The HLA-DR13 haplotype is associated with "benign" multiple sclerosis in northeast Italy

The impact of HLA-DRB1 alleles in a Hellenic, Pediatric-Onset Multiple Sclerosis cohort: Implications on clinical and neuroimaging profile

BACKGROUND

Pediatric-Onset Multiple Sclerosis (POMS) is considered a complex disease entity and several genetic, hormonal, and environmental factors have been associated with disease pathogenesis. Linkage studies in Caucasians have consistently suggested the human leukocyte antigen (HLA) polymorphisms, as the genetic locus most strongly linked to MS, with the HLA-DRB1*15:01 allele, being associated with both adult and pediatric MS patients. Here we aim to investigate the prevalence of the HLA-DRB1 alleles among a Hellenic POMS cohort and any possible associations with clinical and imaging disease features.

MATERIALS AND METHODS

100 POMS patients fulfilling the IPMSSG criteria, 168 Adult-Onset MS (AOMS) patients, and 246 Healthy Controls (HCs) have been enrolled. HLA genotyping was performed with a standard low-resolution sequence-specific oligonucleotide (SSO) technique.

RESULTS

POMS patients display a significantly increased HLA-DRB1*03 frequency compared to both HCs [24% vs. 12.6%, OR [95%CI]: 2.19 (1.21-3.97), p=0.016) and AOMS (24% vs. 13.1%, OR [95%CI]: 2.1 (1.1-3.98), p=0.034] respectively. HLA-DRB1*03-carriers display reduced risk for brainstem lesion development (OR [CI 95%]:0.19 (0.06-0.65), p=0.011). A significantly lower frequency of HLA-DRB1*07 (4% vs 13.4%, OR (95% CI): 0.27 (0.09-0.78), p= 0.017) and HLA-DRB1*11 (37% vs 52%, OR [95% CI]: 0.54 (0.34-0.87), p= 0.016) was observed in POMS compared to HCs.

CONCLUSION

The HLA-DRB1*03 allele was associated with a higher risk for POMS, replicating our previous findings, and with a lower risk for brainstem lesion development, a common clinical and neuroimaging feature in POMS, while HLA-DRB1*07 and HLA-DRB1*11 display a protective role. These findings expand the existing knowledge of HLA associations and POMS.

Pediatric Multiple Sclerosis in Rio de Janeiro: Secondary Progression and Disability

BACKGROUND

The onset of multiple sclerosis (MS) in 2% to 10% of cases occurs prior to 18 years of age. Early age onset appears to affect some aspects of multiple sclerosis. The objective of our study was to evaluate the prevalence, the clinical and demographic characteristics, and the disease progression in a sample of pediatric multiple sclerosis patients from a mixed population.

METHODS

In a cross-sectional design, the prevalence, demographic characteristics, and initial clinical forms were compared between 75 cases of pediatric multiple sclerosis (PMS) and 689 adults with MS. Sixty-five PMS patients with complete data and 260 randomly selected adults with relapsing-remitting multiple sclerosis were compared. A Kaplan-Meier analysis was conducted to compare the age at and time to Expanded Disability Status Scale (EDSS) 3, EDSS 6, and secondary progressive multiple sclerosis (SPMS).

RESULTS

A total of 9.8% of all MS cases with available data were PMS. All cases of PMS consisted of relapsing-remitting multiple sclerosis. Brazilians of African descent comprised 34.6% of the sample, and the female-to-male ratio was 2.4:1. At the first attack, motor alterations were more common. Benign forms were more common in PMS (84.6% versus 62.2%). Fewer PMS patients reached EDSS 6 (11.6% versus 25.4%) (P = 0.0017) and SPMS (11.1% versus 28.1%) (P = 0.005). PMS patients took longer to reach EDSS 3 (P = 0.017), EDSS 6 (P = 0.001), and SPMS (P < 0.001); however, they reached EDSS 3 earlier (P < 0.001).

CONCLUSIONS

In this mixed cohort, the prevalence of PMS was similar to that reported in other studies, and the pediatric patients had a more benign course than adults with MS.

Distinct HLA class I and II genotypes and haplotypes are associated with multiple sclerosis in Bahrain

Multiple sclerosis (MS) has become prevalent in the Arabian Gulf area with high incidence in Bahrain due to environmental influences and genetic susceptibilities, but there is a lack of study into human leukocyte antigen (HLA) types in patients with MS in Bahrain. The present study aimed to study the HLA types expressed in MS patients compared with in control subjects. Blood samples from 50 Bahraini patients with MS and 50 Bahraini control subjects' were subjected to HLA tissue typing by polymerase chain reaction using sequence-specific primers. In comparison with those in control subjects, the allele frequencies of HLA class-I antigens A2, A9, A19, B5, B35 and B40 were higher in MS patients. For class II antigens, the allele frequencies of DR3, DR4 and DR16 were higher in MS patients. The allele frequency of DR15 was lower in MS patients than in control subjects but the difference was not statistically significant (P=0.138). The higher prevalence of the HLA-ABDR allele was common among the female patients with MS, in relapse remission stage, in cases with higher expanded disability status scale scores and with disease duration between 4 and 9 years. Haplotype HLA-A2-B40-DR2 exhibited significantly higher frequency in MS patients compared with in control subjects (P=0.03). In conclusion, the results indicated different alleles associated with MS compared with previous reviews. The present study supports the importance of identifying genetic susceptibilities and targets for therapies in specific populations and individuals, to personalize disease management in terms of prediction, protective measures and treatment.

HLA determinants of susceptibility to multiple sclerosis in an Arabian Gulf population

Background: An association between HLA antigens and susceptibility to multiple sclerosis (MS) has been established, especially in Caucasian populations. Such associations have not been as clearly defined in many Arab populations, where even the frequencies of specific HLA antigens remain unclear. Objective: The study was designed to (i) investigate the frequencies of HLA Class I and II antigens in Kuwaiti Arabs with MS, and; (ii) assess possible inter-relationships between HLA Class II antigens and such clinical phenotypic variables in MS as age at onset, gender, disease subtype and scale of disability. Subjects and methods: HLA Class I (A, B, C) and Class II (DR, DQ) antigens’ tissue-typing was performed by the standard complement-dependent microlymphocytotoxicity technique in two groups of ageand sex-matched Kuwaiti subjects: (i) 67 patients with definite MS (48 relapsing-remitting, 19 relapsing-progressive) and (ii) 145 unrelated healthy controls. The frequencies of specific HLA types were then compared between patients with controls, and in the former, related to specified clinical parameters. Results: The frequencies for the Class I antigens: A9, A10, A19, A33, B5 and CW4 appeared higher with the presence of MS, although the numbers of positive subjects were rather low. For the Class II antigens, frequencies of DR4, DQ5, DQ6, DQ7 and DQ8 were increased while those for DR6 and DR1 were decreased in the patients with MS. HLA types DR15 and DR4 were present at higher frequencies in patients with a younger age at disease onset; DR15 also appeared more frequent in the female patients. Conclusion: There is a trend towards an association between HLA Class II antigens (DR4, DQ6, DQ7 and DQ8) and MS in Kuwaiti subjects. Additionally, it appeared that DR4 and DR15 were more frequent in females and those with an early onset of the disease. These patterns of HLA Class II determinants of susceptibility to MS differ from reports in some other populations, and may reflect the recognized variability in genetic influence on HLA and disease expression.

Benign multiple sclerosis: does it exist?

Although the definition of benign multiple sclerosis (BMS) remains controversial, it is generally applied to a subgroup of MS patients showing little disease progression, with minimal disability decades after disease onset, and is based mainly on changes in motor function. Recent studies, however, reveal that deterioration of cognitive function, fatigue, pain, and depression also occur in BMS patients, causing negative impact on work and social activities, despite complete preservation of motor function. Using conventional MRI techniques, lesion load observed in BMS is similar to levels in other disease subtypes; however, newer quantitative MRI techniques show less tissue damage, as well as greater repair and compensatory efficiency following MS injury. Currently accepted criteria for BMS diagnosis may cause overestimation of true prevalence, underscoring the need for routine monitoring of nonmotor symptoms and imaging studies. Clearly, the definition of BMS currently applied in clinical practice requires reassessment.

African ancestry is a predictor factor to secondary progression in clinical course of multiple sclerosis

Background. Studies on the clinical course of multiple sclerosis have indicated that certain initial clinical factors are predictive of disease progression. Regions with a low prevalence for disease, which have environmental and genetic factors that differ from areas of high prevalence, lack studies on the progressive course and disabling characteristics of the disease. Objective. To analyse the long-term evolution to the progressive phase of the relapsing-remitting multiple sclerosis and its prognosis factors in mixed population. Methods. We performed a survival study and logistic regression to examine the influence of demographic and initial clinical factors on disease progression. Among 553 relapsing-remitting patients assisted at a Brazilian reference centre for multiple sclerosis, we reviewed the medical records of 150 patients who had a disease for ten or more years. Results. African ancestry was a factor that conferred more risk for secondary progression followed by age at the onset of the disease and the number of relapses in the year after diagnosis. A greater understanding of the influence of ancestry on prognosis serves to stimulate genetics and pharmacogenomics research and may clarify the poorly understood neurodegenerative progression of MS.

Relationship between HLA-DRB1 polymorphism and susceptibility or resistance to multiple sclerosis in Caucasians: a meta-analysis of non-family-based studies

OBJECTIVE

To identify the contribution of HLA-DRB1 alleles to susceptibility or resistance to multiple sclerosis (MS) in Caucasians through a meta-analysis of non-family-based studies.

METHODS

A systematic review of case-control studies in Caucasians was performed. Studies examining allele or phenotype frequencies were analyzed separately. Odds ratio (OR) and 95% confidence intervals (CIs) were used. We also used the relatively predispositional effect (RPE) method to analyze several allele frequency studies to avoid skewed results due to some strongly associated alleles.

RESULTS

A total of 5464 cases and 7809 controls from 14 allele frequency studies and a total of 5401 cases and 7538 controls from 23 phenotype frequency studies were analyzed. DRB1*15 was definitely the strongest risk factor for MS (allele group, Pc<0.00013, OR 2.59, 95%CI 2.34-2.87; phenotype group, Pc<0.00013, OR 3.35, 95%CI 2.95-3.80). DRB1*03 frequencies were significantly increased among MS cases in the phenotype group (Pc= 0.0013, OR 1.21, 95%CI 1.09-1.33) but not in the allele group. DRB1*14 and DRB1*07 showed protective effects against MS in both groups (DRB1*14, allele group, Pc<0.00013, OR 0.53, 95%CI 0.42-0.66; phenotype group, Pc<0.00013, OR 0.57, 95%CI 0.45-0.71; DRB1*07, allele group, Pc<0.0026, OR 0.75, 95%CI 0.64-0.87; phenotype group, Pc<0.00013, OR 0.67, 95%CI 0.61-0.73). By RPE method, DRB1*14, and DRB1*07 showed protective effects after excluding DRB1*15 from the analysis. DRB1*03 was significantly higher in MS cases than controls after removing both DRB1*15 and DRB1*14.

CONCLUSIONS

In Caucasians, we highlighted the definite protective role of HLA-DRB1*14 and DRB1*07 for MS. DRB1*03 is probably the only risk factor for MS besides DRB1*15 and a common genetic foundation for autoimmune disease. Targeting to these alleles may have potential values in prevention or therapy for MS in the specific population.

Benign multiple sclerosis: a need for a consensus

OBJECTIVES

To investigate the impact of different definitions on the frequency of benign multiple sclerosis (MS) in patients with a long follow-up, and to study the presence of non-motor symptoms and employment across the definitions.

MATERIALS AND METHODS

All patients alive (n = 188) with disease onset during 1976-1986 in Hordaland County, Norway, were clinically examined including the Expanded Disability Status Scale (EDSS) in 2003. Non-motor symptoms which included depression, cognitive impairment, fatigue and pain, and employment status were also registered. Three definitions of benign MS were used based on the following EDSS cut-off values: 2.0, 3.0 and 4.0. Two additional definitions were added using an EDSS <or=4.0 and incorporating either full-time or full- and part-time employment status.

RESULTS

The frequency of benign MS increased from 14.5% for EDSS <or=2.0 to 40.8% for EDSS <or=4.0, but was only 12.3% for the definition based on full-time employment. Patients with an EDSS <or=2.0 had markedly less non-motor symptoms and lower unemployment rates than the other groups.

CONCLUSIONS

An EDSS score <or=2.0 with at least 10 years of disease duration seems to be the most appropriate criterion in identifying patients with benign MS.

ApolipoproteinE epsilon 4 allele is not associated with disease course and severity in multiple sclerosis

BACKGROUND

No study has assessed the association between apolipoproteinE (APOE) and multiple sclerosis (MS) forms grouped by also taking into account cognitive performance.

AIMS OF THE STUDY

To assess the relationship between APOE and disease course, particularly focusing on benign MS (BMS), defined as also including cognitive preservation.

METHODS

In 173 consecutive patients, we assessed the association between APOE and MS course and severity.

RESULTS

Twenty-nine APOE-epsilon4 carriers were identified. The epsilon4 allele was not associated with BMS. Moreover, it was associated neither with other disease courses nor with the time to reach disability milestones and secondary progression.

CONCLUSION

Although plausible, the association between APOE and MS course (particularly with BMS defined by including cognitive preservation) and disease severity remains controversial.

Analysis of HLA DR2&DQ6 (DRB1*1501, DQA1*0102, DQB1*0602) haplotypes in Iranian patients with multiple sclerosis

Multiple sclerosis (MS) is prototype of inflammatory demyelinating disease of the central nervous system .The etiology of MS remains unclear, but according to current data the disease develops in genetically susceptible individuals and may require additional environmental triggers. The human leukocyte antigen (HLA) class II alleles (DRB1*1501, DQA1*0102, DQB1*0602) may have the strongest genetic effect in MS. In this study, the role of these alleles were investigated in 183 Iranian patients with multiple sclerosis and compared with 100 healthy individuals. HLA typing for DRB1*1501, DQA1*0102, DQB1*0602 was performed by polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP) method. The results show that, HLA DR B1*1501 was significantly more frequent among MS patients (46% vs. 20%, PV = 0.0006) but DQA1*0102 haplotype was negatively associated with MS (30% vs. 50%, PV = 0.0049) and no significant association was found with DQB1*0602 and MS patients in comparison with control group (24% and 30%, PV = 0.43). No significant correlation was observed among these alleles with sex, type of disease; initial symptoms, expanded disability status scale (EDSS), as well as age at onset and familial MS. This study therefore indicates that there is no association of above HLA haplotypes with clinical presentation, disease duration, and disability in Iranian patients with MS which is in line with other previous studies in different ethnic groups.

Clinically benign multiple sclerosis despite large T2 lesion load: can we explain this paradox?

Magnetic resonance imaging (MRI) techniques such as magnetization transfer imaging and magnetic resonance spectroscopy (MRS) may reveal otherwise undetectable tissue damage in multiple sclerosis (MS) and can serve to explain more severe disability than expected from conventional MRI. That an inverse situation may exist where non-conventional quantitative MRI and MRS metrics would indicate less abnormality than expected from T2 lesion load to explain preserved clinical functioning was hypothesized. Quantitative MRI and MRS were obtained in 13 consecutive patients with clinically benign MS (BMS; mean age 44 +/- 9 years) despite large T 2 lesion load and in 15 patients with secondary progressive MS (SPMS; mean age 47 +/- 6 years) matched for disease duration. The magnetization transfer ratio (MTR), magnetization transfer rate (kfor), brain parenchymal fraction (BPF) and brain metabolite concentrations from proton MRS were determined. BMS patients were significantly less disabled than their SPMS counterparts (mean expanded disability status score: 2.1 +/- 1.1 versus 6.2 +/- 1.1; P < 0.001) and had an even somewhat higher mean T2 lesion load (41.2 +/- 27.1 versus 27.9 +/- 24.8 cm3; P = 0.19). Normal appearing brain tissue histogram metrics for MTR and kfor, mean MTR and kfor of MS lesions and mean BPF were similar in BMS and SPMS patients. Levels of N-acetyl-aspartate, choline and myoinositol were comparable between groups. This study thus failed to explain the preservation of function in our BMS patients with large T2 lesion load by a higher morphologic or metabolic integrity of the brain parenchyma. Functional compensation must come from other mechanisms such as brain plasticity.

HLA-DR15 haplotype and multiple sclerosis: a HuGE review

An association between multiple sclerosis (MS) and the human leukocyte antigen (HLA) complex, a dense cluster of genes on the short arm of chromosome 6, was first noted over 30 years ago. In Caucasian populations of Northern European descent, the DR15 haplotype (DRB1*1501-DQA1*0102-DQB1*0602) has been hypothesized to be the primary HLA genetic susceptibility factor for MS. However, studies of other populations have produced varying results. Thus, the authors reviewed the literature for articles on the association between the DR15 haplotype and MS. They identified 72 papers meeting the inclusion criteria: human genetic studies written in English that were published between 1993 and 2004 and that reported allele frequencies for HLA-DRB1*1501, HLA-DQA1*0102, or HLA-DQB1*0602 or the frequency of the DRB1*1501-DQA1*0102-DQB1*0602 haplotype. Most of the studies identified used a case-control design (n = 60), while the remainder used a family-based design (n = 22). In most of these papers, investigators reported a higher frequency of the DR15 haplotype and/or its component alleles among MS cases than among controls. However, the authors' confidence in these results is tempered by factors related to study design that may have biased the outcomes.

The role of HLA-DRB1 alleles on susceptibility and outcome of a Portuguese Multiple Sclerosis population

BACKGROUND

The association between susceptibility to multiple sclerosis (MS) and HLA-DRB1*15 has been reported in various European populations.

OBJECTIVE

To investigate the relationship between MS, HLA-DRB1*15 and other DRB1 alleles in a Portuguese population and their association with clinical course of MS.

METHODS

The HLA-DRB1 alleles were analyzed by PCR-SSP in 248 MS patients and 282 healthy controls. In order to relate HLA-DRB1 alleles to disease aggressiveness, patients with relapsing remitting MS and secondary progressive MS were subdivided into 3 groups: 'benign' MS patients who maintain an Extended Disability Status Scale (EDSS) score of <or=3 at least 10 years after disease onset; non-benign MS patients with EDSS>3 after the same period and 'aggressive' MS those with EDSS>or=6 within 15 years of disease onset.

RESULTS

As expected, a higher frequency of HLA-DRB1*15 was found in MS patients (29.8% vs 19.9%, odds ratio (OR)=1.72, 95% CI=1.15-2.56, p=0.008). The HLA-DRB1*03 allele was positively associated with MS in the overall patient population (22.6% vs 15.6%, OR=1.58, 95% CI=1.02-2.45). Concerning disease aggressiveness, HLA-DRB1*15 occurred more frequently in the group with benign disease (42.6% vs 19.9%, OR=2.99, 95% CI=1.56-5.72) and in the group with non-benign disease (34.1% vs 19.9%, OR=2.09, 95% CI=1.05-4.16) compared with controls. When time to reach an EDSS=3 or EDSS=6 was considered as end point, HLA-DRB1*15 negative patients were found to have a worse prognosis.

CONCLUSIONS

In this population of Portuguese MS patients, the HLA-DRB1*15 allele is established as a genetic marker for susceptibility to MS and is also associated with a better outcome.

Benign course in multiple sclerosis: a review

Since the 1950s, it has been recognized that a subgroup of multiple sclerosis (MS) patients exists that shows little or no progression in the severity of the disease over time. This group is referred to as 'benign' MS. Although a substantial amount of research in MS indicates a multifactorial background in disease severity, to date it is still difficult to predict whether the course will be benign at onset and it is difficult to find factors that influence the course of the disease over time. Maintaining or restoring neural conduction inside a central nervous system lesion seems to be the essence of staying 'benign'.