Functional disability to evaluate the risk of arthritis in First-degree relatives of Rheumatoid Arthritis patients

Objective The events that occur prior to the onset of rheumatoid arthritis (RA) continue to be delineated. We examined the relationship between self-reported joint symptoms, functional disability, and anticitrullinated protein antibody (ACPA) status in a cohort of first-degree relatives (FDR) of RA patients who are at risk of future disease development. Methods We studied a cohort of 607 FDR of First Nations (FN) RA patients who are at increased risk for future RA development, and analyzed data collected at their enrollment study visit. In parallel, we analyzed data from 279 FN People with no family history of RA. A subset of FDR developed inflammatory arthritis and we analyzed longitudinal data in this group. Results The prevalence of joint symptoms and functional disability was higher in FDR compared to non- FDR (all p<0.001). Difficulty walking (37.3% vs 18.0%) and mHAQ were higher in ACPA positive FDR compared to ACPA negative FDR, and mHAQ was independently associated with ACPA seropositivity (OR: 2.79, 1.56-5.00). Longitudinally, in individuals who developed ACPA+ RA, ACPA level and mHAQ score were significantly associated (R = 0.43, p< 0.001) in the preclinical period. Conclusion Compared to population-based controls, FDR have a high burden of joint symptoms and functional disability. Functional disability was most closely associated with ACPA seropositivity in the FDR, suggesting a direct role for ACPA outside of the context of clinically detectable synovitis. mHAQ appears to be particularly valuable in the assessment of individuals at risk for future RA development.

AB0668 THE ONSET OF RHEUMATOID ARTHRITIS AFTER COVID-19 – COINCIDENCE OR CONNECTED?

Background:COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been suggested to induce autoimmune phenomena. Multiple studies have reported the presence of autoantibodies in patients with COVID-19. Also the presence of anti-citrullinated protein antibodies (ACPA) and flaring of rheumatoid arthritis (RA) after COVID-19 has been described.[1, 2] Furthermore, in rheumatology clinics patients may present with polyarthritis compatible with RA shortly after SARS-CoV-2 infection. However, it is unclear how often ACPA occur after COVID-19 and whether preceding COVID-19 impacts on disease presentation of RA and phenotype of the ACPA response.Objectives:This study aims to determine the seroprevalence of ACPA after COVID-19 and to investigate the association between preceding COVID-19 infection and disease presentation of new-onset RA, including clinical phenotype and autoantibody response.Methods:To estimate the prevalence of ACPA after COVID-19 we measured ACPA IgG in samples from 61 patients visiting the specialized post-COVID outpatient clinic of the LUMC 5 weeks after hospitalization, using routine tests or in-house ELISA. Furthermore, we identified 5 patients presenting with polyarthritis compatible with RA after SARS-CoV-2 infection. To study the impact of COVID-19 on disease presentation, we examined clinical phenotype, autoantibody isotype positivity and ACPA IgG variable domain (V-domain) glycosylation of these patients and compared these features to regular RA patients. Autoantibody isotypes, including rheumatoid factor (RF) IgM/IgA, anti-CCP2 IgG/ IgM/IgA and anti-carbamylated protein antibodies (anti-CarP) IgG were measured using in-house ELISA’s. The percentage of V-domain glycosylation of purified ACPA IgG was measured with UHPLC.Results:None of the 61 post-COVID patients tested positive for ACPA 5 weeks after hospitalization, except two patients previously diagnosed with ACPA-positive RA. Thus, we could not observe an increase in ACPA-positivity shortly after COVID-19. Of the 5 patients who developed polyarthritis compatible with RA after SARS-CoV-2 infection, the average age was 63.6 years and 2/5 were female. 4/5 patients had been hospitalized due to severe COVID-19. On average, joint complaints started 6.6 weeks after infection, although two patients reported symptoms before infection. 4/5 patients fulfilled the ACR 2010 criteria for RA. Three patients (patient 1, 4, 5) were phenotypically very similar to regular new-onset RA patients. Patient 3 had a history of seronegative RA and had been in DMARD-free remission for 5 years. She flared 6 weeks after SARS-CoV-2 infection. Patient 2 had a remarkably different presentation. He was admitted with a suspected septic polyarthritis or pneumonia with reactive polyarthritis 6 weeks after COVID-19. ACPA level was low positive. The patient died unexpectedly after two days and autopsy revealed dilating myocarditis of unclear underlying cause. No causative pathogen could be identified.Previous studies have shown that RA-patients are most often either seronegative or triple-positive for RF, ACPA and anti-CarP antibodies. Autoantibody measurements on sera of the post-COVID polyarthritis patients revealed a similar pattern (Figure 1A) with two patients being completely seronegative, and three patients positive for a range of autoantibodies. In all post-COVID samples, the percentage of ACPA IgG V-domain glycosylation was significantly increased compared to total IgG (Figure 1B), similar as in regular RA.Conclusion:In conclusion, we found that the seroprevalence of ACPA is not increased post-COVID and that most patients presenting with polyarthritis after COVID-19 resemble regular RA patients, both regarding clinical phenotype and autoantibody characteristics. Although sample size and follow-up was limited, it appears that RA post-COVID may be coincidence rather than connected.References:[1]Vlachoyiannopoulos et al. Ann Rheum Dis, 2020.[2]Perrot et al. The Lancet Rheumatology, 2020.Disclosure of Interests:None declared.

Knee alterations in rheumatoid arthritis: Comparison of US and MRI

Objective This study was designed to compare the diagnostic efficacy of ultrasonography (US) and magnetic resonance imaging (MRI) in detecting changes in the knee of patients with rheumatoid arthritis (RA) and discover the possible association between the serological index and bone erosion detected by US. Patients and methods In this retrospective study, the US images and MRI findings of the knee in patients with RA from December 2017 to January 2020 were evaluated. Diagnostic outcomes were compared. The rheumatoid factor, C-reactive protein, erythrocyte sedimentation rate, and anti-cyclic citrullinated peptide antibody (ACPA) levels of the patients were recorded. The relation between laboratory index and US findings was analyzed by multivariable logistic regression. Results US showed remarkable accuracy, sensitivity, and specificity in diagnosing synovitis, bone erosion, and soft tissue swelling. In terms of reliability, the agreement between US and MRI was moderate to almost perfect. Meanwhile, a positive association between ACPA level and bone erosion was observed in patients with RA. Conclusions US may have a role as the initial imaging modality in patients with RA. Patients with higher ACPA levels may need more active treatment because they are more likely to have bone erosion detected by US.

Peptidyl Arginine Deiminase Type 4 Gene Promoter Hypo-Methylation in Rheumatoid Arthritis

Protein citrullination is carried out by peptidylarginine deiminase type 4 (PAD4) enzyme. As a consequence of this process, post-translationally modified proteins are formed that become antigens for anti-citrullinated protein antibodies (ACPA). The study aimed at identifying whether the PADI4 gene is subject to epigenetic regulation through methylation of its promoter region, whether the degree of methylation differs in healthy individuals vs. rheumatoid arthritis (RA) patients and changes in correlation with ACPA, anti-PAD4 and disease activity. A total of 125 RA patients and 30 healthy controls were enrolled. Quantitative real-time methylation-specific PCR was used to analyze the methylation status. ACPA and anti-PAD4 antibodies were determined in serum by enzyme-linked immunosorbent immunoassay. The differences were observed in the degree of PADI4 gene promoter methylation between RA patients and HC, along with an upward trend for the methylation in RA, which was inversely proportional to the disease activity. A weak or modest negative correlation between the degree of PADI4 gene methylation and anti-PAD4, disease activity score (DAS28) and ACPA level has been found. The elevated methylation is associated with lower disease activity, lower levels of ACPA and aPAD4. The methylation degree in this area is growing up during effective treatment and might play a role in the RA pathophysiology and therefore could be a future therapeutic target.

AB0227 BASELINE SYNOVIAL LEVELS OF MATRIX METALLOPROTEINASES-9 IN EARLY RHEUMATOID ARTHRITIS-THE ASSOCIATION WITH INITIAL RADIOGRAPHIC CHANGES

Background:Matrics metalloproteinases (MMPs) are the key enzymes responsible for the joint destruction in rheumatoid arthritis (RA).Objectives:The aim of this study was to examine the association of baseline levels of metalloproteinases-9 (MMP-9) in serum and synovial fluid (SF) with structural damage of hand and feet joints in patients with early RA and also with imunoserological markers of the disease.Methods:The study enrolled 134 subjects with knee synovitis: 72 patients with early DMARD-naïve RA (symptom duration ≤12 months) and 62 patients with osteoarthritis (OA), as control group. Synovial fluid was obtained by an arthrocentesis of the knee joint. Joint damage was estimated by hands, knee and feet radiography. With regard to the presence of destructive joint changes on initial x-ray, RA patients were classified as erosive and nonerosive form of disease. ELISA assay was used for the detection of MMP–9 activity in serum and SF as well for the imunoserology tests: rheumatoid factor RF (IgG) and anti-CCP antibody (ACPA).Results:MMP–9 activity in serum and SF of RA patients was significantly higher compared to its activity in serum and SF of control group (p<0.01 and p <0.001 respectly) (table 1).Table 1.MMP–9 activity (ng/ml) in serum and SF of RA and control group patientsGroupMMP-9 activity in BP(ng/ml); mean±SDMMP-9 activity in SF(ng/ml)mean±SDRA(n=72)18.28±7.54**15.07±13.24***Controls -OA(n=62)13.58±3.070.65±0.41RA – rheumatoid arthritis; SD – standard deviation; n – number of subjects; ** – p<0.01, *** p<0,001We did not establish a significant correlation between the activity of MMP 9 in serum and SF in the RA and control groups (Spearman’s rank correlation coefficient in RA was 0,02 and 0,06 in control group).Most of the subjects from RA group (52–72.22%) had verified radiographic erosive changes in joints. Nonerosive arthritis was present in remaning 20 (27.78%) of RA patients. No differences were obtained according to the sex, age or disease duration between erosive and nonerosive RA patients.Table 2 represents MMP–9 activity in serum and SF of patients with erosive and nonerosive RA. The values of MMP–9 activity measured in serum were higher in nonerosive compared to erosive RA (20.35±10.30 vs. 17.46±6.25), but the difference was not statistically significant (p>0.05). However, MMP–9 activity in SF was significantly higher in erosive compared to nonerosive RA (17.53±12.87 vs. 8.76±7.72; p<0.05).Table 2.MMP–9 activity (ng/ml) in serum and SF of patients with erosive and nonerosive RAMMP-9 activityErosive RA(n=52)[ng/ml]Nonerosive RA(n=20)[ng/ml]Serum17.46±6.2520.35±10.30Synovial fluid17.53±12.87*8.76±7.72RA – rheumatoid arthritis; SD – standard deviation; n – number of subjects; * p<0.05;We also examined the correlation of MMP 9 activity in serum and SF with standard imuno serological markers of disease (RF and ACPA). Our results indicate that there is a significant correlation of MMP 9 activity in SF with ACPA level in RA group (Spearman’s rank correlation coefficient is 0,48), but not with RF (Spearman’s rank correlation coefficient is 0.06).Conclusion:MMP–9 activity in serum and synovial fluid of patients with early RA is significantly higher compared to patients with osteoarthritis. High activity of MMP–9 in synovial fluid of patients with early RA correlated with ACPA level and may be a predictor of rapid radiographic progression of disease.References:[1]Prodanovic S, Radunovic G, Babic D. et al. Matrix Metalloproteinases-3 Baseline Serum Levels in Early Rheumatoid Arthritis Patients without Initial Radiographic Changes: A Two-Year Ultrasonographic Study Med Princ Pract 2018;27:378–386[2]S. Fadda, E. Abolkheir, R. Afifi et al. Serum matrix metalloproteinase-3 in rheumatoid arthritis patients: correlation with disease activity and joint destruction, Egypt Rheumatol 2016, 38 (3) 153-159.Disclosure of Interests:None declared

FRI0098 ASSOCIATION BETWEEN THE SEROLOGIC STATUS OF ISOTYPE-SPECIFIC AUTOANTIBODIES AND THERAPEUTIC EFFICACY IN RHEUMATOID ARTHRITIS PATIENTS TREATED WITH ABATACEPT: A PROSPECTIVE ULTRASOUND COHORT STUDY IN JAPAN

Background:The presence of anti-cyclic citrullinated protein antibodies (ACPA) and anti-carbamylated protein (anti-CarP) antibody is specific for rheumatoid arthritis (RA). Recently, it was reported that the serological status of ACPA is associated with the therapeutic response of the T-cell co-stimulation blocker abatacept (1, 2). However, it is currently unclear whether the serological status of each isotype levels of these autoantibodies before treatment introduction or the changes during treatment are associated with the therapeutic response of abatacept.Objectives:To evaluate longitudinal changes in the isotypes of ACPA and anti-CarP in RA patients treated with abatacept, and associations between the baseline serological status/ these changes and clinical response/ ultrasonographic response.Methods:This study is part of an ongoing non-randomized multicenter prospective cohort study of patients with active RA who received biological or targeted DMARD therapy at 13 participating rheumatology centers from the Kyushu region of Japan since June 2013 (3). As of the present report, we enrolled 43 consecutive Japanese patients with active RA who have introduced treatment with abatacept and had finished the first 12-month observation period. We evaluated disease activity by clinical composite measure and ultrasound score at baseline, 3, 6, 9 and 12 months. In ultrasound of bilateral hands from 22 sites, the findings obtained by gray-scale (GS) and power Doppler (PD) assessments were graded on a semi-quantitative scale from 0 to 3 and the sum of GS or PD scores was used as the total GS or PD score. The serum levels of IgG/IgM/IgA-type of ACPA and anti-CarP were measured by the ELISA method in Leiden University Medical Center. We evaluated the association between serologic status of autoantibodies and clinical /ultrasonographic therapeutic efficacy.Results:The median age was 72 years, and the disease duration was 54 months. Methotrexate was concomitant in 22 (51%). Sixteen (37%) patients had a history of previous use of biological DMARDs. Nineteen (44%) and 23 (54%) patients achieved SDAI remission and PD remission (total PD score =0) at 12 months, respectively. The serum levels of all isotypes of ACPA/anti-CarP significantly decreased at 12 months from baseline. The reduction of IgM-ACPA level significantly correlated with the reduction of SDAI (rs=0.33, p=0.031) and total PD score (rs=0.49, p=0.0007). Both clinical and ultrasonographic therapeutic responses were better in patients with the detectable IgM-ACPA at baseline than in patients without that (Figure): the reduction of SDAI (p=0.0078) and that of total PD score (p=0.0079) were significantly larger in the former than in the latter. All isotype of anti-CarP did not associate with therapeutic response.Conclusion:Treatment of abatacept induced to the reduction of the autoantibody levels. The IgM-ACPA level at baseline and the change in IgM-ACPA associated with both clinical and ultrasonographic therapeutic response in patients treated with abatacept. IgM-ACPA, compared with usual IgG-ACPA, better reflects the treatment response of abatcept in patients with RAReferences:[1]Ann Rheum Dis. 2016;75:709, 2) RMD Open. 2018;4:e000564, 3)Arthritis Care Res (Hoboken). 2018;70:1719.Acknowledgments:We have acknowledged for all the members of Kyushu multicenter rheumatoid arthritis ultrasound prospective observational cohort study group.Disclosure of Interests:Shin-ya Kawashiri Grant/research support from: This work was supported by Bristol-Myers Squibb and Ono Pharmaceutical. co., Yushiro Endo: None declared, Ayako Nishino: None declared, Toshimasa Shimizu: None declared, Yukitaka Ueki: None declared, Nobutaka Eiraku: None declared, Akitomo Okada: None declared, Naoki Matsuoka: None declared, Tamami Yoshitama: None declared, Hideki Nakamura: None declared, Mami Tamai: None declared, Tomoki Origuchi: None declared, Rene Toes: None declared, Thomas Huizinga Grant/research support from: Ablynx, Bristol-Myers Squibb, Roche, Sanofi, Consultant of: Ablynx, Bristol-Myers Squibb, Roche, Sanofi, Atsushi Kawakami: None declared

Shared epitope defines distinct associations of cigarette smoking with levels of anticitrullinated protein antibody and rheumatoid factor

ObjectsAlthough the association of cigarette smoking (CS) with susceptibility to rheumatoid arthritis (RA) has been established, the impact of CS on anticitrullinated cyclic peptide/protein antibody (ACPA) and rheumatoid factor (RF) levels in RA has yet been clear, especially in relation to shared epitope (SE) alleles.MethodsA total of 6239 subjects, the largest Asian study ever, from two independent Japanese cohorts were enrolled. Precise smoking histories, levels of ACPA and RF, and HLA-DRB1 allele status were withdrawn from databases. Associations between CS and high ACPA or RF levels, defined by the top quartiles, were evaluated. The effect of HLA-DRB1 alleles on the association was further investigated.ResultsCS at RA onset conferred the risks of high levels of both antibodies, especially RF (OR 2.06, p=7.4×10–14; ACPA, OR 1.29, p=0.012), suggesting that RF level is more sensitive to CS than ACPA level. The patients who had quitted CS before RA onset showed a trend of decreased risks of developing high levels of ACPA or RF, and the risks steadily decreased according to the cessation years. The association of CS with high ACPA level was observed only in subjects carrying SE alleles, while the association of high RF level was observed regardless of SE.ConclusionsCS confers the risks of high autoantibody levels in RA in different manners; CS interacts with SE alleles on ACPA level, while CS impacts on RF level despite SE allele. These data suggest novel distinct production mechanisms of RF and ACPA.

A Metaanalysis of the Increased Risk of Rheumatoid Arthritis-related Pulmonary Disease as a Result of Serum Anticitrullinated Protein Antibody Positivity

Objective.An inconsistent association has been reported between the serum anticitrullinated protein antibodies (ACPA) level and rheumatoid arthritis (RA)-related pulmonary disease risk. We conducted a metaanalysis to reveal the association between them.Methods.An electronic search was performed in PubMed, ScienceDirect, and SpringerLink databases for studies published up to August 2013. The distributions of the serum ACPA level in cases and controls were obtained from eligible studies. The risk of RA-related pulmonary disease associated with serum ACPA positivity was estimated by OR and 95% CI. According to the heterogeneity results, a fixed-effects model or a random-effects model was used to calculate the pooled OR. Publication bias and sensitivity analyses were conducted.Results.Overall, 243 patients with RA-related pulmonary disease and 1442 RA controls were included in the metaanalysis. The results showed that the pooled OR was 2.621 (95% CI, 1.561–4.403, p < 0.001) for the increased risk of RA-related pulmonary disease due to the serum ACPA positivity. In the white population subgroup, an increased OR was 3.453 (95% CI 1.798–6.630, p < 0.001), whereas no association was found in the Asian population subgroup. Additionally, we further revealed that serum ACPA positivity indicated a higher risk for interstitial lung disease (ILD) and interstitial pulmonary fibrosis (IPF) among patients with RA (OR 4.679, 95% CI 2.071–10.572, p < 0.001). The heterogeneity, publication bias, and sensitivity analyses had no statistical significance in any group.Conclusion.To our knowledge, this is the first metaanalysis to reveal that serum ACPA positivity is highly associated with the risk of RA-related pulmonary disease, particularly in RA-related ILD and IPF.