Jing-Shan Wu

Hypothalamic lesions in multiple sclerosis

Objectives To determine the frequency of hypothalamic lesions in patients with multiple sclerosis (MS) using conventional MRI (cMRI) protocols. Methods Brain cMRI (1.5 Tesla) scans of 105 Caucasian patients with classical MS (50 with stable and 55 with more active disease) and 12 patients with longitudinal extensive myelopathy (LEM) were reviewed retrospectively. NMO-IgG antibody was assayed in patients with hypothalamic lesions. Results Hypothalamic lesions were found in 13.3% of MS patients and in none of the LEM patients. A higher frequency of hypothalamic lesions was found in patients with active MS (18.2%) than in the stable group (8.0%), but this did not reach statistical significance (p=0.13). Patients with hypothalamic lesions also had more lesions in other cerebral structures. None of the LEM patients had hypothalamic lesions. No patients with hypothalamic lesions were positive for NMO-IgG. Conclusions Hypothalamic lesions in MS are more frequent than previously reported and are not associated with NMO-IgG antibody.

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.

HLA-DRB1 allele heterogeneity influences multiple sclerosis severity as well as risk in Western Australia

Susceptibility to multiple sclerosis (MS) has been consistently associated with the Human Leukocyte Antigen (HLA)-DRB11501 genotype, however effects on disease severity and clinical outcome have varied in different populations. We present the results of a high-resolution HLA-DRB1 genotyping and genotype-phenotype correlation study in a large West Australian MS cohort. Our findings indicate that in this population, which is of largely Anglo-Celtic and Northern European origin, HLA-DRB11501 is not only a strong determinant of disease risk but may also be associated with disease severity as measured by the Multiple Sclerosis Severity Score (MSSS), with the MSSS increasing by an estimated 0.51 per DRB11501 allele. We also found evidence that the HLA-DRB11201 allele is associated with less severe disease.

Influence of HLA-DRB1 allele heterogeneity on disease risk and clinical course in a West Australian MS cohort: a high-resolution genotyping study

Background: Previous studies on the influence of HLA-DRB1 alleles on multiple sclerosis (MS) susceptibility and clinical course have mostly employed the 2-point genotyping method. Objective: To assess the influence of HLA-DRB1 alleles and allele interactions on disease risk and clinical course in a large West Australian MS patient cohort using high-resolution genotyping. Methods: Four digit HLA-DRB1 genotyping was performed on a group of 466 clinically definite or probable MS patients from the Perth Demyelinating Diseases Database and 189 healthy Caucasian controls from the Busselton Community Health Study. Results: In addition to the known risk allele HLA-DRB1*1501, evidence of increased susceptibility to MS was found for three additional alleles, DRB1*0405, DRB1*1104 and DRB1*1303, though the power was insufficient to sustain significance for these when crudely Bonferroni corrected over all alleles considered. DRB1*0701 was found to be protective even after correction for multiple comparisons. In addition we found evidence that the DRB1*04 sub-allele HLA-DRB1*0407 and HLA-DRB1*0901 may be protective. Among the diplotypes, the highest estimated risk was in HLA-DRB1*1501/*0801 heterozygotes and DRB1*1501 homozygotes and the lowest in HLA-DRB1*0701/*0101 heterozygotes. There was no significant gender association with HLA-DRB1*1501 overall, but the HLA-DRB1*1501/*1104 risk genotype was significantly associated with female gender. HLA-DRB1*1501 was the strongest risk allele in both primary progressive MS and relapsing—remitting MS. Conclusion: Our results demonstrate the advantages of high-resolution HLA genotyping in recognizing risk-modifying alleles and allele combinations in this patient cohort and in recognizing the differential effects of HLA-DRB1*04 and DRB1*11 sub-alleles.

Modifying effects of HLA-DRB1 allele interactions on age at onset of multiple sclerosis in Western Australia

The contribution of genetic factors to the age at onset in multiple sclerosis is poorly understood. Our objective was to investigate the disease modifying effects of HLA-DRB1 alleles and allele interactions on age at onset of multiple sclerosis. High-resolution four-digit HLA-DRB1 genotyping was performed in a cohort of 461 multiple sclerosis patients from the Perth Demyelinating Diseases Database. Carriage of the HLA-DRB1*1501 risk allele was not significantly associated with age at onset but HLA-DRB1*0801 was associated with a later onset of the disease. The HLA-DRB1*0401 allele was associated with a reduced age at onset when combined with DRB1*1501 but may delay age at onset when combined with DRB1*0801. These findings indicate that epistatic interactions at the HLA-DRB1 locus have significant modifying effects on age at onset of multiple sclerosis and demonstrate the value of high-resolution genotyping in detecting such associations.

Spinal cord involvement in multiple sclerosis: a correlative MRI and high-resolution HLA-DRB1 genotyping study.

BACKGROUND There have been few magnetic resonance imaging (MRI) studies of the spinal cord in large multiple sclerosis (MS) patient cohorts and little is known about correlations between cord lesions and human leukocyte antigen (HLA) alleles. OBJECTIVE To investigate the spectrum of MRI changes in the spinal cord in MS and associations with the HLA-DRB1 genotype. METHODS Two hundred and fifty two consecutive MS patients from the Perth Demyelinating Diseases Database had MRI of the spinal cord and brain and high-resolution HLA-DRB1 genotyping. The numbers, locations, shape and segmental extent of cord lesions were analysed and were correlated with carriage of individual HLA-DRB1 alleles and diplotypes. RESULTS Focal cord lesions were present in 82.9% of cases, with numbers being maximal in the cervical cord and increasing with disease duration. Focal lesions were usually round or oval in shape but in 35% of cases subpial wedge-shaped lesions were present. Diffuse cord involvement was present in 10% of cases and correlated with carriage of HLA-DRB1*1501 and with higher disability. Carriage of the minor allele HLA-DRB1*0701 was significantly associated with numbers of wedge-shaped lesions and lesions in the cervical cord, while HLA-DRB1*1104 and DRB1*0103 were significantly associated respectively with higher and lower numbers of thoracic cord lesions. HLA-DRB1*1501 and the HLA-DRB1*11 sub-alleles DRB1*1101 and DRB1*1104 were significantly associated with the segmental length of cord lesions. CONCLUSIONS Our study is the first to investigate the frequency of subpial wedge-shaped lesions in the cord in vivo and has provided preliminary evidence that HLA-DRB1 alleles may play a role in determining the severity and extent of spinal cord involvement in MS.

Clinical profile and HLA-DRB1 genotype of late onset multiple sclerosis in Western Australia

We aimed to characterize the clinical profile and human leukocyte antigen (HLA)-DRB1 genotype of patients with late onset multiple sclerosis (LOMS) in Western Australia. The clinical features, laboratory studies and HLA-DRB1 alleles were analysed in patients with multiple sclerosis (MS) with onset over 50years of age and compared with 100 patients with early onset MS (EOMS). Of a cohort of 829 patients with MS, 73 (8.8%) presented at over 50years of age, including 14 (1.7%) over 60years. Patients with LOMS had a lower female to male ratio, more frequent initial motor dysfunction, less frequent sensory symptoms and optic neuritis, a more frequent primary-progressive course and shorter time to reach Extended Disability Status Scale (EDSS) scores of 3.0 and 6.0. More LOMS patients were initially misdiagnosed compared to patients with EOMS. HLA-DRB1 *1501 was strongly associated with both LOMS and EOMS compared to the Control subjects, while HLA-DRB1 *0801 was over-represented in patients with LOMS. We concluded that patients with LOMS have a different clinical profile when compared to those with EOMS. Carriers of HLA-DRB1 *0801 may be more prone to develop MS at a later age.

Low level of systemic autoimmunity in Western Australian multiple sclerosis patients

Previous autoantibody (AAb) studies in multiple sclerosis MS have produced conflicting results. The objective of this study was to determine AAb frequency and association with the HLA-DRB1 genotype. Antinuclear antibody, antithyroid peroxidase and anti-aquaporin-4 assays and HLA-DRB1 genotyping were performed in 198 MS patients and 188 controls. There were no significant differences in AAb frequency or titres between MS and control subjects. AQP4-IgG was not found in any MS patients. There was no correlation between AAbs and HLA-DRB1 alleles. In conclusion, this study failed to confirm previous reports of increased AAbs in MS or to show an association between HLA-DRB1 genotype and the presence of AAbs.

The influence of non-HLA gene polymorphisms and interactions on disease risk in a Western Australian multiple sclerosis cohort

Non-Human Leukocyte Antigen (HLA) genes have concomitant, although modest, effects on multiple sclerosis (MS) susceptibility; however findings have varied in different populations. Here we present the results of an association study of 16 single nucleotide polymorphisms (SNPs) in 10 non-HLA genes (IL7R, IL2RA, CLEC-16A, TYK2, CD58, IRF5, STAT3, CTLA-4, APOE, ICAM-1) in a Western Australian cohort of 350 MS patients and 498 population control subjects. Our results indicate that in this population, SNPs in IL7R, TYK2, IRF5 and APOE have modifying effects on MS susceptibility. We also found evidence of interactive protective effects between polymorphisms in the IL7R/CD58, CLEC-16A/CTLA-4, and TYK2/IRF5 genes, which in some instances are restricted within HLA- or gender-defined groups.

Wedge-shaped medullary lesions in multiple sclerosis

Multiple sclerosis (MS) is a heterogeneous disease with variable clinical features and magnetic resonance imaging (MRI) findings. We report four MS cases with unusual wedge-shaped lesions in the paramedian ventral medulla oblongata demonstrated on MRI. The clinical features and MRI characteristics of the medullary lesions suggest an impairment of venous drainage. We propose that the formation of these wedge-shaped lesions may be related to the pattern of venous drainage in the ventral medulla and raised venous pressure due to chronic cerebrospinal venous insufficiency which has recently been described in MS.