Lotte A van de Stadt

The extent of the anti-citrullinated protein antibody repertoire is associated with arthritis development in patients with seropositive arthralgia

Objectives To determine the fine specificity of anti-citrullinated protein antibodies (ACPA) in the early phase of arthritis development, the ACPA repertoire in arthralgia patients and the association with arthritis development were studied. Methods A total of 244 patients with arthralgia positive for anti-cyclic citrullinated peptide antibodies (aCCPs) and/or IgM rheumatoid factor (IgM-RF), without arthritis were included. Development of arthritis was defined as presence of one or more swollen joints at clinical examination during follow-up. Sera were tested at baseline for reactivity to five citrullinated peptides derived from fibrinogen (three), vimentin (one) and α-enolase (one) and five corresponding arginine peptides in an ELISA. Results In all, 69 patients (28%) developed arthritis in a median of 3 joints after a median follow-up of 11 (IQR 5–20) months. Reactivity to each peptide was significantly associated with arthritis development (p<0.001). The ACPA repertoire did not differ between patients who did or did not develop arthritis. Among aCCP-positive patients, patients recognising two or more additional citrullinated peptides developed arthritis more often (p=0.04). The number of recognised peptides was positively associated with the aCCP level (p<0.001). Crossreactivity between different peptides was minimal. Conclusions Arthritis development is not associated with recognition of a specific citrullinated peptide once joint complaints are present. The ACPA repertoire in some patients with arthralgia is expanded. High aCCP levels are associated with a qualitatively broad ACPA repertoire. Patients with an extended ACPA repertoire have a higher risk of developing arthritis.

Adalimumab elicits a restricted anti-idiotypic antibody response in autoimmune patients resulting in functional neutralisation

Objectives Millions of patients worldwide are treated with therapeutic monoclonal antibodies. These biological therapeutics can be immunogenic, resulting in anti-drug antibody formation which leads to loss of response. Fully human biological agents, such as the anti-tumour necrosis factor α (anti-TNFα) antibody adalimumab, are considered to be weakly immunogenic, but anti-adalimumab antibodies (AAA) were recently detected in more than half of treated patients with rheumatoid arthritis (RA) within 28 weeks of treatment. A study was undertaken to determine the mechanism by which AAA lead to loss of response. Methods The specificity of the repertoire of AAA was investigated in a cohort of 50 AAA-positive RA patients. Inhibition experiments using TNFα and patient-derived anti-adalimumab monoclonal antibodies were performed. Results The antibody response against adalimumab is highly restricted: Fab fragments of a single monoclonal antibody specific for the idiotype of adalimumab inhibited 98.65% (25th–75th percentiles: 98.25–99.90) of the total anti-adalimumab reactivity in serum from 50 AAA-positive patients. The anti-adalimumab response was confined to the TNFα binding region of adalimumab, thereby neutralising its therapeutic efficacy. In line with this restricted specificity, small immune complexes were found in the circulation of AAA-forming patients. Conclusions The humoral immune response against adalimumab is highly restricted and limited to the idiotype of the therapeutic antibody. All antibodies result in functional neutralisation of the drug, thereby providing a mechanism by which AAA formation leads to clinical non-response.

A prediction rule for the development of arthritis in seropositive arthralgia patients

Objective To predict the development of arthritis in anticyclic citrullinated peptide antibodies and/or IgM rheumatoid factor positive (seropositive) arthralgia patients. Methods A prediction rule was developed using a prospective cohort of 374 seropositive arthralgia patients, followed for the development of arthritis. The model was created with backward stepwise Cox regression with 18 variables. Results 131 patients (35%) developed arthritis after a median of 12 months. The prediction model consisted of nine variables: Rheumatoid Arthritis in a first degree family member, alcohol non-use, duration of symptoms <12 months, presence of intermittent symptoms, arthralgia in upper and lower extremities, visual analogue scale pain ≥50, presence of morning stiffness ≥1 h, history of swollen joints as reported by the patient and antibody status. A simplified prediction rule was made ranging from 0 to 13 points. The area under the curve value (95% CI) of this prediction rule was 0.82 (0.75–0.89) after 5 years. Harrells C (95% CI) was 0.78 (0.73–0.84). Patients could be categorised in three risk groups: low (0–4 points), intermediate (5–6 points) and high risk (7–13 points). With the low risk group as a reference, the intermediate risk group had a hazard ratio (HR; 95% CI) of 4.52 (2.42–8.77) and the high risk group had a HR of 14.86 (8.40–28.32). Conclusions In patients presenting with seropositive arthralgia, the risk of developing arthritis can be predicted. The prediction rule that was made in this patient group can help (1) to inform patients and (2) to select high-risk patients for intervention studies before clinical arthritis occurs.

The value of ultrasonography in predicting arthritis in auto-antibody positive arthralgia patients: a prospective cohort study

IntroductionUltrasonography (US) has better sensitivity than clinical evaluation for the detection of synovitis in early rheumatoid arthritis (RA). Patients presenting with arthralgia and a positive anti-citrullinated protein antibodies (ACPA) and/or Rheumatoid Factor (IgM-RF) status are at risk for developing RA. In the present study, US utility and predictive properties in arthralgia patients at risk for the development of arthritis were studied.Methods192 arthralgia patients with ACPA and/or IgM-RF were included. Absence of clinical arthritis was confirmed by two physicians. US was performed by one of two trained radiologists of any painful joint, and of adjacent and contralateral joints. Joint effusion, synovitis and power Doppler (PD) signal in the synovial membrane of the joints and tenosynovitis adjacent to the joint were evaluated and classified on a 4-grade semi-quantitative scale. Grade 2-3 joint effusion, synovitis, tenosynovitis and grade 1-3 Power Doppler signal were classified as abnormal.ResultsForty-five patients (23%) developed arthritis after a mean of 11 months. Inter-observer reliability for synovitis and PD was moderate (kappa 0.46, and 0.56, respectively) and for joint effusion low (kappa 0.23). The prevalence of tenosynovitis was too low to calculate representative kappa values. At joint level, a significant association was found between US abnormalities and arthritis development in that joint for joint effusion, synovitis and PD. At patient level, a trend was seen towards more arthritis development in patients who had US abnormalities for joint effusion, synovitis, PD and tenosynovitis.ConclusionsUS abnormalities were associated with arthritis development at joint level, although this association did not reach statistical significance at patient level. US could potentially be used as a diagnostic tool for subclinical arthritis in seropositive arthralgia patients. However, further research is necessary to improve test characteristics.

The type I IFN signature as a biomarker of preclinical rheumatoid arthritis

Objectives To validate the presence and demonstrate the clinical value of the type I interferon (IFN)-signature during arthritis development. Method In 115 seropositive arthralgia patients who were followed for the development of arthritis (Amsterdam Reade cohort), and 25 presymptomatic individuals who developed rheumatoid arthritis (RA) later, and 45 population-based controls (Northern Sweden cohort), the expression levels of 7 type I IFN response genes were determined with multiplex qPCR and an IFN-score was calculated. The diagnostic performance of the IFN-score was evaluated using Cox regression and Receiver Operating Characteristics (ROC)-curve analysis. Results In 44 of the 115 at-risk individuals (38%) from the Amsterdam Reade cohort, arthritis developed after a median period of 8 months (IQR 5–13). Stratification of these individuals based on the IFN-score revealed that 15 out of 25 IFNhigh individuals converted to arthritis, compared with 29 out of 90 IFNlow individuals (p=0.011). In the Northern Sweden cohort, the level of the IFN-score was also significantly increased in presymptomatic individuals who developed RA compared with population-based controls (p=0.002). Cox regression analysis of the Amsterdam Reade cohort showed that the hazard ratio (HR) for development of arthritis was 2.38 (p=0.008) for IFNhigh at-risk individuals after correction for anticitrullinated protein antibodies (ACPA) and rheumatoid factor (RF). The ROC-curve area under the curve (AUC) for the IFN-score combined with ACPA and RF in the prediction of arthritis was 78.5% (p=0.0001, 95% CI 0.70 to 0.87). Conclusions The results demonstrated clinical utility for the IFN-signature as a biomarker in the prediction of arthritis development.

Antibodies against Porphyromonas gingivalis in seropositive arthralgia patients do not predict development of rheumatoid arthritis

Clinical studies point towards an association between periodontitis and rheumatoid arthritis (RA).1 ,2 A pathogenic role is suggested for Porphyromonas gingivalis .3 P gingivalis may contribute to the pathogenesis of RA by breaking immune tolerance through formation of (bacterial and human) citrullinated proteins, leading to anticitrullinated protein antibody production (ACPA).4 ,5 Since ACPA production precedes RA development6 and because P gingivalis IgG antibodies are long-term stable in untreated periodontitis patients,7 we investigated whether anti- P gingivalis antibody levels are prognostic for development of RA, by assessing these antibodies in a cohort of 289 adults at risk for RA. Patients with arthralgia and seropositivity for IgM-rheumatoid factor (IgM-RF) and/or ACPA were selected from a prospective follow-up study on arthritis development.8 They are further referred to as seropositive arthralgia patients (SAP); their median follow-up was 30 months (IQR 13–49). Baseline sera were used for measurement of ACPA, IgM-RF, C-reactive protein (CRP) and HLA-DRB1 SE carrier status.8 IgA, IgG and IgM antibody levels against P gingivalis were determined by in-house ELISA with a pooled lysate of clinical isolates of P gingivalis as …

Three-Year Clinical Outcome Following Baseline Magnetic Resonance Imaging in Anti–Citrullinated Protein Antibody–Positive Arthralgia Patients: An Exploratory Study

Advanced imaging may be useful in the detection of subclinical synovitis (i.e., synovitis that cannot be detected by clinical examination) in anti–citrullinated protein antibody (ACPA)–positive arthralgia patients, and it may contribute to timely assessment of which individuals will eventually develop rheumatoid arthritis (RA) (1,2). Therefore, in this pilot study we investigated whether magnetic resonance imaging (MRI) can visualize subclinical inflammation in the hands and/or wrists of ACPA-positive arthralgia patients, and we determined the relationship between baseline MRI and development of clinical arthritis during 3 years of followup. MRI scans in healthy volunteers were included for comparison. The study was embedded in a cohort study that recruited seropositive arthralgia patients at the rheumatology outpatient clinics of the VU University Medical Center and Jan van Breemen Research Institute Reade (3). During 26 months, all arthralgia patients with positive ACPA status (3) (independent of IgM–rheumatoid factor status) were consecutively asked to participate in the present MRI substudy. Inclusion and exclusion criteria have been reported previously (2,3). Baseline MRI was performed on 28 included patients and 4 healthy volunteers without a history of joint disorders or clinical arthritis. Development of clinical arthritis was monitored according to the schedule of the cohort study during at least 3 consecutive years. MRI sequences (Siemens Sonata 1.5T MR scanner) were chosen according to Outcome Measures in Rheumatology (OMERACT) guidelines (4). STIR and 3-dimensional T1-weighted magnetization-prepared rapid gradient-echo images were obtained before and after intravenous gadolinium administration. Synovitis and bone marrow edema were scored by 2 independent observers (NA, CD) according to the OMERACT RA MRI Scoring (RAMRIS) system (4). The MRI protocol included scanning of all proximal interphalangeal (PIP) joints (PIP joints 1–5), metacarpophalangeal (MCP) joints (MCP joints 1–5), and wrist joints of both hands. At the patient level, MRI positivity was defined as the presence of synovitis and/or bone marrow edema in at least 1 joint/bone. Individual cumulative MRI scores (range 0–288) were calculated by summing synovitis and bone marrow edema scores of each hand/wrist joint. At baseline, the median age of the 28 patients was 44 years (interquartile range [IQR] 37–53 years). Twenty-three patients (82%) were women. The median duration of arthralgia was 15 months (IQR 11–35 months). The median age of the 4 healthy controls (1 man, 3 women) was 31 years (IQR 26–56 years). At baseline, MRI abnormalities were frequently found. In 26 of 28 patients (93%), MRI synovitis was present in 1 joint of both hands/wrists (Figure 1A). Ten of 26 patients had a synovitis score of 2 in 1 joint. A synovitis score of 3 was not observed. Bone marrow edema was present in only 3 of 28 patients (11%). MRIs in all healthy controls showed signs of mild synovitis (score of 1) in 1 joint (range 3–23). A score of 2 for synovitis was found in 1 joint of 1 healthy control. Bone marrow edema was not observed on MRIs in healthy controls. The presence of MRI abnormalities at baseline was not associated with dichotomous outcome of development of clinical arthritis (yes/no). Twelve of 28 patients (43%) developed clinical arthritis and were subsequently diagnosed as having RA according to the American College of Rheumatology/European League Against Rheumatism 2010 classification criteria (5). In 10 of 12 patients, arthritis was observed in hand and/or wrist joints. At the patient level, 11 of 12 patients who developed clinical arthritis and all 16 patients who did not develop clinical arthritis had a positive baseline Figure 1. A, Baseline T1-weighted contrast-enhanced magnetic resonance imaging (MRI) scan of the hand/wrist joints of an anti– citrullinated protein antibody (ACPA)–positive arthralgia patient who developed arthritis in hand/wrist joints during 3-year followup. Arrows indicate MRI signs of synovitis (score of 2). B, Cumulative MRI scores (including score of 1 for synovitis and bone marrow edema) of patients with and those without development of arthritis during 3-year followup. Symbols represent individual patients; horizontal bars show the median. C, Survival curves for all included patients, comparing the group with an MRI synovitis score of 2 in at least 1 joint (solid line) and the group with an MRI synovitis score of 1 in at least 1 joint (dashed line). Patients with a synovitis score of 2 developed arthritis faster than those with a synovitis score of 1. Plus sign indicates a censored patient. D, Cumulative MRI scores (including score of 1 for synovitis and bone marrow edema) in relation to age, in individual ACPA-positive arthralgia patients and individual healthy controls.

The Acute-phase Response Is Not Predictive for the Development of Arthritis in Seropositive Arthralgia - A Prospective Cohort Study

Objective. To evaluate whether markers of the acute-phase response in patients presenting with arthralgia and positive anticitrullinated protein antibodies (ACPA) and/or immunoglobulin M rheumatoid factor (IgM-RF) could be predictive for the development of arthritis. Methods. In total, 137 ACPA- and/or IgM-RF-positive patients were included. Patients were followed annually for the development of arthritis, defined as presence of 1 or more swollen joints at clinical examination. High-sensitivity C-reactive protein (hsCRP), procalcitonin (PCT), secretory phospholipase A2 (SPLA2), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), IL-12p70, IL-10, and interferon-γ (IFN-γ) were measured in baseline serum samples. Gene expression focusing on a predefined panel of genes coding for inflammatory molecules was measured by multiplex ligation-dependent probe amplification. Results. Thirty-five patients (26%) developed arthritis within a median time of 11 months (interquartile range 3.7–18 mo). Circulating levels of cytokines, SPLA2, hsCRP, and PCT were not different between patients with progression to clinical arthritis and those without progression. However, a trend for IL-12p70, TNF-α, IL-10, IL-6, and SPLA2 was observed. No correlation between messenger RNA (mRNA) expression levels of inflammatory genes and progression to arthritis was found. Subgroup analysis of patients with early progression to arthritis showed higher levels of mRNA expression of poly(A)-specific ribonuclease and polycomb complex protein BMI-1 compared to patients without progression to arthritis. Conclusion. Although low-grade inflammation is present before onset of clinical arthritis in large cohorts and can be detected using consecutive measurements, a single measurement of acute-phase reactants seems to have limited value for prediction of development of arthritis in individual patients.

B cell signature contributes to the prediction of RA development in patients with arthralgia.

Early recognition followed by treatment of rheumatoid arthritis (RA) helps to maintain joint integrity and functional capacity,1 suggesting it may be beneficial to intervene in patients with arthralgia before RA develops. Anticitrullinated protein antibodies (ACPA) and rheumatoid factor (RF) are established predictive markers,2 ,3 but only 20–40% of ACPA and/or RF positive patients with arthralgia develop RA within 2 years.4 Recently, we have demonstrated that the type I interferon (IFN) signature correctly identifies 52% of patients with arthralgia who will develop RA within 2 years.5 ,6 Our previous study suggested that a B cell related gene signature was associated with protection against arthritis development,6 and could aid in the prediction of arthritis development. We therefore studied the clinical value of the B cell signature, comprising CD19, CD20, CD79α and CD79β, for the prediction of arthritis development in an independent cohort of 115 ACPA and/or RF positive patients with arthralgia followed for median 22 months5 and explored the phenotypical nature of this B cell signature. In total, 44 patients (38%) developed arthritis (defined as one or more swollen joints) within 2 years. Of these, 4 patients had undifferentiated arthritis and 40 patients fulfilled the 2010 American College of Rheumatology (ACR)/ European League Against Rheumatism (EULAR) criteria for RA. Patients were stratified into B cellhigh …

Development of anti-citrullinated protein antibody and rheumatoid factor isotypes prior to the onset of rheumatoid arthritis

Development of anti-citrullinated protein antibody and rheumatoid factor isotypes prior to the onset of rheumatoid arthritis