments include Functional Assessment of Multiple Sclerosis (FAMS), 36-Item Short-Form Health Survey (SF-36), and EQ-5D visual analog scale (EQ-VAS).

Results:

Alemtuzumab-treated patients improved or stabilized all HRQL measures over 6 years with significant improvements from baseline at all time points on EQ-VAS and for up to 5 years on FAMS, SF-36 MCS, and SF-36 PCS. Alemtuzumab-treated patients with HAD showed significant improvements versus baseline at Year 2 on all HRQL measures, and significant improvements versus SC IFNB-1a on SF-36 PCS and EQ-VAS; however, the improvements did not reach the threshold for clinical relevance.

Conclusion:

Alemtuzumab-treated CARE-MS II patients improved or stabilized HRQL versus baseline over 6 years. This is the first study to show long-term HRQL benefits in patients with HAD.

Distribution of disease courses in familial vs sporadic multiple sclerosis

OBJECTIVES

The overall distribution of disease courses in multiple sclerosis (MS) is well established, but little is known about the distribution among familial MS cases. We examine the frequency of the different MS courses among familial and sporadic MS cases and determine whether MS cases within the same family had the same age at diagnosis and have experienced the same disease course.

MATERIALS AND METHODS

This is a nationwide register study, based on data from the Danish MS Registry, the Danish Civil Registration System, and the Danish National Patient Registry. The main variables are MS diagnosis, MS course, and first-degree relatives with MS The statistical analyses were carried out using logistic regression analysis, Kappa coefficient, and intraclass correlations coefficient.

RESULTS

In total, 7402 MS cases were included in the study, of which 531 have an affected first-degree relatives, and 6871 are sporadic. We found that relapsing-remitting MS including secondary progressive MS was more common among familial MS cases than among sporadic MS cases (Odds ratio = 1.64, 95% CI: 1.20-2.24, P = 0.002). We subsequently analyzed data on 133 MS families and found that MS courses correlate between the first and the second MS case diagnosed, while age at diagnosis does not.

CONCLUSION

Familial MS cases are more likely to have relapsing-remitting MS than a progressive course compared to sporadic MS cases. Secondly, we find that within MS families, first-degree relatives are likely to have the same MS course, but we do not find that they are diagnosed at the same age.

Impact of MS genetic loci on familial aggregation, clinical phenotype, and disease prediction

Objective:

To investigate the role of known multiple sclerosis (MS)-associated genetic variants in MS familial aggregation, clinical expression, and accuracy of disease prediction in sporadic and familial cases.

Methods:

A total of 1,443 consecutive patients were screened for MS and familial autoimmune history in a hospital-based Italian cohort. Among them, 461 sporadic and 93 familial probands were genotyped for 107 MS-associated polymorphisms. Their effect sizes were combined to calculate the weighted genetic risk score (wGRS).

Results:

Family history of MS was reported by 17.2% of probands, and 33.8% reported a familial autoimmune disorder, with autoimmune thyroiditis and psoriasis being the most frequent. No difference in wGRS was observed between sporadic and familial MS cases. In contrast, a lower wGRS was observed in probands with greater familial aggregation (>1 first-degree relative or >2 relatives with MS) (p = 0.03). Also, female probands of familial cases with greater familial aggregation had a lower wGRS than sporadic cases (p = 0.0009) and male probands of familial cases (p = 0.04). An inverse correlation between wGRS and age at onset was observed (p = 0.05). The predictive performance of the genetic model including all known MS variants was modest but greater in sporadic vs familial cases (area under the curve = 0.63 and 0.57).

Conclusions:

Additional variants outside the known MS-associated loci, rare variants, and/or environmental factors may explain disease occurrence within families; in females, hormonal and epigenetic factors probably have a predominant role in explaining familial aggregation. The inclusion of these additional factors in future versions of aggregated genetic measures could improve their predictive ability.

Burden of risk variants correlates with phenotype of multiple sclerosis

BACKGROUND

More than 100 common variants underlying multiple sclerosis (MS) susceptibility have been identified, but their effect on disease phenotype is still largely unknown.

OBJECTIVE

The objective of this paper is to assess whether the cumulative genetic risk score of currently known susceptibility variants affects clinical presentation.

METHODS

A cumulative genetic risk score was based on four human leukocyte antigen (HLA) and 106 non-HLA risk loci genotyped or imputed in 842 Belgian MS patients and 321 controls. Non-parametric analyses were applied.

RESULTS

An increased genetic risk is observed for MS patients, including subsets such as oligoclonal band-negative and primary progressive MS patients, compared to controls. Within the patient group, a stronger association between HLA risk variants and the presence of oligoclonal bands, an increased immunoglobulin G (IgG) index and female gender was apparent. Results suggest an association between a higher accumulation of non-HLA risk variants and increased relapse rate as well as shorter relapse-free intervals after disease onset.

CONCLUSION

MS patients display a significantly increased genetic risk compared to controls, irrespective of disease course or presence of oligoclonal bands. Whereas the cumulative burden of non-HLA risk variants appears to be reflected in the relapses of MS patients, the HLA region influences intrathecal IgG levels.

Inverse correlation of genetic risk score with age at onset in bout-onset and progressive-onset multiple sclerosis

We correlated the weighted genetic risk score measured using 107 established susceptibility variants for multiple sclerosis (MS) with the age at onset in bout-onset (BOMS, n=906) and progressive-onset MS Italian patients (PrMS) (n=544). We observed an opposite relationship in the two disease courses: a higher weighted genetic risk score was associated with an earlier age at onset in BOMS (rho= -0.1; p=5 × 10(-3)) and a later age at onset in PrMS cases (rho=0.07; p=0.15) (p of difference of regression=1.4 × 10(-2)). These findings suggest that established MS risk variants anticipate the onset of the inflammatory phase, while they have no impact on, or even delay, the onset of the progressive phase.