Autoimmunity to citrullinated type II collagen in rheumatoid arthritis

Abstract

The production of autoantibodies to citrullinated type II collagen and the citrullination of type II collagen were analyzed in rheumatoid arthritis. Autoantibodies to citrullinated type II collagen were detected in 78.5% of serum samples from 130 rheumatoid arthritis patients. Autoantibodies to native noncitrullinated type II collagen were detected in 14.6% of serum samples, all of which were positive for anti-citrullinated type II collagen antibodies. Serum samples were also positive for anti-citrullinated type II collagen antibodies in 1 of 31 systemic lupus erythematosus patients and 2 of 55 patients with osteoarthritis of the knee. In contrast, sera samples from 24 systemic sclerosis patients, 21 dermatomyositis/polymyositis patients, 21 ankylosing spondylitis patients, and 18 psoriatic arthritis patients were all negative for anti-citrullinated type II collagen antibodies. Anti-citrullinated type II collagen antibodies and fragments of citrullinated type II collagen were found in the synovial fluid obtained from affected knee joints of 15 rheumatoid arthritis patients. Moreover, anti-citrullinated type II collagen antibodies were isolated from the synovium of affected knee joints in 8 rheumatoid arthritis patients using antigen/antibody immunocomplex dissociation buffer but not by using standard buffers. These findings indicate that autoantibodies that react with citrullinated type II collagen are specifically produced and that immunocomplexes composed of fragments of citrullinated type II collagen and autoantibodies are deposited in the inflamed articular synovium in rheumatoid arthritis patients. Assaying for the presence of anti-citrullinated type II collagen antibodies may therefore be useful for diagnosing rheumatoid arthritis, and the deposition of these immunocomplexes in the articular synovium may be involved in pathogenesis.     

Autoimmunity to citrullinated type II collagen in rheumatoid arthritis

The production of autoantibodies to citrullinated type II collagen and the citrullination of type II collagen were analyzed in rheumatoid arthritis. Autoantibodies to citrullinated type II collagen were detected in 78.5% of serum samples from 130 rheumatoid arthritis patients. Autoantibodies to native noncitrullinated type II collagen were detected in 14.6% of serum samples, all of which were positive for anti-citrullinated type II collagen antibodies. Serum samples were also positive for anti-citrullinated type II collagen antibodies in 1 of 31 systemic lupus erythematosus patients and 2 of 55 patients with osteoarthritis of the knee. In contrast, sera samples from 24 systemic sclerosis patients, 21 dermatomyositis/polymyositis patients, 21 ankylosing spondylitis patients, and 18 psoriatic arthritis patients were all negative for anti-citrullinated type II collagen antibodies. Anti-citrullinated type II collagen antibodies and fragments of citrullinated type II collagen were found in the synovial fluid obtained from affected knee joints of 15 rheumatoid arthritis patients. Moreover, anti-citrullinated type II collagen antibodies were isolated from the synovium of affected knee joints in 8 rheumatoid arthritis patients using antigen/antibody immunocomplex dissociation buffer but not by using standard buffers. These findings indicate that autoantibodies that react with citrullinated type II collagen are specifically produced and that immunocomplexes composed of fragments of citrullinated type II collagen and autoantibodies are deposited in the inflamed articular synovium in rheumatoid arthritis patients. Assaying for the presence of anti-citrullinated type II collagen antibodies may therefore be useful for diagnosing rheumatoid arthritis, and the deposition of these immunocomplexes in the articular synovium may be involved in pathogenesis.     

Activity of rheumatoid arthritis and levels of collagen antibodies: a prospective study

Summary Thirty-seven patients with classical or definite rheumatoid arthritis (RA) were studied prospectively over a period of 12 months to assess whether there was a relationship between disease activity and raised levels of antibodies to native or denatured type II collagen. Nineteen patients had inactive RA according to ARA criteria for disease remission and 18 had active RA throughout the study. At the beginning of the study the levels of collagen antibodies were comparable in each group. After 1 year, antibodies to denatured type II collagen in patients with inactive RA had declined to significantly lower levels whereas in patients with active RA the levels of antibodies fluctuated during the period of study and were not significantly different at the end. There was no relationship between levels of antibodies to type II collagen and any specific index of disease activity, severity of X-ray changes in the hands and feet, or progression over 1 year in X-ray changes. The finding of a decline in levels of antibodies to denatured type II collagen in inactive RA suggests that the anticollagen response is an integral component of the rheumatoid process and could have a primary or secondary role in pathogenesis.     

The role of collagen antibodies in mediating arthritis

This review examines evidence that rheumatoid arthritis (RA) depends on autoimmunity to articular collagen, and mechanisms whereby autoantibodies to type II collagen contribute to disease development. Three major autoantigenic reactants have been identified in RA; the corresponding autoantibodies are rheumatoid factor (RF), antibodies to citrullinated peptide antigens (ACPA), citrullinated peptides (anti-CCP), and anti-type II collagen (anti-CII). Both RF and ACPA are well-validated and predictive markers of severe erosive RA, but cannot be linked to pathogenesis. By contrast, in various animal species immunized with CII there occurs an erosive inflammatory arthritis resembling that seen in human RA, together with antibodies to CII with an epitope specificity similar to that in RA. We discuss the well-known role of immune complexes in the induction of inflammation within the joint, and present recent data showing, additionally, that antibodies to CII cause direct damage to cartilage in vitro. The close resemblances between human RA and collagen-induced arthritis in animals suggest that autoimmunity, and particularly autoantibodies to CII, are important for both the initiation and perpetuation of RA in a dual manner: as contributors to the inflammation associated with immune complex deposition, and as agents with direct degradative effects on cartilage integrity and its repair.     

Organ-specific autoantibodies in non-organ-specific autoimmune diseases with special reference to rheumatoid arthritis

Summary Sera from 367 patients with rheumatoid arthritis (RA) and from 102 patients with other non-organspecific (NOS) autoimmune diseases were examined for the presence of organ-specific (OS) autoantibodies. The incidence of these OS autoantibodies was not increased in patients with NOS autoimmune diseases with the exception of thyroglobulin antibodies, which were significantly more frequent in RA (P<0.001) and in Sjögren's syndrome (P<0.05) patients than in normal controls. Investigation of 169 patients with OS autoimmune diseases did not reveal an increased prevalence of NOS autoantibodies. In RA patients, OS autoantibodies correlated with NOS autoantibodies (P<0.04) and with HLA-DR3 antigen (P<0.01).     

Epitope specificity of antibodies to type II collagen in rheumatoid arthritis and systemic lupus erythematosus

Summary Antibodies to human type II collagen were examined in the sera of 105 patients with rheumatoid arthritis (RA), 44 patients with systemic lupus erythematosus (SLE) and 11 patients who fulfilled the criteria of both diseases (RA-SLE overlap), using a solid-phase radioimmunoassay (RIA). The frequencies of antibodies to native and denatured human type II collagen were 20% and 27% in RA, 14% and 16% in SLE, and 45% and 36% in RA-SLE overlap. The specificity of the antibodies was further examined by inhibition with native and denatured type II collagen, by immunoblotting on native and denatured type II collagen, and by immunoblotting on cyanogen-bromide derived polypeptides of type II collagen. We could not identify any disease-specific patterns of reactivity. Thus, in the three disease groups the antibody response was polyclonal; there were antibody populations that reacted with native and/or denatured collagen, and epitopes could be assigned to at least three CB peptides, CB10.5, CB11 and CB8.     

Anti-CCP antibodies in rheumatoid arthritis and psoriatic arthritis

Our aim is to assess the prevalence and associated clinical features of anti-CCP (cyclic citrullinated peptide) antibodies for RF (rheumatoid factor)-positive and RF-negative rheumatoid arthritis (RA) and psoriatic arthritis (PsA). In a prospective, cross-sectional, multi-centre study, we determined the titres of anti-CCP antibodies in 208 RA patients (129 RF-positive, 79 RF-negative), 56 PsA patients and 39 healthy controls (HC). Clinical parameters including disease activity (disease activity score 28-DAS28), physical disability (health assessment questionnaire-HAQ), functional capacity (functional class) and radiological erosions were investigated in patients with RA. In PsA patients, clinical and radiological features were determined. Anti-CCP2 antibodies were measured using a second-generation anti-CCP enzyme-linked immunosorbent assay (Euro-Diagnostica, Netherlands). One-hundred four of 129 RF-positive RA (81%), 16 of 79 RF-negative RA (20%), seven of 56 PsA patients (12.5%) and none of the HC had anti-CCP antibodies. RA patients with anti-CCP antibodies had significantly higher disease activity, greater loss of function and more frequent erosive disease than anti-CCP antibody-negative group. In subgroup analysis, anti-CCP antibodies in RF-negative patients were also associated with erosive disease. All PsA patients with anti-CCP antibodies had symmetric arthritis with higher number of swollen joints. The prevalence of anti-CCP antibodies in RF-positive RA patients was significantly higher than in RF-negative RA and PsA patients. Anti-CCP antibodies were also associated with erosive disease in RF-negative RA patients. Both anti-CCP and RF tests were negative in 30% of the patients. Anti-CCP positivity was a frequent finding in PsA and associated with symmetrical polyarthritis.     

Type II collagen oral tolerance; mechanism and role in collagen-induced arthritis and rheumatoid arthritis

Abstract

Oral tolerance means a diminished immune response to previously fed antigens. Repeated oral administrations of type II collagen (CII) induce oral tolerance and inhibit the development of collagen-induced arthritis (CIA). Dendritic cells (DCs) in the gut-associated lymphoid tissue (GALT) take up the CII and then present it to T cells to generate regulatory T cells (Tregs), which induce systemic immune tolerance to CII. Inhibitory cytokines, such as transforming growth factor (TGF)-β and interleukin (IL)-10, and several immune regulatory molecules, including indoleamine 2,3-dioxygenase (IDO) and retinoic acid, play an important role in Treg generation. Each DC subset may play different roles, and CD11c+CD11b+DCs and IDO+DCs are important in the generation of antigen-inducible Tregs in CII oral tolerance. Upon stimulation with the antigen involved in its generation, Treg is activated and regulates the immune response through inhibitory cytokine production, cell-to-cell contact-dependent mechanisms, DC modification, and bystander suppression. The DCs and Tregs are deeply involved in oral tolerance through reciprocal interactions. Several clinical trials have been conducted in RA patients to examine the efficacy of CII oral tolerance. An understanding the mechanism of oral tolerance to CII would give clinicians new insights into the development of natural immune tolerance and new therapeutic approaches for the treatment of autoimmune diseases.     

Type II collagen serology: a guide to clinical responsiveness to oral tolerance?

A double-blind placebo-controlled randomized trial of oral collagen type II (CII) treatment in rheumatoid arthritis was completed in Berlin. Anti-CII antibody titres were measured before and after the treatment. They showed that: (1) the titre prior to treatment did not identify a responder subgroup, (2) the treatment reduced CII antibody titres, but only in those patients making a clinical response and (3) administration of 10 mg CII per day reduced the titre in these subsets more effectively than 1 mg per day. Although the data are limited, they suggest that a titre drop may be useful for identifying those patients who respond to this form of treatment and that the drop may be a valid parameter for detecting the impact of the treatment on the immune system.     

Serum sclerostin levels in rheumatoid arthritis

BackgroundRheumatoid arthritis (RA) is an autoimmune disease that may lead to joint destruction and disability. Wingless (Wnt) pathway is involved in bone formation and has been found to contribute to bone loss in RA. Sclerostin is a key molecule in Wnt pathway.ObjectiveTo study the serum levels of sclerostin in rheumatoid arthritis patients and to study its association with radiological changes.MethodsForty-five patients with RA and 45 age and gender matched healthy controls were enrolled. Serum sclerostin was measured by ELISA. Modified version of Larsen score was used to assess joint damage in radiographs and Magnetic resonance imaging (MRI) of wrist and hand was assessed for synovitis and bone erosion.ResultsSerum sclerostin levels were higher in patients with RA as compared to controls (p < 0.01). Serum sclerostin levels correlated with ESR (r = 0.655), CRP(r = 0.623), modified DAS 28 (r = 0.711), MRI synovitis (r = 0.802) and MRI erosion score (r = 0.832).ConclusionIncreased serum levels of sclerostin may play a role in joint damage and bone erosion in RA.     

Antineutrophil cytoplasmic antibodies (ANCA) in rheumatoid arthritis: a prospective study

To investigate a possible relationship between the presence of antineutrophil cytoplasmic antibodies (ANCA), rheumatoid factor (RF), antinuclear antibodies (ANA), complement, disease activity and disease severity, 111 clinically well-documented RA patients were studied prospectively for ANCA, RF, ANA, C-reactive protein (CRP), total haemolytic complement (CH50) and complement split product C3d. Disease activity and severity were also assessed clinically, as well as anamnestically, using the Hannover Activity of Daily Living Questionnaire, the functional Steinbrocker grades, and numeric and verbal rating scales. At a serum dilution of 1:50, 20% of the 111 sera showed predominantly an atypical perinuclear staining pattern. There was no correlation between ANCA positivity and serological markers, disease activity and discase severity. Regarding previous therapies with disease-modifying antirheumatic drugs, ANCA⁺ patients took sulphasalazine significantly more often than ANCA^- patients.     

Clinical relevance of antikeratin antibodies in rheumatoid arthritis

Summary Antikeratin antibodies (AKA) were found in 38 out of 96 patients with rheumatoid arthritis (RA); they appeared to be quite characteristic to this disease. There was a very low incidence of AKA positivity in the control groups, i.e., 1 out of 62 healthy subjects and 4 out of 158 other patients. With regard to the sensitivity of the test as a diagnostic tool, AKA was found to be weaker than the rheumatoid factor (RF) and the antiperinuclear factor (APF), whereas the specificity was much better than APF and RF. A clear correlation was shown between the titres of AKA and APF (p<0.001) and also between AKA levels and inflammation (p<0.02).     

Paraoxonase and arylesterase levels in rheumatoid arthritis

It was reported that lipid peroxidation (LPO) products increase in rheumatoid arthritis (RA) patients and increased LPO products reduce many antioxidants. Lipid hydroperoxides (LOOHs) are byproduct of LPO. Paraoxonase (PON), arylesterase (ARE), free sulfhydryl (SH) groups, and ceruloplasmin (CP) are enzymes or proteins with antioxidant characteristics. This study aims to determine the levels of LOOHs and SH, and the activities of PON1, ARE, and CP in RA patients. The study included 47 active RA cases and 23 healthy volunteers. The levels of LOOHs and SH, and the activities of PON1, ARE, and CP were determined using appropriate methods. Student’s t test and Spearman’s correlation analysis methods were employed in the statistical evaluation. The level of LOOHs was found to be higher (p<0.001), while the level of SH and the activities of PON1, ARE, and CP were found to be lower (p<0.001, <0.001, <0.01, and <0.01, respectively) in the RA patient group when compared with the control group. There was a negative correlation between the level of LOOHs and the activity of PON1 in the patient group (r=−0.420 and p<0.01). The results of our study indicate increased oxidant and decreased antioxidant presence in RA patients. PON1 and ARE are known to have antiatherosclerotic effects in addition to their antioxidant characteristics. As the decrease in these antioxidants, resulting from increased oxidative stress in RA patients, development of atherosclerosis besides tissue injury seems inevitable.     

Anti-cyclic citrullinated peptide-2 (CCP2) autoantibodies and extra-articular manifestations in Greek patients with rheumatoid arthritis

The objective of our study was to establish whether there is an association between rheumatoid arthritis with extra-articular manifestations (exRA) and anti-cyclic citrullinated peptide 2 (anti-CCP2) antibodies in Greeks. A retrospective study of 220 Greek patients with RA, 95 with exRA and 125 without extra-articular manifestations (cRA). Serum anti-CCP2 antibodies and IgM rheumatoid factor (RF) were measured. CCP2(+) were 65.3% of exRA and 58.4% of cRA patients. RF(+) were 69.5% of exRA and 60.0% of cRA patients. Among exRA patients, 37.9% had high serum anti-CCP2 antibody levels (>100 IU/ml) compared to 21.6% cRA patients (p = 0.008). Serositis and pulmonary fibrosis were found to be associated with high levels of anti-CCP2 antibodies (52.9 vs 26.6%, p = 0.02 and 63.6 vs 26.8%, p = 0.008, respectively). Serum RF levels were 265.0 ± 52.0 IU/ml (mean ± SEM) in exRA and 205.1 ± 40.6 (mean ± SEM) in cRA (NS). High serum RF levels (>268 IU/ml) were more likely to have sicca syndrome. In Greek patients with rheumatoid arthritis (RA), high serum anti-CCP2 antibodies are associated with serositis and pulmonary fibrosis. Therefore, anti-CCP2 antibodies have prognostic significance in patients with RA.     

HLA-DR antigens in rheumatoid arthritis

Summary In a Swiss multicenter study, a significant increase of HLA-DR4 was found in patients with rheumatoid arthritis when compared with normal controls (P<0.01). This increase was limited to patients with rheumatoid factors; it was strongest in patients with high titers. Similarly, the frequency of HLA-DR4 was higher in patients with larger amounts of circulating immune complexes when compared with patients with low amounts. No correlation with the presence of antinuclear antibodies was found. HLA-DR1 was more frequent in patients with rheumatoid arthritis than in controls (N.S.). This was due to an increase of HLA-DR1 in patients without rheumatoid factors (P<0.05), low amounts of circulating immune complexes (N.S.) and without antinuclear antibodies (P<0.05). Participants: T. L. Vischer (coordination and correspondence), Division of Rheumatology, Hôpital Cantonal, CH-1211 Genève 4;M. Jeannet and V. von Fliedner (HLA-antigen determinations), Transplantation Immunology Unit, Division of Immunology; A. Cruchaud (antinuclear antibodies), Division of Immunology; A. Micheli (rheumatoid factors), Division of Rheumatology; N. Carpentier and P.H. Lambert (C1q-binding tests), WHO Immunology Research and Training Laboratory; all from the Department of Medicine, University of Geneva. P. Vuagnat (statistics), Department of Mathematics, University of Geneva Centers: Basel: U. Steiger (Medizinische Universitätsklinik); Bern: N. Gerber (Universitäts-Rheumaklinik); Fribourg: I. Radi (Hôpital Cantonal); Genève: T. L. Vischer (Hôpital Cantonal); La Chaux-de-Fonds: H. Ott (Service de Physiatrie, Hôpital de la Chaux-de-Fonds); Lausanne: T. Bitter and J. C. Gerster (Service de Physiatrie, CHUV);Leukerbad: N. Fellmann (Rheumaklinik); Valens: B. Stojan (Klinik Valens); Winterthur: H. Hunziker (Kantonsspital); Zürich: M. Baumgartner (Klinik Wilhelm Schulthess), D. Gross and M. Lamoth (Triemlispital), K. Fehr and M. Felder (Universitäts-Rheumaklinik); Zurzach: W. Kunz (Rheumaklinik)     

Anti-IL-8 autoantibodies and complexes in rheumatoid arthritis: polyclonal activation in chronic synovial tissue inflammation

The chemokine interleukin-8 (IL-8) is frequently associated with inflammatory diseases, and autoantibodies against IL-8 are present in the periphery at elevated levels in such conditions as rheumatoid arthritis (RA). Circulating free anti-IL-8 IgG autoantibodies correlate with inflammatory parameters and disease severity in RA. In this study, correlations were sought between these disease parameters and other antibody subclasses. We assayed IgM, IgA and IgG anti-IL-8 antibodies and IL-8 immunoglobulin immune complexes in the serum of 29 healthy controls and 56 patients with defined RA, and compared the results with clinical and humoral disease parameters. IgG and IgM antibodies directed against IL-8 were present in all samples. In the disease groups, all isotypes of free anti-IL-8 antibodies correlated with increasing humoral disease parameters like CRP and CIC and their related anti-IL-8 immune complexes. Samples which contained high titers of anti-IL-8 antibody subclasses and complexes were RF subclass-positive, while IgM RF-negative sera showed low levels of anti-IL-8 and complexes. Detectable levels of IgG and IgA RF were found in all sera. Patients with extra-articular organ manifestation showed significantly increased free IgA and IgA/IL-8 complexes, with no correlation to the IgA RF titer or IgA hypergamma-globulinemia. The highest titers were seen in two RA cases with vasculitis and in one patient with colitis. Polyclonal activation of the humoral antibody system, which normally precedes the resolution of an inflammatory response, can itself lead to secondary stimulation of inflammatory processes via immune complex formation. In the immune pathology of RA, it degenerates into a persistent chronic inflammation accompanied by progressive joint destruction. The presence of elevated IgA subclass anti-IL-8 autoantibodies in RA patients with extra-articular manifestations suggests these autoantibodies as a clinically useful marker of disease severity and extra-articular manifestations. Received: 10 June 1998 / Accepted: 5 October 1998     

Serum IgG4 anti-Fab antibodies in rheumatoid arthritis are constitutively expressed

Summary IgG4 comprises a significant proportion of the total anti-Fab antibody (aFABA) response in many but not all patients with rheumatoid arthritis (RA). Analyses of the dynamics of IgG aFABA subclass expression in 11 RA patients for periods of up to 11 months demonstrated that IgG4 aFABA was restricted to 6 of the 11 RA patients' sera initially studied and comprised approximately 25% (or more) of the total IgG aFABA response. Quantities of IgG4 aFABA in subsequent, serially obtained serum samples from these patients remained stable throughout the study period, whereas the remaining RA patients whose initial sera possessed small quantities of serum IgG4 aFABA failed to generate any augmented IgG4 aFABA response during the study. Elevated expression of IgG4 aFABA did not appear to be a consequence of a generalized polyclonal gammopathy or a generalized increase in autoantibody expression, though patients with higher total IgG4 serum levels expressed significantly greater quantities of IgG4 aFABA. These results indicate that the differential expression of IgG4 aFABA among RA patients reflects constitutive production within a subset of RA patients in whom IgG4 appears to comprise a significant proportion of the total IgG aFABA response.     

Antibodies to type II collagen and their association with HLA DR1 alleles in Japanese patients with rheumatoid arthritis

 To investigate whether immunological responses to type II collagen (CII) play an important role in the pathogenesis of rheumatoid arthritis (RA), the presence of anti-CII antibodies was examined by enzyme immunoassay in 130 Japanese patients with RA, 10 systemic lupus erythematosus (SLE) patients, and 30 healthy subjects. In addition, the HLA-DRB1 genes of 40 RA patients were determined, and their association with positive findings of anti-CII antibodies was examined. A significantly high frequency of positive findings of anti-CII antibodies was detected in sera from RA patients (19%, P < 0.05) in comparison with that in sera from healthy subjects (3%). High frequencies of DRB1^*0405 and 0101 alleles were observed in the 40 RA patients examined (40.0% and 30.0%, respectively). Patients with DRB1^*0101 had a significantly higher rate of positive findings of anti-CII antibodies than those without DRB1^*0101 (66.7% and 28.6%, respectively, P < 0.05). No such association was observed for DRB1^*0405. From these findings, we suggest that immunological responses to CII may play an important role in the development of arthritis in some RA patients. Received: April 9, 2002 / Accepted: June 13, 2002 Acknowledgment We thank Dr. T. Sakamaki, Division of Clinical Research, Sakura National Hospital, Japan, for technical assistance and useful advices on HLA typing. Correspondence to:T. Sumida     

Anti-mutated citrullinated vimentin antibodies in rheumatoid arthritis patients: Relation to disease activity and manifestations

Aim of the workTo evaluate the frequency of anti-mutated citrullinated vimentin antibodies (MCV) in rheumatoid arthritis (RA) patients and to correlate it with disease activity and various disease manifestations.Patients and methodsFifty RA patients were recruited from the rheumatology and rehabilitation outpatient clinic, Kasr Al-Aini. Thirty healthy subjects served as controls. All patients were subjected to full history taking and clinical examination including general and joint assessment. Disease activity was assessed by the disease activity score (DAS-28) and functional ability was evaluated by the Modified Health Assessment Questionnaire (MHAQ). Anti-MCV and anti-cyclic citrullinated peptide (anti-CCP) were assayed by ELISA in patients and controls. Plain X-ray was performed on the hands and wrists and Sharp score was used to assess the erosions and joint space narrowing.ResultsA highly significant elevation of serum anti-MCV in RA patients (135.82 ± 126.81 U/ml) compared to controls (13.63 ± 8.48 U/ml) (p < 0.0001) was found. Anti-MCV showed a sensitivity of 84% and specificity of 80%. There was a significant difference between anti-MCV positive and anti-MCV negative patients as regards MHAQ (1.07 ± 0.74 vs. 0.52 ± 0.37, p = 0.005) and Sharp erosion score (12.93 ± 23.55 vs. 4 ± 2.2, p = 0.02). Anti-CCP showed a sensitivity of 70% and specificity of 100%. There was a significant difference between the specificities of both markers (p = 0.03). There was no significant correlation of the anti-MCV with the clinical manifestations, MHAQ, DAS28 or Sharp score. Anti-MCV significantly correlated with anti-CCP (p < 0.0001).ConclusionAnti-MCV test has a significant association with the functional disability and radiologic progression in RA and could be considered as a promising biomarker.     

Rare copresent rheumatoid arthritis and gout: comparison with pure rheumatoid arthritis and a literature review

Copresent rheumatoid arthritis (RA) and gout is seldom reported. This study summarizes the findings of eight cases of copresent RA and gout and compares them with 31 pure RA cases. Additional reported cases were retrieved from the current literature by Medline search. Patients with copresent RA and gout were older (p = 0.014) and predominantly male (p < 0.01). Synovial fluid, positive for urate crystals, was aspirated most frequently from the knee (five out of eight), followed by the first metatarsophalangeal joint (three out of eight). Serum creatinine and urate levels in the copresent group were significantly higher (p < 0.01, both), and serum hemoglobin was lower (p = 0.04) than those with pure RA. Copresent subjects had much lower percentage of positive rheumatoid factor (RF) tests than patients with pure RA (37.5 vs 80.6%). Only one copresent subject had both RF and anti-cyclic citrullinated peptide antibody. Of copresent subjects, 75% had gouty arthritis before diagnosis of RA, which is consistent with earlier reports. Seven copresent subjects had gout attacks under disease-modifying antirheumatic drug use. This study revealed that polyarthritis negative for RF in a previously gouty patient may be RA and vice versa. This combination occurs more frequently in males. Moreover, anti-CCP antibody examination is not helpful for this diagnosis. Therefore, physicians must obtain synovial fluid for analysis in joints with intense swelling, especially in old RA subjects with renal insufficiency or involvement of lower extremities. Conversely, RA must be considered in gouty patients with polyarticular involvement.