Biomedical subjects

Wendy Thomson

Publications and source records attributed to Wendy Thomson.

29 records · Page 2Linked to original sources

PubMed2002

Evidence for linkage of HLA loci in juvenile idiopathic oligoarthritis: independent effects of HLA-A and HLA-DRB1.

OBJECTIVE: Although multiple associations between HLA loci and juvenile oligoarthritis have previously been documented, evidence for linkage of HLA loci in oligoarthritis in UK Caucasians with juvenile idiopathic arthritis (JIA) has not been described. The aim of this study was to investigate linkage of HLA-A, B, and DRB1 in UK Caucasian JIA patients with oligoarthritis. METHODS: One hundred forty-two families comprising affected offspring and their parents (45 with one parent available and 97 with both parents available) were typed for HLA-A, B, and DRB1 by polymerase chain reaction-sequence-specific oligonucleotide probe. Single-point and multipoint analyses were performed using various modifications of the extended transmission disequilibrium test. Linkage disequilibrium (LD) analysis was performed using the EH-Plus system. RESULTS: Linkage to HLA-A and HLA-DRB1 was seen in oligoarthritis and in the International League of Associations for Rheumatology-defined subgroups of persistent oligoarthritis and extended oligoarthritis. Linkage to HLA-A, B, and DRB1 was also observed in female patients with oligoarthritis. Linkage of the HLA loci seemed to be attributable to maternal preferential transmission of alleles. Furthermore, LD patterns between the HLA-A, B, and DRB1 loci were investigated. HLA-A and HLA-DRB1 were confirmed as independent susceptibility loci for oligoarthritis. CONCLUSION: This is the first study to establish linkage of HLA-A and HLA-DRB1 in oligoarthritis and to show that the 2 loci contribute independently to disease. Further studies are being performed to determine whether it is these loci or other genes in LD with them that are responsible for susceptibility to oligoarthritis in UK Caucasian patients with JIA.

Alleles↗

PubMed2002

Linkage and association studies of single-nucleotide polymorphism-tagged tumor necrosis factor haplotypes in juvenile oligoarthritis.

OBJECTIVE: The presence of increased levels of tumor necrosis factor (TNF) in serum and synovial fluid of patients and the encouraging outcome of anti-TNF therapy have implicated TNFalpha in the etiopathogenesis of juvenile oligoarthritis. Although the locus is polymorphic, no study has investigated all TNF single-nucleotide polymorphisms (SNPs) with respect to disease. The aim of this study was to examine the association of multiple TNF SNPs with juvenile oligoarthritis and to construct and analyze SNP-tagged TNF haplotypes. METHODS: A total of 144 simplex families consisting of parent and affected child, as well as 88 healthy, unrelated control subjects were available for study. In these individuals, 9 polymorphic positions of TNF were typed by a high-throughput genotyping method based on the SNaPshot assay. The chi-square and extended transmission disequilibrium tests were used to test for association and linkage, respectively. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were also calculated. Haplotype-tagging SNPs (htSNPs) for the locus were identified by ordering the haplotypes according to their frequencies. RESULTS: The study detected association of several TNF SNPs and established linkage of the locus to juvenile oligoarthritis. The most significant association observed was between the intronic +851 TNF SNP and the persistent oligoarthritis subgroup (OR 3.86, 95% CI 1.6-9.2). Haplotype data mining showed that only 4 of the 9 SNPs need to be typed in order to capture the most frequent TNF haplotypes. CONCLUSION: The TNF locus is linked and associated with juvenile oligoarthritis. Information on the htSNPs can be useful in genetic studies of diseases in which TNF may be of relevance.

Adult↗

PubMed2002

Lack of association between juvenile idiopathic arthritis and fas gene polymorphism.

OBJECTIVE: Juvenile idiopathic arthritis (JIA) is a complex genetic disease of autoimmune etiology. Fas is a molecule with a pivotal role in apoptosis and hence in immune regulation. Elevated transcriptional levels of Fas in the synovial fluid of patients with JIA suggest that it might be implicated in disease etiopathogenesis. We investigated whether a polymorphism in the Fas promoter region (-670) confers susceptibility to JIA. METHODS: In this association study, 342 UK patients with JIA and 255 healthy individuals were genotyped for the polymorphism using polymerase chain reaction restriction fragment length polymorphism. Comparisons of the genotypic frequencies were made using chi-square analysis. RESULTS: No statistically significant differences were found when the genotype frequencies of the -670 Fas polymorphism were compared between the JIA cases and the control panel. Similarly, no differences were seen between the JIA subgroups, or when the patients were divided on the basis of rheumatoid factor or antinuclear antibody positivity. CONCLUSION: The -670 polymorphism of Fas does not appear to be associated with susceptibility to JIA.

Apoptosis↗

PubMed2002

Patients chosen for treatment with cyclosporine because of severe rheumatoid arthritis are more likely to carry HLA-DRB1 shared epitope alleles, and have earlier disease onset.

OBJECTIVE: To determine whether patients with rheumatoid arthritis (RA) selected for treatment with cyclosporin A (CSA) because of severe disease are more likely to carry HLA-DRB1 alleles encoding the conserved "shared epitope" (SE) sequence. METHODS: The majority of patients (n = 178) were currently being treated with methotrexate (MTX), either alone or in combination with chloroquine and/or CSA. In about 30% of patients, treatment with CSA had been initiated because of limited response to MTX or MTX and chloroquine. Patients were treated as clinically indicated without knowledge of their HLA-DRB1 status. HLA-DRB1 typing was by a reverse dot blot method. RESULTS: Patients that had been treated with CSA were significantly more likely to carry an SE allele than patients not treated with CSA (81.5% vs 60.5%; OR 2.9, p = 0.006). Patients with 2 SE alleles were the most likely to have been treated with CSA. Results were still significant after correction for age, sex, and disease duration in a logistic regression model. There was no association between rheumatoid factor positivity and requirement for CSA therapy. Examination of individual SE alleles by multiple logistic regression analysis indicated that the strongest association was with presence of HLA-DRB1**0401 (p = 0.004). The DRB1*0401/*0404 genotype provided the greatest risk of requiring CSA treatment. Patients selected for CSA treatment had developed RA at a significantly earlier age than those not requiring CSA (44.4 vs 51.3 yrs; p = 0.004). CONCLUSION: Patients requiring treatment with CSA because of severe RA were significantly more likely to carry an SE allele than patients not requiring such treatment. CSA treated patients were also more likely to have had earlier age of disease onset. These data provide further evidence that bearing the SE (particularly 2 alleles) is associated with development of severe RA.

Adult↗

PubMed2002

Intercellular adhesion molecule-1 gene polymorphisms in isolated polymyalgia rheumatica.

OBJECTIVE: In untreated polymyalgia rheumatica (PMR), high levels of circulating soluble intercellular adhesion molecule-1 (ICAM-1) have been observed. To investigate the clinical implication of ICAM-1 polymorphisms in isolated PMR, we examined their potential influence in an unselected series of patients. METHODS: We studied 72 patients with isolated PMR and 129 ethnically matched controls from Lugo, Spain. Patients and controls were genotyped for HLA-DRB1 and ICAM-1 polymorphism at codons 241 and 469 by molecular methods. RESULTS: The distribution of alleles and genotypes for each ICAM-1 polymorphism did not show significant differences between patients with isolated PMR and controls. There were also no associations between ICAM-1 polymorphisms and relapses of the disease. The latter was primarily associated with carriage of an HLA-DRB1*0401 allele (OR 7.2, p = 0.01), although all relapsed patients with HLA-DRB1*0401 also carried the GG genotype of the ICAM-1 polymorphism at codon 241. The presence of both HLA-DRB1*0401 and the GG241 ICAM-1 genotype gave an OR of 15.2 (p = 0.005) after correction for age and sex. CONCLUSION: Although ICAM-1 polymorphisms alone do not appear to be associated with disease severity in isolated PMR, the presence of both HLA-DRB1*0401 and the ICAM-1 codon 241 GG homozygosity was significantly associated with increased risk of relapses in these patients.

Gene Frequency↗

PubMed2002

Henoch-Schönlein purpura and cutaneous leukocytoclastic angiitis exhibit different HLA-DRB1 associations.

OBJECTIVE: To examine the HLA-DRB1 genotype of patients with cutaneous leukocytoclastic angiitis (CLA), a small-sized blood vessel vasculitis limited to skin, and determine if differences exist with Henoch-Schönlein purpura (HSP), a small-sized blood vessel vasculitis with cutaneous and systemic complications. METHODS: A retrospective study was performed on an unselected population of patients from Northwest Spain with primary cutaneous vasculitis classified according to proposed criteria. Patients who fulfilled classification criteria for hypersensitivity vasculitis were included in this study if they had a biopsy proven leukocytoclastic vasculitis limited to skin and, due to this, they also met the Chapel Hill Consensus Conference on the Nomenclature of Systemic Vasculitis definitions for CLA. Patients were included in this study if they had at least 2 years' followup. We studied 96 Caucasian patients (58 HSP, 38 CLA). Patients and ethnically matched controls (n = 145) were HLA-DRB1 genotyped from DNA using molecular based methods. RESULTS: No HLA-DRB1 genotype differences between patients with CLA and controls were seen. HLA-DRB1*01 was increased and HLA-DRB1*07 reduced in HSP patients compared to controls. When HLA-DRB1 genotypes of patients with CLA and HSP were compared a significant increase of HLA-DRB1*15/16 and especially of HLA-DRB1*07 was observed in the patients fulfilling definitions for CLA compared to those with HSP. CONCLUSION: HSP and CLA exhibit different HLA-DRB1 genotype associations.

Adult↗

PubMed2002

HLA-B35 association with nephritis in Henoch-Schönlein purpura.

OBJECTIVE: To investigate the implications of the HLA-B locus in the susceptibility to Henoch-Schönlein purpura (HSP) and determine if there are associations with renal and gastrointestinal (GI) manifestations of the disease. METHODS: A retrospective study was performed on an unselected population of patients with HSP from Northwest Spain. Forty-eight Caucasian patients (24 women), 11 of them older than 20 years, were studied. Patients and ethnically matched controls were HLA-B genotyped from DNA using molecular based methods. RESULTS: When patients with HSP were compared with matched controls, no differences in HLA-B frequencies were observed. No HLA-B associations with GI manifestations were observed. In contrast, an increased frequency of HLA-B35 was observed in patients with renal manifestations (10 of 31) compared to those without (0 of 17). No significant distortions in frequency were seen for any other HLA-B alleles with HSP subgroups. CONCLUSION: Our results support a role of HLA-B35 in the susceptibility for nephritis in unselected patients with HSP.

Adult↗

PubMed2002

Interleukin 1 receptor antagonist gene polymorphism is associated with severe renal involvement and renal sequelae in Henoch-Schönlein purpura.

OBJECTIVE: To assess the influence of interleukin 1 receptor antagonist gene polymorphism (IL1RN) in the incidence of Henoch-Schönlein purpura (HSP) and cutaneous leukocytoclastic angiitis (CLA) and to determine if implications exist with severe systemic complications of HSP, in particular with severe renal involvement and permanent renal dysfunction (renal sequelae). METHODS: Patients from Northwest Spain with primary cutaneous vasculitis classified as HSP or hypersensitivity vasculitis (HV) according to proposed criteria were studied. Patients with HV were included if they had a biopsy proven small size blood vessel leukocytoclastic vasculitis limited to skin and also fulfilled the Chapel Hill Consensus Conference on the Nomenclature of Systemic Vasculitis definitions for CLA. All patients were required to have had at least 2 years' followup. Patients and ethnically matched controls were genotyped for IL-1 receptor antagonist intron 2 VNTR polymorphism. RESULTS: We examined 96 Caucasian patients (58 HSP and 38 CLA) and 109 controls. No allele or genotype differences between the whole group of HSP or CLA patients and controls were observed. We found a significant association between carriage of IL-1 receptor antagonist allele 2 (ILRN*2) and severe renal involvement, manifested as nephrotic syndrome and/or renal insufficiency (p = 0.016), and permanent renal involvement (renal sequelae) (p = 0.012). CONCLUSION: In unselected patients with cutaneous vasculitis, carriage of ILRN*2 alleles influences disease severity rather than susceptibility.

Adolescent↗

PubMed2002

Macrophage migration inhibitory factor gene polymorphism is associated with sarcoidosis in biopsy proven erythema nodosum.

OBJECTIVE: To assess whether polymorphism of the macrophage migration inhibitory factor (MIF) gene at the position -173 is implicated in the development of sarcoidosis. METHODS: Twenty-eight patients with biopsy proven erythema nodosum (EN) associated with sarcoidosis, 70 patients with biopsy proven EN related to other etiologies, and 122 healthy matched controls from the Lugo region of Northwest Spain were studied. Patients and controls were genotyped for a single nucleotide polymorphism in the 5'-flanking region at position -173 of the MIF gene, using SNapshot ddNTP primer extension, followed by capillary electrophoresis (ABI 3100). RESULTS: A significantly increased frequency of the C mutant allele was observed in patients with EN secondary to sarcoidosis compared to controls (p = 0.0016; p(corr) = 0.0032; OR 2.78, 95% CI 1.45, 5.35) and also compared to patients with EN unrelated to sarcoidosis (p = 0.0004; p(corr) = 0.0008; OR 3.72, 95% CI 1.75, 7.87). Patients with EN carrying an MIF 173 C allele were found to have an increased risk of sarcoidosis (57% in EN secondary to sarcoidosis vs 24% in patients with EN related to other etiologies; p = 0.002; p(corr) = 0.004; OR 4.16, 95% CI 1.64, 10.50). CONCLUSION: This is the first attempt to assess the influence of MIF genetic polymorphism at position -173 in the development of sarcoidosis. The MIF 173 C allele is associated with a significantly increased risk of developing sarcoidosis in patients with EN.

Adolescent↗

PubMed2002

Nodular disease in rheumatoid arthritis: association with cigarette smoking and HLA-DRB1/TNF gene interaction.

OBJECTIVE: To investigate the association of nodular disease in rheumatoid arthritis (RA) with smoking, seropositivity, and polymorphisms at HLA-DRB1 and TNF loci. METHODS: Consecutive patients with RA (n = 420) attending a hospital clinic were examined for the presence of subcutaneous nodules. Rheumatoid factor (RF) status and HLA-DRB1 genotype were determined on every patient, and their smoking history was recorded. TNFa microsatellite polymorphisms were examined in a subgroup of 144 patients. The relationships between smoking, RF status, HLA-DRB1 genotype, TNFa microsatellite polymorphism, and the presence of nodules were examined using chi-square tests and logistic regression analyses. RESULTS: Current smokers were more likely to have nodular disease than those who had never smoked (OR 1.8, 95% CI 1.0-2.9). An association was also found between RF positivity and nodular disease (OR 2.2, 95% CI 1.2-3.8) that remained significant after correction for current smoking. A combination of current smoking and seropositivity increased the risk of nodular disease (OR 3.9, 95% CI 1.7-9.1). Analysis of HLA-DRB1 genotypes in this RA population revealed that only DRB1*0401 homozygotes were associated with nodular disease, and that this was independent of the influence of smoking and seropositivity. Individual TNFa microsatellite alleles were not associated with the presence of nodules, but an interactive effect was found between the TNF a6 allele and homozygosity for DRB1*0401. CONCLUSION: Our data indicate that nodular disease in RA is independently associated with current cigarette smoking, seropositivity, and homozygosity for HLA-DRB1*0401. The latter association involves a possible interaction with the TNF a6 microsatellite allele.

Adult↗

PubMed2002

Interleukin 8 gene polymorphism is associated with increased risk of nephritis in cutaneous vasculitis.

OBJECTIVE: To assess the influence of interleukin-8 (IL-8), epithelial cell-derived neutrophil-activating peptide (ENA-78), and regulated upon activation normal T cell expressed and secreted (RANTES) gene polymorphisms in the susceptibility and clinical expression of patients fulfilling classification criteria for Henoch-Schönlein purpura (HSP). METHODS: Fifty patients (25 men) from Northwest Spain with primary cutaneous vasculitis classified as HSP according to proposed criteria were studied. All patients were required to have had at least 2 years' followup. Patients and ethnically matched controls were genotyped for IL-8, ENA-78, and RANTES gene polymorphisms. RESULTS: No allele or genotype differences between patients fulfilling HSP classification criteria and controls were observed for any of the chemokines. However, a significantly increased frequency of allele A of the IL-8 gene polymorphism was found in patients with HSP who developed renal manifestations compared with patients without renal involvement (p = 0.02; pcorr = 0.036). Moreover, the genotype distribution in HSP patients with and without renal involvement showed statistically significant differences (p = 0.02). CONCLUSION: In unselected patients with cutaneous vasculitis, carriage of IL-8 allele A influences the susceptibility to renal involvement.

Adolescent↗