Gilles Boire

Autoantibodies and microvascular damage are independent predictive factors for the progression of Raynaud's phenomenon to systemic sclerosis: A twenty‐year prospective study of 586 patients, with validation of proposed criteria for early systemic sclerosis

OBJECTIVE To identify in patients with Raynauds phenomenon (RP) independent markers that predict progression to definite systemic sclerosis (SSc) and to determine in patients with progression to SSc the type and sequence of microvascular damage and its relationship to SSc-specific autoantibodies. METHODS Consecutive patients referred for evaluation of RP who had no definite connective tissue disease were evaluated for microvascular damage by nailfold capillary microscopy (NCM) and for anticentromere (anti-CENP-B), anti-Th/To, anti-topoisomerase I, and anti-RNA polymerase III (anti-RNAP III) autoantibodies by specific assays. Patients were studied prospectively. RESULTS Of the 586 patients who were followed up for 3,197 person-years, 74 (12.6%) developed definite SSc. A characteristic sequence of microvascular damage was identified, starting with enlarged capillaries, followed by capillary loss, and then by capillary telangiectases. Definite SSc was diagnosed in close temporal relationship to capillary loss. Enlarged capillaries, capillary loss, and SSc-specific autoantibodies independently predicted definite SSc. Anti-CENP-B and anti-Th/To antibodies predicted enlarged capillaries; these autoantibodies and anti-RNAP III predicted capillary loss. Each autoantibody was associated with a distinct time course of microvascular damage. At followup, 79.5% of patients with 1 of these autoantibodies and abnormal findings on NCM at baseline had developed definite SSc. Patients with both baseline predictors were 60 times more likely to develop definite SSc. The data validated the proposed criteria for early SSc. CONCLUSION In RP evolving to definite SSc, microvascular damage is dynamic and sequential, while SSc-specific autoantibodies are associated with the course and type of capillary abnormalities. Abnormal findings on NCM at baseline together with an SSc-specific autoantibody indicate a very high probability of developing definite SSc, whereas their absence rules out this outcome.

Anti-Sa antibodies and antibodies against cyclic citrullinated peptide are not equivalent as predictors of severe outcomes in patients with recent-onset polyarthritis

The prognostic value of two antibodies targeting citrullinated antigens, anti-Sa and anti-cyclic citrullinated peptide (CCP), present at inclusion, was evaluated prospectively in a cohort of 165 consecutive patients with recent-onset or early polyarthritis (EPA) followed for up to 30 months. Patients were treated according to current Good Clinical Practice standards. Predefined outcomes were severe arthritis and persistent arthritis. At inclusion, a median of 3 months after disease onset, 133 (81%) patients fulfilled at least four American College of Rheumatology criteria for rheumatoid arthritis and 30 (18%) had erosive changes on radiographs of hands and feet. Disease-modifying anti-rheumatic drugs were used in close to 80% of the patients at 30 months. Joint damage increased linearly over time, whereas disease activity declined markedly and remained low at each follow-up. Autoantibodies were identified in 76 (46%) patients: rheumatoid factor (RF) in 68 (41%), anti-CCP in 53 (33%), and anti-Sa in 46 (28%). All three antibodies were correlated, but anti-Sa antibodies best predicted severity at 18 and 30 months. RF and anti-CCP performed less well. For both outcomes, anti-Sa alone performed better than any combination of antibodies. The presence of any autoantibody identified about 50 to 60% of the patients with poor outcomes. In multivariate analysis, anti-Sa (odds ratio (OR) 8.83), the presence of erosions at inclusion (OR 3.47) and increasing age (OR 1.06/year) were significantly associated with severity, whereas RF and anti-CCP were not significant predictors. Persistent arthritis was present in up to 84% of patients; autoantibodies were specific but poorly sensitive predictors of this outcome. We conclude that assays for antibodies against citrullinated antigens differ in their ability to predict poorer outcomes in patients with EPA. In our EPA cohort treated in accordance with current standards, detection of anti-Sa but not of RF or anti-CCP antibodies, in combination with clinical and radiological variables present at the first encounter, allowed the identification of a subgroup of EPA patients suffering more rapid and more severe joint damage over 30 months.

The outcomes of juvenile idiopathic arthritis in children managed with contemporary treatments: results from the ReACCh-Out cohort

Objective To describe clinical outcomes of juvenile idiopathic arthritis (JIA) in a prospective inception cohort of children managed with contemporary treatments. Methods Children newly diagnosed with JIA at 16 Canadian paediatric rheumatology centres from 2005 to 2010 were included. Kaplan–Meier survival curves for each JIA category were used to estimate probability of ever attaining an active joint count of 0, inactive disease (no active joints, no extraarticular manifestations and a physician global assessment of disease activity <10 mm), disease remission (inactive disease >12 months after discontinuing treatment) and of receiving specific treatments. Results In a cohort of 1104 children, the probabilities of attaining an active joint count of 0 exceeded 78% within 2 years in all JIA categories. The probability of attaining inactive disease exceeded 70% within 2 years in all categories, except for RF-positive polyarthritis (48%). The probability of discontinuing treatment at least once was 67% within 5 years. The probability of attaining remission within 5 years was 46–57% across JIA categories except for polyarthritis (0% RF-positive, 14% RF-negative). Initial treatment included joint injections and non-steroidal anti-inflammatory drugs for oligoarthritis, disease-modifying antirheumatic drugs (DMARDs) for polyarthritis and systemic corticosteroids for systemic JIA. Conclusions Most children with JIA managed with contemporary treatments attain inactive disease within 2 years of diagnosis and many are able to discontinue treatment. The probability of attaining remission within 5 years of diagnosis is about 50%, except for children with polyarthritis.

Early outcomes and improvement of patients with juvenile idiopathic arthritis enrolled in a Canadian multicenter inception cohort

To determine early outcomes and early improvements in a prospective inception cohort of children with juvenile idiopathic arthritis (JIA) treated with current standard therapies.

Predictors of early inactive disease in a juvenile idiopathic arthritis cohort: Results of a Canadian multicenter, prospective inception cohort study

OBJECTIVE To determine early predictors of 6-month outcomes in a prospective cohort of patients with juvenile idiopathic arthritis (JIA). METHODS Patients selected were those enrolled in an inception cohort study of JIA, the Research in Arthritis in Canadian Children Emphasizing Outcomes Study, within 6 months after diagnosis. The juvenile rheumatoid arthritis core criteria set and quality of life measures were collected at enrollment and 6 months later. Outcomes evaluated included inactive disease, Juvenile Arthritis Quality of Life Questionnaire (JAQQ) scores, and Childhood Health Assessment Questionnaire (C-HAQ) scores at 6 months. RESULTS Thirty-three percent of patients had inactive disease at 6 months. Onset subtype and most baseline core criteria set measures correlated with all 3 outcomes. Relative to oligoarticular JIA, the risks of inactive disease were lower for enthesitis-related arthritis, polyarthritis rheumatoid factor (RF)-negative JIA, and polyarthritis RF-positive JIA, and were similar for psoriatic arthritis. In multiple regression analyses, the baseline JAQQ score was an independent predictor of all 3 outcomes. Other independent baseline predictors included polyarthritis RF-negative and systemic JIA for inactive disease; C-HAQ score and polyarthritis RF-positive JIA for the 6-month C-HAQ score; and active joint count, pain, and time to diagnosis for the 6-month JAQQ score. CONCLUSION Clinical measures soon after diagnosis predict short-term outcomes for patients with JIA. The JAQQ is a predictor of multiple outcomes. Time to diagnosis affects quality of life in the short term.

Reduced proportions of natural killer T cells are present in the relatives of lupus patients and are associated with autoimmunity

IntroductionSystemic lupus erythematosus is a genetically complex disease. Currently, the precise allelic polymorphisms associated with this condition remain largely unidentified. In part this reflects the fact that multiple genes, each having a relatively minor effect, act in concert to produce disease. Given this complexity, analysis of subclinical phenotypes may aid in the identification of susceptibility alleles. Here, we used flow cytometry to investigate whether some of the immune abnormalities that are seen in the peripheral blood lymphocyte population of lupus patients are seen in their first-degree relatives.MethodsPeripheral blood mononuclear cells were isolated from the subjects, stained with fluorochrome-conjugated monoclonal antibodies to identify various cellular subsets, and analyzed by flow cytometry.ResultsWe found reduced proportions of natural killer (NK)T cells among 367 first-degree relatives of lupus patients as compared with 102 control individuals. There were also slightly increased proportions of memory B and T cells, suggesting increased chronic low-grade activation of the immune system in first-degree relatives. However, only the deficiency of NKT cells was associated with a positive anti-nuclear antibody test and clinical autoimmune disease in family members. There was a significant association between mean parental, sibling, and proband values for the proportion of NKT cells, suggesting that this is a heritable trait.ConclusionsThe findings suggest that analysis of cellular phenotypes may enhance the ability to detect subclinical lupus and that genetically determined altered immunoregulation by NKT cells predisposes first-degree relatives of lupus patients to the development of autoimmunity.

Retropseudogenes derived from the human Ro/SS-A autoantigen-associated hY RNAs

We report the characterization in the human genome of 966 pseudogenes derived from the four human Y (hY) RNAs, components of the Ro/SS-A autoantigen. About 95% of the Y RNA pseudogenes are found in corresponding locations on the chimpanzee and human chromosomes. On the contrary, Y pseudogenes in mice are both infrequent and found in different genomic regions. In addition to this rodent/primate discrepancy, the conservation of hY pseudogenes relative to hY genes suggests that they occurred after rodent/primate divergence. Flanking regions of hY pseudogenes contain convincing evidence for involvement of the L1 retrotransposition machinery. Although Alu elements are found in close proximity to most hY pseudogenes, these are not chimeric retrogenes. Point mutations in hY RNA transcripts specifically affecting binding of Ro60 protein likely contributed to their selection for direct trans retrotransposition. This represents a novel requirement for the selection of specific RNAs for their genomic integration by the L1 retrotransposition machinery. Over 40% of the hY pseudogenes are found in intronic regions of protein-coding genes. Considering the functions of proteins known to bind subsets of hY RNAs, hY pseudogenes constitute a new class of L1-dependent non-autonomous retroelements, potentially involved in post-transcriptional regulation of gene expression.

Incidence and predictors of secondary fibromyalgia in an early arthritis cohort

Objectives Secondary fibromyalgia (FM) is common among patients with inflammatory arthritis, but little is known about its incidence and the factors leading to its development. The authors examined the incidence of secondary FM in an early inflammatory arthritis cohort, and assessed the association between pain, inflammation, psychosocial variables and the clinical diagnosis of FM. Methods Data from 1487 patients in the Canadian Early Arthritis Cohort, a prospective, observational Canadian cohort of early inflammatory arthritis patients were analysed. Diagnoses of FM were determined by rheumatologists. Incidence rates were calculated, and Cox regression models were used to determine HRs for FM risk. Results The cumulative incidence rate was 6.77 (95% CI 5.19 to 8.64) per 100 person-years during the first 12 months after inflammatory arthritis diagnosis, and decreased to 3.58 (95% CI 1.86 to 6.17) per 100 person-years 12–24 months after arthritis diagnosis. Pain severity (HR 2.01, 95% CI 1.17 to 3.46) and poor mental health (HR 1.99, 95% CI 1.09 to 3.62) predicted FM risk. Citrullinated peptide positivity (HR 0.48, 95% CI 0.26 to 0.88) was associated with decreased FM risk. Serum inflammatory markers and swollen joint count were not significantly associated with FM risk. Conclusions The incidence of FM was from 3.58 to 6.77 cases per 100 person-years, and was highest during the first 12 months after diagnosis of inflammatory arthritis. Although inflammation was not associated with the clinical diagnosis of FM, pain severity and poor mental health were associated with the clinical diagnosis of FM. Seropositivity was inversely associated with the clinical diagnosis of FM.

A targeted association study in systemic lupus erythematosus identifies multiple susceptibility alleles

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease. Multiple genetic and environmental factors contribute to the pathogenesis of this disease. Recent genome-wide association studies have added substantially to the number of genes associated with SLE. To replicate some of these susceptibility loci, single-nucleotide polymorphisms reported to be associated to SLE were evaluated in a cohort of 245 well-phenotyped Canadian SLE trios. Our results replicate previously reported associations to alleles of interferon regulatory factor 5 (IRF5), major histocompatibility complex (MHC), tumor necrosis factor (ligand) superfamily member 4 (TNFSF4), Kell blood group complex subunit-related family member 6 (XKR6), B-cell scaffold protein with ankyrin repeats 1 (BANK1), protein tyrosine phosphatase non-receptor type 22 (PTPN22), ubiquitin-conjugating enzyme E2L 3 (UBE2L3) and islet cell autoantigen 1 (ICA1). We also identify putative associations to cytotoxic T-lymphocyte-associated protein 4 (CTLA4), a gene associated with several autoimmune disorders, and ERBB3, a locus on 12q13 that was previously reported to be associated with type 1 diabetes. This study confirms the existence of multiple genetic risk factors for SLE, and supports the notion that some risk factors for SLE are shared with other inflammatory disorders.

Remission in Early Rheumatoid Arthritis — A Comparison of New ACR/EULAR Remission Criteria to Established Criteria

Objective. To describe the frequency of remission in an early rheumatoid arthritis (ERA) cohort. Methods. The frequency of remission was evaluated, based on 8 definitions including the Boolean-based American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria. Results. Of 369 patients, remission at 12 months ranged from 18% according to the ACR/EULAR clinical trial criteria to 40% according to the 28-joint Disease Activity Score (DAS28) < 2.6. Higher tender joint count, swollen joint count, and physician global scores were seen for DAS28-based definitions, and patient global assessment (PtGA) scores were almost 5-fold higher for DAS28 remission. Conclusion. Remission is achievable in ERA but its frequency differs according to the remission definition applied. Adoption of the new ACR/EULAR definition will limit the number classified as in remission, especially if the PtGA criteria are rated high for reasons other than inflammatory arthritis.