1.
Interleukin 15 levels in serum may predict a severe disease course in patients with early arthritis.
Source
Rheumatology Service, Hospital Universitario de La Princesa, IIS Princesa, Madrid, Spain.
Abstract
BACKGROUND:
Interleukin-15 (IL-15) is thought to be involved in the physiopathological mechanisms of RA and it can be detected in the serum and the synovial fluid of inflamed joints in patients with RA but not in patients with osteoarthritis or other inflammatory joint diseases. Therefore, the objective of this work is to analyse whether serum IL-15 (sIL-15) levels serve as a biomarker of disease severity in patients with early arthritis (EA).
METHODOLOGY AND RESULTS:
Data from 190 patients in an EA register were analysed (77.2% female; median age 53 years; 6-month median disease duration at entry). Clinical and treatment information was recorded systematically, especially the prescription of disease modifying anti-rheumatic drugs. Two multivariate longitudinal analyses were performed with different dependent variables: 1) DAS28 and 2) a variable reflecting intensive treatment. Both included sIL-15 as predictive variable and other variables associated with disease severity, including rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (ACPA). Of the 171 patients (638 visits analysed) completing the follow-up, 71% suffered rheumatoid arthritis and 29% were considered as undifferentiated arthritis. Elevated sIL-15 was detected in 29% of this population and this biomarker did not overlap extensively with RF or ACPA. High sIL-15 levels (β Coefficient [95% confidence interval]: 0.12 [0.06-0.18]; p<0.001) or ACPA (0.34 [0.01-0.67]; p = 0.044) were significantly and independently associated with a higher DAS28 during follow-up, after adjusting for confounding variables such as gender, age and treatment. In addition, those patients with elevated sIL-15 had a significantly higher risk of receiving intensive treatment (RR 1.78, 95% confidence interval 1.18-2.7; p = 0.007).
CONCLUSIONS:
Patients with EA displaying high baseline sIL-15 suffered a more severe disease and received more intensive treatment. Thus, sIL-15 may be a biomarker for patients that are candidates for early and more intensive treatment.
Peptidyl-arginine deiminase: an additional marker of rheumatoid arthritis.
Source
Biotechnology Department, Heritage Institute of Technology, Chowbagha Road, Anandapur, Kolkata, India. psbasu.heritage@gmail.com
Abstract
BACKGROUND:
Antibodies against cyclic citrullinated peptide (anti-CCP) were thought to be more specific than rheumatoid factor (RF) for the diagnosis of rheumatoid arthritis (RA). The determination of anti-CCP in addition to RF could be helpful in the serological diagnosis and monitoring of patients with RA. Citrullination of proteins involves the enzymatic conversion of protein containing arginine residues to citrulline residues by the enzyme peptidylarginine deiminase (PAD). The present investigation was undertaken to estimate serum PAD enzyme activity in RA patients with a view to find its importance as a new diagnosis marker in a rheumatology clinic.
METHODS:
The activity of the PAD enzyme was measured by spectrophotometric method at 530 nm in sera of control subjects and in patients of RA (Group I: RF negative and CCP positive: Group II: both RF and CCP positive) in terms of citrulline formation using benzoyl-arginine ethyl ester (BAEE) as substrate. Anti-CCP and RF were also estimated in two groups by enzyme immunoassay and immunoturbidimetry for comparison. Clinical variables (duration of morning stiffness, swollen and tender joint counts, patient's assessment of pain) and C-reactive protein were also evaluated.
RESULTS:
A marked increase in PAD enzyme activity (p < 0.001) was noted in RA patients in comparison to controls and the level diminished appreciably along with two known serological markers (anti-CCP and RF) after six months of disease modifying antirheumatic drug (DMARD) treatment. The Group II RA patients showed much higher enzyme activity than Group I RA patients. However, clinical variables did not differ significantly between the two Groups of RA patients.
CONCLUSIONS:
We conclude that determination of PAD enzyme activity may be used as an additional marker for monitoring disease progression and regression along with anti-CCP and RF in patients with RA. Moreover, this method is rapid, sensitive, and inexpensive and can be adopted in a laboratory having modest facilities.
- PMID:
- 22239037
- [PubMed - in process]
Anti-cyclic citrullinated peptide antibodies in scleroderma patients.
Source
Rheumatology Unit, Evangelical University Hospital of Curitiba, Curitiba, Paraná, Brazil.
Abstract
Anti-CCP (cyclic citrullinated peptide) is considered the most useful laboratory tool in the diagnosis of rheumatoid arthritis (RA). Some authors have also found this autoantibody in patients with scleroderma (SSc). The study aimed to investigate the prevalence of anti-CCP antibodies in SSc patients from Southern Brazil and their association with clinical and serological profile of the disease. We studied 76 patients with SSc and 100 healthy volunteers for presence of anti-CCP. SSc patients charts were reviewed for clinical and laboratory data. In the SSc group, the diffuse form was present in 20.5%; 62.8% had the limited form; 14.1% had overlap with systemic lupus or polymyositis and 2.5% had SSc sine scleroderma. Anti-CCP was found in nine of 78 (11.5%) SSc patients and in one of 100 healthy volunteers (p = 0.0054). No relationship was found with arthritis, skin Rodnan m score, esophageal dysmotility, myocarditis, pulmonary hypertension and lung fibrosis. Positive association was observed with arthralgias (p = 0.02). Also, no relationship was noted with the presence of anti-centromere antibodies, anti-Scl-70, anti-RNP or rheumatoid factor. Anti-CCP are more common in SSc patients than in controls. Arthralgias but not arthritis or rheumatoid factor are more frequent in anti-CCP positive patients.
Should rheumatoid factor in rheumatoid arthritis be sent to Davy Jones's Locker?
Source
Department of Rheumatology, University Hospital of North Norway , Tromsø , Norway.
Abstract
This article reviews the characteristics and weaknesses of the rheumatoid factor (RF) assay compared with anti-citrullinated peptide antibody (ACPA) testing in the work-up of patients with synovitis. This should lead physicians to change their ordering habits and replace RF by ACPA. For RA diagnosis, good clinical judgement based on clinical history, physical examination and routine laboratory work exceeds the value of RF and ACPA assays. In settings of both low and high pretest probability, the added value of each of these assays is low. In cases with intermediate probability, ACPA assays are superior to immunoglobulin (Ig)M-RF because of their higher specificity, and they should be the first choice in a RA diagnostic work-up. Dual testing brings few additional advantages and increases costs significantly. ACPA and IgM-RF are both imperfect tests; around 30% of patients with manifest RA will test negative in both assays and therefore caution needs to be exercised when interpreting negative results. Since 2009, the anti-cyclic citrullinated peptide (anti-CCP) antibody assay has been the only assay available at our institution for RA work-up, with IgM-RF available on a case-by-case basis for non-RA diseases. This has led to a 70% reduction in RF assays performed annually.
The clinical significance of anti-cyclic citrullinated peptide antibody in primary Sjögren syndrome.
Source
Division of Rheumatology, Department of Internal Medicine, Konkuk University School of Medicine, Konkuk University Hospital, 265 Guuiro, Gwangjin-gu, Seoul, 143-729, Korea.
Abstract
Anti-cyclic citrullinated peptide antibody (anti-CCP) is a specific marker for the diagnosis of rheumatoid arthritis. However, this antibody can be detected in other rheumatic diseases and even in healthy people. This study aims to determine the prevalence and the clinical significance of anti-CCP in patients with primary Sjögren syndrome (pSS). We analyzed the clinical and laboratory data of 95 patients with pSS by retrospective review of their medical records. Anti-CCP was measured by ELISA kit. Anti-CCP, rheumatoid factor (RF), anti-nuclear antibody, anti-Ro and anti-La antibodies, and clinical data were investigated. We analyzed clinical and serologic characteristics of anti-CCP-positive patients. Twenty-one patients (22.1%) had positive anti-CCP (mean titer 61.6 ± 15.6 U/ml) and 40 patients (42.1%) had positive RF (mean titer 98.8 ± 22.7 IU/ml). Seventy-nine patients (83.1%) had arthralgia, and 31 patients (32.6%) had non-erosive arthritis on physical examination and radiologic images. Anti-CCP-positive patients had more frequently positive RF (71.4% vs. 41.8%, P = 0.01) and anti-Ro antibody (85.7% vs. 60.8%, P = 0.03). Anti-CCP-positive patients had non-erosive arthritis more frequently than anti-CCP-negative patients (76.1% vs. 21.6%, P < 0.01). The prevalence of anti-CCP was 22.1% in pSS, and anti-CCP was associated with non-erosive arthritis, and positivity of RF and anti-Ro antibody.
Serum anti-cyclic citrullinated peptide antibodies may predict disease activity in rheumatoid arthritis.
Source
Internal Medicine Ward, Division of Rheumatology, Shahid Beheshti Hospital, Kashan University of Medical Sciences, Kashan, Iran.
Abstract
To define the relationship between serum anti-cyclic citrullinated peptide antibodies (anti-CCP) and disease activity, and to construct a new disease activity index by using anti-CCP in rheumatoid arthritis (RA). One hundred and five RA patients were included. Disease activity based on DAS28-ESR and serum anti-CCP was measured. There was correlation between serum anti-CCP and DAS28-ESR. (R (2) = 0.71, P value < 0.01). New disease activity index was developed by replacing anti-CCP with ESR in DAS28-ESR. There was correlation between new model and DAS28-ESR. (R (2) = 0.91, P value < 0.01) The new composite index best cut-off values corresponding to DAS28-ESR values of 2.6, 3.2, and 5.1 were 3.21, 3.38, and 4.74, respectively. There was agreement between new model and DAS28-ESR for determination of patients in different disease activity categories. (Kappa = 0.71, P value < 0.01). The new disease activity index that applies serum anti-CCP may predict disease activity in RA.
The presence of anti-citrullinated protein antibodies (ACPA) and rheumatoid factor on patients with rheumatoid arthritis (RA) does not interfere with the chance of clinical remission in a follow-up of 3 years.
Source
Rheumatology Division, Hospital Universitário de Brasília da Universidade de Brasília, SHLS 716/916 Bloco E salas 501-502, Centro Médico de Brasília, Asa Sul, Brasilia, DF, CEP: 71660020, Brazil, licia@unb.br.
Abstract
Autoantibodies in early rheumatoid arthritis (RA) have important diagnostic value. The association between the presence of autoantibodies against cyclic citrullinated peptide and the response to treatment is controversial. To prospectively evaluate a cohort of patients with early rheumatoid arthritis (<12 months of symptoms) in order to determine the association between serological markers (rheumatoid factor (RF), anti-citrullinated protein antibodies) such as anti-cyclic citrullinated peptide antibodies (anti-CCP) and citrullinated anti-vimentin (anti-Sa) with the occurrence of clinical remission, forty patients diagnosed with early RA at the time of diagnosis were evaluated and followed for 3 years, in use of standardized therapeutic treatment. Demographic and clinical data were recorded, disease activity score 28 (DAS 28), as well as serology tests (ELISA) for RF (IgM, IgG, and IgA), anti-CCP (CCP2, CCP3, and CCP3.1) and anti-Sa in the initial evaluation and at 3, 6, 12, 18, 24, and 36 months of follow-up. The outcome evaluated was the percentage of patients with clinical remission, which was defined by DAS 28 lower than 2.6. Comparisons were made through the Student t test, mixed-effects regression analysis, and analysis of variance (significance level of 5%). The mean age was 45 years, and a female predominance was observed (90%). At the time of diagnosis, RF was observed in 50% of cases (RF IgA-42%, RF IgG-30%, and RF IgM-50%), anti-CCP in 50% (no difference between CCP2, CCP3, and CCP3.1) and anti-Sa in 10%. After 3 years, no change in the RF prevalence and anti-CCP was observed, but the anti-Sa increased to 17.5% (P = 0.001). The percentage of patients in remission, low, moderate, and intense disease activity, according to the DAS 28, was of 0, 0, 7.5, and 92.5% (initial evaluation) and 22.5, 7.5, 32.5, and 37.5% (after 3 years). There were no associations of the presence of autoantibodies in baseline evaluation and in serial analysis with the percentage of clinical remission during follow-up of 3 years The presence of autoantibodies in early RA has no predictive value for clinical remission in early RA.
Airways abnormalities and rheumatoid arthritis-related autoantibodies in subjects without arthritis: Early injury or initiating site of autoimmunity?
Source
Division of Rheumatology, University of Colorado School of Medicine, Aurora, CO.
Abstract
OBJECTIVE:
To evaluate the presence of pulmonary abnormalities in subjects with rheumatoid arthritis (RA)-related autoantibody (Ab) positivity without inflammatory arthritis (IA).
METHODS:
42 subjects without IA but with elevations of anti-cyclic citrullinated peptide antibodies and/or 2 or more rheumatoid factor isotypes (a profile that is 96% specific for RA), 15 Ab(-) controls and 12 patients with early established seropositive RA (<1 year duration) underwent spirometry and high-resolution computed tomographic (HRCT) lung imaging.
RESULTS:
The median age of Ab(+) subjects was 54 years-old, 52% were female and 38% were smokers (not significantly different than Ab(-) controls). No Ab(+) subject had IA on joint examination. On HRCT, 76% of Ab(+) subjects had airways abnormalities including bronchial wall thickening, bronchiectasis, centrilobular opacities and air trapping, compared to 33% of Ab(-) controls (p=0.005). The Ab(+) subjects had similar prevalence and type of lung abnormalities compared to patients with early RA. Two Ab(+) subjects with airways disease developed IA classifiable as articular RA ∼13 months after lung evaluation.
CONCLUSION:
Airways abnormalities that are consistent with inflammation are common in Ab(+) subjects without IA, and similar to airways abnormalities seen in early RA. These findings suggest that the lung may be an early site of autoimmune-related injury, and potentially a site of generation of RA-related autoimmunity. Further studies are needed to define the mechanistic role of lung inflammation in the development of RA.
Copyright © 2011 by the American College of Rheumatology.
The effectiveness of Echinacea extract or composite glucosamine, chondroitin and methyl sulfonyl methane supplements on acute and chronic rheumatoid arthritis rat model.
Source
Faculty of Science, Biology Department, Jazan University, Jazan, Saudi Arabia.
Abstract
The study aimed to investigate the effect of the oral administration for 15 days of either Echinacea (E) or genuphil (a composite of chondroitin sulphate, glucosamine and methyl sulfonyl methane [GCM]) nutraceutical supplements on female rat model of acute or chronic arthritis induced by bacterial outer membrane protein (OMP) from faecal flora of healthy and rheumatic humans. Anti-cyclic citrullinated peptide (anti-CCP2), C-reactive protein (CRP) and rheumatoid factor (RF) values increased (p < 0.05) in both arthritic groups as compared to normal values. The rheumatic markers anti-CCP2, CRP and RF values decreased significantly in E- and GCM-treated groups compared to arthritic none-treated acute or chronic groups. The results of RF values of GCM-treated groups in acute and chronic models decreased exhibiting no statistical difference compared with the normal value. Histological examinations of the hind paw sections revealed moderate inflammation, oedema and mild proliferation of synovial cells in acute arthritic rats and more damage to cartilage and bone with severe inflammation in chronic ones. Echinacea acute treated group showed edema with proliferated synovial membrane and partial damage in cartilage and bone. While in the E-chronic treated group, rough edge with destructed cartilage and bone existed. However, the acute GCM group revealed mild cartilage damage. But the chronic GCM group showed mild synovial cells proliferation and revealed no inflammation with mild cartilage damage edge. Results demonstrated the OMP arthropathic property and through promising light on arthritis treatment using E- or GCM, with the advantage of GMC results over that of E-. The composite GCM is needed for further studies over the dose and duration to assess its preventive effects against the bacterial OMP arthrogenicity.
Inflammatory and noninflammatory arthropathy in patients with 18q deletion syndrome.
Source
From the *Pediatric Residency Program, Department of Pediatrics, and†Division of Pediatric Rheumatology, Children's Hospital of Michigan; and ‡Wayne State University School of Medicine, Detroit, MI.
Abstract
ABSTRACT: A 7-year-old girl with 18q deletion syndrome developed chronic progressive polyarticular inflammatory arthropathy. Atypical features of her arthritis included lack of morning stiffness, absence of pain and discomfort, normal acute-phase reactants, and the presence of clinodactyly, low-set thumbs, metatarsus adductus of her feet, and overriding nontender swollen toes. She had a positive antinuclear antibody test, negative rheumatoid factor and anti-cyclic citrullinated peptide, and undetectable immunoglobulin A level. Magnetic resonance imaging of the right knee and the result of the synovial biopsy were consistent with synovitis. She was treated with naproxen, short course of prednisone, and methotrexate with good clinical response that plateaued over time. We analyzed the scarce reports of inflammatory arthropathy in 18q deletion syndrome and proposed an outline for investigating arthropathies in patients with chromosomal aberrations.
Significance of complement components C1q and C4 bound to circulating immune complexes in juvenile idiopathic arthritis: support for classical complement pathway activation.
Source
Division of Adult and Pediatric Rheumatology, Saint Louis University School of Medicine, Saint Louis, MO, USA. dobblerb@slu.edu.
Abstract
OBJECTIVES:
Immune complexes (ICs) from sera of juvenile idiopathic arthritis (JIA) patients show increased complement opsonisation; however, a definitive role for involvement of the classical or alternative pathway is not entirely clear. To delineate the role of these pathways, we measured activated complement products bound to circulating IC (CICs) in the sera of JIA patients.
METHODS:
Sera from 100 JIA patients and 22 healthy children were collected. C1q, C4, C3, C3d, and membrane attack complex (MAC) bound to CICs were measured by enzyme-linked immunosorbent assay. Data was compared to IgM rheumatoid factor (RF), IgG anti-cyclic citrullinated peptide (CCP) antibodies, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) levels.
RESULTS:
Mean levels of C1q, C4, and MAC bound to CICs were significantly elevated in JIA patients compared to healthy children. C1q correlated significantly with C4 and MAC bound to CICs and C4 and MAC also demonstrated significant correlation. No significant differences were noted in complement components bound to CICs when evaluating IgM RF, anti-CCP antibody, and CRP positivity. A significant correlation was noted between MAC bound to CICs and ESR. C1q and MAC bound to CICs mean levels were significantly higher in patients with an elevated ESR compared to those with a normal ESR level.
CONCLUSIONS:
JIA patients have elevated levels of complement components bound to CICs, particularly from the classical pathway. Moreover, classical pathway components were associated with ESR, a marker of disease activity. MAC bound to CICs also correlated significantly with ESR, further supporting the notion of complement-mediated tissue injury that is triggered by IC-mediated classical pathway activation.
Anti-CCP and RF IgM: predictors of impaired endothelial function in rheumatoid arthritis patients.
Source
Lillehammer Hospital for Rheumatic Diseases, Lillehammer, Norway. Gunn.Hjeltnes@Revmatismesykehuset.no
Abstract
OBJECTIVE:
To determine whether the presence of anti-cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor immunoglobulin M (RF IgM) is associated with endothelial dysfunction in patients with rheumatoid arthritis (RA).
METHODS:
We studied the presence of anti-CCP antibodies and RF IgM and endothelial function in terms of the reactive hyperaemic index (RHI) in 53 consecutive RA patients. Endothelial function was measured by using a finger plethysmograph.
RESULTS:
RHI was significantly lower in anti-CCP-positive RA patients (n = 33, RHI = 1.78, SD = 0.30) than in anti-CCP-negative RA patients (n = 20, RHI = 2.19, SD = 0.59; p = 0.008). A similar result was found in RF IgM-positive patients (n = 34, RHI = 1.77, SD = 0.30) vs. RF IgM-negative patients (n = 19, RHI = 2.23, SD = 0.58; p = 0.003). There were no significant differences between the groups regarding age, gender, traditional cardiovascular risk markers, Disease Activity Score using 28 joint counts (DAS28), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), extra-articular manifestations (EAMs), use of glucocorticosteroids, statins, angiotensin-converting enzyme (ACE) inhibitors, and non-steroidal anti-inflammatory drugs (NSAIDs).
CONCLUSION:
The presence of anti-CCP antibodies and RF IgM was related to impaired endothelial function independent of other cardiovascular risk factors in RA patients. Thus, these autoantibodies might reflect an early reversible stage of the atherosclerotic process, and may indicate increased risk of cardiovascular disease (CVD). Further studies are needed to explore whether anti-CCP antibodies and RF IgM may act directly or indirectly to cause endothelial dysfunction, or merely reflect endothelial dysfunction in RA patients.
Assessment of disease activity and treatment outcomes in rheumatoid arthritis.
Source
Division of Rheumatology and Clinical Immunogenetics, University of Texas Health Science Center, Houston, TX 77030, USA. Kiran.Farheen@uth.tmc.edu
Abstract
BACKGROUND:
Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease which primarily causes a symmetric polyarthritis. Clinical manifestations of the disease include joint pain, stiffness, and swelling. Unless treated, this debilitating disease can progress into long-term disability. Medications for RA include synthetic disease-modifying antirheumatic drugs (DMARDs) and biologic agents. The rapid expansion of new RA drugs into the market has led to a need for health care practitioners to understand the effectiveness of each medication and the indications of use including when to initiate and stop therapies. Clinical assessment tools, including biomarkers used to indicate RA and the progression of the disease, have been proven effective for making a diagnosis and determining effective treatment regimens. Disease activity scales are also useful for guiding diagnoses and monitoring patients to assess treatment effectiveness.
OBJECTIVES:
To review the various clinical assessment tools that have been designed to confirm an early diagnosis of RA, measure disease progression, and assist in determining the most optimal treatment regimens for patients with RA.
SUMMARY:
The diagnosis of RA combines the patient history of joint pain and stiffness and the physical examination documentation of symmetric polyarticular joint swelling (synovitis). Laboratory tests including radiographs and blood tests for biomarkers can provide useful information to confirm the diagnosis of RA. Various autoantibodies have been reported in the blood of RA patients, but only the rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP) have been incorporated as diagnostic measures in routine clinical practice. Monitoring and assessment instruments for RA include the Disease Activity Score 28 (DAS28), the Simplified Disease Activity Index (SDAI), and the Clinical Disease Activity Index (CDAI). Although these clinical assessment tools have limitations, health care providers can use them as measures of disease progression and to assist in planning treatment strategies to modify disease activity and improve the quality of life for the patient.
Precipitating and perpetuating factors of rheumatoid arthritis immunopathology: linking the triad of genetic predisposition, environmental risk factors and autoimmunity to disease pathogenesis.
Source
Department of Rheumatology, Guy's Hospital, Great Maze Pond, London, UK. ian.c.scott@btinternet.com
Abstract
Rheumatoid arthritis (RA) is considered to occur when genetic and environmental factors interact to trigger immunopathological changes and consequently an inflammatory arthritis. Over the last few decades, epidemiological and genetic studies have identified a large number of risk factors for RA development, the most prominent of which comprise cigarette smoking and the shared epitope alleles. These risks appear to differ substantially between anti-cyclic citrullinated peptide (ACPA)-positive and ACPA-negative disease. In this article, we will summarise the risk factors for RA development that have currently been identified, outlining the specific gene-environment and gene-gene interactions that may occur to precipitate and perpetuate autoimmunity and RA. We will also focus on how this knowledge of risk factors for RA may be implemented in the future to identify individuals at a high risk of disease development in whom preventative strategies may be undertaken.
Copyright © 2011 Elsevier Ltd. All rights reserved.
The fine specificity of IgM anti-citrullinated protein antibodies (ACPA) is different from that of IgG ACPA.
Source
Department of Rheumatology, Leiden University Medical Center (LUMC), PO Box 9600, NL-2300 RC Leiden, The Netherlands. L.A.Trouw@lumc.nl.
Abstract
ABSTRACT:
INTRODUCTION:
The antigen recognition pattern of immunoglobulin M (IgM) could, when directed against protein antigens, provide an indication of the antigenic moieties triggering new B cells. The half-life of IgM is short and memory B cells against T-cell-dependent protein antigens typically produce IgG and not IgM antibodies. In this study, we analyzed whether a difference exists between the fine specificity of IgM versus IgG anti-citrullinated protein antibodies (ACPAs).
METHODS:
We determined the fine specificity of IgM and IgG ACPAs in 113 ACPA-positive rheumatoid arthritis patients with IgM cyclic citrullinated peptide 2 (CCP2) levels above 100 AU/ml. Fine specificity was assessed by performing ELISA using citrullinated peptides derived from vimentin, fibrinogen-β, fibrinogen-α and α-enolase, as well as citrullinated proteins fibrinogen and myelin basic protein. The arginine counterparts were used as controls.
RESULTS:
Recognition of defined citrullinated antigens by IgM ACPA was confined to samples that also displayed recognition by IgG ACPA. However, the IgM ACPA response displayed a more restricted antigen recognition profile than IgG ACPA (OR = 0.26, P < 0.0001).
CONCLUSION:
Our data show that several defined citrullinated antigens are recognized only by IgG ACPA, whereas others are also recognized by IgM ACPA. These observations suggest that not all citrullinated antigens are able to activate new B cells despite concurrent recognition by IgG ACPA.
Inflammation and autoantibody markers identify rheumatoid arthritis patients with enhanced clinical benefit following rituximab treatment.
Source
Genentech, South San Francisco, California 94080, USA.
Abstract
OBJECTIVE:
Rituximab significantly improves the signs and symptoms of rheumatoid arthritis (RA) and slows the progression of joint damage. The aim of this study was to identify clinical characteristics and biomarkers that identify patients with RA in whom the clinical benefit of rituximab may be enhanced.
METHODS:
The study group comprised 1,008 RA patients from 2 independent randomized placebo-controlled phase III clinical trials (REFLEX [Randomized Evaluation of Long-Term Efficacy of Rituximab in Rheumatoid Arthritis] and SERENE [Study Evaluating Rituximab's Efficacy in Methotrexate Inadequate Responders]). A novel threshold selection method was used to identify baseline candidate biomarkers present in at least 20% of patients that enriched for placebo-corrected American College of Rheumatology 50% improvement (ACR50 response; a high clinical efficacy bar) at week 24 after the first course of rituximab.
RESULTS:
The presence of IgM rheumatoid factor (IgM-RF), IgG-RF, IgA-RF, and IgG anti-cyclic citrullinated peptide(anti-CCP) antibodies together with an elevated C-reactive protein (CRP) level were associated with enhanced placebo-corrected ACR50 response rates in the REFLEX patients with RA who had an inadequate response to anti-tumor necrosis factor therapies. These findings were independently replicated using samples from patients in SERENE who had an inadequate response to disease-modifying antirheumatic drug treatment. The combination of an elevated baseline CRP level together with an elevated level of any RF isotype and/or IgG anti-CCP antibodies was further associated with an enhanced benefit to rituximab.
CONCLUSION:
The presence of any RF isotype and/or IgG anti-CCP autoantibodies together with an elevated CRP level identifies a subgroup of patients with RA in whom the benefit of rituximab treatment may be enhanced. Although the clinical benefit of rituximab was greater in the biomarker-positive population compared with the biomarker-negative population, the clinical benefit of rituximab compared with placebo was also clinically meaningful in the biomarker-negative population.
Copyright © 2011 by the American College of Rheumatology.
Autoantibodies in early rheumatoid arthritis: Brasília cohort: results of a three-year serial analysis.
Source
Serviço de Reumatologia Clínica Médica, Universidade de Brasília. liciamhmota@yahoo.com.br
Abstract
The diagnostic and prognostic value of the serial measurement of antibodies, such as rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), and anti-citrullinated vimentin (anti-Sa) antibodies, has not been defined in early rheumatoid arthritis (ERA).
OBJECTIVES:
To prospectively assess the presence of RF, anti-CCP, and anti-Sa in ERA patients.
PATIENTS AND METHODS:
Forty ERA (less than 12 months) patients of the Brasília cohort were evaluated and followed up for three years. Both clinical and demographic data were recorded, in addition to the results (ELISA) of RF (IgM, IgG, and IgA), anti-CCP (CCP2, CCP3, and CCP3.1), and anti-Sa at the baseline assessment and after 3, 6, 12, 18, 24 and 36 months of follow-up. The results were compared by use of Student t test and paired t test.
RESULTS:
The patients' mean age was 45 years, and 90% of them were female. At the time of diagnosis, RF was identified in 50% of the patients (RF IgA, 42%; RF IgG, 30%; and RF IgM, 50%), anti-CCP in 52.5% (no difference between CCP2, CCP3, and CCP3.1), and anti-Sa in 10%. After three years, no difference was observed in RF and anti-CCP prevalence, but anti-Sa increased to 17.5% (P = 0.001).
CONCLUSION:
Repeated RF and anti-CCP measurement, including different isotypes, during three years of follow-up showed no significant changes. The third generation of anti-CCP assays did not increase the diagnostic value of the second-generation assays.
- PMID:
- 22124591
- [PubMed - in process]
Antibodies to mutated citrullinated vimentin and anti-cyclic citrullinated peptideantibodies in inflammatory bowel disease and related arthritis.
Source
Department of Medicine, Faculty of Medicine, Kuwait University, Safat, Kuwait. aljarallah@hsc.edu.kw.
Abstract
BACKGROUND:
Antibodies that react with citrullinated proteins (anti-mutated citrullinated vimentin [anti-MCV] and second-generation anti-cyclic citrullinated peptide antibodies [anti-CCP2]) are markers for rheumatoid arthritis. Recent studies have demonstrated that these antibodies are present in other arthropathies including the spondyloarthritis, psoriatic arthritis, and juvenile idiopathic arthritis. Arthritis associated with inflammatory bowel disease (IBD) takes various forms, with some shared similarities with classic spondylarthropathies. Our objective was to investigate the role of anti-MCV and anti-CCP2 as potential biomarkers in IBD and related arthritis.
METHODS:
In all, 125 IBD patients (71 males, 54 females) were compared to 81 age- and sex-matched healthy controls. Anti-MCV and Anti-CCP2 IgG were measured using an enzyme linked immunosorbent assay.
RESULTS:
In the 125 IBD patients (mean age 32.6 ± 12.3 years), 44 (35.2%) had ulcerative colitis and 81 (64.8%) had Crohn's disease. Forty-four (35.2%) IBD patients developed arthritic manifestations. Antibody positivity was observed in 24/125 (19.2%) IBD patients and in 18/81 (22.2%) healthy subjects. The proportion of anti-MCV positivity among IBD patients and healthy individuals were similar: 16.8% vs. 16.0%, P = 0.887. Anti-CCP2 positivity among IBD patients and healthy individuals was also comparable: 6.4% vs. 6.2%, P = 0.948. Similarly, the presence of anti-MCV and anti-CCP2 antibodies was not different among IBD patients with and without arthritis. The mean titers of antibodies were low: anti-MCV (29.6 ± 7.5 U/mL) and anti-CCP2 (27.6 ± 4.0 U/mL) in IBD patients with arthritis.
CONCLUSIONS:
Autoantibodies to citrullinated proteins were low in IBD-related arthritis. These findings suggest that these antibodies are not useful biomarkers in IBD to predict who may develop IBD-related arthropathy. (Inflamm Bowel Dis 2011;).
Copyright © 2011 Crohn's & Colitis Foundation of America, Inc.
Detection of autoantibodies to citrullinated BiP in rheumatoid arthritis patients and pro-inflammatory role of citrullinated BiP in collagen-induced arthritis.
Source
Department of Allergy and Rheumatology, Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. kfujio-tky@umin.ac.jp.
Abstract
ABSTRACT:
INTRODUCTION:
Anti-citrullinated protein/peptide antibodies (ACPAs) are highly specific to rheumatoid arthritis (RA) patients and are thought to have a close relationship with the pathogenesis of arthritis. Several proteins, including fibrinogen, vimentin, and alpha-enolase, were reported as ACPA-target antigens, and their importance in RA pathogenesis was widely proposed. We identified citrullinated immunoglobulin binding protein (citBiP) as another ACPA target in RA patients and examined its pro-inflammatory role in arthritis.
METHODS:
We measured the levels of anti-citBiP, anti-BiP, and anti-cyclic citrullinated peptide (CCP) antibodies in the serum of RA patients (n = 100), systemic lupus erythematosus (SLE) patients (n = 60), and healthy controls (n = 30) using ELISA and immunoblotting. Epitope mapping was performed using 27 citBiP-derived peptides. In the mouse study, after DBA/1J mice were immunized with BiP or citBiP, serum titers of ACPAs were measured by ELISA and immunohistochemistry. The development of collagen-induced arthritis (CIA) was observed in BiP- or citBiP-pre-immunized mice.
RESULTS:
The serum levels of anti-BiP and anti-citBiP antibodies were significantly increased in RA patients, although only anti-BiP antibodies were slightly increased in SLE patients. Interestingly, anti-citBiP antibody levels were higher than anti-BiP antibody levels in 72% of RA patients, whereas no significant increase in anti-citBiP antibody levels was detected in SLE patients and healthy controls. The serum levels of anti-CCP antibodies were correlated with those of anti-citBiP antibodies in RA patients (R2 = 0.41). Several citrulline residues of citBiP were determined to be major epitopes of anti-citBiP antibodies, one of which showed cross-reactivity with CCP. Immunization of DBA/1J mice with citBiP induced several kinds of ACPAs, including anti-CCP and anti-citrullinated fibrinogen antibodies. Pre-immunization with citBiP exacerbated CIA, and anti-CCP antibody levels were increased in citBiP-pre-immunized CIA mice.
CONCLUSIONS:
CitBiP is a newly described ACPA target that may play a pro-inflammatory role in arthritis.
Allograft Inflammatory Factor-1 Gene Polymorphisms in Patients with Rheumatoid Arthritis.
Source
1 Department of Pharmacokinetics and Therapeutic Drug Monitoring, Pomeranian Medical University , Szczecin, Poland .
Abstract
Aim: Allograft inflammatory factor-1 (AIF-1) is a cytoplasmic, inflammation-responsive protein. The increased expression of AIF-1 in synovial tissues and fluid from rheumatoid arthritis (RA) patients has been detected. Several single-nucleotide polymorphisms have been identified in the AIF1 gene, among them three leading to changes in amino acid sequence. The aim of this study was to examine the association between AIF1 rs2259571:A>C, rs2736182:G>A, and rs13195276:C>T polymorphisms and RA. We examined 380 patients with RA and 376 control subjects. Results: There were no statistically significant differences in distribution of rs2736182 and rs2259571 genotypes and alleles between RA patients and control group. Moreover, there were no significant associations with the age of disease diagnosis, rheumatoid factor, extra-articular manifestation, and anti-cyclic citrullinated peptide (CCP) antibodies, whereas the active form of RA (patients with disease activity score (DAS28)>2.4) was more frequently diagnosed in patients with rs2259571 CC genotypes compared with patients with AA genotype (p=0.007, odds ratio=2.30, 95% confidence interval=1.25-4.25). Conclusion: Our results suggest that the AIF1 rs2259571 CC genotype is associated with the active form of RA.
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