CTLA-4 gene polymorphism may modulate disease in Japanese multiple sclerosis patients

Multiple sclerosis (MS) is widely believed to have a T-cell-mediated autoimmune etiology. The CTLA-4 gene is a strong candidate for involvement in autoimmune diseases because it plays an important role in the termination of T-cell activation. To examine the genetic association of the CTLA-4 gene locus with MS, we analyzed the CTLA-4 gene exon 1 A/G polymorphism in 74 Japanese MS patients and 93 controls. We also investigated the possible interactions of the CTLA-4 gene polymorphism with clinical course and severity, with MRI findings, with another genetic marker-HLA antigens, and with oligoclonal bands (OCB) in the cerebrospinal fluid (CSF). The CTLA-4 exon 1 polymorphism was similar between MS patients and controls. Conversely, clinical disability was significantly more severe in AA homozygous patients than in the other patients, and the allele frequency and the phenotype frequency of the A allele were significantly higher in patients with severe-grade MRI findings of cerebral white matter than in patients with mild-grade MRI findings. The allele frequency and the phenotype frequency of the A allele were significantly higher in patients with OCB than in patients without. This CTLA-4 polymorphism may modulate the prognosis of patients with MS and may be relevant to generation of OCB in the CSF.     

The CTLA-4 gene is associated with multiple sclerosis.

We have investigated whether three intragenic polymorphisms of the CTLA-4 gene, a C/T base exchange in the promoter (p.-318), an A/G substitution in exon 1 (p.49) and a dinucleotide repeat polymorphism in exon 4 (p.642), were associated with genetic susceptibility to multiple sclerosis (MS). We observed a significant association (p < 0.05) for homozygosity for the G49 allele in a case-control analysis of 378 MS patients and 237 controls, and a transmission disequilibrium (p < 0.02) for the G49 allele in 31 MS families. This was further corroborated by evidence for linkage by the affected pedigree member (APM) analysis (p < 0.0002) and a transmission distortion (p < 0.05) of the exon 4(642) polymorphism. Sequencing of the promoter, the first and second exons and the parts of the first intron revealed no further polymorphisms. Our results suggest that a dysregulation of CTLA-4-driven downregulation of T-cell activation could be involved in the pathogenesis of MS.     

HLA-DR15 is associated with lower age at onset in multiple sclerosis

To date, more than a dozen studies have investigated the role of HLA genes in determining clinical course and disease severity in multiple sclerosis (MS); in each of these studies, however, patient sample size has been small, and no consistent pattern has emerged from the results. For the present study, we determined HLA class II genotypes and catalogued clinical and demographic data for a total of 948 patients, making our data set the largest ever used to investigate HLA genes in MS. Our goals were both to investigate the impact of HLA-DRB1 alleles on clinical course and disease severity in MS and to compare the frequencies of the established susceptibility allele DR15 in various clinicodemographic subgroups of MS patients. We found that, in addition to DR15, DR17 is positively associated with susceptibility to MS; that none of the HLA-DRB1 alleles influences course or outcome in MS; that carriers of DR15 are prone to MS development at an earlier age than noncarriers; and that differences in DR15 positivity rates, after stratification for diagnostic category and examination results, seem to reflect a gradient of phenocopy contamination, with rates increasing in proportion to the degree of clinical or paraclinical verification of the MS diagnosis.     

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.     

Decreased expression of HLA-DR antigens on monocytes in patients with multiple sclerosis

Immunofluorescence, cell binding assays and enzyme immunoassays were used to investigate the expression of class II major histocompatibility antigens on peripheral blood monocytes in 67 patients with multiple sclerosis. Monocytes from patients with active disease expressed fewer HLA-DR molecules on their surface than normal monocytes; furthermore the percentage of cells which exhibited detectable amounts of surface HLA-DR antigens was decreased in patients with active multiple sclerosis. During the inactive stage of the disease both deficiencies were milder, probably representing secondary pathogenetic phenomena. Quantitation of monocyte surface HLA-DR antigen expression could be valuable in assessing the clinical disease activity. The demonstration of a molecular defect in patients with multiple sclerosis will improve our understanding of the pathogenesis of the disease.     

Progression of multiple sclerosis is associated with exon 1 CTLA-4 gene polymorphism

OBJECTIVES: Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system which is widely believed to have a T-cell-mediated etiology. The cytotoxic T-lymphocyte antigen-4 (CTLA-4) antigen molecule plays a key role in the downregulation of T-cell responses. To examine the genetic association of the CTLA-4 gene locus with MS, we analyzed an exon 1 (A49G) transition. MATERIAL AND METHODS: One hundred and fifty-two MS patients and 154 controls were examined. The A/G transition was genotyped by a polymerase chain reaction followed by labeling with a SNaPshot kit and detection using a capillary genetic analyzer. RESULTS: The genotype, allele and phenotype frequencies did not differ significantly between MS patients and controls. Those MS patients with AA and AG genotypes had 4.36 times greater risk of progressing from the relapsing-remitting to the secondary progressive form of the disease than those with the GG genotype. CONCLUSION: The results of our study indicate that CTLA-4 (A49G) exon 1 polymorphism is associated with MS progression.     

No evidence of a significant role for CTLA-4 in multiple sclerosis

Variation in the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) gene plays a significant role in determining susceptibility to autoimmune thyroid disease and type 1 diabetes. Its role in multiple sclerosis is more controversial. In order to explore this logical candidate more thoroughly, we genotyped 771 multiple sclerosis trio families from the United Kingdom for the 3' untranslated region variable number tandem repeat, the CT60 single nucleotide polymorphism (SNP) and five haplotype-tagging SNPs. No individual marker or common haplotype showed evidence of association with disease. These data suggest that any effect of CTLA-4 on multiple sclerosis susceptibility is likely to be very small.     

Prothymosin-alpha enhances HLA-DR antigen expression on monocytes from patients with multiple sclerosis

Monocytes from patients with multiple sclerosis (MS) express decreased numbers of class II major histocompatibility complex (MHC) antigens in peripheral blood and are poor stimulators in the autologous mixed lymphocyte reaction (autoMLR). We assessed the effect of prothymosin-alpha (ProT alpha) on the expression of MHC class II antigens by monocytes. Immediately after isolation, monocytes were analyzed for MHC class II antigen expression using a radiolabelled monoclonal antibody specific for a monomorphic determinant on HLA-DR antigens. After incubation with ProT alpha we observed significant increases in HLA-DR antigens on MS monocytes (1.5- to 4-fold increase compared to freshly isolated monocytes). Kinetic analysis revealed that enhancement peaked after 2 days of incubation with ProT alpha. The increase in HLA-DR antigen on MS monocytes resulted in the restoration of the deficient autoMLR in MS patients. This is the first demonstration suggesting a link between HLA-DR antigen expression and cellular immune defects in MS. The significance of low autoMLR responses for T suppressor levels in MS patients is discussed.     

HLA-DR 15 is associated with female sex and younger age at diagnosis in multiple sclerosis.

BACKGROUND: The association between multiple sclerosis and class II alleles of the major histocompatibility complex, in particular the DRB1*1501-DQB1*0602 haplotype, is well established but their role in determining specific features of this clinically heterogeneous disease is unknown as few studies involving large sample sizes have been performed. METHODS: 729 patients with multiple sclerosis were typed for the HLA DR15 phenotype. All patients underwent clinical assessment and a detailed evaluation of their clinical records was undertaken. RESULTS: The presence of DR15 was associated with younger age at diagnosis and female sex but there was no association with disease course (relapsing-remitting or secondary progressive v primary progressive type), disease outcome, specific clinical features (opticospinal v disseminated form), diagnostic certainty (clinically and laboratory supported definite v clinically probable multiple sclerosis), and paraclinical investigations including the presence of oligoclonal bands in the CSF or characteristic abnormalities on MRI imaging of the central nervous system. CONCLUSION: Even though DR15 carriers are more likely to be female and prone to an earlier disease onset, the results indicate that there is no association with other specific clinical outcomes or laboratory indices examined here. This suggests that DR15 exerts a susceptibility rather than disease modifying effect in multiple sclerosis.     

Multiple sclerosis immunopathic trait and HLA-DR(2)15 as independent risk factors in multiple sclerosis

We analysed HLA haplotypes in pairs of 78 sporadic multiple sclerosis (MS) patients and 78 healthy siblings. The presence of 2 oligoclonal IgG bands, detected by immunoblotting of the cerebrospinal fluid in healthy siblings, has previously been defined as MS immunopathic trait (MSIT), based on a cut-off derived from healthy unrelated volunteers. The frequency of MSIT was 17.9% (n=14/78 siblings). The HLA-DR(15)2 allelle was present in 21.4% (n=3/14) of the siblings with MSIT, in 40.6% (n =26/64) of the siblings without MSIT, and in 59% (n =46/78) of the patients with clinically-definite (CD) MS. The distribution of zero, one or two HLA-DR(2)15 alleles was significantly skewed towards a lower allelle count in the siblings with MSIT compared with the group of unrelated siblings with MS (P=0.002), and also lower than their related siblings with MS (P=0.1). These results suggest that the MS susceptibility gene, HLA-DR(2)15 type, does not induce MSIT, and conceivably these are two separate risk factors in the development of MS. The effect of HLA-DR(2)15 and MSIT in sporadic MS appears to be synergistic.     

Additive effect of the HLA-DR15 haplotype on susceptibility to multiple sclerosis.

Multiple sclerosis (MS) has been associated with the human leukocyte antigen DR15 allele in Caucasians of North and Central European origin. However, the relative effect of the DR15 homozygous and the DR15 heterozygous genotypes on the disease susceptibility is unclear. Based upon results from three North European studies we have examined this by meta-analysis. Our results suggested that the effect of the DRB1*1501,DQA1*0102,DQB1*0602 haplotype on the susceptibility to MS is additive, perhaps reflecting that development of the disease is facilitated by a high density surface expression of the antigen presenting molecules encoded by this haplotype. Possible implications of our finding to future studies of the genetic background of MS is discussed.     

Effects of 4-aminopyridine in patients with multiple sclerosis

4-Aminopyridine (4-AP) was administered to two groups of patients with multiple sclerosis (MS). The first group consisted of 5 patients with labile visual symptoms, 2 of whom had arcuate scotomata. 4-AP improved visual performance of most patients in this group and reduced the size of scotomata. The second group consisted of 5 patients with the spinal form of MS who were in a stable state; in this group 4-AP had little effect clinically or on tests of visual function.     

Sardinian multiple sclerosis is associated with HLA-DR4: a serologic and molecular analysis

HLA haplotypes in 45 unrelated Sardinian multiple sclerosis patients and in six multiplex families were defined, using both serologic and restriction fragment length polymorphism (RFLP) analysis. In unrelated MS patients, we found an association with HLA-DR4 (p less than 0.01, relative risk = 2.5) and DQw3 (p less than 0.04, relative risk = 2.2). Using a beta-DR cDNA probe, we observed no variation of the DR4 RFLP profile in sporadic or related MS patients compared with DR4-specific pattern in controls. Using a beta-DQ cDNA probe, we identified two DQw3 patterns (DQw3.1 and DQw3.2) with similar frequency in patients and in controls. No specific RFLPs were observed in association with different disease courses. The frequency of haplotype sharing in affected members of multiplex families was not different from that expected by chance. This study shows that Sardinian MS patients carry predominantly the HLA-DR4 allele, in contrast to the DR2 prevalence reported in Caucasian populations. The lack of association with HLA haplotypes in affected members of multiplex families may indicate that genetic factors outside the HLA system play a substantial role in families with MS.     

IL-15 is elevated in sera of patients with relapsing-remitting multiple sclerosis

Interleukin-15 is a novel cytokine produced by monocytes/macrophages and sharing several biological activities with IL-2. IL-15 induces T cell proliferation, enhances natural killer (NK) cell cytotoxicity and also stimulates B cells to proliferate and secrete immunoglobulins. The purpose of our study was to measure IL-15 levels in the serum and CSF of 21 patients with relapsing-remitting form of MS, 9 with active gadolinium enhancing lesions in MRI, 12 without enhancing MRI lesions and to compare the results with the control group. IL-15 levels were measured by ELISA. We found a significant increase of IL-15 in the sera of patients with MS in comparison with the control group consisting of 8 patients with tension headache. IL-15 serum levels were highest in patients with active, gadolinium enhancing lesions. IL-15 CSF levels were low and there was no difference between studied groups. The results may suggest the contribution of IL-15 in the immunopathogenesis of multiple sclerosis.     

CTLA-4 and multiple sclerosis: the A49G single nucleotide polymorphism shows no association with multiple sclerosis in a Southern Australian population

Multiple sclerosis (MS) is a chronic autoimmune disorder that causes inflammatory demyelination and axonal damage in the central nervous system (CNS). We have investigated whether the A49G single nucleotide polymorphism (SNP) genotype of the CTLA-4 gene influenced the development of MS in Southern Australians as well as the interaction of this SNP with the DRB1*15 haplotype. There were no significant (P<0.05) associations between the A49G genotype and risk of MS, either before or after stratification for presence of the DR15 haplotype.     

IFN-beta treatment modulates the CD28/CTLA-4-mediated pathway for IL-2 production in patients with relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system probably mediated by Th1 lymphocytes. IFN-beta is an established therapy for relapsing MS patients, although the mechanisms underlying its efficacy are yet to be well characterized. We determined IL-2 production, CD25 expression and T-cell proliferation from relapsing-remitting MS patients before and three months after starting therapy. A decrease in the percentage of CD80-induced IL-2-producing cells was observed after in vivo IFN-beta treatment. These data support that one of the immunomodulatory effects of IFN-beta treatment in MS may be a limitation of the autoimmune response modifying the CD80:CD28/CTLA-4 pathway.