Ten-year prognosis in multiple sclerosis: a better outcome in relapsing-remitting patients but not in primary progressive patients.

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) prognosis remains a challenge for both patients and physicians. Complementary to natural history studies, updated population-based data from the first event suggestive of MS, at the time of the first approved disease modifying drug (DMD), are needed. Our objective was to provide a 10-year history of MS from clinical onset at time of first approved DMDs in a population-based cohort. METHODS: A population-based cohort of patients whose first clinical event suggestive of MS had occurred in Brittany between 2000 and 2001 was prospectively selected. History of relapses, treatments and disability up to 10 years after onset were collected. RESULTS: In all, 278 patients with either attack-onset (n = 244) or progressive-onset (n = 34) were recruited. Amongst attack-onset patients, 30% remained as clinically isolated syndrome and 70% had a second relapse after a median time of 1.7 years (95% confidence interval 1.2-2.4). 80% of relapsing-remitting MS patients received DMDs for at least 6 months. 29% reached disability status scale (DSS) 3 and 8% DSS 6. Amongst progressive-onset patients, 100% reached DSS 3 and 59% DSS 6. CONCLUSION(S): Our population-based study reports a lower risk of disability progression at 10-year follow-up in the relapsing-remitting MS group than previously reported. This better prognosis was not observed in the progressive-onset MS group. This finding impacts the prognosis given to patients in clinical practice.

Register-based incidence of multiple sclerosis in Brittany (north-western France), 2000-2001.

OBJECTIVES: To report on multiple sclerosis (MS) incidence in Brittany, north-western France. MATERIALS & METHODS: From 2000, we set up a population-based register for patients presenting a putative incident MS (PIMS), that is first symptoms compatible with MS onset. We used 3 medical sources of case ascertainment (neurologists, CSF, regional MS-Clinic). Eligibility criteria required both clinical onset and being permanent resident of Brittany in 2000 or 2001. From 2010, all medical records were tracked, the 10-year follow-up allowing previously reported data to be updated. RESULTS: Of 313 eligible PIMS, there were 208 definite MS (both McDonald and Poser criteria), 41 CIS-probable MS (Poser criteria), 32 CIS-possible MS and 32 non-MS. Our incident cohort of 249 MS cases with definite/probable MS (sex ratio 2.95) gave a crude annual incidence of 4.28 per 100,000 inhabitants (6.22 for women, 2.23 for men), and age-standardized rates (adjustment to the European population) of 4.41 [3.32-5.51], 6.68 [4.75-8.60], and 2.21 [1.12-3.31], respectively. Age-specific rates by gender and initial course showed that attack onset MS peaked at 25-29 years and progressive onset MS at 40-44 years in women (20-24 years and 45-49 years in men, respectively). CONCLUSIONS: Brittany is confirmed a high-risk region for MS. Our data show marked differences in sex-specific pattern of MS incidence by clinical course and point out 25- to 29-year-old women as having the highest MS risk. While temporal variations cannot be excluded, comparison with overall French data suggests that other factors rather than latitude may influence the MS risk in France.

'Clinically definite benign multiple sclerosis', an unwarranted conceptual hodgepodge: evidence from a 30-year observational study.

BACKGROUND: Benign multiple sclerosis (BMS) is a controversial concept which is still debated. However identification of this kind of patients is crucial to prevent them from unnecessary exposure to aggressive and/or long term medical treatments. OBJECTIVES: To assess two definitions of 'clinically definite benign multiple sclerosis' (CDBMS) using long-term follow-up data, and to look for prognostic factors of CDBMS. METHODS: In 874 patients with definite relapsing-remitting MS, followed up for at least 10 years, disability was assessed using the Disability Status Scale (DSS). CDBMS was defined by either DSS score≤2 (CDBMS1 group) or DSS score≤ 3 (CDBMS2 group) at 10 years. We estimated the proportion of patients who were still benign at 20 and 30 years after clinical onset. RESULTS: CDBMS frequency estimates were 57.7% and 73.9% when using CDBMS1 and CDBMS2 definitions, respectively. In the CDBMS1 group, only 41.7% (105/252) of cases were still benign 10 years later, and 41.1% (23/56) after an additional decade, while there were 53.8% (162/301) and 59.5% (44/74) respectively in the CDBMS2 group. CONCLUSIONS: This 30-year observational study, which is one of the largest published series, indicates that favourable 10-year disability scores of DSS 2 or 3 fail to ensure a long-term benign course of multiple sclerosis. After every decade almost half of the CDBMS were no longer benign. CDBMS, as currently defined, is an unwarranted conceptual hodgepodge. Other criteria using new biomarkers (genetic, biologic or MRI) should be found to detect benign cases of MS.

Season of birth and not vitamin D receptor promoter polymorphisms is a risk factor for multiple sclerosis.

Both genetic and environmental factors contribute to multiple sclerosis, the most common neurodegenerative disorder with onset in young adults. The objective of the current study is, based on the hypothesis that environmentally predisposed individuals are at risk for multiple sclerosis, to investigate whether they also carry genetic variants within the vitamin D machinery. Using medical files and DNA samples from 583 trios (a patient and both parents) of the French Multiple Sclerosis Genetics Group as well as data from the French Statistics Bureau, we aimed to assess whether: (1) a seasonality of birth was observed in French multiple sclerosis patients; (2) three single nucleotide polymorphisms within the promoter region of the vitamin D receptor were associated with multiple sclerosis susceptibility; and (3) the combination of a high risk month of birth and vitamin D receptor polymorphisms were correlated to multiple sclerosis incidence. We observed a significantly reduced number of individuals born in November who were later diagnosed as multiple sclerosis patients. However, we found no association between the three studied vitamin D receptor polymorphisms and multiple sclerosis. In conclusion, our data suggest that high levels of vitamin D during the third trimester of pregnancy could be a protective factor for multiple sclerosis.

HLA-DRB1*15 allele influences the later course of relapsing remitting multiple sclerosis.

Most of the published works so far have aimed at finding genes associated with multiple sclerosis (MS) susceptibility. Very few studies have attempted to correlate disease features with DNA variants. In a well-characterized sample (651 patients) representative of multiple sclerosis natural history, we engaged a comprehensive study of the role of human leukocyte antigen (HLA) in the course of the disease. We investigated the role of HLA-DRB1*15 allele in samples stratified according to severity evaluated by the Multiple Sclerosis Severity Score (MSSS), time to reach EDSS 6.0 and disease type. We found that HLA-DRB1*15 genotype does not influence MS severity even among patients presenting with a given type of the disease. However, we show for the first time that HLA-DRB1*15 allele modulates the course of MS for relapsing-remitting (RR) onset patients likely by precipitating the secondary progressive (SP) phase.

IL2RA and IL7RA genes confer susceptibility for multiple sclerosis in two independent European populations.

Multiple sclerosis (MS) is the most common chronic inflammatory neurologic disorder diagnosed in young adults and, due to its chronic course, is responsible for a substantial economic burden. MS is considered to be a multifactorial disease in which both genetic and environmental factors intervene. The well-established human leukocyte antigen (HLA) association does not completely explain the genetic impact on disease susceptibility. However, identification and validation of non-HLA-genes conferring susceptibility to MS has proven to be difficult probably because of the small individual contribution of each of these genes. Recently, associations with two single nucleotide polymorphisms (SNPs) in the IL2RA gene (rs12722489, rs2104286) and one SNP in the IL7RA gene (rs6897932) have been reported by several groups. These three SNPs were genotyped in a French and a German population of MS patients using the hME assay by the matrix-assisted laser desorption/ionization time of flight technology (Sequenom, San Diego, CA, USA). We show that these SNPs do contribute to the risk of MS in these two unrelated European MS patient populations with odds ratios varying from 1.1 to 1.5. The discovery and validation of new genetic risk factors in independent populations may help toward the understanding of MS pathogenesis by providing valuable information on biological pathways to be investigated.

Familial factors influence disability in MS multiplex families. French Multiple Sclerosis Genetics Group.

BACKGROUND: Both genetic and environmental factors play a role in the pathophysiology of MS and may influence the clinical expression of the disease. OBJECTIVE: To determine the contribution of familial factors to the clinical expression of MS. METHODS: The French Multiple Sclerosis Genetics Group identified 87 sibling pairs. For each patient, sex, age at onset, duration of the disease, and disease course from onset were recorded. Disability was determined by the progression index (PI), defined as the ratio of the Expanded Disability Status Scale (EDSS) score disease duration when the latter exceeded 5 years. Statistical analyses were performed either with a group of patients (clinical features, relation between human leukocyte antigen and clinical features) or with a group of sibpairs (concordance for clinical features). RESULTS: The mean age at onset was 29.6 years, the ratio of women to men was 59:28, and the mean PI was 0.27. There was no correlation for disease course and age at onset between sibs with MS. In contrast, we observed a weak but significant correlation of the PI in MS sibpairs (r = 0.234, p = 0.03). CONCLUSION: This study revealed a concordance in MS sibling pairs for the disease severity, supporting the hypothesis that the degree of disability might be partly influenced by familial factors (environmental or genetic).

The role of HLA-DR-DR and HLA-DR-DP interactions in genetic susceptibility to rheumatoid arthritis.

In order to analyze the relationships between the DR and DP loci in the genetic susceptibility to RA, HLA-DRB1 and -DPB1 polymorphism was studied in 155 RA patients compared to 150 controls, using a reverse dot-blot analysis. Our data were consistent with the involvement of the amino acid in position 71 of the third hypervariable region of the DR beta 1 chain in susceptibility to the disease. The higher risk for RA was observed in patients who carried the association of a lysine (K), characterizing the DRB1* 0401 susceptibility allele, with an arginine (R), observed in all the other DRB1* susceptibility alleles (21.9% vs 0.6%, p(c) < 10(-6), OR = 42) In the absence of arginine, the presence of lysine was still associated with the disease (33% vs 19%, p(c) < 0.03, OR = 2). In contrast, in the absence of lysine, the frequency of arginine in position 71 was similar in patients and controls (30% vs 26%, p = NS). On another hand, the analysis of the HLA-DPB1 locus showed that the DPB1 *0401 allele frequency was significantly increased in the RA patient group (n = 47) who expressed only arginine at the position 71 of the beta 1 chain (82% vs 56% in controls, p < 0.008), with role of HLA-DR--DR and -DR-DP interactions in the genetic susceptibility to RA.

Percent transferrin saturation in segregating hemochromatosis.

The segregation of genetic hemochromatosis was analyzed by using percent transferrin saturation (TS) as a phenotypic marker of the disease. Homozygotes for the disease were readily discernable with the added information provided by the quantitative indicator. However, there was no evidence of partial expression of TS abnormalities in heterozygotes, contrary to previous studies.

Genetic hemochromatosis: distribution analysis of six laboratory measures of iron metabolism.

Six laboratory measures of iron metabolism were studied in a control sample, and a family sample was ascertained on the basis of probands with clinically diagnosed genetic hemochromatosis. The respective distribution of each variable evidenced a mixture of components, presumably arising from the segregation of an HLA-linked locus for hemochromatosis. There were significant differences in the distributional characteristics with respect to sex and genotype-specific variances. These aspects of the data have important implications for subsequent segregation and linkage analyses, which traditionally assume homoscedasticity and homogeneity of the genetic effect.

[Should we screen for hemochromatosis? Critical analysis of the literature]. / Faut-il dépister l'hémochromatose? Analyse critique de la littérature.

This paper focus on the main issues to evaluate before planning public health interventions which may optimise the prevention of hemochromatosis. The main indicators are considered: prevalence, morbidity and mortality of the disease, efficacy of the available treatment, sensitivity, specificity and predictive values of the screening tests; potential benefit of a national screening program in a public health perspective. These are evaluated through a critical appraisal of the clinical, epidemiologic and economic literature on hemochromatosis. The paper emphasizes how individual behavior and preferences become crucial to take into account when well-being subjects will face a population-based screening program. We conclude that further arguments are required before the implementation of a national screening program for hemochromatosis.

[Molecular genetics of hemochromatosis]. / Génétique moléculaire de l'hémochromatose.

Haemochromatosis is an inherited disorder of iron metabolism characterized by a general iron over loading. Without diagnosis and early treatment, it is a serious and potentially fatal disease by cardiac failure or hepatocellular carcinoma in particular. Gene prevalence was estimated at 0.06 in Brittany, so that haemochromatosis may be the most common genetic disease in this area. The biochemical defect of the disease is unknown; only one fact is well established: the iron absorption through duodenal mucosa is excessive. However we don't know if it is a primary event. The gene is also unknown but in 1975 it was located on the short arm of chromosome 6, closely linked to the HLA class I region, less than 1 cM from HLA-A. None of the genes coding for the known iron proteins could be the haemochromatosis gene because of their chromosomal localization. In order to locate this gene with precision, we have used a reverse genetic approach now called positional cloning. Characterization of new polymorphic markers and linkage disequilibrium analysis, have led us to locate the gene within a 350 kb region around HLA-A. We have then searched for all the structural genes in this region. Seven new genes have been so identified and located with precision. A structural analysis of these genes was undertaken to find an eventual abnormality in patients.

MGAT5 alters the severity of multiple sclerosis.

Multiple Sclerosis (MS) is a genetically complex immune mediated, demyelinating disease of the central nervous system. To date no genetic variants have been unambiguously linked to disease severity. We have conducted a genome wide screen, using Affymetrix Genechip 500K technology, for severity in 1040 MS patients. Two markers within MGAT5, a gene coding for a glycosylation enzyme, were found to be significantly associated with outcome in the screening as well as in an independent population (combined p-values: 2.8 x 10(-6) and 1.5 x 10(-7)).

Long-term survival of patients with multiple sclerosis in West France.

In France no data have been published about comparing survival in multiple sclerosis (MS) patients with the general French population. We estimated survival probabilities in MS patients from a major centre for MS in West France. We also compared MS survival with the general population and assessed prognostic parameters. All patients with MS onset after January 1976 and classified as dead or alive on 1 January 2004 were included. One thousand eight-hundred and seventy-nine patients (sex ratio W: M 2.3; relapsing/progressive onset 77.4%/22.6%) fulfilled these criteria, disease duration ranged from one to 28 years. By 2004, 68 patients died (51 due to MS) and the 15 and 25-year survival probabilities were 96% and 88%. Male gender, progressive course (either primary or secondary), polysymptomatic onset, and increased annual relapse rate during the first two years of MS were related to a worse prognosis. After a mean follow-up duration of 12.7 years since clinical onset, MS increased the number of deaths compared with the general population. However taking into account disability status, we found that less disabled MS patients had a better survival and highly disabled patients a worse survival (eight-fold increase of mortality) compared with the French population.

Diabetes and haemochromatosis: current concepts, management and prevention.

Haemochromatosis is a common autosomal recessive disorder of iron metabolism caused by a gene in tight linkage with HLA class I genes. Despite intensive research, the molecular defect and underlying biochemical anomaly are still unknown. Diabetes, a serious complication of haemochromatosis, is frequently associated with cirrhosis which reduces life expectancy. Its development is related to iron excess, directly or through associated liver involvement, although the precise mechanisms of iron toxicity remain unclear. New concepts concerning its pathogenesis include insulin resistance and beta-cell dysfunction which are apparent well before insulin deficiency and can be reversed if iron depletion is promptly initiated. Today, earlier recognition of iron overload through active diagnostic approaches has a direct impact in reducing the frequency of diabetes among hemochromatosis patients. Presymptomatic diagnosis in the general population and among relatives of affected subjects currently relies on the detection of increased iron stores through medical awareness and family screening. Indirect gene diagnosis with serological and molecular markers of the HLA region can be provided for relatives of proven cases. As part of a genetic counselling process, this allows the identification of at-risk subjects before the onset of iron accumulation. Isolation of the gene and identification of the metabolic defect leading to increased iron absorption may have significant implications for future diagnostic procedures and preventive strategies in haemochromatosis.

Combined segregation and linkage analysis of genetic hemochromatosis using affection status, serum iron, and HLA.

Characterizing the distribution of parameters of iron metabolism by hemochromatosis genotype remains an important goal vis-à-vis potential screening strategies to identify individuals at genetic risk, since a specific marker to detect the abnormal gene has not been identified as yet. In the present investigation, we analyze serum iron values in ascertained families using a method which incorporates both segregation of the clinical affection status and the HLA linkage information to identify the underlying genotypes. The analysis is performed using an extension of the model presented by Bonney et al., comprising regressive models for segregation analysis and the multipoint linkage strategy implemented in LINKAGE. The gene was found to be completely recessive with respect to both clinical manifestations and serum iron abnormalities, with significant differences in expression by sex. Clinical manifestations were present for all male homozygotes in this data set, suggesting that the recessive hemochromatosis genotype is fully penetrant at all ages in males. This was not the case for younger females. Significant genotype-specific age and sex effects were found for serum iron values. It is interesting that deletion of the HLA marker information did not affect our ability to resolve the genetic model when we analyzed a bivariate phenotype. This serves as a reminder that a search for relevant biological markers can be equally important in discerning the genetic etiology of a disease trait, as a search for linked genetic markers.