Both the HLA-CPB1 and -DRB1 alleles correlate with risk for multiple sclerosis in Japanese: clinical phenotypes and gender as important factors

Association of VEGFA, TIMP-3, and IL-6 gene polymorphisms with predisposition to optic neuritis and optic neuritis with multiple sclerosis

BACKGROUND

The etiology of the inflammatory ON is multifactorial. Much attention is paid to the inflammatory and immune processes that are likely to contribute to the demyelination and MS development. IL-6, VEGFA, and TIMP-3 genes are thought to be involved in the inflammatory processes and manifestation of CNS demyelination, so we aimed to determine the relationship between VEGFA rs1413711, TIMP-3 rs9621532, IL-6 rs1800796 gene polymorphisms and ON, and ON with MS.

MATERIALS AND METHODS

Patients with ON, ON with MS, and a random sample of healthy population were enrolled. The genotyping of VEGFA rs1413711, TIMP-3 rs9621532, and IL-6 rs1800796 polymorphisms was carried out using the real-time polymerase chain reaction method.

RESULTS

T/C and C/C genotypes of VEGFA rs1413711 were associated with about threefold increased odds of developing ON in the dominant and codominant models. Each allele C at VEGFA rs1413711 was associated with 1.7-fold increased odds of ON development. IL-6 rs1800796 allele C was more frequent in the ON with MS group compared to the control: 17.6% vs. 7.5%, respectively (p = .040). No statistically significant associations were found between TIMP-3 rs9621532 and the ON development.

CONCLUSION: VEGFA

rs1413711 is associated with the ON development.

Expression Analysis of Long Non-coding RNA Lnc-DC in HLA-DRB1*15:01-Negative Patients with Multiple Sclerosis: A Probable Cause for Gender Differences in Multiple Sclerosis Susceptibility?

Multiple sclerosis is a disease that affects male and female patients differently. Several studies have been performed to explain the gender differences in MS susceptibility, but the genetic causes underlying gender differences remain unknown. The association between multiple sclerosis and the HLA-DRB1*15:01 haplotype has been confirmed to be female-specific. We hypothesized other immunological components such as lnc-DC may be gender-specific among multiple sclerosis patients, especially when MS patients are negative for the HLA-DRB1*15:01 allele. Therefore, the current study, considering the results of previous studies, aimed to evaluate the expression level of the lnc-DC gene in HLA-DRB1*15:01-negative female patients with relapsing remitting MS (RRMS). A total of 50 MS female patients and 50 female healthy controls were enrolled in this observational case-control study. HLA-DRB1*15:01, as a critical risk factor for MS, was ruled out in all patients. The peripheral blood mononuclear cells were obtained from all patients and total RNA was isolated and cDNA synthesis was carried out. The gene expression of lnc-DC was evaluated by real-time quantitative PCR. Our results have shown that lnc-DC expression level was significantly higher in total MS female patients compared with female controls (P = 0.0044). In addition, the correlation between lnc-DC with disease duration, EDSS, and age at onset did not reach a statistical significance in our study (r = 0.0336, P = 0.817; r = 0.0914, P = 0.5278 and r = 0.0743, P = 0.6083, respectively). Our results give further evidence that lnc-DC may play a gender-dependent role in MS pathogenesis.

HLA-DPB1*03 as Risk Allele and HLA-DPB1*04 as Protective Allele for Both Early- and Adult-Onset Multiple Sclerosis in a Hellenic Cohort

Background: Human Leucocyte Antigens (HLA) represent the genetic loci most strongly linked to Multiple Sclerosis (MS). Apart from HLA-DR and HLA–DQ, HLA-DP alleles have been previously studied regarding their role in MS pathogenesis, but to a much lesser extent. Our objective was to investigate the risk/resistance influence of HLA-DPB1 alleles in Hellenic patients with early- and adult-onset MS (EOMS/AOMS), and possible associations with the HLA-DRB1*15:01 risk allele. Methods: One hundred MS-patients (28 EOMS, 72 AOMS) fulfilling the McDonald-2010 criteria were enrolled. HLA genotyping was performed with standard low-resolution Sequence-Specific Oligonucleotide techniques. Demographics, clinical and laboratory data were statistically processed using well-defined parametric and nonparametric methods and the SPSSv22.0 software. Results: No significant HLA-DPB1 differences were found between EOMS and AOMS patients for 23 distinct HLA-DPB1 and 12 HLA-DRB1 alleles. The HLA-DPB1*03 allele frequency was found to be significantly increased, and the HLA-DPB1*02 allele frequency significantly decreased, in AOMS patients compared to controls. The HLA-DPB1*04 allele was to be found significantly decreased in AOMS and EOMS patients compared to controls. Conclusions: Our study supports the previously reported risk susceptibility role of the HLA-DPB1*03 allele in AOMS among Caucasians. Additionally, we report for the first time a protective role of the HLA-DPB1*04 allele among Hellenic patients with both EOMS and AOMS.

Comprehensive meta-analysis reveals an association of the HLA-DRB1*1602 allele with autoimmune diseases mediated predominantly by autoantibodies

The human leukocytes antigen (HLA)-DRB1*16:02 allele has been suggested to be associated with many autoimmune diseases. However, a validation of the results of the different studies by a comprehensive analysis of the corresponding meta data is lacking. In this study, we performed a meta-analysis of the association between HLA-DRB1*16:02 allele with various autoimmune disorders. Our analysis shows that HLA-DRB1*16:02 allele was associated with systemic lupus erythematosus, anti-N-Methyl-d-Aspartate receptor (NMDAR) encephalitis, Graves' disease, myasthenia gravis, neuromyelitis optica and antibody-associated systemic vasculitis with microscopic polyangiitis (AASV-MPA). However, no such association was found for multiple sclerosis, autoimmune hepatitis type 1, rheumatoid arthritis, type 1 diabetes and Vogt-Koyanagi-Harada syndrome. Re-analysis of the studies after their categorization into autoantibody-dependent and T cell-dependent autoimmune diseases revealed that the HLA-DRB1*16:02 allele was strongly associated with disorder predominantly mediated by autoantibodies (OR = 1.93; 95% CI = 1.63-2.28, P = 1.95 × 10^-14) but not with those predominantly mediated by T cells (OR = 1.08; 95% CI = 0.87-1.34, P = .474). In addition, amino acid sequence alignment of common HLA-DRB1 subtypes demonstrated that HLA-DRB1*16:02 carries a unique motif of amino acid residues at position 67-74 which encodes the third hypervariable region. Taken together, the distinct pattern of disease association and the unique amino acid sequence of the third hypervariable region of the HLA-DRB1 provide some hints on how HLA-DRB1*16:02 is involved in the pathogenesis of autoimmune diseases.

Novel Variants Identified in Multiple Sclerosis Patients From Southern China

Background: Multiple sclerosis (MS) is an autoimmune and demyelinating disease. Genome-wide association studies have shown that MS is associated with many genetic variants in some human leucocyte antigen genes and other immune-related genes, however, those studies were mostly specific to Caucasian populations. We attempt to address whether the same associations are also true for Asian populations by conducting whole-exome sequencing on MS patients from southern China.

Methods: Genomic DNA was extracted from the peripheral blood mononucleocytes of 8 MS patients and 26 healthy controls and followed by exome sequencing.

Results: In total, 41,227 variants were found to have moderate to high impact on their protein products. After filtering per allele frequencies according to known database, 17 variants with the allele frequency <1% or variants with undetermined frequency were identified to be unreported and have significantly different frequencies between the MS patients and healthy controls. After validation via Sanger sequencing, one rare variant located in exon 7 of TRIOBP (Chr22: 37723520G>T, Ala322Ser, rs201693690) was found to be a novel missense variant.

Conclusion: MS in southern China may have association with unique genetic variants, our data suggest TRIOBP as a potential novel risk gene.

Mechanisms underlying lesion development and lesion distribution in CNS autoimmunity

It is widely accepted that development of autoimmunity in the central nervous system (CNS) is triggered by autoreactive T cells, that are activated in the periphery and gain the capacity to migrate through endothelial cells at the blood-brain barrier (BBB) into the CNS. Upon local reactivation, an inflammatory cascade is initiated, that subsequently leads to a recruitment of additional immune cells ultimately causing demyelination and axonal damage. Even though the interaction of immune cells with the BBB has been in the focus of research for many years, the exact mechanisms of how immune cells enter and exit the CNS remains poorly understood. In this line, the factors deciding immune cell entry routes, lesion formation, cellular composition as well as distribution within the CNS have also not been elucidated. The following factors have been proposed to represent key determinants for lesion evaluation and distribution: (i) presence and density of (auto) antigens in the CNS, (ii) local immune milieu at sites of lesion development and resolution, (iii) trafficking routes and specific trafficking requirements, especially at the BBB and (iv) characteristics and phenotypes of CNS infiltrating cells and cell subsets (e.g. features of T helper subtypes or CD8 cells). The heterogeneity of lesion development within inflammatory demyelinating diseases remains poorly understood until today, but here especially orphan inflammatory CNS disorders such as neuromyelitis optica spectrum disorder (NMOSD), Rasmussen encephalitis or SUSAC syndrome might give important insights in critical determinants of lesion topography. Finally, investigating the interaction of T cells with the BBB using in vitro approaches or tracking of T cells in vivo in animals or even human patients, as well as the discovery of lymphatic vasculature in the CNS are teaching us new aspects during the development of CNS autoimmunity. In this review, we discuss recent findings which help to unravel mechanisms underlying lesion topography and might lead to new diagnostic or therapeutic approaches in neuroinflammatory disorders including multiple sclerosis (MS).

B7-H1 shapes T-cell-mediated brain endothelial cell dysfunction and regional encephalitogenicity in spontaneous CNS autoimmunity

Molecular mechanisms that determine lesion localization or phenotype variation in multiple sclerosis are mostly unidentified. Although transmigration of activated encephalitogenic T cells across the blood-brain barrier (BBB) is a crucial step in the disease pathogenesis of CNS autoimmunity, the consequences on brain endothelial barrier integrity upon interaction with such T cells and subsequent lesion formation and distribution are largely unknown. We made use of a transgenic spontaneous mouse model of CNS autoimmunity characterized by inflammatory demyelinating lesions confined to optic nerves and spinal cord (OSE mice). Genetic ablation of a single immune-regulatory molecule in this model [i.e., B7-homolog 1 (B7-H1, PD-L1)] not only significantly increased incidence of spontaneous CNS autoimmunity and aggravated disease course, especially in the later stages of disease, but also importantly resulted in encephalitogenic T-cell infiltration and lesion formation in normally unaffected brain regions, such as the cerebrum and cerebellum. Interestingly, B7-H1 ablation on myelin oligodendrocyte glycoprotein-specific CD4⁺ T cells, but not on antigen-presenting cells, amplified T-cell effector functions, such as IFN-γ and granzyme B production. Therefore, these T cells were rendered more capable of eliciting cell contact-dependent brain endothelial cell dysfunction and increased barrier permeability in an in vitro model of the BBB. Our findings suggest that a single immune-regulatory molecule on T cells can be ultimately responsible for localized BBB breakdown, and thus substantial changes in lesion topography in the context of CNS autoimmunity.

HLA-DPB1*0501 is not uniquely associated with opticospinal multiple sclerosis in Japanese patients. Important role of DPB1*0301

Apart from its unique lesion distribution pattern, the opticospinal form of multiple sclerosis (OSMS) is distinct among Japanese patients who satisfy the diagnostic criteria of MS. OSMS has been suggested to be strongly associated with HLA-DPB1*0501 in Japanese. However, association of DPB1*0301 with non-OSMS and lack of DPB1*0301 in OSMS were also reported. To verify the role of DPB1*0501 and DPB1*0301 in Japanese MS patients we determined the frequencies of these alleles in 26 patients with OSMS, 167 with non-OSMS and 156 normal subjects, who were all residents of Hokkaido, the northernmost island of Japan. All (100%) OSMS were negative for DPB1*0301 while 32 (19%) of the non-OSMS were positive for the allele. In DPB1*0301-negatives, the frequencies of DPB1*0501 in OSMS (85%) and non-OSMS (82%) were similar, but both were higher than in the controls (66%). In DPB1*0301-positives, the frequency of DPB1*0501 was low but similar in non-OSMS (12/32; 38%) and controls (6/14; 43%). Periventricular white matter lesions (PVL) were noted in 31 of 32 (97%) DPB1*0301-positive non-OSMS patients but in only 22 out of 135 (16%) DPB1*0301-negative non-OSMS patients and two out of 26 (8%) OSMS patients. Our findings indicate that DPB1*0501 plays an important role in the development of MS in general, but not in OSMS. The strong association of DPB1*0501 with OSMS may be due to the over-representation of the DPB1*0301 allele among individuals in the non-OSMS group. In addition, DPB1*0301 might be relevant to the development of periventricular lesions in Japanese patients with MS.

Vitamin D receptor biochemical and genetic profiling and HLA-class II genotyping among Lebanese with multiple sclerosis - A pilot study

BACKGROUND

Multiple sclerosis (MS) is an autoimmune demyelinating disease affecting mostly young adult females with multifactorial etiology. Recent studies suggested that adequate vitamin D levels may lower the risk of developing MS.

OBJECTIVES

Our aim was to explore the relationship between vitamin D receptor (VDR) polymorphism, HLA-DR locus genotype, and serum vitamins D and A levels in the Lebanese population.

METHODS

Fifty MS patients were recruited for this study. The control group consisted of 48 healthy and 51 patients with other neurological disorders (non-MS). Biochemical analysis included serum 25 hydroxyvitamin D (25OHD) and vitamin A. Molecular analysis targeted VDR genotypes (ApaI, TaqI and BsmI) and low resolution HLA typing for DRB1 locus.

RESULTS

Healthy and non-MS groups had comparable parameters and were combined into one control group. No significant differences were found between MS and control groups for VDR genotypes. The frequency of HLA-DRB1*15 was significantly higher in MS patients (22%) compared to controls (8%) (p=0.018). Odds ratio for MS in the presence of DRB1*15 allele was 3.21 (p=0.018). Cosegregation with A (ApaI) and b (BsmI) alleles did not influence the risk for MS. 25OHD levels were significantly higher in MS patients compared to controls (p=0.002), due to more frequent oral supplementation (p=0.005). Vitamin A levels were comparable between the two groups. When all parameters were included in a logistic regression model adjusted for supplementation, only HLA-DRB1*15 (OR=3.42; p=0.027) contributed significantly to MS risk.

CONCLUSION

There was no association between serum vitamin D or A or VDR genotypes and MS. HLA-DRB1*15 was the major factor imposing more than 3 folds greater risk for developing MS among Lebanese.

Multiple sclerosis and mitochondrial gene variations: a review

Multiple sclerosis (MS) is a debilitating disease of the central nervous system. Its etiology is still an unanswered enigma; its symptoms are varied and unpredictable; and there is no cure for it. Genetics has been introduced as a contributing factor to MS. Not only may MS stem from nuclear gene variations/mutations, but also it may arise from mitochondrial gene variations/mutations. The association of mitochondrial DNA variations/mutations with the pathogenesis of MS has, so far, been analyzed by several studies. This paper reviews the literature with regard to MS and corresponding mitochondrial DNA variations.

Genetic and infectious profiles of Japanese multiple sclerosis patients

BACKGROUND

Nationwide surveys conducted in Japan over the past thirty years have revealed a four-fold increase in the estimated number of multiple sclerosis (MS) patients, a decrease in the age at onset, and successive increases in patients with conventional MS, which shows an involvement of multiple sites in the central nervous system, including the cerebrum and cerebellum. We aimed to clarify whether genetic and infectious backgrounds correlate to distinct disease phenotypes of MS in Japanese patients.

METHODOLOGY/PRINCIPAL FINDINGS

We analyzed HLA-DRB1 and -DPB1 alleles, and IgG antibodies specific for Helicobacter pylori, Chlamydia pneumoniae, varicella zoster virus, and Epstein-Barr virus nuclear antigen (EBNA) in 145 MS patients and 367 healthy controls (HCs). Frequencies of DRB1*0405 and DPB1*0301 were significantly higher, and DRB1*0901 and DPB1*0401 significantly lower, in MS patients as compared with HCs. MS patients with DRB1*0405 had a significantly earlier age of onset and lower Progression Index than patients without this allele. The proportion and absolute number of patients with DRB1*0405 successively increased with advancing year of birth. In MS patients without DRB1*0405, the frequency of the DRB1*1501 allele was significantly higher, while the DRB1*0901 allele was significantly lower, compared with HCs. Furthermore, DRB1*0405-negative MS patients were significantly more likely to be positive for EBNA antibodies compared with HCs.

CONCLUSIONS

Our study suggests that MS patients harboring DRB1*0405, a genetic risk factor for MS in the Japanese population, have a younger age at onset and a relatively benign disease course, while DRB1*0405-negative MS patients have features similar to Western-type MS in terms of association with Epstein-Barr virus infection and DRB1*1501. The recent increase of MS in young Japanese people may be caused, in part, by an increase in DRB1*0405-positive MS patients.

Genetic and environmental backgrounds responsible for the changes in the phenotype of MS in Japanese subjects

There are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as opticospinal (OSMS) and conventional (CMS) forms. In Japan, the results of four nationwide surveys of MS conducted between 1972 and 2004 have revealed a four-fold increase in the estimated number of clinically definite MS patients in 2003 compared with 1972; a shift in the peak age at onset from the early 30s in 1989 to the early 20s in 2003; a successive proportional decrease in optic-spinal involvement in clinically definite MS patients; an increase in the number of CMS patients with Barkhof brain lesions with advancing birth year and a decrease in the number of OSMS patients with LESCLs. These findings suggest that MS phenotypes are drastically altered by environmental factors such as latitude and "Westernization". Helicobacter pylori infection rates, reflecting sanitary conditions in infancy, are significantly different between CMS and OSMS patients. Both phenotypes show distinct HLA class II gene associations. Therefore, changes in environmental factors may have differentially influenced susceptibility to each disease subtype, given that disease susceptibility is only partly genetically determined.

HLA-DRB1*15:01 and multiple sclerosis: a female association?

BACKGROUND

The association between multiple sclerosis (MS) and the HLA-DRB1*15:01 haplotype has been proven to be strong, but its molecular basis remains unclear. Vitamin D receptor (VDR) gene variants and sex have been proposed to modulate this association.

OBJECTIVES

1) Test the association of MS with *15:01 and VDR variants; 2) check whether VDR variants and/or sex modulate the risk conferred by *15:01; 3) study whether *15:01, VDR variants and/or sex affect HLA II gene expression.

METHODS

Peripheral blood from 364 MS patients and 513 healthy controls was obtained and DNA and total RNA were extracted from leukocytes. HLA-DRB1, DRB5 and DQA1 gene expression measurements and *15:01 genotyping were performed by qPCR. VDR variants were genotyped by PCR-RFLP.

RESULTS

Our data confirms that the *15:01 haplotype confers a higher risk of suffering from MS (OR = 1.364; 95% CI = 1.107-1.681). No association was found between VDR variants and MS, but they were shown to moderately modulate the risk conferred by *15:01. Sex confers a much stronger modulation and the *15:01-MS association seems to be female specific. A higher *15:01 frequency has been observed in Basques (45.1%). *15:01 positive samples showed a significant overexpression of DRB1 (p < 0.001), DRB5 (p < 0.001) and DQA1 (p = 0.004) in patients. DRB1 (p = 0.004) and DRB5 (p < 0.001) were also overexpressed in *15:01 controls.

CONCLUSIONS

We confirm the *15:01-MS association and support that it is female specific. The relevance of ethnic origin on association studies has also been highlighted. HLA-DRB1*15:01 seems to be a haplotype consistently linked to high HLA II gene expression.

Relapsing neuromyelitis optica: demographic and clinical features in Iranian patients

BACKGROUND

Neuromyelitis Optica (NMO) is a severe inflammatory demyelinating disease of the central nervous system with distinguishing features from multiple sclerosis (MS). NMO has an unknown etiology with poor prognosis in which anti-aquaporin-4 receptor IgG seems to play a major role. The purpose of this study is to represent a clinical and demographic data of NMO in Iranian population.

METHODS

Of 1800 patients attending our MS clinic, 44 patients with NMO were recruited from 2006 to 2009.

RESULTS

Female to male ratio was 3:1 and the disease affected women in younger ages than men (P = 0.04). The median expanded disability status scale score was 3 and the mean duration of symptoms was 4.53 +/- 3.41 (median = 4) years with annual relapse rate of 1.13 year/patient. The most frequent symptoms at presentation were optic neuritis 22 (50%) and transverse myelitis 14 (31.8%). Out of 12 patients whose titer of NMO-IgG was measured, four (30.7%) patients were seropositive. Twenty-eight patients (63%) received azathioprine for a mean duration of 16.84 +/- 27.91 months with significantly lower annual relapse rate (0.4 year/patient).

CONCLUSIONS

Iranian patients as a Caucasian population living in Asia seem to have the same clinical features in comparison with the reported studies from Western countries. Although the duration of follow-up was not too long, but they may possibly have a more benign course.

Is neuromyelitis optica associated with human leukocyte antigen?

BACKGROUND

To establish whether or not multiple sclerosis (MS) and neuromyelitis optica (NMO) are different pathological entities, we wondered whether MS patients and NMO patients share the same pattern of human leukocyte antigen (HLA) predisposition.

OBJECTIVE

To study a putative association between susceptibility to NMO and HLA class I or class II loci in Caucasians.

METHODS

A total of 39 unrelated Caucasian patients with NMO and six patients at a high risk of converting to NMO were studied. DNA genotyping of HLA class I and class II loci was assessed and allelic frequencies were reported at a high-resolution level. A case-control study by comparing the allelic distribution in the NMO patients with that of a French Caucasian MS group and a French Caucasian healthy group was carried out.

RESULTS

The frequencies of HLA-DQA1, DQB1, and HLA-DRB1 DR2 alleles in the NMO group were intermediate between the healthy control group and the MS group. The DPB1*0501 allele was not increased in the NMO group compared with the healthy control group. The distribution of HLA-DRB1 allele enabled to distinguish between NMO-IgG-positive patients and healthy controls (P = 0.01). NMO-IgG-negative patients presented an HLA II pattern closer to that of the MS group (P = 0.01).

CONCLUSION

In contrast to the reported results in Asian opticospinal MS, we found no association between the DPB1*0501 allele and NMO in our Caucasian patients. Moreover, we suggest that NMO-IgG-positive patients could represent a distinct NMO group in terms of their genetic susceptibility.

Neuromyelitis optica and asian phenotype of multiple sclerosis

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS), whereas neuromyelitis optica (NMO) is an inflammatory disease of the CNS selectively affecting the optic nerves and spinal cord. The pathological hallmark in MS is sharply demarcated demyelinating plaque with axons relatively preserved, whereas in NMO both axons and myelin are involved, resulting in necrotic cavitation. The nosological position of NMO has long been a matter of debate. In Asians, MS is rare; however, when it appears, the selective but severe involvement of the optic nerves and spinal cord is characteristic. This form, termed opticospinal MS (OSMS), has similar features to those of the relapsing form of NMO in Western populations. Recent discovery of a specific immunoglobulin G (IgG) against NMO, designated NMO-IgG, suggests that NMO is a distinct disease entity with a fundamentally different etiology from that of MS. Because NMO-IgG has been reported to be present in about 50%-60% of OSMS patients with longitudinally extensive spinal cord lesions (LESCLs), OSMS in Asians has been suggested to be the same entity as NMO. About half of the patients with the anti-aquaporin 4 (AQP4) antibody demonstrate brain lesions fulfilling the Barkhof criteria, whereas OSMS patients without the anti-AQP4 antibody show significantly fewer brain lesions. These findings indicate that the mechanism of LESCLs in Asians is heterogeneous, both related and unrelated to anti-AQP4 antibody, and that the disease condition with anti-AQP4 antibody does not completely overlap OSMS in Asians. This review discusses possible mechanisms for OSMS and anti-AQP4 autoimmune syndrome of the CNS.

Association of the HLA-DRB1 alleles with characteristic MRI features of Asian multiple sclerosis

Background

In Asian patients with multiple sclerosis (MS), a paucity of brain lesions and longitudinally extensive spinal cord lesions (LESCLs) extending three or more vertebral segments are characteristic findings on magnetic resonance imaging (MRI). We aimed to disclose possible factors contributing to the development of such MRI features.

Method

Genotyping of HLA-DRB1 and -DPB1 alleles was performed in 121 consecutive Japanese patients with clinically definite MS based on the Poser criteria and 125 healthy controls. Possible factors associated with MRI features were determined by multiple logistic analysis. Patients with MS were classified based on the presence or absence of brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) and LESCLs. Barkhof brain lesion–negative (−) patients had a markedly lower frequency of HLA-DRB1*0901 than controls ( Pcorr < 0.05), whereas the frequency of DRB1*1501 was increased in the Barkhof brain lesion–positive (+) group, although this increase was not significant after correction. No Barkhof(−)LESCL(+) patients carried DRB1*0901 ( Pcorr < 0.05), despite this being the most common allele in Japanese. The Barkhof(−)LESCL(−) group showed a significant increase in the frequency of DRB1*0405 compared with controls ( Pcorr < 0.05). None of the DPB1 alleles were significantly different among the groups. Using multiple logistic analysis, the absence of oligoclonal bands was positively associated with an absence of Barkhof brain lesions, whereas a higher EDSS score was positively associated with the presence of LESCLs; however, the presence of anti-aquaporin-4 antibodies was not associated with either feature.

Conclusion

The characteristic MRI features in Asians are partly related to distinct HLA-DRB1 gene alleles and an absence of oligoclonal bands.

Differential regulation of central nervous system autoimmunity by T(H)1 and T(H)17 cells

Multiple sclerosis is an inflammatory, demyelinating disease of the central nervous system (CNS) characterized by a wide range of clinical signs. The location of lesions in the CNS is variable and is a crucial determinant of clinical outcome. Multiple sclerosis is believed to be mediated by myelin-specific T cells, but the mechanisms that determine where T cells initiate inflammation are unknown. Differences in lesion distribution have been linked to the HLA complex, suggesting that T cell specificity influences sites of inflammation. We demonstrate that T cells that are specific for different myelin epitopes generate populations characterized by different T helper type 17 (T(H)17) to T helper type 1 (T(H)1) ratios depending on the functional avidity of interactions between TCR and peptide-MHC complexes. Notably, the T(H)17:T(H)1 ratio of infiltrating T cells determines where inflammation occurs in the CNS. Myelin-specific T cells infiltrate the meninges throughout the CNS, regardless of the T(H)17:T(H)1 ratio. However, T cell infiltration and inflammation in the brain parenchyma occurs only when T(H)17 cells outnumber T(H)1 cells and trigger a disproportionate increase in interleukin-17 expression in the brain. In contrast, T cells showing a wide range of T(H)17:T(H)1 ratios induce spinal cord parenchymal inflammation. These findings reveal critical differences in the regulation of inflammation in the brain and spinal cord.

Multiple sclerosis patients show sexual dimorphism in cytokine responses to myelin antigens

Multiple sclerosis affects more women than men. The reasons for this are unknown. Previously, we have shown significant differences in women versus men in inflammatory cytokine responses to the major protein component of myelin, proteolipid protein (PLP), which is thought to be a target in MS patients. Here, using the ELISPOT assay, we examined sex differences in single-cell secretion of Th1 and Th2 cytokines from freshly isolated PBMC between relapsing remitting (RR) MS patients and healthy individuals. Cells were stimulated with MS-associated antigens including proteolipid protein (PLP), myelin basic protein (MBP), myelin oligodendrocyte glycoprotein (MOG), and non-disease related antigens. Our data show a sex bias in the cytokine responses to multiple MS-relevant myelin antigens: Women with MS show IFNgamma-skewed responses and men with MS show IL-5-skewed responses. These data extend our previous findings [Pelfrey, C.M., Cotleur, A.C., Lee, J.C., Rudick, R.A. 2002. Sex differences in cytokine responses to myelin peptides in multiple sclerosis. J. Neuroimmunol. 130, 211-223.]: (1) by demonstrating gender skewing in cytokine responses to an expanded myelin antigen repertoire, which includes MBP, MOG and PLP; (2) by showing TNFalpha and IL-10 do not display comparable gender skewing compared to IFNgamma and IL5; (3) by defining the patient population as early, untreated RRMS patients to avoid confounding factors, such as different disease stages/disability and immunomodulatory therapy; and (4) by showing HLA type does not appear to underlie the gender differences. These findings may explain increased susceptibility to MS in women and could contribute to the differences in disease severity between men and women.

The spectrum of neuromyelitis optica

Neuromyelitis optica (also known as Devic's disease) is an idiopathic, severe, demyelinating disease of the central nervous system that preferentially affects the optic nerve and spinal cord. Neuromyelitis optica has a worldwide distribution, poor prognosis, and has long been thought of as a variant of multiple sclerosis; however, clinical, laboratory, immunological, and pathological characteristics that distinguish it from multiple sclerosis are now recognised. The presence of a highly specific serum autoantibody marker (NMO-IgG) further differentiates neuromyelitis optica from multiple sclerosis and has helped to define a neuromyelitis optica spectrum of disorders. NMO-IgG reacts with the water channel aquaporin 4. Data suggest that autoantibodies to aquaporin 4 derived from peripheral B cells cause the activation of complement, inflammatory demyelination, and necrosis that is seen in neuromyelitis optica. The knowledge gained from further assessment of the exact role of NMO-IgG in the pathogenesis of neuromyelitis optica will provide a foundation for rational therapeutic trials for this rapidly disabling disease.

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.

A three-dimensional approach for understanding the spectrum of idiopathic inflammatory demyelinating disorders: importance of the 'attack-related severity' axis

Understanding the spectrum of idiopathic inflammatory demyelinating disorders (IIDD) of the central nervous system is an important issue for accurate diagnosis and advancing research on the pathogenesis as well as treatment strategies, but the nosology and the classification of the IIDD remains confusing. Until now, we have tried to apply each disorder within the spectrum to an adequate co-ordinate on a two-dimensional plane. One axis is clinical course and the other is lesion distribution. We reviewed some disorders of the IIDD spectrum, and our recent findings on the fulminant nature of each attack and the expansion of each lesion, which we called attack-related severity in Japanese multiple sclerosis (MS). From our findings and the literature, attack-related severity appears to be a third important factor, in addition to lesion distribution and clinical course. Introduction of the third axis produces a three-dimensional space for a better understanding of the heterogeneous characteristics of IIDD and 'MS' syndrome, and can advance treatment strategies for these disorders. As severe attacks seem to be relatively common in Asians but rare in the west, ethnic-related heterogeneity should be considered in understanding the spectrum of IIDD, and there is an urgent need to develop a common general concept of the spectrum, especially for MS.

TNF-related apoptosis inducing ligand (TRAIL) gene polymorphism in Japanese patients with multiple sclerosis

TNF-related apoptosis inducing ligand (TRAIL) has been reported to induce apoptosis of autoreactive T cells and other inflammatory cells, and thus, it is a strong candidate gene for involvement in the development of autoimmune diseases. We investigated single nucleotide polymorphisms (SNPs) in the coding region of the gene at position 1595 in exon 5 in 128 Japanese patients with conventional/classical multiple sclerosis (MS) and 158 healthy controls. Patients with optico-spinal MS (OSMS) or atypical clinical attacks were excluded from the study. The frequency of CC genotype at position 1595 was significantly different between patients and controls (p=0.0027), and the C allele was more prevalent in the patients than in the controls (p=0.0138, OR=1.546, 95% CI=1.092-2.188). Logistic analysis, adjusted for HLA-DRB1*1501-positivity, revealed the independent association of the CC genotype with susceptibility to MS (p=0.0006, OR=2.393, 95% CI=1.453-3.943). There were no significant associations between +1595 polymorphism and the clinical features of MS. The results indicate that the presence of the CC genotype at position 1595 in exon 5 represents a higher risk of MS.

CSF pleocytosis and expansion of spinal lesions in Japanese Multiple sclerosis with special reference to the new diagnostic criteria

New diagnostic criteria for multiple sclerosis (MS) were recently proposed from the international panel on the diagnosis of MS, and they include exclusion criteria, such as lesions extending over more than two vertebral segments on spinal MRI and CSF pleocytosis of more than 50/mm3. We reviewed the clinical features of 158 patients who satisfied the diagnostic criteria for MS except for having the above atypical paraclinical findings. All patients exhibited two or more clinical attacks and objective clinical evidence of multiple lesions without any evidence of other disorders. Thirty-three (20.9%) patients had one or both atypical paraclinical findings. Twenty-one out of the 33 patients were classified as having optico-spinal MS (OSMS), and the other 12 as non-OSMS patients with atypical large expanding or destructive cerebral, cerebellar or brainstem lesions on MRI as well as one or both atypical paraclinical findings. Based on this heterogeneity in clinical findings in MS, there is an urgent need to develop a common general concept of the "MS" syndromes, and the ethnic-related heterogeneity should be considered in the revised criteria for the diagnosis of MS.

CTLA-4 gene polymorphism is not associated with conventional multiple sclerosis in Japanese

We investigated the polymorphisms of exon 1 (+49A/G) and promoter (-318C/T and -651C/T) regions of the CTLA-4 gene in 133 Japanese patients with conventional/classical multiple sclerosis (MS) and 156 healthy controls. Patients with optico-spinal MS (OSMS) or atypical clinical attacks were excluded from the study. There was no significant difference in the distribution of polymorphisms between patients and controls. Furthermore, there were no associations between polymorphisms and clinical characteristics, such as age at onset, disease prognosis, and HLA profiles. Our results suggest that CTLA-4 gene polymorphisms are neither conclusively related to susceptibility nor to the clinical characteristics of MS, especially in Japanese patients with conventional/classical form and clinical features identical to those of their counterparts in Western countries.

Optic neuritis, multiple sclerosis and human leukocyte antigen: results of a 4-year follow-up study

In the present study the relation between human leukocyte antigen (HLA), optic neuritis (ON) and multiple sclerosis (MS) has been investigated in 56 Iranian patients (46 females and 10 males). HLA-A and -B typing by microlymphocytotoxicity method and HLA-DRB, DQA and DQB by polymerase chain reaction based on sequence specific primers method was performed for the selected patients with ON. The diagnosis of clinically defined MS (CDMS) was confirmed in 15 of them (26.7%) during their follow-up. HLA-A24 was significantly higher in ON patients, whilst A23, A26, and A30 showed a significant decrease in these patients. HLA-A10 and A26 were absent in CDMS patients and A2 and A11 were significantly decreased in ON and CDMS patients. HLA-B5, B51, B38, B27, and B35 were significantly increased in ON patients compared with control subjects. HLA-B44, B16 and B38 alleles were not present in CDMS patients. Regarding DR locus, the frequency of HLA-DRB1*15 and DRB1*04 has been increased in CDMS patients, whilst the frequency of HLA-DRB1*07 and *11 was much higher in ON patients. In DQA region, the most frequent allele in the MS patients was DQA1*0102, which was significantly higher than ON patients, and control group. The frequency of DQA1*0103 was significantly increased in both patients group. In DQB1, the frequency of DQB1*0602 increased significantly in the MS patients. In conclusion existence of common genetic basis for early manifestations of MS could be suggested.

Attack-related severity: a key factor in understanding the spectrum of idiopathic inflammatory demyelinating disorders

Understanding the spectrum of idiopathic inflammatory demyelinating disorders (IIDD) is a fundamental issue for the diagnosis and treatment of these disorders as well as for the approach to their pathogenesis. The spectrum of IIDD is usually classified according to clinical course and lesion distribution. We compared the demographic features, clinical characteristics, laboratory findings, and genetic backgrounds between 193 Japanese patients with and without clinically or radiographically fulminant attacks who all satisfied the diagnostic criteria for multiple sclerosis (MS). "Fulminant attacks" in the current study represent attack-related clinically or radiologically severe relapses but do not necessarily mean severe disability. Patients with fulminant attacks were clinically and immunogenetically distinct from those free of such attacks, and the previously described characteristics of the opticospinal form of MS (OSMS) or neuromyelitis optica (NMO) were mostly shared by patients with fulminant attacks. HLA profiles were similar among patients with fulminant attacks irrespective of the lesion distributions. The GG homozygous and G alleles of the CTLA4 gene A/G coding SNP at position 49 in exon 1 were significantly more common in patients with fulminant attacks than in those without. Attack-related severity may be an important factor if validated by prospective studies defining criteria and establishing relationships to disease course and treatment regimens.

Platelet-activating factor acetylhydrolase gene polymorphism and its activity in Japanese patients with multiple sclerosis

We evaluated the association of the plasma platelet-activating factor acetylhydrolase (PAF-AH) gene polymorphism (G(994)-->T) and PAF-AH activity with susceptibility and severity of multiple sclerosis (MS) in Japanese. DNA was collected from 216 patients with clinically definite MS (65 opticospinal MS (OS-MS) and 151 conventional MS (C-MS)) and from 213 healthy controls. The missense mutation G(994)-->T that disrupts the PAF-AH activity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). No statistically significant difference in the frequency of genotypes and alleles of the plasma PAF-AH polymorphism was observed among OS-MS patients, C-MS patients and healthy controls. However, the missense mutation tended to be associated with the severity of OS-MS, especially in females (GT/TT genotypes; 51.7% in female rapidly progressive OS-MS vs. 26.6% in female controls, p=0.0870). Moreover, PAF-AH activities were significantly lower in MS than in controls, irrespective of clinical subtypes, among those carrying the identical polymorphism in terms of nucleotide position 994 of the PAF-AH gene. These findings suggest that the PAF-AH gene missense mutation has no relation to either susceptibility or severity of C-MS, yet its activity is down-regulated, and that the mutation has no relation with susceptibility of OS-MS, yet it may confer the severity of female OS-MS.

C–C chemokine receptor 2 gene polymorphism in Japanese patients with multiple sclerosis

C-C chemokine receptor 2 (CCR2) is a receptor for chemoattractant protein-1 (MCP-1) and associated with infiltrating lymphocytes in chronic active multiple sclerosis (MS) lesions. To study the role of CCR2 gene in the development of MS, we investigated the CCR2-64I polymorphism in 122 MS patients and 112 healthy controls in a Japanese population. We also analysed the influence of CCR2-64I polymorphism on the clinical course, age at disease onset, and severity. The distribution of the CCR2-64I allele was significantly different between patients and controls (p=0.0187), and the 64I/64I homozygote was significantly less common in MS than in control. Logistic analysis, adjusted for HLA-DRB1*1501-positivity, revealed negative association between the CCR2-64I and MS (p=0.0204). There were no significant associations between CCR2 polymorphism and the clinical features of MS. Our results indicate that the presence of CCR2-64I allele seems to provide protection against the development of MS.

HLA-related subpopulations of MS in Japanese with and without oligoclonal IgG bands. Human leukocyte antigen

BACKGROUND

Oligoclonal IgG bands (OCB) are present in most patients with MS in Western countries; however, in Japanese MS patients, the OCB-positive rate is not as high. A relationship between immunogenetic backgrounds, namely, human leukocyte antigen (HLA) DR2 and DR4 positivity, and OCB production in MS patients from Hokkaido, the northernmost island of Japan, has been previously suggested by the authors.

OBJECTIVES

To investigate the role of OCB in Japanese MS and to verify the interaction between immunogenetic backgrounds and OCB positivity.

METHODS

OCB, DR2(15), and DR4 positivity were studied in 45 patients with newly diagnosed MS. In addition to confirming the authors' previous findings, the clinical and demographic features, MRI findings, OCB positivity, and DRB1*15 and DRB1*04 polymorphisms of an expanded data set of 99 MS patients were investigated by using multivariate analysis. Patients with opticospinal MS (OS-MS) were excluded from this study.

RESULTS

A relatively low OCB-positive rate (53.3%), HLA-DR15 association with OCB-positive MS (p = 0.0044), and DR4 association with OCB-negative MS (p = 0.0410) were confirmed. DR15 was not associated with OCB-negative MS. Demographic features, disease course, and disability were similar in the OCB-negative and OCB-positive group, whereas there was a preponderance of women in the OCB-positive group. An independent negative association of DRB1*0405 (p = 0.0021, adjusted odds ratio = 0.21) with OCB positivity was found.

CONCLUSIONS

MS is heterogeneous in its association with HLA alleles, and based on the immunogenetic differences, the MS patients in this population include at least two HLA-related subpopulations with and without OCB.

Multiple sclerosis in the Japanese population

Multiple sclerosis (MS) in Asian populations is characterised by the selective and severe involvement of the optic nerve and spinal cord as well as low prevalence rates. 15-40% of cases of MS in Japan are of this "opticospinal" type. This form of MS generally has a higher age at onset and a higher female to male ratio than conventional MS. Opticospinal MS is also characterised by frequent relapses, severe disability, few brain lesions visible on MRI, long lesions extending over many vertebral segments visible on spinal-cord MRI, pleocytosis and an absence of oligoclonal bands in the CSF, and a pronounced shift in the responses of T-helper-1 and T-cytotoxic-1 cells throughout relapse and remission phases. Conventional MS in Japanese people is, like MS in white people, associated with HLA-DRB1*1501, whereas opticospinal MS is associated with HLA-DPB1*0501. In Japanese people born after modernisation in the 1960s, the ratio of conventional to opticospinal MS has increased rapidly. Opticospinal MS is likely to have a distinct immune-mediated mechanism, which is not operative in conventional MS.

DPB1 disparities contribute to severe GVHD and reduced patient survival after unrelated donor bone marrow transplantation

In order to evaluate the impact of HLA-DBP1 incompatibilities on the occurrence of acute graft-versus-host disease (GVHD) in unrelated hematopoietic cell transplantation, we studied 57 donor/recipient pairs characterized by their allelic identity for HLA-A, B, C, DRB1 and DQB1 and also for DRB3, 4, 5 loci and aimed to correlate DPB1 mismatches to already described risk factors for GVHD using multivariate Cox regression analysis. DPB1 identity between donor and recipient was observed in 24% and DPB1 compatibility (GVHD vector) in 42%. Two factors were independently associated with severe acute GVHD: two DP incompatibilities (RR = 8.25, 95% confidence interval (CI): 1.67-40.10, P = 0.010) and disease risk (RR = 10.23, 95% CI: 1.12-93.13, P = 0.012). Two DPB1 incompatibilities appeared also to be a factor in poorer survival independent of its effect on acute GVHD (RR = 4.97, 95% Cl: 1.80-13.71, P = 0.002). A correlation between acute GVHD and matching for each individual DPB1 polymorphic region and for residue 69 of the DP beta molecule, which seems to be a key residue in the alloimmune response, was not observed. Our data indicate that the outcome of unrelated hematopoietic cell transplantation in terms of GVHD but also survival, could be improved through HLA-DPB1 matching or at least by avoiding two DPB1 mismatches.

Increased IL-13 but not IL-5 production by CD4-positive T cells and CD8-positive T cells in multiple sclerosis during relapse phase

In the present study, we flow cytometrically analyzed the intracellular production of interleukin (IL)-5 and IL-13 in peripheral blood CD4(+) and CD8(+) T cells from patients with multiple sclerosis (MS), human T-lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and healthy controls. IL-13-producing T cells were significantly increased in both T cell subsets in MS at relapse, markedly in the conventional form of MS and modestly in the optocospinal form of MS, and returned to normal at remission. However, IL-5-producing T cells did not vary regardless of clinical phase or type. HAM/TSP showed no significant change in the number of IL-5- and IL-13-producing cells. A distinct profile of IL-13 and IL-5 production by disease and by phase of MS suggests an active involvement of these type 2 cytokines in central nervous system (CNS) inflammation.

Genetics of multiple sclerosis: linkage and association studies

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system caused by an interplay of environmental and genetic factors. The only genetic region that has been clearly demonstrated by linkage and association studies to contribute to MS genetic susceptibility is the human leukocyte antigen (HLA) system. The majority of HLA population studies in MS have focused on Caucasians of Northern European descent, where the predisposition to disease has been consistently associated with the class II DRB1*1501-DQA1*0102-DQB1*0602 haplotype. A positive association with DR4 was detected in Sardinians and in other Mediterranean populations. Moreover DR1, DR7, DR11 have been found to be protective in several populations. Systematic searches aimed at identifying non-HLA susceptibility genes were undertaken in several populations by means of linkage studies with microsatellite markers distributed across the whole genome. The conclusion of these studies was that there is no major MS locus, and genetic susceptibility to the disease is most likely explained by the presence of different genes each conferring a small contribution to the overall familial aggregation. The involvement of several candidate genes was tested by association studies, utilizing either a population-based (case control) or a family-based (transmission disequilibrium test) approach. Candidate genes were selected mainly on the basis of their involvement in the autoimmune pathogenesis and include immunorelevant molecules such as cytokines, cytokine receptors, immunoglobulin, T cell receptor subunits and myelin antigens. With the notable exception of HLA, association studies met only modest success. This failure may result from the small size of the tested samples and the small number of markers considered for each gene. New tools for large scale screening are needed to identify genetic determinants with a low phenotypic effect. Large collaborative studies are planned to screen several thousands of patients with MS with several thousands of genetic markers. The tests are increasingly based on the DNA pooling procedure.

Estrogen receptor gene polymorphism and multiple sclerosis in Japanese patients: interaction with HLA-DRB1*1501 and disease modulation

We investigated PvuII and XbaI polymorphism in the estrogen receptor gene (ERG) and HLA-DRB1*1501 positivity in 116 conventional multiple sclerosis (MS) patients and 101 healthy controls in a Japanese population. Logistic analysis revealed independent associations of [P] allele in the profiles for PvuII (p=0.0005, adjusted odds ratio (aOR)=3.17) and DRB1*1501 (p=0.0089, aOR=2.61) with conventional MS. Synergistic elevated risk of MS due to interaction between the [P] allele and HLA-DRB1*1501 allele was found among female patients (odds ratio=16.0; 95% CI=3.99-63.8, p<0.0001). The [P] allele-positive patients with disease duration of more than 5 years had a significantly higher progression index (PI) of disability (p=0.0230) and a worse ranked MS severity score (p=0.0152) than their non-[P] counterparts.

Association of HLA-DQB1*0301 and HLA-DQB1*0602 with different subtypes of gastric cancer in Taiwan

Gastric cancer (GC) is a heterogeneous disorder with multifactorial etiologies. Genetic predisposition, environmental factors, and Helicobacter pylori infection are thought to interact in the manifestation of GC. Particular human leukocyte antigen (HLA) alleles play a pivotal role in cellular immunity and may be an important genetically determined host trait. To elucidate the association between the genotype of HLA class II genes and the clinical phenotype of GC, polymorphisms of HLA-DRB1 and HLA-DQB1 were determined by polymerase chain reaction with sequence-specific primers in 106 Taiwanese patients with GC and in 208 healthy controls. Comparison of allele frequencies between GC patients and healthy controls showed no significant difference at the HLA-DRB1 locus. Patients with GC had a higher frequency of DQB1(*)0602 (9.4% vs. 3.6%, P < 0.05, odds ratio 2.79, 95% confidence interval 1.41 - 5.47) and a lower frequency of DQB1(*)0301 (14.6% vs. 23.8%, P < 0.05, odds ratio 0.55, 95% confidence interval 0.35 - 0.85) compared to healthy controls. Correlation of HLA-DQB1 status with clinicopathologic features revealed predominance of male gender (16/3 vs. 50/37, P < 0.05) and proximal location (12/7 vs. 28/59, P < 0.05) in patients with positive HLA-DBQ1(*)0602 compared to those with negative HLA-DBQ1(*)0602. In contrast, a higher ratio of diffuse/intestinal subtype (20/10 vs. 30/46, P < 0.05) and a lower seropositivity of Helicobacter pylori (14/30 vs. 58/76, P < 0.005) were noted in patients with positive HLA-DQB1(*)0301 compared to those with negative HLA-DQB1(*)0301. In conclusion, HLA-DQB1(*)0602 confers susceptibility to gastric cancer, especially for male Taiwanese and proximal tumor location, while HLA-DQB1(*)0301 may have a protective effect on GC, probably through resistance to Helicobacter pylori infection. HLA-DQB1 alleles are associated with susceptibility or resistance to GC and also influence its clinical features.

Tc1/Tc2 and Th1/Th2 balance in Asian and Western types of multiple sclerosis, HTLV-I-associated myelopathy/tropical spastic paraparesis and hyperIgEaemic myelitis

CD8+ T cells, like CD4+ T cells, can differentiate into at least two subsets with distinct cytokine patterns: Tc1 cells produce Th1-like cytokines and Tc2 cells produce Th2-like cytokines. To clarify the immunopathological roles of Tc1 and Tc2 cells in central nervous system (CNS) inflammation, we examined intracellular cytokines in CD8+ and CD4+ T cells by flow cytometry and analyzed the Tc1/Tc2 balance as well as the Th1/Th2 balance in 80 patients with various CNS inflammatory diseases, including 20 with optico-spinal multiple sclerosis (OS-MS), 21 with conventional MS (C-MS), 22 with human T-lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and 17 with hyperIgEaemic myelitis. Twenty-two healthy subjects were also examined as controls. Patients with OS-MS showed a significantly higher percentage of INF-gamma+IL-4- CD8+ T cells as well as CD4+ T cells and a significantly higher intracellular interferon-gamma (IFN-gamma)/interleukin-4 (IL-4) ratio both in CD8+ and CD4+ T cells throughout the relapse and remission phases than the healthy controls. Furthermore, the patients with OS-MS showed a significantly lower percentage of INF-gamma-IL-4+ CD4+ T cells as well as CD8+ T cells during the relapse phase than the healthy controls. On the other hand, the patients with C-MS showed a significantly higher percentage of IFN-gamma-IL-4+ CD8+ T cells in addition to more IFN-gamma+IL-4- CD4+ T cells during the relapse phase than the healthy controls. The HAM/TSP patients showed a significantly higher percentage of INF-gamma+IL-4- CD8+ T cells and a significantly higher intracellular IFN-gamma/IL-4 ratio in CD8+ T cells than the healthy controls. In contrast, in hyperIgEaemic myelitis, in addition to a significantly lower intracellular IFN-gamma/IL-4 ratio in CD4+ T cells, a tendency toward a lower intracellular IFN-gamma/IL-4 ratio in CD8+ T cells in comparison to the healthy controls was observed. These results clarified for the first time the distinct Tc1/Tc2 balance in each disease condition as follows: Tc1 cell response is predominant in OS-MS and HAM/TSP, while Tc2 cell response is predominant in hyperIgEaemic myelitis and at relapse phase of C-MS. Furthermore, our results suggest that CD8+ T cells play an adjunctive role in disease induction and the clinical course of MS.

HLA-DPA1 and DPB1 polymorphism in four Pacific Islands populations determined by sequencing based typing

Class II HLA-DP antigens are heterodimers comprised of alpha and beta chains coded by HLA-DPA1 and HLA-DPB1 genes. Both genes are polymorphic with substantial variation between different populations world wide. This work describes DPA1 and DPB1 polymorphism in four Pacific Island populations of Cook Islands, Samoa, Tokelau and Tonga, living in New Zealand. Using sequencing based typing four DPA1 alleles and twelve DPB1 alleles were observed in total among the four populations. There are two predominant DPA1 alleles DPA1*01031 and DPA1*02022 and three predominant DPB1 alleles DPB1*02012, DPB1*0401 and DPB1*0501. Fourteen DPA1-DPB1 haplotypes in total are present in these four populations with three predominant haplotypes: DPA1*02022-DPB1*0501, DPA1*01031-DPB1*02012, and DPA1*01031-DPB1*0401. Strong positive and negative disequilibrium was observed for individual DPA1-DPB1 haplotypes. Significant differences in DPA1 and DPB1 allele and haplotype frequencies were observed between Tokelauan and other three populations. Phylogenetic analysis of genetic distances between the four Pacific Island populations and other Asian Oceanian populations have shown that Cook Islanders, Samoans and Tongans are more closely related to Asian populations whereas Tokelauans cluster towards non-Austronesian populations of Papua New Guinea Highlanders and Australian Aborigines.

Classification of demyelinating diseases at the interface between etiology and pathogenesis

The classical demyelinating diseases include the 'autoimmune' inflammatory demyelinating diseases, the inflammatory demyelinating diseases of infectious aetiology, and the demyelinating or dysmyelinating diseases of genetic/hereditary background. In addition, primary demyelination is present in other conditions, such as brain ischaemia and intoxication. Irrespective of the primary aetiology, selective demyelination can be mediated through various pathogenetic pathways: the immune-mediated inflammatory pathway; the metabolic pathway; and the ischaemic/excitotoxic pathway. These pathways are only partly segregated with distinct aetiologies of demyelinating diseases, but they also reflect the way in which the patient copes with the disease-inciting event in relation to their particular genetic background. For future therapeutic strategies it will be important to interfere with the specific pathogenetic pathways of demyelination, which may be common to various demyelinating diseases, but may differ in subgroups of patients who suffer from a particular clinical demyelinating disease entity.

HLA-B*51 and B*15 alleles confer predisposition to Behçet's disease in Moroccan patients

HLA class I polymorphism in Moroccan patients with Behçet's disease has not been investigated so far. In this study, HLA-B* phenotype frequencies were analyzed in 86 unrelated Moroccan patients (45 males, 41 females) and 111 ethnically matched healthy controls. The predisposing effect of the B*51 was confirmed (30.2% in patients and 15.3% in controls, OR = 2.39, 95% CI [1.2-4.8], p = 0.015). It was mostly observed in males with young age at disease onset (OR= 5.5 [1.9-15.9], p = 0.002 compared to controls). The Moroccan BD group also presented a previously unknown association with HLA-B*15 (25.6% of patients versus 11.7% of controls, OR = 2.59 [1.2-5.5], p = 0.014), both in females and in males with late-onset of the disease. Altogether, the B*15 and/or B*51 alleles were expressed in 55.8% of patients compared to 27% of controls (OR = 3.4 [1.9-6.2], p < 10-4, Pc = 0.003). Our data indicate HLA-B effects on BD pathogenesis should be considered separately for men and women.