HLA DRB1*1501 and intrathecal inflammation in multiple sclerosis

Latitude and HLA-DRB1 alleles independently affect the emergence of cerebrospinal fluid IgG abnormality in multiple sclerosis

BACKGROUND

It is unclear whether the prevalence of oligoclonal IgG bands (OCBs) in multiple sclerosis (MS) is different between northern and southern regions of Asia.

OBJECTIVE

This study aimed to compare the prevalence of OCBs and positive cerebrospinal fluid (CSF) findings between northern and southern regions of Japan and to investigate the association of these CSF findings with HLA-DRB1 alleles.

METHODS

The study included 180 MS patients from Hokkaido (northern Japan) and 184 patients from Kyushu (southern Japan). The IgG index was defined as increased if it was >0.658. Presence of CSF OCBs and/or increased IgG index was defined as positive CSF findings.

RESULTS

Positive CSF findings and OCB positivity were significantly higher in MS patients from Hokkaido than in those from Kyushu (p < 0.0001 for both). Logistic regression analysis revealed that after adjusting for covariates that can be related to abnormal CSF IgG production, the geographic region (Hokkaido) showed odds ratios (ORs) of 4.08 and 2.57, whereas the HLA-DRB1*04:05 allele showed ORs of 0.36 and 0.30 for positive CSF findings and OCB positivity, respectively.

CONCLUSIONS

The results indicate that latitude and HLA-DRB1 alleles independently affect the emergence of CSF IgG abnormalities in Japanese patients with MS.

Genetic and infectious profiles influence cerebrospinal fluid IgG abnormality in Japanese multiple sclerosis patients

BACKGROUND

Abnormal intrathecal synthesis of IgG, reflected by cerebrospinal fluid (CSF) oligoclonal IgG bands (OBs) and increased IgG index, is much less frequently observed in Japanese multiple sclerosis (MS) cohorts compared with Western cohorts. We aimed to clarify whether genetic and common infectious backgrounds influence CSF IgG abnormality in Japanese MS patients.

METHODOLOGY

We analyzed HLA-DRB1 alleles, and IgG antibodies against Chlamydia pneumoniae, Helicobacter pylori, Epstein-Barr virus nuclear antigen (EBNA), and varicella zoster virus (VZV) in 94 patients with MS and 367 unrelated healthy controls (HCs). We defined CSF IgG abnormality as the presence of CSF OBs and/or increased IgG index (>0.658).

PRINCIPAL FINDINGS

CSF IgG abnormality was found in 59 of 94 (62.8%) MS patients. CSF IgG abnormality-positive patients had a significantly higher frequency of brain MRI lesions meeting the Barkhof criteria compared with abnormality-negative patients. Compared with HCs, CSF IgG abnormality-positive MS patients showed a significantly higher frequency of DRB1 1501, whereas CSF IgG abnormality-negative patients had a significantly higher frequency of DRB1 0405. CSF IgG abnormality-positive MS patients had a significantly higher frequency of anti-C. pneumoniae IgG antibodies compared with CSF IgG abnormality-negative MS patients, although there was no difference in the frequency of anti-C. pneumoniae IgG antibodies between HCs and total MS patients. Compared with HCs, anti-H. pylori IgG antibodies were detected significantly less frequently in the total MS patients, especially in CSF IgG abnormality-negative MS patients. The frequencies of antibodies against EBNA and VZV did not differ significantly among the groups.

CONCLUSIONS

CSF IgG abnormality is associated with Western MS-like brain MRI features. DRB1 1501 and C. pneumoniae infection confer CSF IgG abnormality, while DRB1 0405 and H. pylori infection are positively and negatively associated with CSF IgG abnormality-negative MS, respectively, suggesting that genetic and environmental factors differentially contribute to MS susceptibility according to the CSF IgG abnormality status.

Multiple sclerosis risk genotypes correlate with an elevated cerebrospinal fluid level of the suggested prognostic marker CXCL13

Background:

The mechanisms of multiple sclerosis (MS) pathogenesis are still largely unknown. The heterogeneity of disease manifestations make the prediction of prognosis and choice of appropriate treatment protocols challenging. Recently, increased cerebrospinal fluid (CSF) levels of the B-cell chemokine CXCL13 was proposed as a possible marker for a more severe disease course and conversion from clinically isolated syndrome (CIS) to relapsing–remitting MS (RRMS).

Objective:

To investigate whether there are genetic susceptibility variants in MS that correlate with the levels of CXCL13 present in the CSF of MS patients.

Methods:

We genotyped the human leukocyte antigens HLA-DRB1 and HLA-A, plus a panel of single nucleotide polymorphisms (SNPs) that have been associated with susceptibility to MS and then correlated the genotypes with the levels of CXCL13, as measured with ELISA in the CSF of a total of 663 patients with MS, CIS, other neurological diseases (OND) or OND with an inflammatory component (iOND).

Results:

Presence of the HLA-DRB1*15 and the MS risk genotypes for SNPs in the RGS1, IRF5 and OLIG3/TNFAIP3 gene regions correlated significantly with increased levels of CXCL13.

Conclusion:

Our results pointed towards a genetic predisposition for increased CXCL13 levels, which in MS patients correlates with the severity of the disease course. These findings encourage further investigation and replication, in an independent patient cohort.

Association of HLA-DRB1*15 allele and CSF oligoclonal bands in a Spanish multiple sclerosis cohort

BACKGROUND AND OBJECTIVE

The HLA-DRB1*15 allele is consistently associated with multiple sclerosis (MS) susceptibility in most studied populations. This study investigated the association between HLA-DRB1 alleles and the presence of oligoclonal immunoglobulin G bands (OCB) in the cerebrospinal fluid (CSF) in a Spanish population with MS.

METHODS

The HLA-DRB1 typing was performed in 268 patients with sporadic MS and the detection of OCB in CSF. HLA-DRB1 allelic frequencies were compared between OCB-positive and OCB-negative patients, and both groups were also compared with 1088 unrelated healthy controls. Moreover, we correlated the various HLA-DRB1 genotypes, considering all the combinations of both parental alleles found with the presence or absence of OCB.

RESULTS

We found 206 OCB-positive and 62 OCB-negative patients. The HLA-DRB1*15 allele in OCB-positive patients had a higher frequency when compared with OCB-negative patients (39.3% in OCB-positive vs. 16.1% in OCB-negative, OR = 1.38 95% CI = 1.18-1.61, P < 0.001). The other alleles did not show differences. When we compared with controls, the HLA-DRB1*15 allele was associated with the disease only in the OCB-positive patients group. None of the 55 genotypes found showed any association with the presence or absence of OCB.

CONCLUSIONS

HLA-DRB1*15 allele is associated with OCB-positive patients with MS when studying a Spanish MS population.

Presence of CSF oligoclonal bands (OCB) is associated with the HLA-DRB1 genotype in a West Australian multiple sclerosis cohort

High-resolution HLA-DRB1 genotyping was performed in 97 OCB-positive and 68 OCB-negative cases with demyelinating disease to determine the influence of HLA-DRB1 alleles on the presence of OCB in a West Australian multiple sclerosis (MS) cohort. Carriage of the HLA-DRB1*1501 allele was associated with both OCB-positive and OCB-negative MS compared with controls, but more strongly with the OCB-positive group, and increased the likelihood of having OCB 2.1-fold with evidence of a dominant dose-effect. The HLA-DRB1*0301 allele was negatively correlated with OCB, with all homozygotes OCB-negative, suggesting a possible recessive protective effect of HLA-DRB1*0301. There was no significant correlation between OCB and the DRB1*04 alleles which have been associated with OCB-negative MS in previous Swedish and Japanese studies. Evidence of allelic interactions was found with HLA-DRB1*1501/*1301 heterozygotes having a reduced frequency of OCB and HLA-DRB1*0301/*0401 heterozygotes all being OCB-negative. These findings confirm the strong association between HLA-DRB1*1501 and OCB which has been found in other populations but indicate that the influence of other HLA-DRB1 alleles varies in different populations. Our study is the first to show that HLA-DRB1 allele interactions and dose-effects influence the frequency of OCB.

The prognostic significance of cerebrospinal fluid in multiple sclerosis

BACKGROUND

Multiple Sclerosis (MS) patients lacking CSF oligoclonal bands are purported to have a milder course of disease. We reviewed the natural history of oligoclonal band (OCB) - negative (OCB-) compared to OCB positive (OCB+) patients.

METHOD

A retrospective study of 451 MS patients.

RESULTS

Only 48/451 patients (10.6%) were CSF OCB-. The mean age at onset was 37.1+/-8.8 years with female:male ratio=2. First CNS location presentation was less well defined in OCB- vs. OCB+ patients with significantly more supratentorial presentation. The clinical course of OCB- vs OCB+ was somewhat different; 22.9 vs 15.1% PPMS; 18.8 vs 12.4% SPMS; and 56.3 vs 71% RRMS, respectively. There were significantly fewer WBC, less IgG and a lower IgG index in OCB- cases. Fewer OCB- cases fulfilled McDonald MRI criteria. There were no discernable differences in disease severity between the two groups as determined by the EDSS, progression index, MSSS, number of relapses or annualized relapse rate.

CONCLUSION

The presence of OCB correlates better with other indications of acute inflammatory MS, especially an RR course. This study suggests that the simple lack of OCB positivity does not necessarily insure a more benign disease course.

The immunogenetics of multiple sclerosis

The discoveries in the 1970s of strong associations between various diseases and certain human leukocyte antigen (HLA) factors were a revolution within genetic epidemiology in the last century by demonstrating for the first time how genetic markers can help unravel the genetics of disorders with complex genetic backgrounds. HLA controls immune response genes and HLA associations indicate the involvement of autoimmunity. Multiple sclerosis (MS) was one of the first conditions proven to be HLA associated involving primarily HLA class II factors. We review how HLA studies give fundamental information on the genetics of the susceptibility to MS, on the importance of linkage disequilibrium in association studies, and on the pathogenesis of MS. The HLA-DRB1*1501 molecule may explain about 50% of MS cases and its role in the pathogenesis is supported by studies of transgenic mice. Studies of polymorphic non-HLA genetic markers are discussed based on linkage studies and candidate gene approaches including complete genome scans. No other markers have so far rivaled the importance of HLA in the genetic susceptibility to MS. Recently, large international collaborations provided strong evidence for the involvement of polymorphism of two cytokine receptor genes in the pathogenesis of MS: the interleukin 7 receptor alpha chain gene (IL7RA) on chromosome 5p13 and the interleukin 2 receptor alpha chain gene (IL2RA (=CD25)) on chromosome 10p15. It is estimated that the C allele of a single nucleotide polymorphism, rs6897932, within the alternative spliced exon 6 of IL7RA is involved in about 30% of MS cases.

Dipeptidyl peptidase IV (DP IV, CD26) and aminopeptidase N (APN, CD13) as regulators of T cell function and targets of immunotherapy in CNS inflammation

The ectoenzymes dipeptidyl peptidase IV (DP IV, CD26) and aminopeptidase N (APN, CD13) have been implicated in the regulation of T cell activation and function. Both DP IV and APN serve as targets of efficient enzymatic inhibitors which induce autocrine production of TGF-beta1 and subsequent suppression of T cell proliferation and cytokine release. Here, we tested the hypothesis that the simultaneous inhibition of DP IV and APN enzymatic activity on leukocytes potentiates the anti-inflammatory effect of single DP IV or APN inhibitors. Our data show that the combined application of DP IV and APN inhibitors increased suppression of DNA synthesis in human peripheral blood mononuclear cells and isolated T cells in vitro when compared to the use of a single ectopeptidase inhibitor. Moreover, the combined action of DP IV and APN inhibitors markedly increased TGF-beta1 production associated with the observed immunosuppressive effects. In vivo, targeting DP IV and APN provided a potent therapeutic approach for the treatment of experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. Taken together, our study suggests that combined DP IV and APN inhibition on pathogenic T cells represents a novel and efficient therapy for autoimmune disease of the central nervous system by a mechanism that involves an active TGF-beta1-mediated anti-inflammatory effect at the site of pathology.

Systemic T-cell activation in acute clinically isolated optic neuritis

We examined untreated 60 patients with acute monosymptomatic optic neuritis (ON). Patients examined early after onset showed increased expression of HLA-DR and CD45R0 on CD4 and CD8 T cells. Expression of HLA-DR on CD4 T cells was higher in patients without IgG oligoclonal bands. Expression of HLA-DR on CD4 and CD8 T cells correlated negatively with measures of disease activity and positively with measures of good visual function, and expression of CD45R0 on CD4 T cells correlated negatively with measures of disease activity. We hypothesize that HLA-DR expression may characterize a protective T-cell subset in ON.

Immunology of multiple sclerosis

Multiple sclerosis (MS) develops in young adults with a complex predisposing genetic trait and probably requires an inciting environmental insult such as a viral infection to trigger the disease. The activation of CD4+ autoreactive T cells and their differentiation into a Th1 phenotype are a crucial events in the initial steps, and these cells are probably also important players in the long-term evolution of the disease. Damage of the target tissue, the central nervous system, is, however, most likely mediated by other components of the immune system, such as antibodies, complement, CD8+ T cells, and factors produced by innate immune cells. Perturbations in immunomodulatory networks that include Th2 cells, regulatory CD4+ T cells, NK cells, and others may in part be responsible for the relapsing-remitting or chronic progressive nature of the disease. However, an important paradigmatic shift in the study of MS has occurred in the past decade. It is now clear that MS is not just a disease of the immune system, but that factors contributed by the central nervous system are equally important and must be considered in the future.

Chemokines and matrix metalloproteinase-9 in leukocyte recruitment to the central nervous system

Chemokines and matrix metalloproteinases (MMPs) play key roles in leukocyte migration across the blood-brain barrier (BBB) in infectious and inflammatory diseases, including multiple sclerosis (MS). In MS some chemokine receptors are expressed by an increased percentage of T cells in blood, the CSF concentration of chemokine ligands for these receptors is increased, and there is accumulation of T cells expressing relevant chemokine receptors in CSF and in the CNS parenchyma. Chemokine receptor expression patterns appear to reflect disease activity and disease stage in MS. MMPs are constitutively expressed or induced by proinflammatory cytokines and chemokines in leukocytes and CNS-resident cells. Several MMPs are expressed in MS plaques, and the CSF concentration of MMP-9 is increased in MS. The CSF concentration of MMP-9 may reflect disease activity in MS, and the CSF concentration of MMP-9 is higher in patients carrying the MS-associated HLA type DRB1 1501. We review how chemokines and MMP-9 may be involved in the pathogenesis of MS by controlling leukocyte migration between different functional compartments. Measuring expression of these molecules may find use as surrogate markers of disease activity in MS, and interfering with their function holds promise as a novel therapeutic strategy in 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.

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.