Inflammatory biomarkers do not distinguish between patients with sciatica and referred leg pain within a primary care population: results from a nested study within the ATLAS cohort.

BACKGROUND: There is increasing interest in the role of pro-inflammatory cytokines in the pathogenesis of sciatica and whether these could be potential targets for treatment. We sought to investigate serum biomarker levels in patients with low back-related leg pain, including sciatica. METHODS: Primary care consulters aged > 18 with low back-related leg pain were recruited to a cohort study (ATLAS). Participants underwent a standardised clinical assessment, lumbar spine MRI and a subsample (n = 119) had samples taken for biomarker analysis. Participants were classified having: a) clinically confirmed sciatica or referred leg pain, and then subdivided into those with (or without) MRI confirmed nerve root compression due to disc prolapse. Seventeen key cytokines, chemokines and matrix metalloproteinases (MMPs) implicated in sciatica pathogenesis including TNFα and IL-6, were assayed in duplicate using commercial multiplex detection kits and measured using a Luminex suspension array system. Median biomarker levels were compared between the groups using a Mann Whitney U test. Multivariate logistic regression analysis was used to investigate the association between clinical measures and biomarker levels adjusted for possible confounders such as age, sex, and symptom duration. RESULTS: No difference was found in the serum level of any of the 17 biomarkers tested in patients with (n = 93) or without (n = 26) clinically confirmed sciatica, nor between those with (n = 44) or without (n = 49) sciatica and MRI confirmed nerve root compression. CONCLUSION: In this cohort, no significant differences in serum levels of TNFα, IL-6 or any other biomarkers were seen between patients with sciatica and those with back pain with referred leg pain. These results suggest that in patients with low back-related leg pain, serum markers associated with inflammation do not discriminate between patients with or without clinically confirmed sciatica or between those with or without evidence of nerve root compression on MRI.

An initial investigation into endothelial CC chemokine expression in the human rheumatoid synovium.

Rheumatoid arthritis (RA) is a destructive and chronic autoimmune inflammatory disease. Synovial inflammation is a major feature of RA and is associated with leukocyte recruitment. Leukocytes cross the endothelial cells (ECs) into the synovial tissue and fluid and this migration is mediated via a range of chemokines and adhesion molecules on the ECs. As important mediators of leukocyte extravasation, a number of chemokines from each of the chemokine families have been established as expressed in the RA joint. However, as little information is available on which chemokines are expressed/presented by the ECs themselves, the purpose of the study was to ascertain which of the CC chemokines were localised in RA ECs. Immunofluoresence was used to assess the presence of the CC-family chemokines in RA synovial ECs using von-Willebrand factor (VWF) as a pan-endothelial marker and a range of human chemokine antibodies. The percentage of VWF positive vessels which were positive for the chemokines was determined. The presence of the four most highly expressed novel chemokines were further investigated in non-RA synovial ECs and the sera and synovial fluid (SF) from patients with RA and osteoarthritis (OA). Statistical analysis of immunofluorescence data was carried out by Student's t-test. For analysis of ELISA data, Kruskal-Wallis ANOVA followed by Dunn's multiple comparison test was utilised to analyse differences in sera and SF levels for each chemokine between RA and OA. Spearman rank correlations of sera and SF chemokine levels with a range of clinical variables were also performed. Chemokine detection varied, the least abundant being CCL27 which was present in 8.3% of RA blood vessels and the most abundant being CCL19 which was present in 80%. Of the 26 chemokines studied, 19 have not been previously observed in RA ECs. Four of these novel chemokines, namely CCL7, CCL14, CCL16 and CCL22 were present on ≥60% of vessels. CCL14 and CCL22 were shown to be increased in RA ECs compared to non-RA ECs, p=0.0041 and p=0.014 respectively. EC chemokines CCL7, CCL14, CCL16 and CCL22 also occurred in RA synovial fluid and sera as established by ELISA. CCL7 was shown to be significantly increased in sera and SF from RA patients compared to that from osteoarthritis (OA) patients (p<0.01), and to have a highly significant correlation with the level of anti-CCP (R=0.93, p=0.001). Less abundant chemokines shown to be present in RA ECs were CCL1-3, CCL5, CCL10-13, CCL15, CCL17, CCL18, CCL20, CCL21 and CCL23-28. In conclusion, this initial study is the first to show the presence of a number of CC chemokines in RA ECs. It provides evidence that further validation and investigation into the presence and functionality of these novel chemokines expressed at RA synovial ECs may be warranted.

Clinical efficacy of oral alendronate in ankylosing spondylitis: a randomised placebo-controlled trial.

OBJECTIVES: A prospective, double blind, randomised, placebo controlled trial over 2 years was performed to test the efficacy of alendronate, an oral aminobisphosphonate, in improving symptoms and arrest disease progression in patients with mild to severe ankylosing spondylitis (AS). METHODS: 180 patients with AS were randomised to receive weekly alendronate 70 mg or placebo (1:1 randomisation). BAS-G was the primary outcome measure with Bath indices as secondary outcomes. Vertebral x-rays were performed at 0 and 24 months. Biomarkers (including CRP, IL-1beta, IL6, VEGF, MMP-1, and MMP-3) were collected during the first 12 months. RESULTS: There was no significant difference between the placebo and treatment groups in any of the recorded outcomes over the 2 years including clinical indices, biomarkers, and radiology. The change in BAS-G, the primary outcome measure, was -0.21 for the treatment group and -0.42 for the placebo group p=0.57. Change in all other clinical outcome measures were also non-significant; BASDAI p=0.86, BASFI p=0.37, BASMI p=0.021. Sub-group analysis of those subjects with a baseline BASDAI >4 were also non-significant. CONCLUSIONS: This prospective study demonstrates that alendronate 70mg weekly for 2 years was no more efficacious than placebo in improving clinical or laboratory measures of disease activity or measures of physical impact in subjects with mild to severe active AS. TRIAL REGISTRATION: ID SRCTN12308164, registered on 15.12.2015.

DNA methylation at diagnosis is associated with response to disease-modifying drugs in early rheumatoid arthritis.

AIM: A proof-of-concept study to explore whether DNA methylation at first diagnosis is associated with response to disease-modifying antirheumatic drugs (DMARDs) in patients with early rheumatoid arthritis (RA). PATIENTS & METHODS: DNA methylation was quantified in T-lymphocytes from 46 treatment-naive patients using HumanMethylation450 BeadChips. Treatment response was determined in 6 months using the European League Against Rheumatism (EULAR) response criteria. RESULTS: Initial filtering identified 21 cytosine-phosphate-guanines (CpGs) that were differentially methylated between responders and nonresponders. After conservative adjustment for multiple testing, six sites remained statistically significant, of which four showed high sensitivity and/or specificity (≥75%) for response to treatment. Moreover, methylation at two sites in combination was the strongest factor associated with response (80.0% sensitivity, 90.9% specificity, AUC 0.85). CONCLUSION: DNA methylation at diagnosis is associated with disease-modifying antirheumatic drug treatment response in early RA.

Genome-wide profiling in treatment-naive early rheumatoid arthritis reveals DNA methylome changes in T and B lymphocytes.

AIM: Although aberrant DNA methylation has been described in rheumatoid arthritis (RA), no studies have interrogated this epigenetic modification in early disease. Following recent investigations of T and B lymphocytes in established disease, we now characterize in these cell populations genome-wide DNA methylation in treatment-naive patients with early RA. PATIENTS & METHODS: HumanMethylation450 BeadChips were used to examine genome-wide DNA methylation in lymphocyte populations from 23 early RA patients and 11 healthy individuals. RESULTS: Approximately 2000 CpGs in each cell type were differentially methylated in early RA. Clustering analysis identified a novel methylation signature in each cell type (150 sites in T lymphocytes, 113 sites in B lymphocytes) that clustered all patients separately from controls. A subset of sites differentially methylated in early RA displayed similar changes in established disease. CONCLUSION: Treatment-naive early RA patients display novel disease-specific DNA methylation aberrations, supporting a potential role for these changes in the development of RA.

DNA methylation profiling of synovial fluid FLS in rheumatoid arthritis reveals changes common with tissue-derived FLS.

AIM: Alterations in DNA methylation contribute to the abnormal phenotype of fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA). We profiled genome-wide DNA methylation in these cells from synovial fluid, a more readily accessible source of disease-associated cells. PATIENTS & METHODS: Genome-wide DNA methylation was interrogated in fluid-derived FLS from five RA and six osteoarthritis patients using Human Methylation 450 Bead Chip and bisulfite pyrosequencing. RESULTS: Array analysis identified 328 CpGs, representing 195 genes, that were differentially methylated between RA and osteoarthritis fluid-derived FLS. Comparison with the genes identified in two independent studies of tissue-derived FLS revealed 73 genes in common (~40%), of which 22 shared identity with both studies. Pyrosequencing confirmed altered methylation of these genes. CONCLUSION: Synovial fluid-derived RA FLS show methylation changes common with tissue-derived FLS, supporting the use of fluid-derived FLS for future investigations.

The role of parvovirus B19 and the immune response in the pathogenesis of acute leukemia.

In this article, we review the evidence suggesting a possible role for B19 virus in the pathogenesis of a subset of cases of acute leukemia. Human parvovirus B19 infection may complicate the clinical course of patients with acute leukemia and may also precede the development of acute leukemia by up to 180 days. Parvovirus B19 targets erythroblasts in the bone marrow and may cause aplastic crisis in patients with shortened-red cell survival. Aplastic crisis represents a prodrome of acute lymphoblastic leukemia in 2% patients. There is a significant overlap between those HLA classes I and II alleles that are associated with a vigorous immune response and development of symptoms during B19 infection and those HLA alleles that predispose to development of acute leukemia. Acute symptomatic B19 infection is associated with low circulating IL-10 consistent with a vigorous immune response; deficient IL-10 production at birth was recently found to be associated with subsequent development of acute leukemia. Anti-B19 IgG has been associated with a particular profile of methylation of human cancer genes in patients with acute leukemia, suggesting an additional hit and run mechanism. The proposed role for parvovirus B19 in the pathogenesis of acute leukemia fits well with the delayed infection hypothesis and with the two-step mutation model, which describes carriage of the first mutation prior to birth, followed by suppression of hematopoiesis, which allows rapid proliferation of cells harboring the first mutation, acquisition of a second activating mutation, and expansion of cells carrying both mutations, resulting in acute leukemia.

Genome-wide DNA methylation profiling in rheumatoid arthritis identifies disease-associated methylation changes that are distinct to individual T- and B-lymphocyte populations.

Changes to the DNA methylome have been described in patients with rheumatoid arthritis (RA). In previous work, we reported genome-wide methylation differences in T-lymphocyte and B-lymphocyte populations from healthy individuals. Now, using HumanMethylation450 BeadChips to interrogate genome-wide DNA methylation, we have determined disease-associated methylation changes in blood-derived T- and B-lymphocyte populations from 12 female patients with seropositive established RA, relative to 12 matched healthy individuals. Array data were analyzed using NIMBL software and bisulfite pyrosequencing was used to validate array candidates. Genome-wide DNA methylation, determined by analysis of LINE-1 sequences, revealed higher methylation in B-lymphocytes compared with T-lymphocytes (P ≤ 0.01), which is consistent with our findings in healthy individuals. Moreover, loci-specific methylation differences that distinguished T-lymphocytes from B-lymphocytes in healthy individuals were also apparent in RA patients. However, disease-associated methylation differences were also identified in RA. In these cases, we identified 509 and 252 CpGs in RA-derived T- and B-lymphocytes, respectively, that showed significant changes in methylation compared with their cognate healthy counterparts. Moreover, this included a restricted set of 32 CpGs in T-lymphocytes and 20 CpGs in B-lymphocytes (representing 15 and 10 genes, respectively, and including two, MGMT and CCS, that were common to both cell types) that displayed more substantial changes in methylation. These changes, apparent as hyper- or hypo-methylation, were independently confirmed by pyrosequencing analysis. Validation by pyrosequencing also revealed additional sites in some candidate genes that also displayed altered methylation in RA. In this first study of genome-wide DNA methylation in individual T- and B-lymphocyte populations in RA patients, we report disease-associated methylation changes that are distinct to each cell type and which support a role for discrete epigenetic regulation in this disease.

Epigenome-wide profiling identifies significant differences in DNA methylation between matched-pairs of T- and B-lymphocytes from healthy individuals.

Multiple reports now describe changes to the DNA methylome in rheumatoid arthritis and in many cases have analyzed methylation in mixed cell populations from whole blood. However, these approaches may preclude the identification of cell type-specific methylation, which may subsequently bias identification of disease-specific changes. To address this possibility, we conducted genome-wide DNA methylation profiling using HumanMethylation450 BeadChips to identify differences within matched pairs of T-lymphocytes and B-lymphocytes isolated from the peripheral blood of 10 healthy females. Array data were processed and differential methylation identified using NIMBL software. Validation of array data was performed by bisulfite pyrosequencing. Genome-wide DNA methylation was initially determined by analysis of LINE-1 sequences and was higher in B-lymphocytes than matched T-lymphocytes (69.8% vs. 65.2%, P ≤ 0.01). Pairwise analysis identified 679 CpGs, representing 250 genes, which were differentially methylated between T-lymphocytes and B-lymphocytes. The majority of sites (76.6%) were hypermethylated in B-lymphocytes. Pyrosequencing of selected candidates confirmed the array data in all cases. Hierarchical clustering revealed perfect segregation of samples into two distinct clusters based on cell type. Differentially methylated genes showed enrichment for biological functions/pathways associated with leukocytes and T-lymphocytes. Our work for the first time shows that T-lymphocytes and B-lymphocytes possess intrinsic differences in DNA methylation within a restricted set of functionally related genes. These data provide a foundation for investigating DNA methylation in diseases in which these cell types play important and distinct roles.

Influence of adult height on rheumatoid arthritis: association with disease activity, impairment of joint function and overall disability.

OBJECTIVES: To investigate whether normal variation of adult height is associated with clinical characteristics in rheumatoid arthritis (RA), including disease activity (DAS28), impairment of joint function (mechanical joint score, MJS) and overall disability (health assessment questionnaire, HAQ). METHODS: A cohort (134 males, 287 females) of consecutively recruited RA patients of Northern European origin was studied. Height, weight and demographic information were obtained. A core set of disease measurements, including DAS28, MJS and HAQ, were recorded at baseline, 12 and 24 months. Other clinical variables (e.g. disease duration, IgM rheumatoid factor, antibodies to cyclic citrullinated peptide, C-reactive protein, erythrocyte sedimentation rate) were recorded at baseline. Socioeconomic status, smoking status, comorbid condition, other autoimmune conditions and drug therapy were also recorded. Associations were analyzed using univariate statistics and multivariate linear regression models. Mediation tests were also carried out for evaluating the relationship between gender, height and disease measures. RESULTS: In males, height was inversely associated with DAS28, MJS and HAQ (at baseline and over 24 months) independent of other factors (e.g. weight, body mass index, age, disease duration, osteoporosis, autoantibodies, erosive disease, joint replacement, steroid use, smoking status, socioeconomic status and comorbid disease). In females, a similar trend was seen but the relationships were non significant. In the whole population, the association of female gender with more active disease and poor function disappeared after adjustment for height. Mediation analysis indicated that height served as a full mediator in the relationship of gender with disease activity and overall disability. Confirmation of these findings was demonstrated in a second RA population (n = 288). CONCLUSION: Adult height is inversely associated with disease activity, impairment of joint function and overall disability in RA, particularly in males. The association of female sex with more severe disease activity and disability appears to be mediated by smaller stature.

Association of circulating levels of MMP-8 with mortality from respiratory disease in patients with rheumatoid arthritis.

INTRODUCTION: Matrix metalloproteinases (MMPs) are implicated in the destruction of the joint and have been shown to be strongly associated with inflammation in rheumatoid arthritis (RA). Circulating MMPs have also been associated with cardiovascular disease in the general population, and are predictive of cardiovascular mortality. The purpose of the present study was to determine whether circulating levels of MMPs are predictive of mortality in RA. METHODS: A multiplex suspension array system (Luminex®) was used to measure levels of MMPs (1, 2, 3, 8 and 9) in sera taken at recruitment of RA patients (n = 487) in a study of factors associated with mortality in RA. Patients were tracked on the National Health Service Central Register for notification of death, and the relationship between baseline MMP levels and mortality was analysed using Cox proportional hazards regression analysis. RESULTS: At the time of follow-up, 204/486 patients had died, of which 94 (46.1%) had died of circulatory diseases, 49 of malignancy (24.0%), and 42 (20.6%) of respiratory diseases. In a stepwise analysis which included all MMPs, only MMP-8 was significantly associated with all cause mortality (P = 0.0007, 0.6% hazard ratio increase per ng/ml). No association was found between MMP levels and mortality due to circulatory disease or malignancy. However MMP-8 levels were strongly associated with mortality due to respiratory disease (P < 0.0001, 1.3% hazard ratio increase per ng/ml). The association with respiratory disease related mortality remained highly significant in multivariate models which included smoking as well as markers of severity and disease activity such as rheumatoid factor, nodular disease, and C-reactive protein (CRP). CONCLUSIONS: The serum level of MMP-8 is a strong predictor of mortality in RA, especially that due to respiratory disease. This finding is consistent with increased activation of neutrophils in RA and identifies serum MMP-8 as a useful marker for increased risk of premature death.

Age at onset of rheumatoid arthritis: association with polymorphisms in the vascular endothelial growth factor A(VEGFA) gene and an intergenic locus between matrix metalloproteinase (MMP) 1 and 3 genes.

OBJECTIVES: The present paper aims to investigate whether polymorphisms in the vascular endothelial growth factor A (VEGFA) gene and the loci of matrix metalloproteinase (MMP) 1 and 3 genes are associated with age at onset of RA. METHODS: A sample of 413 hospital-based RA patients of Caucasian origin was studied. Common single-nucleotide polymorphisms (SNP) with likely importance were typed, including rs699947, rs833061, rs2010963 and rs3025039 in VEGFA, and rs1799750 in the MMP1 gene, rs3025058, rs679620 in the MMP3 gene and rs495366 located within the region between the MMP1 and MMP3 genes. Age at onset of RA was obtained on each patient. Demographic variables, smoking information, and a core set of clinical characteristics measured at recruitment were recorded. Hazard ratios (HR) that measured the effect size of genetic risk on age at RA onset were computed using Cox regression models. RESULTS: The T allele at rs3025039 was associated with an increased risk of early onset (HR=1.25 [95% CI 1.0-1.58] for the risk over time; HR=1.84 [95% CI 1.20-2.83] for the risk of onset <40 years old). The AA genotype at rs495366 was also associated with an increased risk (HR=1.92 [95% CI 1.27-2.89] over time; HR=2.54 [95% CI 1.30-4.95] for onset <40 years old). These associations were independent of other risk factors such as sex, smoking and anti-CCP status. CONCLUSIONS: Polymorphisms in the VEGFA gene and the MMP1-3 intergenic locus may influence age at onset of RA.

Association of cytokine and matrix metalloproteinase profiles with disease activity and function in ankylosing spondylitis.

INTRODUCTION: The pathology of ankylosing spondylitis (AS) suggests that certain cytokines and matrix metalloproteinases (MMPs) might provide useful markers of disease activity. Serum levels of some cytokines and MMPs have been found to be elevated in active disease, but there is a general lack of information about biomarker profiles in AS and how these are related to disease activity and function. The purpose of this study was to investigate whether clinical measures of disease activity and function in AS are associated with particular profiles of circulating cytokines and MMPs. METHODS: Measurement of 30 cytokines, five MMPs and four tissue inhibitors of metalloproteinases was carried out using Luminex® technology on a well-characterised population of AS patients (n = 157). The relationship between biomarker levels and measures of disease activity (Bath ankylosing spondylitis disease activity index (BASDAI)), function (Bath ankylosing spondylitis functional index) and global health (Bath ankylosing spondylitis global health) was investigated. Principal component analysis was used to reduce the large number of biomarkers to a smaller set of independent components, which were investigated for their association with clinical measures. Further analyses were carried out using hierarchical clustering, multiple regression or multivariate logistic regression. RESULTS: Principal component analysis identified eight clusters consisting of various combinations of cytokines and MMPs. The strongest association with the BASDAI was found with a component consisting of MMP-8, MMP-9, hepatocyte growth factor and CXCL8, and was independent of C-reactive protein levels. This component was also associated with current smoking. Hierarchical clustering revealed two distinct patient clusters that could be separated on the basis of MMP levels. The high MMP cluster was associated with increased C-reactive protein, the BASDAI and the Bath ankylosing spondylitis functional index. CONCLUSIONS: A profile consisting of high levels of MMP-8, MMP-9, hepatocyte growth factor and CXCL8 is associated with increased disease activity in AS. High MMP levels are also associated with smoking and worse function in AS.

Hypoalbuminaemia, systemic albumin leak and endothelial dysfunction in peritoneal dialysis patients.

BACKGROUND: Inflammation, hypoalbuminaemia and peritoneal protein clearance are important predictors of survival in patients treated with peritoneal dialysis (PD). We hypothesized that the common link is abnormal endothelial barrier function. To test this, we explored associations between hypoalbuminaemia, systemic albumin leak and soluble markers of systemic inflammation and endothelial injury. METHODS: This was a cross-sectional study of 41 prevalent PD patients. Endothelial barrier function was measured as transcapillary escape rate of (125)I albumin [transcapillary escape rate of albumin (TER(alb))]. Seventeen plasma biomarkers including pro-inflammatory cytokines, endothelial biomarkers and metalloproteinases were measured. Hierarchical clustering analysis (HCA) and principal component analysis (PCA) were used to explore the hypothesis. RESULTS: The mean TER(alb) was 13.7 ± 8.9 (%/h), higher than in non-uraemic subjects 8.22 ± 5.8 (%/h). Three patient clusters were defined from HCA according to their biomarker patterns. Cluster 1 was characterized by inflammation, hypoalbuminaemia, overhydration and intermediate TER(alb). Cluster 2 was non-inflamed, preserved muscle mass and more normal TER(alb). Cluster 3 had highest TER(alb), platelet activation, preserved plasma albumin and intermediate high-sensitivity C-reactive protein levels. Two principal components (PCs) were identified from the biomarker matrix, PC1, indicating platelet activation and PC2, pro-inflammatory. TER(alb) was positively related to PC1 but not PC2. Diabetes and ischaemic heart disease were associated with PC1 and PC2, respectively. CONCLUSIONS: This exploratory analysis indicates that endothelial barrier function is decreased in PD patients and is associated with diabetic status and markers of platelet activation more than inflammation. In contrast, hypoalbuminaemia is associated more with inflammation and atherosclerotic disease indicating a more complex relationship between systemic endothelial barrier function, inflammation and hypoalbuminaemia which requires further validation.

Interaction between smoking and functional polymorphism in the TGFB1 gene is associated with ischaemic heart disease and myocardial infarction in patients with rheumatoid arthritis: a cross-sectional study.

INTRODUCTION: Transforming growth factor-beta1 (TGF-beta1) is a pleiotropic cytokine that plays important roles in immunity and inflammation. Some studies have suggested that polymorphism in the TGFB1 gene is associated with heart disease in the general population. The purpose of the present study was to determine whether common single-nucleotide polymorphisms (SNP) in the TGFB1 gene are associated with ischaemic heart disease (IHD) and/or myocardial infarction (MI) in patients with rheumatoid arthritis (RA), and to investigate the influence of smoking on any association. METHODS: PCR-based assays were used to determine the genotypes of TGFB1 SNPs including TGFB1-509 C/T (rs1800469, in the promoter region), +868 T/C (rs1800470, in exon 1) and +913 G/C (rs1800471, in exon 1) in 414 subjects with established RA. Genotyping for the +868 SNP was also carried out on a second study population of RA patients (n = 259) with early disease. Serum levels of TGF-beta1 were measured using a commercial ELISA kit. Smoking history and IHD/MI status were obtained on each patient. Associations with IHD/MI were assessed using contingency tables and logistic regression analyses. RESULTS: The heterozygous genotype of TGFB+868 was associated with an increased risk of IHD (OR 2.14, 95% CI 1.30 - 3.55) and MI (OR 2.42, 95% CI 1.30-4.50), compared to the homozygous genotypes combined. Smoking was an independent risk for IHD and MI, and evidence of interaction between smoking and TGFB+868 was found. Multivariate analyses indicated that the strongest associations with IHD and MI were due to the combined effect of the TGFB1+868 TC genotype and smoking (OR 2.75, 95% CI 1.59-4.75; and OR 2.58 95% CI 1.33-4.99, respectively), independent of other cardiovascular risk factors. The association of the +868 TC genotype and evidence of +868 TC-smoking interaction with IHD were replicated in a second population of RA patients with early disease. Serum TGF-beta1 levels were not associated with TGFB1 genetic variations, smoking or IHD/MI status. CONCLUSIONS: Interaction between smoking and polymorphism in the TGFB1 gene may influence the risk of IHD and MI in patients with RA.

Polymorphism in the vascular endothelial growth factor A (VEGFA) gene is associated with serum VEGF-A level and disease activity in rheumatoid arthritis: differential effect of cigarette smoking.

OBJECTIVE: To assess the impact of common genetic variants in the vascular endothelial growth factor A (VEGFA) gene on circulating VEGF-A levels and disease activity in patients with rheumatoid arthritis (RA). METHODS: A cohort (n=419) of consecutively recruited RA patients of Caucasian origin was studied. Disease activity (DAS28) was recorded on a regular basis (0, 12 and 24 months). Smoking history (never, past and current) was obtained. PCR-RFLP assays were used to determine the genotypes of VEGFA single-nucleotide polymorphisms (SNP) including VEGFA-2578 (rs699947), -460 (rs833061), +405 (rs2010963) and +936 (rs3025039). Circulating levels of VEGF-A were measured in serum samples using a fluorescent bead-based assay system (Luminex®). Associations were analyzed using univariate and multivariate statistics. RESULTS: VEGFA-2578 AA genotype was associated with lower serum VEGF-A levels, as was the most frequent haplotype (A(-2578)-C(-460)-G(+405), 48.1%) within the 5'-flanking region of the gene. The same genotype and haplotype were also associated with decreased disease activity in RA. This was seen only in patients who had never smoked. In multivariate multiple regression models, the VEGFA-2578 SNP was shown to be associated with disease activity at presentation (p=0.029) and over time (p=0.016) in patients who never smoked, independent of serum VEGF-A levels and other confounding factors. CONCLUSION: Genetic variation in the VEGFA gene is associated with serum VEGF-A levels in RA, and shows an association with disease activity in RA patients who have never smoked, independent of serum VEGF-A levels.

Relationship between smoking and patient-reported measures of disease outcome in ankylosing spondylitis.

OBJECTIVE: To investigate the relationship between smoking and disease activity, pain, function, and quality of life in patients with ankylosing spondylitis (AS). METHODS: Patients with AS (n = 612) from areas across the United Kingdom took part in a cross-sectional postal survey. Patient-reported outcome measures including the Bath AS Disease Activity Index, the Bath AS Functional Index (BASFI), a numerical rating scale (NRS) of pain, the AS quality of life questionnaire (ASQoL), and the evaluation of AS quality of life measures (EASi-QoL) were analyzed in terms of smoking status and relationship with pack-year history. The influence of potential confounding factors [age, sex, disease duration, and social deprivation (Townsend Index)] were tested in multivariate logistic regression analyses. RESULTS: Median scores of BASFI, pain NRS, ASQoL, and the 4 EASi-QoL domains were all higher in the group that had ever smoked compared to those who had never smoked (p < 0.0001, p = 0.04, p = 0.003, p < 0.02, respectively). In stepwise multivariate logistic regression analyses, high disease activity and more severe pain were associated primarily with current smoking, disease duration, and Townsend Index score, while decreased function and poor quality of life measures were associated more closely with increasing pack-year history, disease duration, and Townsend Index score. These associations were independent of age and sex. CONCLUSION: Smoking has a dose-dependent relationship with measures of disease severity in AS. The association with increased disease activity, decreased function, and poor quality of life in smokers was independent of age, sex, deprivation level, and disease duration.