Purpose of review
To review the optimal criteria and conditions for establishing a clinical registry, as well as detailing their application in a number of ankylosing spondylitis (AS) and axial spondyloarthritis (axSpA) Registries already in existence.
Recent genetic studies and studies of long-term treatment efficacy and side-effects have underscored the need for large numbers of patients, much larger than would be possible from a single center or consortium. An optimal Registry should have its aims established upfront, with appropriate governance and oversight, and inclusion and exclusion criteria for participating collaborators and subject defined. Collaborators contributing subjects to a Registry should use validated instruments for which they have been previously trained. The numerous cross-sectional and longitudinal Registries on AS and axSpA have been recently established that differ widely depending on the referral and selection issues.
The challenge of large-scale examinations of genetics, comorbidities, medication usage, and side-effects in spondyloarthritis underscores the need for combining data from well characterized registries of AS patients which require careful planning. There are currently many such registries available internationally, offering promise for collaborations and data pooling that can answer some of the pressing questions facing rheumatology clinicians and researchers.
genetics; patient cohorts; registries; spondyloarthritis; treatment outcome
Ankylosing spondylitis (AS)is associated with both significant direct and indirect costs,which vary by country, and have generally increased dramatically since the introduction of anti-TNF therapy. The cost-effectiveness of biologic agents is controversial, although cost-effectiveness studies need to consider the potential impact of anti-TNF treatments on work ability. Alternatives to reduce costs associated with biologics have been examined, including on-demand dosing and lower dose alternatives. Other treatment measures, such as total hip arthroplasty and physical therapy, are also effective in reducing pain and improving function in patients with AS, although the optimal type or combination of physical therapy treatment modalities, the optimal frequency and duration of treatment, and whether therapy is equally effective in stable disease and uncontrolled AS needs to be determined. No studies have examined differences in patient outcomes based on subspecialty care. Establishing an evidence base for these questions would help inform policy decisions to design the most cost-effective measures to treat AS.
Spondyloarthritis; Ankylosing Spondylitis; Psoriatic Arthritis; Economics; anti-TNF Treatment
The aims of this study were to examine the predictors of time-to-neuropsychiatric (NP) damage and its impact on mortality in 632 systemic lupus erythematosus (SLE) African American, Hispanic and Caucasian LUMINA patients, age ≥ 16 years and disease duration ≤ 5 years at baseline (T0). Time-to-NP damage and its impact on mortality were examined by Cox proportional hazards regressions. One-hundred eighty-five (29.3%) patients developed NP-damage over a mean (SD) disease duration of 5.6 (3.7) years. After adjusting for neuropsychiatric manifestations present, older age [Hazard ratio (HR)=1.02; 95% [Confidence interval (CI) 1.00–1.04)], Caucasian ethnicity (HR=1.87; 95% CI 1.22-2.87), disease activity over the disease course (HR=1.16; 95% CI 1.12–1.21), diabetes (HR=3.47; 95% CI 1.44–8.38) and abnormal illness-related behaviors (HR=1.05; 95% CI 1.02–1.08) were associated with a shorter time to NP-damage. Photosensitivity (HR=0.65; 95% CI 0.44–0.95), anemia (HR=0.56; 95% CI 0.31–0.98), Raynaud’s phenomenon (HR=0.49; 95% CI 0.34–0.72), a medium dose of prednisone (HR=0.56; 95% CI 0.35–0.92) and hydroxychloroquine use (HR=0.58; 95% CI 0.36–0.93) were associated with a longer time. NP-damage did not contribute to mortality. Older age, Caucasian ethnicity, disease activity and abnormal illness-related behaviors are associated with a shorter time-to-NP damage; hydroxychloroquine and a medium dose of prednisone with a longer time.
To determine the factors associated with peripheral vascular damage in systemic lupus erythematosus (SLE) patients and its impact on survival from LUMINA, a longitudinal multiethnic cohort. Peripheral vascular damage was defined by the Systemic Lupus International Collaborating Clinics (SLICC) Damage Index (SDI). Factors associated with peripheral vascular damage were examined by univariable and multivariable logistic regression models and its impact on survival by a Cox multivariable regression. Thirty-four (5.3%) of 637 patients (90% women, mean [SD] age 36.5 [12.6] (16-87) years developed peripheral vascular damage. Age and the SDI (without peripheral vascular damage) were statistically significant (odds ratio [OR] =1.05, 95% confidence interval [CI] 1.01-1.08; p=0.0107 and OR=1.30, 95% CI 0.09-1.56; p=0.0043, respectively) in multivariable analyses. Azathioprine, warfarin and statins were also statistically significant, glucocorticoid use was borderline statistically significant (OR=1.03, 95% CI 0.10-1.06; p=0.0975). In the survival analysis, peripheral vascular damage was independenly associated with a diminished survival (Hazard Ratio =2.36; 95% CI 1.07-5.19; p=0.0334). In short, age was independently associated with peripheral vascular damage, but so was the presence of damage in others organs (ocular, neuropsychiatric, renal, cardiovascular, pulmonary, musculoskeletal and integument) and some medications (probably reflecting more severe disease). Peripheral vascular damage also negatively affected survival.
Little is known about the genetic etiology of systemic lupus erythematosus (SLE) in individuals of African ancestry, despite its higher prevalence and greater disease severity. Overproduction of nitric oxide (NO) and reactive oxygen species are implicated in the pathogenesis and severity of SLE, making NO synthases and other reactive intermediate related genes biological candidates for disease susceptibility. This study analyzed variation in reactive intermediate genes for association with SLE in two populations with African ancestry.
A total of 244 SNPs from 53 regions were analyzed in non-Gullah African Americans (AA; 1432 cases and 1687 controls) and the genetically more homogeneous Gullah of the Sea Islands of South Carolina (133 cases and 112 controls) and. Single-marker, haplotype, and two-locus interaction tests were computed for these populations.
The glutathione reductase gene GSR (rs2253409, P=0.0014, OR [95% CI]=1.26 [1.09–1.44]) was the most significant single-SNP association in AA. In the Gullah, the NADH dehydrogenase NDUFS4 (rs381575, P=0.0065, OR [95%CI]=2.10 [1.23–3.59]) and nitric oxide synthase gene NOS1 (rs561712, P=0.0072, OR [95%CI]=0.62 [0.44–0.88]) were most strongly associated with SLE. When both populations were analyzed together, GSR remained the most significant effect (rs2253409, P=0.00072, OR [95%CI]=1.26 [1.10–1.44]). Haplotype and two-locus interaction analyses also uncovered different loci in each population.
These results suggest distinct patterns of association with SLE in African-derived populations; specific loci may be more strongly associated within select population groups.
systemic lupus erythematosus; African Americans; genetic association studies; oxygen compounds; single nucleotide polymorphism
The first genome-wide association study (GWAS) of systemic sclerosis (SSc) demonstrated three non-major histocompatibility complex (MHC) susceptibility loci. The goal of this study was to investigate the impact of these gene variants on survival and severity of interstitial lung disease (ILD) in SSc.
The authors examined 1443 Caucasian SSc patients enrolled in the Genetics versus Environment In Scleroderma Outcome Study (GENISOS) and Scleroderma Family Registry (n = 914 – discovery cohort) and The Johns Hopkins Scleroderma Cohort (n = 529 – replication cohort). Forced vital capacity (FVC)% predicted was used as a surrogate for ILD severity. Five single nucleotide polymorphisms, IRF5 (rs10488631, rs12537284, rs4728142), STAT4 (rs3821236), CD247 (rs2056626) reached genome-wide significance in the SSc-GWAS and were examined in the current study.
Overall, 15.5% of the patients had died over the follow-up period of 5.5 years. The IRF5 rs4728142 minor allele was predictive of longer survival in the discovery cohort (p = 0.021) and in the independent replication cohort (p = 0.047) and combined group (HR: 0.75, 95% CI 0.62 to 0.90, p = 0.002). The association of this SNP with survival was independent of age at disease onset, disease type and autoantibody profile (anticentromere and antitopoisomerase antibodies). The minor allele frequency of IRF5 rs4728142 was 49.4%.
Moreover, IRF5 rs4728142 minor allele correlated with higher FVC% predicted at enrolment (p = 0.019). Finally, the IRF5 rs4728142 minor allele was associated with lower IRF5 transcript expression in patients and controls (p = 0.016 and p = 0.034, respectively), suggesting that the IRF5, rs4728142 SNP, may be functionally relevant.
An SNP in the IRF5 promoter region (rs4728142), associated with lower IRF5 transcript levels, was predictive of longer survival and milder ILD in patients with SSc.
Inflammatory bowel disease (IBD) and ankylosing spondylitis (AS) are similar chronic inflammatory diseases whose definitive etiology is unknown. Following recent clinical and genetic evidence supporting an intertwined pathogenic relationship, we conducted a pilot study to measure fecal calprotectin (fCAL) and IBD-related serologies in AS patients.
Consecutive AS patients were recruited from a long-term prospectively collected longitudinal AS cohort at Cedars-Sinai Medical Center. Controls were recruited from Cedars-Sinai Medical Center employees or spouses of patients with AS. Sera were tested by ELISA for IBD-associated serologies (antineutrophil cytoplasmic antibodies (ANCA), anti-Saccharomyces cerevisiae antibody IgG and IgA, anti-I2, anti-OmpC, and anti-CBir1). The Bath Ankylosing Spondylitis Disease Activity Index, the Bath Ankylosing Spondylitis Functional Index, and the Bath Ankylosing Spondylitis Radiology Index were completed for AS patients.
A total of 81 subjects (39 AS patients and 42 controls) were included for analysis. The average age of AS patients was 47 years and the average disease duration was 22 years. AS patients were predominantly male; 76% were HLA-B27-positive. Median fCAL levels were 42 μg/g and 17 μg/g in the AS group and controls, respectively (P < 0.001). When using the manufacturer's recommended cutoff value for positivity of 50 μg/g, stool samples of 41% of AS patients and 10% of controls were positive for fCAL (P = 0.0016). With the exception of ANCA, there were no significant differences in antibody levels between patients and controls. Median ANCA was 6.9 ELISA units in AS patients and 4.3 ELISA units in the controls. Among AS patients stratified by fCAL level, there were statistically significant differences between patients and controls for multiple IBD-associated antibodies.
Calprotectin levels were elevated in 41% of patients with AS with a cutoff value for positivity of 50 μg/g. fCAL-positive AS patients displayed higher medians of most IBD-specific antibodies when compared with healthy controls or fCAL-negative AS patients. Further studies are needed to determine whether fCAL can be used to identify and characterize a subgroup of AS patients whose disease might be driven by subclinical bowel inflammation.
Many challenges have made it difficult to determine the prevalence of spondyloarthritis (SpA) in North America. They include the ethnic heterogeneity of the population, the lack of feasibility of applying current criteria (such as requirements for HLA-B27 testing and imaging studies such are pelvic radiographs and MRI scanning) and the transient nature of some SpA symptoms (ie, peripheral arthritis, enthesitis). Current estimates of the prevalence of SpA in the United States range between 0.2% and 0.5% for ankylosing spondylitis, 0.1% for psoriatic arthritis, 0.065% for enteropathic peripheral arthritis, between 0.05% and 0.25% for enteropathic axial arthritis, and an overall prevalence of SpA as high as over one percent. With newer population-based instruments becoming available, the availability of the widely validated European Spondyloarthropathy Study Group (ESSG) criteria and the lower cost and greater feasibility of genetic testing, opportunities for true population-based studies of SpA are possible and will likely soon ensue.
Epidemiology; ankylosing spondylitis; psoriatic arthritis; enteropathic arthritis; spondyloarthritis
Several genetic risk variants for ankylosing spondylitis (AS) have been identified in genome wide association studies. Our objective was to examine whether familial AS cases have a higher genetic load of these susceptibility variants.
Overall, 502 AS patients were examined, consisting of 312 who had first-degree relatives (FDR) with AS (familial) and 190 who had no FDR with AS or spondyloarthritis (sporadic). All patients and affected FDRs fulfilled the modified New York Criteria for AS. The patients were recruited from two U.S. cohorts (NASC and PSOAS) and from the United Kingdom- Oxford cohort. The frequencies of AS susceptibility loci in IL23R, IL1R2, ANTRX2, ERAP1, two intergenic regions on chromosomes 2p15 and 21q22, and HLA-B27 status as determined by the tag SNP rs4349859 were compared between familial and sporadic cases. Association between SNPs and multiplex status was assessed by logistic regression controlling for sibship size.
HLA-B27 was significantly more prevalent in familial than sporadic cases of AS (p=0.0001, OR: 4.44, CI: (2.06–9.55)). Furthermore, the AS risk allele at chromosome 21q22 intergenic region showed a trend towards higher frequency in the multiplex cases (p=0.08). The frequency of the other AS risk variants did not differ significantly between familial and sporadic cases, either individually or combined.
HLA-B27 is more prevalent in familial than sporadic cases of AS, demonstrating higher familial aggregation of AS in patients with HLA-B27 positivity. The frequency of the recently described non-MHC susceptibility loci is not markedly different between the sporadic and familial cases of AS.
To determine the clinical manifestations and disease damage associated with discoid rash in a large multiethnic systemic lupus erythematosus (SLE) cohort.
SLE patients (per ACR criteria), age ≥ 16 years, disease duration ≤ 10 years at enrollment, and defined ethnicity (African American, Hispanic or Caucasian), from a longitudinal cohort were studied. Socioeconomic-demographic features, clinical manifestations and disease damage [as per the Systemic Lupus International Collaborating Clinics Damage Index (SDI)] were determined. The association of DLE with clinical manifestations and disease damage was examined using multivariable logistic regression.
A total of 2,228 SLE patients were studied. The mean (standard deviation, SD) age at diagnosis was 34.3 (12.8) years and the mean (SD) disease duration was 7.9 (6.0) years; 91.8% were women. Discoid lupus was observed in 393 (17.6%) of patients with SLE. In the multivariable analysis, patients with discoid lupus were more likely to be smokers and of African-American ethnicity, and to have malar rash, photosensitivity, oral ulcers, leukopenia and vasculitis. DLE patients were less likely to be of Hispanic (from Texas) ethnicity, and to have arthritis, end-stage renal disease (ESRD), and antinuclear, anti-dsDNA and anti-phospholipid antibodies. Patients with DLE had more damage accrual, particularly chronic seizures, scarring alopecia, scarring of the skin, and skin ulcers.
In this cohort of SLE patients, discoid lupus was associated with several clinical features including serious manifestations such as vasculitis and chronic seizures.
discoid rash; systemic lupus erythematosus; disease damage
Human leucocyte antigen (HLA) B*27 is a susceptibility allele to ankylosing spondylitis (AS). However, major AS-associated subtypes of HLA-B*27 and other HLA-B alleles vary in different ethnic populations. Herein, we examined HLA-B alleles in a total of 360 AS patients and 350 controls of Chinese Han ancestry. The HLA-B genotyping was performed with sequence-based typing (SBT) method. Six HLA-B*27 subtypes B*27:04, B*27:05, B*27:07, B*27:08, B*27:10 and B*27:15 were observed in the cohorts. HLA-B*27:04:01 and -B*27:05:02 appeared significantly increased in AS patients, which indicated as two major susceptibility alleles to AS. Homozygous B*27 was observed only in AS patients. There are 30 HLA-B alleles identified in the studies. HLA-B*15, especially B*15:01:01:01, appeared as the major allele type in the Chinese controls. Some common HLA-B alleles such as HLA-B*15, B*13, B*46 and B*51 were significantly reduced in Chinese AS patients. In conclusion, the studies profiled the HLA-B alleles, and identified major susceptibility subtypes of B27 to AS in Han Chinese population
Ankylosing spondylitis (AS); HLA-B27; Chinese Han.
Objectives. To explore whether helplessness, internality and depression would mediate the relationship between disease activity and functional limitations in patients with AS in a 12-month longitudinal study.
Methods. A total of 294 participants with AS meeting modified New York criteria completed clinical and psychological assessments at 6-month intervals. Psychological measures evaluated helplessness, depression and internality. Path analysis evaluated the direct and indirect effects of baseline disease activity on 12-month functional limitations via the psychological measures of helplessness, internality and depression at 6 months.
Results. Baseline disease activity demonstrated direct and indirect effects on 12-month functional limitations. Helplessness and depression, but not internality, served as mediators of the relationship between disease activity and functional limitations.
Conclusion. Higher baseline disease activity predicted greater functional limitations at 12 months through helplessness and depression. Our findings suggest that helplessness and depression may constitute future treatment targets in reducing functional limitations in patients with AS.
Ankylosing spondylitis; Disease activity; Functional limitations; Depression; Internality; Helplessness
Immunoregulatory cytokine interleukin-10 (IL-10) is elevated in sera from patients with systemic lupus erythematosus (SLE) correlating with disease activity. The established association of IL10 with SLE and other autoimmune diseases led us to fine map causal variant(s) and to explore underlying mechanisms. We assessed 19 tag SNPs, covering the IL10 gene cluster including IL19, IL20 and IL24, for association with SLE in 15,533 case and control subjects from four ancestries. The previously reported IL10 variant, rs3024505 located at 1 kb downstream of IL10, exhibited the strongest association signal and was confirmed for association with SLE in European American (EA) (P = 2.7×10−8, OR = 1.30), but not in non-EA ancestries. SNP imputation conducted in EA dataset identified three additional SLE-associated SNPs tagged by rs3024505 (rs3122605, rs3024493 and rs3024495 located at 9.2 kb upstream, intron 3 and 4 of IL10, respectively), and SLE-risk alleles of these SNPs were dose-dependently associated with elevated levels of IL10 mRNA in PBMCs and circulating IL-10 protein in SLE patients and controls. Using nuclear extracts of peripheral blood cells from SLE patients for electrophoretic mobility shift assays, we identified specific binding of transcription factor Elk-1 to oligodeoxynucleotides containing the risk (G) allele of rs3122605, suggesting rs3122605 as the most likely causal variant regulating IL10 expression. Elk-1 is known to be activated by phosphorylation and nuclear localization to induce transcription. Of interest, phosphorylated Elk-1 (p-Elk-1) detected only in nuclear extracts of SLE PBMCs appeared to increase with disease activity. Co-expression levels of p-Elk-1 and IL-10 were elevated in SLE T, B cells and monocytes, associated with increased disease activity in SLE B cells, and were best downregulated by ERK inhibitor. Taken together, our data suggest that preferential binding of activated Elk-1 to the IL10 rs3122605-G allele upregulates IL10 expression and confers increased risk for SLE in European Americans.
Systemic lupus erythematosus (SLE), a debilitating autoimmune disease characterized by the production of pathogenic autoantibodies, has a strong genetic basis. Variants of the IL10 gene, which encodes cytokine interleukin-10 (IL-10) with known function of promoting B cell hyperactivity and autoantibody production, are associated with SLE and other autoimmune diseases, and serum IL-10 levels are elevated in SLE patients correlating with increased disease activity. In this study, to discover SLE-predisposing causal variant(s), we assessed variants within the genomic region containing IL10 and its gene family member IL19, IL20 and IL24 for association with SLE in case and control subjects from diverse ancestries. We identified SLE-associated SNP rs3122605 located at 9.2 kb upstream of IL10 as the most likely causal variant in subjects of European ancestry. The SLE-risk allele of rs3122605 was dose-dependently associated with elevated IL10 expression at both mRNA and protein levels in peripheral blood samples from SLE patients and controls, which could be explained, at least in part, by its preferential binding to Elk-1, a transcription factor activated in B cells during active disease of SLE patients. Elk-1-mediated IL-10 overexpression could be downregulated by inhibiting activation of mitogen-activated protein kinases, suggesting a potential therapeutic target for SLE.
The Spondyloarthritis Research and Therapy Network (SPARTAN), founded in 2003 to promote research, education, and treatment of ankylosing spondylitis (AS) and related forms of spondyloarthritis (SpA), held its sixth Annual Research and Education Meeting in July 2008 in Cleveland, Ohio. The overall theme of the meeting was entheses and bones in SpA, which included presentations on the anatomy and physiology of the synovial-entheseal complex; bone formation and destruction, and the impact of inflammation on bone; the Th17 axis, HLA-B27, IL23R, and ARTS1; and breakout sessions on epidemiology and registries.
ankylosing spondylitis; epidemiology; spondyloarthritis; spondyloarthropathies
Systemic lupus erythematosus is a clinically heterogeneous autoimmune disease. A number of genetic loci that increase lupus susceptibility have been established. This study examines if these genetic loci also contribute to the clinical heterogeneity in lupus.
Materials and methods
4001 European-derived, 1547 Hispanic, 1590 African-American and 1191 Asian lupus patients were genotyped for 16 confirmed lupus susceptibility loci. Ancestry informative markers were genotyped to calculate and adjust for admixture. The association between the risk allele in each locus was determined and compared in patients with and without the various clinical manifestations included in the ACR criteria.
Renal disorder was significantly correlated with the lupus risk allele in ITGAM (p=5.0×10−6, OR 1.25, 95% CI 1.12 to 1.35) and in TNFSF4 (p=0.0013, OR 1.14, 95% CI 1.07 to 1.25). Other significant findings include the association between risk alleles in FCGR2A and malar rash (p=0.0031, OR 1.11, 95% CI 1.17 to 1.33), ITGAM and discoid rash (p=0.0020, OR 1.20, 95% CI 1.06 to 1.33), STAT4 and protection from oral ulcers (p=0.0027, OR 0.89, 95% CI 0.83 to 0.96) and IL21 and haematological disorder (p=0.0027, OR 1.13, 95% CI 1.04 to 1.22). All these associations are significant with a false discovery rate of <0.05 and pass the significance threshold using Bonferroni correction for multiple testing.
Significant associations were found between lupus clinical manifestations and the FCGR2A, ITGAM, STAT4, TNSF4 and IL21 genes. The findings suggest that genetic profiling might be a useful tool to predict disease manifestations in lupus patients in the future.
The aim of this study was to develop a clinical-grade, automated, multiplex system for the differential diagnosis and molecular stratification of rheumatoid arthritis (RA).
We profiled autoantibodies, cytokines, and bone-turnover products in sera from 120 patients with a diagnosis of RA of < 6 months' duration, as well as in sera from 27 patients with ankylosing spondylitis, 28 patients with psoriatic arthritis, and 25 healthy individuals. We used a commercial bead assay to measure cytokine levels and developed an array assay based on novel multiplex technology (Immunological Multi-Parameter Chip Technology) to evaluate autoantibody reactivities and bone-turnover markers. Data were analyzed by Significance Analysis of Microarrays and hierarchical clustering software.
We developed a highly reproducible, automated, multiplex biomarker assay that can reliably distinguish between RA patients and healthy individuals or patients with other inflammatory arthritides. Identification of distinct biomarker signatures enabled molecular stratification of early-stage RA into clinically relevant subtypes. In this initial study, multiplex measurement of a subset of the differentiating biomarkers provided high sensitivity and specificity in the diagnostic discrimination of RA: Use of 3 biomarkers yielded a sensitivity of 84.2% and a specificity of 93.8%, and use of 4 biomarkers a sensitivity of 59.2% and a specificity of 96.3%.
The multiplex biomarker assay described herein has the potential to diagnose RA with greater sensitivity and specificity than do current clinical tests. Its ability to stratify RA patients in an automated and reproducible manner paves the way for the development of assays that can guide RA therapy.
To determine the prevalence, correlates, and predictors of work disability (WD) in the Genetics versus ENvironment In Scleroderma Outcome Study (GENISOS). We hypothesized that WD in systemic sclerosis (SSc) is a function of demographic, clinical, and psychosocial factors.
Patients enrolled in the GENISOS cohort were subdivided in 3 groups: work disabled, working, and retired or homemakers. The latter group (n=29) was excluded from further analysis. We used logistic regression analysis with a forward hierarchical variable selection strategy to investigate the independent correlates of WD at enrollment. Cox regression proportional Hazard’s model with a similar variable selection strategy was utilized to determine the predictors of WD in those working at enrollment.
Overall, 284 patients with mean age of 48.7 years and disease duration of 2.5 (±1.6) years were enrolled into the GENISOS cohort, consisting of 83.5% female, 46.8% Caucasian, 28.9% Hispanic, and 20.4% African American. Patients were longitudinally followed for 3.9 (±3.6) years in 1438 study visits. At enrollment, 124 patients (43.7%) were work disabled whereas 131 (46.1%) were working. Lower education (p<0.001), higher Medsger Lung Severity Index (p=0.012), higher Fatigue Severity Score (FSS) (p=0.008), and less social support (p<0.001) correlated independently with WD. Of those working at baseline, 35 (26.7%) eventually developed WD. Non-Caucasian ethnicity (p=0.038), lower DLCO %predicted value (p=0.038), and higher FSS (p=0.009) at enrollment independently predicted WD on follow-up visits.
Demographic, clinical, and psychosocial factors correlate with WD cross-sectionally and predict WD longitudinally in the patients with SSc.
Work disability; Systemic Sclerosis; Medsger Lung Severity Index; ISEL; SF-36; Fatigue
To examine the clinical and radiographic features in men and women in the Prospective Study of Outcomes in Ankylosing Spondylitis cohort, a large well‐defined cross‐sectional study of patients with AS, in order to understand the influence of gender in determining the severity of ankylosing spondylitis.
Extensive clinical assessments and spine radiographs were performed in 302 men and 100 women with AS of ⩾20 years duration. Radiographs were scored using the Bath Ankylosing Spondylitis Radiographic Index Spine (BASRI‐spine) score (range 2–12). Functional impairment was measured by the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Health Assessment Questionnaire for the Spondyloarthropathies (HAQ‐S).
Radiographic severity was worse among men. The unadjusted median BASRI‐spine score for men was 10, compared with 6.5 for women (p<0.001). Functional disability, as measured by the BASFI and HAQ‐S, was not different between men and women. However, after adjusting for radiographic spinal damage, women were found to report worse functioning than men at any given level of radiographic damage. Women had a slightly earlier age of disease onset; however, disease duration was identical in both groups. Women more frequently reported family histories of AS in first‐degree relatives and were more likely to be treated with intra‐articular steroids, sulphasalazine and prednisone.
Among patients with longstanding AS, men have more severe radiographic changes; findings of treatment differences suggest that women may have more peripheral arthritis. At any given level of radiographic damage, self‐reported functional limitations were worse for women.
To examine the predictive role of HLA genetic markers for scleroderma renal crisis (SRC) beyond the known clinical correlates in a large population of patients with systemic sclerosis (SSc).
SSc patients from the Scleroderma Family Registry and DNA Repository, Genetics versus Environment in Scleroderma Outcomes Study (GENISOS) and rheumatology divisional registry at the University of Texas Health Science Center at Houston were included in the study. Relevant clinical data were obtained by chart review and autoantibodies were detected utilizing commercially available kits. HLA Class II genotyping was performed on extracted and purified genomic DNA.
Overall, 1519 SSc patients were included in this study, from which 90 patients (6%) had developed SRC. Among the 90 patients with SRC, diffuse cutaneous subtypes were found in 76%, anti-toposiomerase (ATA) in 9%, anti-centromere antibodies(ACA) in 2%, and anti-RNA polymerase III (ARA) in 50% of patients. In the multivariate analysis of clinical and demographic parameters, diffuse disease type and ARA were strong risk factors for presence of SRC, whereas ACA and ATA were protective. In the final multivariate analysis after inclusion of HLA alleles, we identified HLA-DRB1*0407 (OR=3.21, 95% CI 1.27–8.08; P=0.013) and DRB1*1304 (OR=4.51, 95% CI 1.30–15.65; P=0.018) as independent risk factors for SRC. Only 3 clinical characteristics, diffuse disease type, ARA, and ACA remained significant in the final model.
This study suggests that DRB1*0407 and *1304 are independent risk factors for development of SRC beyond the known clinical correlates.
Protein tyrosine phosphatase non-receptor type 22 (PTPN22) is a negative regulator of T-cell activation associated with several autoimmune diseases, including systemic lupus erythematosus (SLE). Missense rs2476601 is associated with SLE in individuals with European ancestry. Since the rs2476601 risk allele frequency differs dramatically across ethnicities, we assessed robustness of PTPN22 association with SLE and its clinical sub-phenotypes across four ethnically diverse populations. Ten SNPs were genotyped in 8220 SLE cases and 7369 controls from in European-Americans (EA), African-Americans (AA), Asians (AS), and Hispanics (HS). We performed imputation-based association followed by conditional analysis to identify independent associations. Significantly associated SNPs were tested for association with SLE clinical sub-phenotypes, including autoantibody profiles. Multiple testing was accounted for by using false discovery rate. We successfully imputed and tested allelic association for 107 SNPs within the PTPN22 region and detected evidence of ethnic-specific associations from EA and HS. In EA, the strongest association was at rs2476601 (P = 4.7×10−9, OR = 1.40 (95% CI = 1.25–1.56)). Independent association with rs1217414 was also observed in EA, and both SNPs are correlated with increased European ancestry. For HS imputed intronic SNP, rs3765598, predicted to be a cis-eQTL, was associated (P = 0.007, OR = 0.79 and 95% CI = 0.67–0.94). No significant associations were observed in AA or AS. Case-only analysis using lupus-related clinical criteria revealed differences between EA SLE patients positive for moderate to high titers of IgG anti-cardiolipin (aCL IgG >20) versus negative aCL IgG at rs2476601 (P = 0.012, OR = 1.65). Association was reinforced when these cases were compared to controls (P = 2.7×10−5, OR = 2.11). Our results validate that rs2476601 is the most significantly associated SNP in individuals with European ancestry. Additionally, rs1217414 and rs3765598 may be associated with SLE. Further studies are required to confirm the involvement of rs2476601 with aCL IgG.
Functional status is an integral component of health-related quality of life in patients with ankylosing spondylitis (AS). The purpose of this study was to investigate the role of psychological variables in self-reported functional limitation in patients with AS, while controlling for demographic and medical variables.
294 AS patients meeting modified New York Criteria completed psychological measures evaluating depression, resilience, active and passive coping, internality and helplessness at the baseline visit. Demographic, clinical, and radiologic data were also collected. Univariate and multivariate analyses were completed to determine the strength of correlation of psychological variables with functional limitation, as measured by the Bath AS Functional Index (BASFI).
In the multivariate regression analysis, the psychological variables contributed significantly to the variance in BASFI scores, adding an additional 24% to the overall R-square beyond that accounted by demographic and medical variables (R-square 32%), resulting in a final R-square of 56%. Specifically, arthritis helplessness, depression and passive coping beside age, ESR and the Bath AS Radiograph Index accounted for a significant portion of the variance in BASFI scores in the final model.
Arthritis helplessness, depression, and passive coping accounted for significant variability in self-reported functional limitation beyond demographic and clinical variables in patients with AS. Psychological health should be examined and accounted for when assessing functional status in the AS patients.
Ankylosing spondylitis (AS) and inflammatory bowel disease (IBD) share similarities and are classified as spondyloarthropathies. In IBD, anti-Saccharomyces cerevisiae antibody (ASCA), anti-I2 (associated with anti-Pseudomonas activity), anti-Escherichia coli outer membrane porin C (anti-OmpC), anti-flagellin (anti-CBir1), and antineutrophil cytoplasmic antibodies (ANCA) possess clinical significance. Because of the overlap between the two conditions, a pilot study was designed to compare the frequency of these antibodies in AS patients compared to normal controls.
Serum stored from 80 AS patients and 80 control subjects was available for analysis. ASCA, anti-I2, anti-OmpC, anti-CBir1, and ANCA studies were completed on all serum samples using Enzyme-Linked Immunosorbent Assay (ELISA) methodology. The following analyses were performed: comparison of positivity based on the established values in IBD, median values, the number of subjects in each serology in the 4th quartile of a normal distribution, and the mean quartile sum of all the antibodies.
There was no difference in positivity rates between AS and control groups with the established IBD values. The median anti-I2 response was significantly higher in AS than in controls (11.78 vs 7.86, p = 0.017). Significantly more AS patients had quartile scores of 4 for the following antibody responses: ASCA IgG (26% vs 13%, p = 0.016, OR = 2.49, CI 1.168 - 5.313), ASCA IgG and IgA (27% vs 12%, p = 0.006, OR = 2.9, CI: 1.342 - 6.264), and anti - I2 (25% vs 14%, p = 0.0424, OR = 2.15, CI: 1.018 - 4.538). The mean quartile sum of the antibody responses was elevated in AS patients when ANCA was excluded (10.526 vs 9.519, p = 0.03). When ANCA was included, this difference lost significance.
The data from this pilot study points towards mucosal dysregulation as an important pathway in AS. We were able to demonstrate that anti-I2 could play a pathologic role in AS. The elevated mean total antibody response being significant only with ANCA exclusion is consistent with the histopathological evidence that intestinal inflammation in AS is similar to Crohn's disease. To better define the roles of these antibodies in AS, larger studies with more precisely defined patient characteristics are required.
To identify differentially expressed genes in peripheral blood cells
(PBC) of patients with ankylosing spondylitis (AS) relative to healthy
controls and controls with systemic inflammation.
We investigated PBC samples of 16 patients with AS and 14 matched
controls, in addition to systemic lupus erythematosus (SLE) and systemic
sclerosis (SSc) samples utilizing Illumina Human Ref-8 BeadChips. Candidate genes were confirmed using
quantitative PCR. Subsequently, these genes were also validated in a
separate sample of 27 patients with AS [before and after antitumor necrosis
factor (anti-TNF) treatment] and 27 matched controls.
We identified 83 differentially expressed transcripts between AS
patients and controls. This gene list was filtered through the lists of
differentially expressed transcripts in SLE and SSc, which resulted in
identification of 52 uniquely dysregulated transcripts in AS. Many of the
differentially expressed genes belonged to Toll-like receptor (TLR) and
related pathways. TLR4 and TLR5 were the
only dysregulated TLR subtypes among AS patients. We confirmed the
overexpression of TLR4 and TLR5 in AS
patients in comparison to controls (p = 0.012 and p = 0.006, respectively)
and SLE (p = 0.002, p = 0.008) using quantitative PCR in the same sample.
Similarly, TLR4 (p = 0.007) and TLR5 (p =
0.012) were significantly upregulated among the AS patients before anti-TNF
treatment in the confirmatory sample. TLR4 (p = 0.002) and
TLR5 (p = 0.025) decreased significantly after anti-TNF
PBC gene expression profiling in AS shows an upregulation of
TLR4 and TLR5. This supports the
importance of TLR subtypes in the pathogenesis of AS that are responsible
for the immune response to Gram-negative bacteria.
ANKYLOSING SPONDYLITIS; TOLL-LIKE RECEPTORS; IMMUNE SYSTEM; AUTOIMMUNITY; BACTERIA; GENE EXPRESSION PROFILING
To identify susceptibility loci for ankylosing spondylitis, we undertook a genome-wide association study in 2,053 unrelated ankylosing spondylitis cases among people of European descent and 5,140 ethnically matched controls, with replication in an independent cohort of 898 ankylosing spondylitis cases and 1,518 controls. Cases were genotyped with Illumina HumHap370 genotyping chips. In addition to strong association with the major histocompatibility complex (MHC; P < 10−800), we found association with SNPs in two gene deserts at 2p15 (rs10865331; combined P = 1.9 × 10−19) and 21q22 (rs2242944; P = 8.3 × 10−20), as well as in the genes ANTXR2 (rs4333130; P = 9.3 × 10−8) and IL1R2 (rs2310173; P = 4.8 × 10−7). We also replicated previously reported associations at IL23R (rs11209026; P = 9.1 × 10−14) and ERAP1 (rs27434; P = 5.3 × 10−12). This study reports four genetic loci associated with ankylosing spondylitis risk and identifies a major role for the interleukin (IL)-23 and IL-1 cytokine pathways in disease susceptibility.