Interval prolongation of etanercept in rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis: a randomized controlled trial

OBJECTIVE

The majority of patients with a rheumatic disease treated with etanercept may be overexposed. Data regarding etanercept tapering are scarce, particularly in psoriatic arthritis (PsA) and ankylosing spondylitis (AS). We compared extending the dose interval to continuation of the standard dose and studied the success rate of etanercept discontinuation. Etanercept concentrations were measured throughout the study.

METHOD

160 patients with rheumatoid arthritis (RA), PsA, or AS with sustained minimal disease activity (MDA) were enrolled in this 18-month, open-label, randomized controlled trial. The intervention group doubled the dosing interval at baseline and discontinued etanercept 6 months later. The control group continued the standard dose for 6 months and doubled the dosing-interval thereafter. The primary outcome was the proportion of patients maintaining MDA at 6 month follow-up.

RESULTS

At 6 months, MDA status was maintained in 47 patients (63%) in the intervention group and 56 (74%) in the control group (p = 0.15), with comparable results in all rheumatic diseases. And median etanercept concentrations decreased from 1.50 µg/mL (interquartile range 1.06- 2.65) to 0.46 µg/mL (0.28-0.92). In total, 40% discontinued etanercept successfully with maintained MDA for at least 6 months.

CONCLUSION

Etanercept tapering can be done without losing efficacy in RA, PsA, and AS patients in sustained MDA. A substantial proportion of patients could stop etanercept for at least 6 months. In many patients, low drug concentrations proved sufficient to control disease activity. However, the risk of minor and major flares is substantial, even in patients continuing standard dosing.

Elevated Fab glycosylation of anti-hinge antibodies

OBJECTIVE

Rheumatoid arthritis (RA) is characterized by systemic inflammation and the presence of anti-citrullinated protein antibodies (ACPAs), which contain remarkably high levels of Fab glycosylation. Anti-hinge antibodies (AHAs) recognize immunoglobulin G (IgG) hinge neoepitopes exposed following cleavage by inflammation-associated proteases, and are also frequently observed in RA, and at higher levels compared to healthy controls (HCs). Here, we investigated AHA specificity and levels of Fab glycosylation as potential immunological markers for RA.

METHOD

AHA serum levels, specificity, and Fab glycosylation were determined for the IgG_1/4-hinge cleaved by matrix metalloproteinase-3, cathepsin G, pepsin, or IdeS, using enzyme-linked immunosorbent assay and lectin affinity chromatography, in patients with early active RA (n = 69) and HCs (n = 97).

RESULTS

AHA reactivity was detected for all hinge neoepitopes in both RA patients and HCs. Reactivity against CatG-IgG₁-F(ab´)₂s and pepsin-IgG₄-F(ab´)₂s was more prevalent in RA. Moreover, all AHA responses showed increased Fab glycosylation levels in both RA patients and HCs.

CONCLUSIONS

AHA responses are characterized by elevated levels of Fab glycosylation and highly specific neoepitope recognition, not just in RA patients but also in HCs. These results suggest that extensive Fab glycosylation may develop in response to an inflammatory proteolytic microenvironment, but is not restricted to RA.

OP0178 COVID-19 BREAKTHROUGH INFECTIONS IN VACCINATED PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASES AND CONTROLS – DATA FROM TWO PROSPECTIVE COHORT STUDIES

Background

Concerns have been raised regarding risks of COVID-19 breakthrough infections in vaccinated patients with immune-mediated inflammatory diseases (IMIDs) treated with immunosuppressants, but data on COVID-19 breakthrough infections in these patients are still scarce.

Objectives

The primary objective was to compare the incidence and severity of COVID-19 breakthrough infections with the SARS-CoV-2 delta variant between fully vaccinated IMID patients with immunosuppressants, and controls (IMID patients without immunosuppressants and healthy controls). The secondary objective was to explore determinants of breakthrough infections.

Methods

In this study we pooled data collected from two large ongoing prospective multi-center cohort studies (Target to-B! [T2B!] study and ARC study). Clinical data were collected between February and December 2021, using digital questionnaires, standardized electronic case record forms and medical files. Post-vaccination serum samples were analyzed for anti-RBD antibodies (T2B! study only) and anti-nucleocapsid antibodies to identify asymptomatic breakthrough infections (ARC study only). Logistic regression analyses were used to assess associations with the incidence of breakthrough infections. Multivariable models were adjusted for age, sex, cardiovascular disease, chronic pulmonary disease, obesity and vaccine type.

Results

We included 3207 IMID patients with immunosuppressants and 1810 controls (985 IMID patients without immunosuppressants and 825 healthy controls). The incidence of COVID-19 breakthrough infections was comparable between patients with immunosuppressants (5%) and controls (5%). The absence of SARS-CoV-2 IgG antibodies after COVID-19 vaccination was independently associated with an increased incidence of breakthrough infections (P 0.044). The proportion of asymptomatic COVID-19 breakthrough cases that were additionally identified serologically in the ARC cohort was comparable between IMID patients with immunosuppressants and controls; 66 (10%) of 695 patients vs. 64 (10%) of 647 controls. Hospitalization was required in 8 (5%) of 149 IMID patients with immunosuppressants and 5 (6%) of 86 controls with a COVID-19 breakthrough infection. Hospitalized cases were generally older, and had more comorbidities compared with non-hospitalized cases (Table 1). Hospitalization rates were significantly higher among IMID patients treated with anti-CD20 therapy compared to IMID patients using any other immunosuppressant (3 [23%] of 13 patients vs. 5 [4%] of 128 patients, P 0.041; Table 1).

Table 1.

Determinants of the severity of COVID-19 breakthrough infections.

Ambulatory care (n = 222)Hospitalized (n = 13)Group - no. (%)IMID patients with immunosuppressants141(64)8(62)IMID patients without immunosuppressants49(22)3(23)Healthy controls32(14)2(15)Patient characteristicsAge, years – mean (SD)51(14)60(11)Female sex – no. (%)143(64)4(31)Comorbidities – no. (%)Cardiovascular disease17(8)5(39)Chronic pulmonary disease17(8)4(31)Diabetes15(7)3(23)Obesity34(15)5(39)Immunosuppressants– no. (%)Methotrexate36(16)2(15)TNF inhibitor48(22)2(15)Anti-CD20 therapy13(6)3(23)Mycophenolate mofetil3(1)0(0)S1P modulator5(2)0(0)Other immunosuppressants70(32)3(23)

Conclusion

The incidence of COVID-19 breakthrough infections in IMID patients with immunosuppressants was comparable to controls, and infections were mostly mild. Anti-CD20 therapy might increase patients’ susceptibility to severe COVID-19 breakthrough infections, but traditional risk factors also continue to have a critical contribution to the disease course of COVID-19. Therefore, we argue that most patients with IMIDs should not necessarily be seen as a risk group for severe COVID-19, and that integrating other risk factors should become standard practice when discussing treatment options, COVID-19 vaccination, and adherence to infection prevention measures with patients.

Disclosure of Interests

None declared

POS1520-HPR RHEUMATOLOGY PATIENTS TREATED WITH A bDMARD PERSPECTIVE TOWARDS THERAPEUTIC DRUG MONITORING

Background

Therapeutic Drug Monitoring (TDM) is a tool to determine the optimal dose of a drug for individual patients using measurement of blood concentrations and, optionally, anti-drug antibodies (ADA). In the field of rheumatology interest in applying TDM is increasing. A recent study by Syversen et al., the NOR-DRUM B trail, supports TDM as a treatment strategy. This study showed that treatment with proactive TDM was more effective then treatment without TDM. Applying TDM creates a more personalized treatment for individual patients, therefore it is relevant to understand the patients perspective towards TDM.

Objectives

To study the perspective of rheumatology patients treated with a bDMARD in a personalized fashion using TDM.

Methods

Adult rheumatology patients from the Amsterdam Rheumatology and immunology Center who participate in the COVID-19 prospective cohort study (Nederlands Trial Register, trial ID NL8513) received a digital questionnaire which comprised, in addition to demographic items, of three TDM topics: familiarity, attitude and risk assessment.

Results

Participants were selected based on the following criteria: treatment with a bDMARD and a fully completed questionnaire (n=888). Table 1 shows characteristics of study population.

Table 1.

Characteristics of study population

Total N= 888Age, yr Mean (SD)55(13)Gender, female - N (%)575(65)Diagnosis* - N (%)RA511(58)PSA172(19)AS203(23)Axial and peripheral SpA21(3)Other17(2)bDMARD** - N (%)Adalimumab242(27)Etanercept352(40)Other297(33)

* Some patients reported more than one diagnosis

** Three patients reported more than one bDMARD

Sixty-six percent (n=582) of the participants had never heard of the concept ‘personalized dosing, using TDM’. After explaining the concept 60% (n=535) of the participants answered they have a positive attitude towards the concept (Figure 1). Participants with a positive attitude received a follow-up question. They were asked which of the following related aspects: individual dosing, costs, safety and other, they thought was most relevant regarding the concept. Multiple answers were possible. Ninety-four percent (n=502) reported as the main reason for having a positive attitude, that the treatment can be personally adjusted. The second and third reasons, respectively, were safety 43% (n=230) and costs 27% (n=142) of the treatment.

Figure 1.

Attitude towards concept of TDM against being familiar with concept of TDM

Five percent (n=43) of the participants had a negative attitude towards the concept. Main reasons were; previous experience with unsuccessful dose reduction and unwillingness to change current treatment due to the fact that several previous treatments were ineffective.

Participants were also asked what amount of risk they are willing to take when presented with five different situations; worsening rheumatologically symptoms: e.g. pain and swelling, increased fatigability, necessary treatment with prednisone, switching to another bDMARD or more frequent visits to rheumatologist. Majority of the patients reported for each of the five situations, respectively: 37% (n=330), 40% (n=359), 51% (n=453), 48% (n= 426) and 29% (n=262) that they would only be willing to take a negligible risk, < 0.1%.

Conclusion

Majority of participants was not familiar with the concept of personalized dosing using TDM. However, the majority had a positive attitude towards the concept. The main reason for a positive attitude is that the treatment can be personally adjusted. On the other hand, patients who are currently being treated with a bDMARD were only willing to take a negligible risk when it comes to their own treatment.

References

[1]Syversen, S. W., Jorgensen, K. K., Goll, G. L., Brun, M. K., Sandanger, O., Bjorlykke, K. H., Haavardsholm, E. A. (2021). Effect of Therapeutic Drug Monitoring vs Standard Therapy During Maintenance Infliximab Therapy on Disease Control in Patients With Immune-Mediated Inflammatory Diseases: A Randomized Clinical Trial. JAMA, 326(23), 2375-2384. doi:10.1001/jama.2021.21316

Disclosure of Interests

Maureen Leeuw: None declared, Sadaf Atiqi: None declared, Fenna de Vries: None declared, Laura Boekel: None declared, Femke Hooijberg: None declared, Michael Nurmohamed Speakers bureau: Abbvie, Jansen, Celgene, Consultant of: Abbvie, Grant/research support from: Abbvie, Amgen, Pfizer, Galapagos, BMS, Gert-Jan Wolbink: None declared, Charlotte Krieckaert: None declared

POS0589 CARDIOVASCULAR DISEASE RISK IN INFLAMMATORY ARTHRITIS STILL ELEVATED IN 2021!

Background

Patients with inflammatory rheumatic diseases as rheumatoid arthritis (RA), psoriatic arthritis (PsA) and spondyloarthritis (SpA) are at higher risk for developing cardiovascular diseases (CVD) than the general population. This is due to a higher prevalence of ‘traditional’ CV risk factors as hypertension and dyslipidemia, and the underlying systemic inflammation. During the past two decades, the burden of inflammation has been reduced by more efficacious anti-rheumatic treatment, leading to a reduced CVD risk, albeit still elevated in comparison to the general population. Therefore, it remains important to monitor the presence of CVD in rheumatic patients in systematically controlled cohorts.

Objectives

To evaluate whether, nowadays, the CVD risk of patients with inflammatory rheumatic diseases still differs from the general population.

Methods

In March 2020, all adult patients with an inflammatory rheumatic disease from the Amsterdam Rheumatology and Immunology Center, location “Reade” were systematically asked to participate in a prospective cohort study, which focused on the impact of the COVID-19 pandemic. The patients were compared with age and sex matched controls. In the third questionnaire, sent out in January 2021, questions regarding CV risk factors and comorbidities were added. Baseline characteristics and prevalence of CV risk factors and CVD were compared between RA, PsA or SpA patients, and healthy controls.

Results

2050 consecutive patients with an inflammatory rheumatic disease (1312 RA patients, 353 PsA patients, 385 SpA patients), and 939 healthy controls completed the questionnaires (Table 1). The prevalence of at least one CV comorbidity was more frequently reported in RA, PsA and SpA patients compared to healthy controls: 69 (5%), 24 (7%), 17 (4%) compared to 31 (3%), respectively. Events were primarily cardiac (i.e. myocardial infarction and coronary angioplasty). Inflammatory arthritis patients more often had hypertension or hypercholesterolemia than healthy controls, which were untreated in nearly half the cases. RA patients most often used anticoagulant medication.

Table 1.

Baseline characteristics. Values are displayed as mean ± standard deviation (SD) or frequencies with percentages (%). RA = rheumatoid arthritis, PsA = psoriatic arthritis, SpA = spondyloarthritis, CV = cardiovascular, DMARD = disease modifying anti-rheumatic drug

Patient characteristicsAll patients (n = 2050)RA(n = 1312)PsA(n = 353)SpA(n = 385)Control(n = 939)Mean age – yr57 ± 1360 ± 1257 ± 1251 ± 1355 ± 13Female sex - no (%)1266 (63)923 (70)164 (47)179 (47)636 (69)CV risk factors - no (%)Hypertension746 (37)482 (38)134 (39)130 (34)213 (23) Antihypertensive med411 (20)271 (21)78 (22)62 (16)131 (14)Hypercholesterolemia594 (30)391 (31)102 (30)101 (27)197 (21) Statins335 (16)223 (17)59 (17)53 (14)98 (10)Anticoagulants246 (12)180 (14)34 (10)32 (8)74 (8)CV diseases - no (%)Overall110 (5)69 (5)24 (7)17 (4)31 (3)Cardiac91 (4)60 (5)17 (5)14 (4)26 (3)Cerebral27 (1)12 (1)9 (3)6 (2)4 (0)Peripheral14 (1)10 (1)3 (1)1 (0)3 (0)Anti-rheumatic drugs - no (%)Prednisone202 (10)175 (13)17 (5)10 (3)n/aConventional synthetic DMARD1118 (55)902 (69)184 (52)32 (8)n/aBiological DMARD895 (44)512 (39)166 (47)217 (56)n/aTargeted synthetic DMARD20 (1)11 (1)5 (1)4 (1)n/a

Conclusion

The prevalence of CVD was approximately 1.5 times higher in patients with inflammatory rheumatic diseases compared to healthy controls (5% vs 3%), similar to older investigations. The prevalence of CV risk factors also remained elevated, and often undertreated. This indicates that the CVD risk in arthritis patients is still elevated in 2021 compared to the general population, despite improved anti-rheumatic treatment. Therefore, adequate and timely treatment of CV risk factors and optimization of anti-rheumatic drug treatment remains important in all inflammatory arthritis patients.

References

[1]Hooijberg F et al. (2020) Patients with rheumatic diseases adhere to COVID-19 isolation measures more strictly than the general population. The Lancet Rheumatology 2, 582-585.

Disclosure of Interests

None declared.

POS0659 LONG-TERM DYNAMICS OF ANTIBODY RESPONSE TO ADALIMUMAB DETECTED WITH A DRUG TOLERANT ASSAY

Background

Immunogenicity of adalimumab (ADL) has been the subject of extensive research, with the primary focus on its incidence, antibody titers and effects on clinical outcome. However, the temporal evolution of antibodies, i.e. dynamic and variation in titers, time point of emergent and persistence or transience of the response, remains under elucidated. To investigate this further, it is essential to collect samples at regular intervals and over a longer period of time. Also, a drug tolerant assay should be used to conquer with the phenomenon of drug interference (1).

Objectives

To evaluate the temporal evolution and to distinguish dynamic patterns of antibody response. Secondly, to assess the clinical impact and factors influencing these dynamic patterns.

Methods

ADA and adalimumab concentration were measured in sera of 511 consecutive ADL treated rheumatoid arthritis patients. Serum samples were drawn at week 0, 4, 16, 28, 52, 78 and 104. ADA were measured with a drug tolerant assay (Acid dissociation RadioImmunoAssay). Logistic regression analysis was carried out. Benjamini-Hochberg was used to correct for multiple testing.

Results

Baseline characteristics are depicted in Table 1. Fifty-nine percent of patients (n=300) developed ADA. Based on visual observations patients were clustered in 9 groups, taking the next features in to account (Figure 1); the presence or absence of ADA, the height of ADA titers (higher or lower than 100AU/mL), emergent (early vs. late; cutoff week 28) and its persistence. Based on these features 397 (77%) patients were assigned to one of the groups. Due to missing data at crucial time points the remainder of patients were excluded. In the ‘High early’ and High early LTF’ group was the rate of MTX use (adjusted odds ratio (AOR) 0.033 [95%CI 0.01-0.09] P<0.0001 respectively 0.79 [95%CI 0.03-0.22] P <0.0001), adalimumab concentration above 5mg/L (AOR 0.022[95%CI 0.01-0.08] P<0.001 respectively 0.026 [95%CI 0.01-0.09] P<0.001) and low disease activity (DAS28 <3.2) at week 52 (AOR 0.191[95%CI 0.07-0.56] P<0.002 respectively 0.102 [95%CI 0.03-0.31] P<0.001) significantly lower, compared to the negative group. Furthermore, the failure rate was in both groups significantly higher (AOR 9.19 [95%CI 3.7-22.87] P<0.0001 respectively 23.94 [95%CI 8.13-70.53] P<0.0001). In contrast to forgoing studies, our data does not show any differences in clinical outcomes between groups with persistent and transient ADA response.

Table 1.

Baseline characteristics

Totaal N=511Follow-upMedian weeks (IQR)78 (28-104)DemographicsAge mean SD53,7; ± 12,5Female No (%)409 (79.8)Disease statusDisease duration years median (IQR)6,7 (3-13)IgM rheumatoid factor + (%)327 (68.2)Anti-citrullinated protein antibody + (%)315 (73.2)Erosive (%)296 (61.6)DAS28-score mean SD4.5 ± 1.5MedicationMethotrexate use no (%)378 (73)

Conclusion

The majority of patients have an immune response to ADL. Based on ADA concentration, time point of emergence and its persistence, certain patterns of ADA response can be distinguished. Only high ADA concentration at early time points, causing low ADL concentration, are associated with unfavorable clinical effects. All the remaining distinctive patterns does not have any association with clinical outcomes. This suggests a regulated immune response in the majority of patients.

References

[1]Atiqi S, Hooijberg F, Loeff FC, Rispens T, Wolbink GJ. Immunogenicity of TNF-Inhibitors. Front Immunol. 2020 Feb 26;11:312. doi:10.3389/fimmu.2020.00312. PMID: 32174918; PMCID: PMC7055461

Disclosure of Interests

Sadaf Atiqi: None declared, Maureen Leeuw: None declared, Femke Hooijberg: None declared, Laura Boekel: None declared, Floris Loeff: None declared, Karien Bloem: None declared, Charlotte Krieckaert: None declared, Annick de Vries: None declared, Michael Nurmohamed Speakers bureau: AbbVie, Bristol-Myers Squibb, Eli Lilly, Roche, and Sanofi, Grant/research support from: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen, MSD, Mundipharma, Novartis, Pfizer, Roche, and Sanof, Theo Rispens Speakers bureau: AbbVie, Pfizer, and Regeneron, Grant/research support from: Genmab, Gert-Jan Wolbink Speakers bureau: UCB, Pfizer, AbbVie, Biogen and BMS, Grant/research support from: Pfeizer (paid to institution)

Longitudinal humoral response after SARS-CoV-2 vaccination in ocrelizumab treated MS patients: To wait and repopulate?

OBJECTIVE

The objective of this study was to measure humoral responses after SARS-CoV-2 vaccination in MS patients treated with ocrelizumab (OCR) compared to MS patients without disease modifying therapies (DMTs) in relation to timing of vaccination and B-cell count.

METHODS

OCR treated patients were divided into an early and a late group (cut-off time 12 weeks between infusion and first vaccination). Patients were vaccinated with mRNA-1273 (Moderna). B-cells were measured at baseline (time of first vaccination) and SARS-CoV-2 antibodies were measured at baseline, day 28, 42, 52 and 70.

RESULTS

87 patients were included (62 OCR patients, 29 patients without DMTs). At day 70, seroconversion occurred in 39.3% of OCR patients compared to 100% of MS patients without DMTs. In OCR patients, seroconversion varied between 26% (early group) to 50% (late group) and between 27% (low B-cells) to 56% (at least 1 detectable B-cell/µL).

CONCLUSIONS

Low B-cell counts prior to vaccination and shorter time between OCR infusion and vaccination may negatively influence humoral response but does not preclude seroconversion. We advise OCR treated patients to get their first vaccination as soon as possible. In case of an additional booster vaccination, timing of vaccination based on B-cell count and time after last infusion may be considered.

Spinning straw into gold: description of a disruptive rheumatology research platform inspired by the COVID-19 pandemic

Clinical research projects often use traditional methods in which data collection and signing informed consent forms rely on patients' visits to the research institutes. However, during challenging times when the medical community is in dire need of information, such as the current COVID-19 pandemic, it becomes more urgent to use digital platforms that can rapidly collect data on large numbers of patients. In the current manuscript, we describe a novel digital rheumatology research platform, consisting of almost 5000 patients with autoimmune diseases and healthy controls, that was set up rapidly during the COVID-19 pandemic, but which is sustainable for the future. Using this platform, uniform patient data can be collected via questionnaires and stored in a single database readily available for analysis. In addition, the platform facilitates two-way communication between patients and researchers, so patients become true research partners. Furthermore, blood collection via a finger prick for routine and specific laboratory measurements has been implemented in this large cohort of patients, which may not only be applicable for research settings but also for clinical care. Finally, we discuss the challenges and potential future applications of our platform, including supplying tailored information to selected patient groups and facilitation of patient recruitment for clinical trials.

POS0524 CARDIOVASCULAR DISEASE RISK IN INFLAMMATORY ARTHRITIS PATIENTS STILL SUBSTANTIALLY ELEVATED IN 2020

Background:

Patients with inflammatory rheumatic diseases such as rheumatoid arthritis (RA), psoriatic arthritis (PsA) and ankylosing spondylitis (AS) are at a higher risk for developing cardiovascular diseases (CVD) than the general population. This increased risk is partly due to a higher incidence of traditional cardiovascular (CV) risk factors, such as hypertension and dyslipidemia, and partly due to the underlying systemic inflammation. During the past two decades, the burden of the systemic inflammation has been reduced by more efficacious anti-inflammatory treatment, which somewhat attenuated the increased CV risk of rheumatic patients. However, it remains important to monitor the effects of these new treatment strategies on the prevalence of CVD in patients with a rheumatic disease in systematically controlled cohorts.

Objectives:

The aim of the current report was to evaluate whether the CV risk of patients with inflammatory rheumatic diseases still differs from the general population, despite advances In anti-rheumatic treatment strategies.

Methods:

In March 2020, all adult patients with an inflammatory rheumatic disease from the Amsterdam Rheumatology and Immunology Center, location “Reade” were systematically asked to participate in a prospective cohort study. The primary aim of this study was to monitor the impact of the COVID-19 pandemic on patients with inflammatory rheumatic diseases compared to age and sex matched healthy controls. Between April 26, 2020 and May 27, 2020, participants completed the first online questionnaire of the study. Amongst others, information on demographic data, including CV comorbidities and risk factors, and medication use was collected. The baseline characteristics and prevalence of CVD were compared between RA, PsA or AS and healthy controls.

Results:

In total, 1455 consecutive patients with an inflammatory rheumatic disease (979 RA patients, 261 PsA patients and 215 AS patients), and 414 healthy controls completed the first questionnaire, as shown in table 1. CV comorbidities were more frequently reported in RA, PsA and AS patients compared to healthy controls; 107 (11%), 28 (11%) and 22 (10%) compared to 30 (7%), respectively.

Table 1.

Biological DMARD usage in RA, PsA and AS patients

Patient characteristicsAll patients (n=1455)RA (n=979)PsA (N=261)AS (n=215)Controls (n=414)Mean age - yr55 ± 1358 ± 1255 ± 1348 ± 1353 ± 13Female sex - no (%)934 (64)728 (74)119 (46)87 (41)298 (72)BMI (IQR)25 (23-28)25 (22-28)26 (24-30)25 (22-28)24 (22-27)Smoking - no (%)178 (12)126 (13)17 (7)35 (16)34 (8)Cardiovascular disease – no (%)157 (11)107 (11)28 (11)22 (10)30 (7)Rheumatic medication - no (%)csDMARDs877 (60)712 (73)148 (57)17 (8)N.A.Oral glucocorticoids161 (11)139 (14)17 (7)5 (2)2 (0.4)TNF inhibitor563 (39)336 (34)121 (46)106 (49)N.A.IL-6 inhibitor19 (1)19 (2)00N.A.IL-17 inhibitor17 (1)2 (0.2)7 (3)8 (4)N.A.

Table 1. Baseline characteristics. Values are displayed as mean ± standard deviation (SD), median with interquartile range (IQR) or frequencies with percentages (%). RA = rheumatoid arthritis, PsA = psoriatic arthritis, AS = ankylosing spondylitis, BMI = body mass index, TNF = anti-tumor necrosis factor, IL = interleukin.

Conclusion:

We demonstrated that the prevalence of CVD is approximately 1.5 times higher in patients with rheumatic diseases compared to healthy controls (11% vs. 7%, respectively). This corresponds with previous research, although the reported prevalence of CVD in PsA and AS patients is even higher compared to prior studies. This suggests that the CVD risk of patients with rheumatic diseases is still elevated in 2020 compared to the general population, despite the improved management of rheumatic disease activity. Therefore, adequate and timely treatment of CV risk factors remains relevant, not only in patients with RA, but in patients other rheumatic diseases as well.

References:

[1]Hooijberg F et al. (2020) Patients with rheumatic diseases adhere to COVID-19 isolation measures more strictly than the general population. The Lancet rheumatology 2(10), 583-585.

Disclosure of Interests:

None declared

OP0209 INTERVAL PROLONGATION IN ETANERCEPT-TREATED PATIENTS WITH RHEUMATOID ARTHRITIS, ANKYLOSING SPONDYLITIS OR PSORIATIC ARTHRITIS: AN OPEN-LABEL, RANDOMISED CONTROLLED TRIAL

Background:

The majority of patients with a rheumatic disease treated with etanercept may be overexposed. Data regarding etanercept tapering is scarce, particularly in psoriatic arthritis (PsA) and ankylosing spondylitis (AS). Dose reductions can potentially reduce blood drug levels too much, resulting in loss of effect.

Objectives:

We compared extending the dose interval to continuation of the standard dose and studied the success rate of etanercept discontinuation. Etanercept concentrations were measured throughout the study.

Methods:

160 consecutive patients with rheumatoid arthritis (RA), PsA or AS with sustained minimal disease activity (MDA) were enrolled in this 18-month, open-label, randomised controlled trial. The intervention group doubled the dosing-interval at baseline and discontinued etanercept 6 months later. The control group continued the standard dose up to 6 months, after which the dosing-interval was doubled. Primary outcome was the proportion of patients maintaining MDA after 6 months follow-up.

Results:

At 6 months, MDA status was maintained in 47 (63%) patients in the intervention group and 56 (74%) in the control group (p=0.15), with comparable results in all rheumatic diseases. Median etanercept concentrations decreased from 1.50 µg/mL (25-75thpercentile 1.06-2.65) to 0.46 µg/mL (0.28-0.92) after 6 months of interval prolongation (figure 1). In total, 40% discontinued etanercept successfully with maintained MDA for at least 6 months.

Figure 1.

Median (with Q1 to Q3 boxplots) etanercept concentrations (per protocol) during the first 6 months of follow-up in the intervention group (prolongation; gray boxplots) and the control group (continuation; white boxplots), separated by disease (RA, PsA, AS). Bars represent 10-90 percentile and outliers are shown separately (dots).

Conclusion:

As observed in RA, etanercept tapering can be safely attempted in PsA and AS patients in sustained MDA. A substantial proportion of patients could stop etanercept for at least 6 months. In many patients low drug concentrations proved sufficient to control disease activity. However, the risk of minor and major flares is substantial, even in patients continuing standard dosing.

References:

none

Disclosure of Interests:

Merel J. l’Ami Speakers bureau: Novartis, Jill Ruwaard: None declared, Eva L. Kneepkens: None declared, Charlotte L.M. Krieckaert: None declared, Michael Nurmohamed Grant/research support from: Not related to this research, Consultant of: Not related to this research, Speakers bureau: Not related to this research, Femke Hooijberg: None declared, J.C. van Denderen: None declared, Arno Van Kuijk: None declared, Lot Burgemeister: None declared, Maarten Boers: None declared, Gert-Jan Wolbink: None declared

Serum drug concentrations to optimize switching from adalimumab to etanercept in rheumatoid arthritis

Objectives: Inadequate response to adalimumab can be caused by insufficient blockade of the target tumour necrosis factor (TNF) at low serum concentrations. In such cases, patients may respond to another TNF inhibitor. We investigated whether the serum adalimumab concentration is related to the efficacy of a second TNF inhibitor, etanercept, in rheumatoid arthritis (RA). Methods: Patients with RA starting etanercept treatment were prospectively observed in the Reade Rheumatology Registry. In patients previously on adalimumab, serum concentrations were determined before treatment discontinuation. According to this concentration, three subgroups were formed: < 0.5 μg/mL, 0.5-5.0 μg/mL, and ≥ 5.0 μg/mL. The European League Against Rheumatism (EULAR) good/moderate response rate after 52 weeks of etanercept was compared between the switcher subgroups and biologic-naive patients. Results: In total, 449 consecutive patients were included, of whom 69 switched from adalimumab (15%) and 380 were biologic naive (85%). EULAR good or moderate response was achieved by 74% of the biologic-naive patients and by 72%, 50%, and 52% of switchers with adalimumab concentration < 0.5 μg/mL, 0.5-5.0 μg/mL, and ≥ 5.0 μg/mL, respectively (p = 0.15). Patients with an adalimumab concentration ≥ 0.5 μg/mL were significantly less likely to achieve EULAR good/moderate response on etanercept compared to biologic-naive patients, whereas patients with a concentration < 0.5 μg/mL did not significantly differ from patients starting etanercept without prior biologic treatment. Conclusion: RA patients with an inadequate response to adalimumab, in the presence of sufficient drug concentrations, benefit less from switching to another TNF inhibitor, etanercept.

The antibody response against human and chimeric anti-TNF therapeutic antibodies primarily targets the TNF binding region

Background

In a subset of patients, anti tumour necrosis factor (TNF) therapeutic antibodies are immunogenic, resulting in the formation of antidrug antibodies (ADAs). Neutralising ADAs compete with TNF for its binding site and reduces the effective serum concentration, causing clinical non-response. It is however unknown to which extent ADAs are neutralising.

Objectives

To study which proportion of antibodies to human(ised) anti-TNF (adalimumab, golimumab, certolizumab) as well as chimeric anti-TNF (infliximab) is neutralising.

Methods

Neutralising capacity of ADAs was assessed using a TNF competition assay in ADA-positive sera of patients treated with adalimumab (n=21), golimumab (n=4), certolizumab (n=9) or infliximab (n=34) sent in to our diagnostic department.

Results

In 34 sera with ADAs to adalimumab, golimumab or certolizumab, >97% of the antibodies were neutralising. In 34 sera with ADAs to infliximab >90% of the antibodies were neutralising. Further characterisation of the broader antibody response to infliximab revealed that non-neutralising antibodies to infliximab do not target murine domains, but may bind infliximab-unique domains not involved in TNF binding (located outside the paratope).

Conclusions

Our study shows that ADAs to human(ised) as well as chimeric anti-TNF therapeutic antibodies are largely neutralising. This highly restricted ADA response suggests an immunodominant role for the paratope of anti-TNF therapeutics.

Lower etanercept levels are associated with high disease activity in ankylosing spondylitis patients at 24 weeks of follow-up

BACKGROUND

Previous data have shown that etanercept levels are associated with clinical response in rheumatoid arthritis. However, for ankylosing spondylitis (AS), data regarding this topic are inconclusive.

OBJECTIVES

To investigate the relationship between etanercept levels and clinical response in patients with AS.

METHODS

Observational prospective cohort study of 162 patients with AS =treated with etanercept, monitored during 24 weeks of treatment. Etanercept trough levels were determined, retrospectively, using an ELISA. Disease activity was measured using AS Disease Activity Score (ASDAS), including C-reactive protein (CRP) and Bath AS Disease Activity index (BASDAI). Active disease was defined as ASDAS≥2.1. Since etanercept is a drug administered at home there might have been some variation in trough level sampling.

RESULTS

At 24 weeks etanercept levels were significantly higher in patients with ASDAS<2.1, (3.8 mg/L; IQR 2.5-5.2) compared with patients with ASDAS≥2.1 (2.3 mg/L; IQR 1.2-3.4; p≤0.001). Generalised estimating equation analysis demonstrated a statistically significant association between etanercept levels and ASDAS, BASDAI, CRP and erythrocyte sedimentation rate (all p<0.001). When patients were categorised into quartiles according to etanercept levels, the lowest quartile (etanercept<1.80 mg/L) comprised 35% of all patients with ASDAS≥2.1 while the highest quartile comprised only 14%.

CONCLUSIONS

Disease activity and inflammation are associated with etanercept levels in patients with AS at 24 weeks of treatment. Measuring etanercept levels might help in identifying overtreatment and undertreatment and optimise etanercept therapy in AS.

Patients non-responding to etanercept obtain lower etanercept concentrations compared with responding patients

Objective

To investigate the relationship between serum etanercept levels and clinical response.

Methods

In 292 etanercept-treated patients with rheumatoid arthritis clinical and pharmacological data were determined at baseline and after 1, 4 and 6 months of etanercept treatment. Differences in etanercept levels between good, moderate and European League Against Rheumatism (EULAR) non-responders were assessed after 6 months of therapy.

Results

After 6 months of therapy etanercept levels were significantly higher in good responders (median (IQR) 3.78 (2.53–5.17)) compared with both moderate 3.10 (2.12–4.47) and EULAR non-responders 2.80 (1.27–3.93) (all p<0.05). There was a significant association between clinical response and serum etanercept levels (regression coefficient 0.54, 95% CI 0.21 to 0.86, p=0.001). When patients were categorised into quartiles according to the height of etanercept levels, the lowest quartile (etanercept level <2.1 mg/l) comprised 40% of all non-responders. The highest quartile (etanercept level >4.7 mg/l) comprised 35% of all good EULAR responders. Anti-etanercept antibodies were detected in none of the sera.

Conclusion

The authors demonstrated that lower etanercept levels were associated with non-response. Therapeutic drug monitoring and the possibility of the adjusted dosing regimes in the selected groups of patients should be investigated further as a possible tool to optimise treatment with etanercept.

Venous and arterial thromboembolic events in adalimumab-treated patients with antiadalimumab antibodies: a case series and cohort study

OBJECTIVE

We observed 3 patients who developed severe venous and arterial thromboembolic events during treatment with adalimumab, 2 of whom had rheumatoid arthritis (RA) and 1 of whom had psoriatic arthritis. Antiadalimumab antibodies were detected in all 3 patients. We undertook this study to determine whether the development of antiadalimumab antibodies was associated with thromboembolic events during adalimumab treatment.

METHODS

A retrospective search (with blinding with regard to antiadalimumab antibody status) for thromboembolic events was performed in a prospective cohort of 272 consecutively included adalimumab-treated RA patients. Incidence rates were calculated and hazard ratios (HRs) were estimated using Cox regression. None of the index patients were part of the cohort.

RESULTS

Antiadalimumab antibodies were detected in 76 of 272 patients (28%). Eight thromboembolic events were found, 4 of which had occurred in patients with antiadalimumab antibodies. The incidence rate was 26.9/1,000 person-years for patients with antiadalimumab antibodies and 8.4/1,000 person-years for patients without those antibodies (HR 3.8 [95% confidence interval 0.9-15.3], P = 0.064). After adjustment for duration of followup, age, body mass index, erythrocyte sedimentation rate, and prior thromboembolic events, the HR was 7.6 (95% confidence interval 1.3-45.1) (P = 0.025).

CONCLUSION

These findings suggest that the occurrence of venous and arterial thromboembolic events during adalimumab treatment is higher in patients with antiadalimumab antibodies than in those without antiadalimumab antibodies. Patient numbers were relatively small; therefore, validation in other cohorts is mandatory.

Anti-infliximab antibodies are already detectable in most patients with rheumatoid arthritis halfway through an infusion cycle: an open-label pharmacokinetic cohort study

Background

This study in patients with rheumatoid arthritis (RA) treated with infliximab describes prospectively the course of (anti)infliximab levels within an infusioncycle to assess at what moment patients develop low/no infliximab trough levels and/or detectable anti-infliximab levels.

Methods

Infliximab treated RA patients were included in this descriptive open-label cohort study. During one infusioncycle (anti-)infliximab levels were assessed just before and one hour after infusion, and subsequently at 50%, 75% and at the end of the infusioncycle (pre-infusion).

Results

27 patients were included. The median infliximab levels decreased from 77.0 mg/l (p25-p75: 65-89) one hour after the infusion to pre-infusion levels of 0.0 mg/l (p25-p75: 0.0-3.1). In 7 (26%) patients pre-infusion anti-infliximab antibodies were detected; these antibodies were already present halfway through the infusioncycle in 5 of the 7 individuals. Patients with detectable pre-infusion anti-infliximab antibodies have significantly more often low/no infliximab levels (< 1 mg/l) halfway trough the infusioncycle (in 5/7 patients) compared to patients without detectable pre-infusion anti-infliximab antibodies (0/20 patients, p < 0.001).

Conclusions

Most anti-infliximab forming patients have detectable anti-infliximab antibodies halfway through an infusioncycle, which implies that these patients are exposed to nontherapeutical infliximab levels during more than halve of their infusion cycle. As none of the patients without anti-infliximab antibodies had no/low-infliximab levels halfway through the infusioncycle, the presence of pre-infusion anti-infliximab antibodies seems a sensitive and specific predictor for no/low infliximab-levels

The formation of autoantibodies and antibodies to TNF-α blocking agents in relation to clinical response in patients with ankylosing spondylitis

OBJECTIVES

To investigate the influence of antibody formation to TNF-α blocking agents on the clinical response in AS patients treated with infliximab (IFX), etanercept (ETA), or adalimumab (ADA), and to investigate the development of ANA, ANCA, and anti-dsDNA antibodies in association with the formation of antibodies to TNF-α blocking agents.

METHODS

Consecutive AS outpatients with active disease who started treatment with IFX (n=20), ETA (n=20), or ADA (n=20) were included in this longitudinal observational study. Clinical data were collected prospectively at baseline and after 3, 6, and 12 months of anti-TNF-α treatment. At the same time points, serum samples were collected. In these samples, antibodies to TNF-α blocking agents, serum TNF-α blocker levels, and ANA, ANCA, and anti-dsDNA antibodies were measured retrospectively.

RESULTS

Anti-IFX, anti-ETA, and anti-ADA antibodies were induced in 20%, 0%, and 30% of patients, respectively. Although ANA, ANCA, and anti-dsDNA antibodies were detected during anti-TNF-α treatment, no significant association was found between the presence of these autoantibodies and the formation of antibodies to TNF-α blocking agents. Patients with anti-IFX or anti-ADA antibodies had significantly lower serum TNF-α blocker levels compared to patients without these antibodies. Furthermore, significant negative correlations were found between serum TNF-α blocker levels and assessments of disease activity.

CONCLUSIONS

This study indicates that antibody formation to IFX or ADA is related to a decrease in efficacy and early discontinuation of anti-TNF-α treatment in AS patients. Furthermore, autoantibody formation does not seem to be associated with antibody formation to TNF-α blocking agents.

Clinical response, pharmacokinetics, development of human anti-chimaeric antibodies, and synovial tissue response to rituximab treatment in patients with rheumatoid arthritis

OBJECTIVES

To analyse whether persistence of synovial B lineage cells and lack of clinical response to rituximab treatment in patients with rheumatoid arthritis (RA) are associated with low rituximab serum levels and anti-rituximab antibody (ARA) formation.

METHODS

Fifty-eight patients with RA were treated with rituximab. The clinical response was determined 24 weeks after each treatment course using the Disease Activity Score evaluated in 28 joints (DAS28) and EULAR response criteria. Rituximab serum levels, ARAs and synovial B lineage cell numbers were determined before and after treatment.

RESULTS

Four weeks after treatment rituximab serum levels were highly variable. Low rituximab levels were associated with ARA formation (in five patients (8.6%)) and high baseline erythrocyte sedimentation rate. Interestingly, serum rituximab levels were not related to persistence of synovial B lineage cells or clinical response. Furthermore, response to treatment and re-treatment was similar in ARA-positive and ARA-negative patients.

CONCLUSION

There is clear variability in serum levels after rituximab treatment, but rituximab levels are not lower in patients with persistence of synovial B lineage cells or lack of clinical response. The current treatment schedule suffices to induce and maintain a clinical response, even when ARAs are formed.

Anti-infliximab and anti-adalimumab antibodies in relation to response to adalimumab in infliximab switchers and anti-tumour necrosis factor naive patients: a cohort study

OBJECTIVE

To investigate how antibodies against anti-tumour necrosis factor (anti-TNF) agents influence response after switching from infliximab to adalimumab in rheumatoid arthritis (RA).

METHODS

This cohort study consisted of 235 patients with RA, all treated with adalimumab. At baseline 52 patients (22%) had been previously treated with infliximab ('switchers'), and 183 (78%) were anti-TNF naive. Disease activity (using the 28-joint count Disease Activity Score (DAS28)) and presence of antibodies against infliximab and adalimumab were assessed. Clinical response to adalimumab was compared between switchers and anti-TNF naive patients and their anti-infliximab and anti-adalimumab antibody status.

RESULTS

After 28 weeks of adalimumab treatment the decrease in DAS28 (Delta DAS28) for the 235 patients was 1.6+/-1.5 (mean+/-SD). Anti-adalimumab antibodies were detected in 46 patients (20%). Delta DAS28 was 1.8+/-1.4 in patients without anti-adalimumab and 0.6+/-1.3 in patients with anti-adalimumab (p<0.0001). Thirty-three of the 52 switchers (63%) had anti-infliximab antibodies. Patients with anti-infliximab more often developed anti-adalimumab than anti-TNF naive patients (11 (33%) vs 32 (18%); p=0.039). Delta DAS28 was greater for anti-TNF naive patients (1.7+/-1.5) than for switchers without anti-infliximab antibodies (Delta DAS28=0.9+/-1.4) (p=0.009). Delta DAS28 for switchers with anti-infliximab was 1.2+/-1.3 and did not differ significantly from anti-TNF naive patients (p=0.262).

CONCLUSION

Switchers with anti-infliximab antibodies more often develop antibodies against adalimumab than anti-TNF naive patients. Response to adalimumab was limited in switchers without anti-infliximab antibodies, which raises the question whether a second anti-TNF treatment should be offered to patients with RA for whom an initial treatment with an anti-TNF blocker fails, in the absence of anti-biological antibodies.

Improvement of lipid profile is accompanied by atheroprotective alterations in high-density lipoprotein composition upon tumor necrosis factor blockade: a prospective cohort study in ankylosing spondylitis

OBJECTIVE

Cardiovascular mortality is increased in ankylosing spondylitis (AS), and inflammation plays an important role. Inflammation deteriorates the lipid profile and alters high-density lipoprotein cholesterol (HDL-c) composition, reflected by increased concentrations of serum amyloid A (SAA) within the particle. Anti-tumor necrosis factor (anti-TNF) treatment may improve these parameters. We therefore undertook the present study to investigate the effects of etanercept on lipid profile and HDL composition in AS.

METHODS

In 92 AS patients, lipid levels and their association with the inflammation markers C-reactive protein (CRP), erythrocyte sedimentation rate, and SAA were evaluated serially during 3 months of etanercept treatment. HDL composition and its relationship to inflammation markers was determined in a subgroup of patients, using surface-enhanced laser desorption/ionization time-of-flight analysis.

RESULTS

With anti-TNF treatment, levels of all parameters of inflammation decreased significantly, whereas total cholesterol, HDL-c, and apolipoprotein A-I (Apo A-I) levels increased significantly. This resulted in a better total cholesterol:HDL-c ratio (from 3.9 to 3.7) (although the difference was not statistically significant), and an improved Apo B:Apo A-I ratio, which decreased by 7.5% over time (P=0.008). In general, increases in levels of all lipid parameters were associated with reductions in inflammatory activity. In addition, SAA was present at high levels within HDL particles from AS patients with increased CRP levels and disappeared during treatment, in parallel with declining plasma levels of SAA.

CONCLUSION

Our results show for the first time that during anti-TNF therapy for AS, along with favorable changes in the lipid profile, HDL composition is actually altered whereby SAA disappears from the HDL particle, increasing its atheroprotective ability. These findings demonstrate the importance of understanding the role of functional characteristics of HDL-c in cardiovascular diseases related to chronic inflammatory conditions.

Arthritis development in patients with arthralgia is strongly associated with anti-citrullinated protein antibody status: a prospective cohort study

BACKGROUND

Anti-citrullinated protein antibodies (ACPA) are associated with increased risk for rheumatoid arthritis.

OBJECTIVE

To investigate the effect of the presence and levels of ACPA on arthritis development in patients with arthralgia.

METHODS

Patients with arthralgia positive for ACPA or IgM rheumatoid factor (IgM-RF) were tested for the shared epitope (SE) and were prospectively followed up for at least 12 months. Absence of clinical arthritis at inclusion and arthritis development during follow-up were independently confirmed by two investigators. Cox regression hazard analyses were used to calculate hazard ratios (HRs) for arthritis development.

RESULTS

147 patients with arthralgia were included (50 ACPA positive, 52 IgM-RF positive and 45 positive for both antibodies). After a median follow-up of 28 months (interquartile range (IQR) 19-39), 29 patients developed arthritis in a median of 4 (IQR 3-6) joints and 26 (90%) of these were ACPA positive. The presence of ACPA (HR = 6.0; 95% confidence interval (95% CI) 1.8 to 19.8; p = 0.004), but not of IgM-RF (HR = 1.4, 95% CI 0.6 to 3.1) nor the SE (HR = 1.5, 95% CI 0.7 to 3.0), was associated with arthritis development. Within the group of ACPA-positive patients, the risk for arthritis was enhanced by the presence of IgM-RF (HR = 3.0; 95% CI 1.4 to 6.9; p = 0.01) and high ACPA levels (HR = 1.7; 95% CI 1.1 to 2.5; p = 0.008), but not the SE (HR = 1.0; 95% CI 0.5 to 2.1; p = 1.0).

CONCLUSION

In patients with arthralgia the presence of ACPA (but not of IgM-RF or SE) predicts arthritis development. The risk in ACPA-positive patients may be further increased by the concomitant presence of IgM-RF or high levels of ACPA.

Arthritis development in patients with arthralgia is strongly associated with anti-citrullinated protein antibody status: a prospective cohort study

BACKGROUND

Anti-citrullinated protein antibodies (ACPA) are associated with increased risk for rheumatoid arthritis.

OBJECTIVE

To investigate the effect of the presence and levels of ACPA on arthritis development in patients with arthralgia.

METHODS

Patients with arthralgia positive for ACPA or IgM rheumatoid factor (IgM-RF) were tested for the shared epitope (SE) and were prospectively followed up for at least 12 months. Absence of clinical arthritis at inclusion and arthritis development during follow-up were independently confirmed by two investigators. Cox regression hazard analyses were used to calculate hazard ratios (HRs) for arthritis development.

RESULTS

147 patients with arthralgia were included (50 ACPA positive, 52 IgM-RF positive and 45 positive for both antibodies). After a median follow-up of 28 months (interquartile range (IQR) 19-39), 29 patients developed arthritis in a median of 4 (IQR 3-6) joints and 26 (90%) of these were ACPA positive. The presence of ACPA (HR = 6.0; 95% confidence interval (95% CI) 1.8 to 19.8; p = 0.004), but not of IgM-RF (HR = 1.4, 95% CI 0.6 to 3.1) nor the SE (HR = 1.5, 95% CI 0.7 to 3.0), was associated with arthritis development. Within the group of ACPA-positive patients, the risk for arthritis was enhanced by the presence of IgM-RF (HR = 3.0; 95% CI 1.4 to 6.9; p = 0.01) and high ACPA levels (HR = 1.7; 95% CI 1.1 to 2.5; p = 0.008), but not the SE (HR = 1.0; 95% CI 0.5 to 2.1; p = 1.0).

CONCLUSION

In patients with arthralgia the presence of ACPA (but not of IgM-RF or SE) predicts arthritis development. The risk in ACPA-positive patients may be further increased by the concomitant presence of IgM-RF or high levels of ACPA.

Immunogenicity negatively influences the outcome of adalimumab treatment in Crohn's disease

BACKGROUND

Adalimumab is an effective treatment in patients with Crohn's disease; as it is a humanized anti-tumour necrosis factor monoclonal antibody, immunogenicity is thought not to be of any significance.

AIM

To assess whether antibodies to adalimumab (ATAs) affect adalimumab treatment outcome in patients with Crohn's disease previously treated with infliximab.

METHODS

A retrospective study was performed. Patients with active Crohn's disease and who had lost response or were intolerant to infliximab were treated with adalimumab. Clinical response and side effects were assessed as were serum ATAs and antibodies to infliximab (ATIs).

RESULTS

In total 30 patients [M/F (7/23)], median age 36 years (range 21-73) were treated with adalimumab for 318 days (median range 83-632). Clinical response was 77% (23/30), a dose escalation was necessary in eight (27%) patients and side effects were observed in 47% (14/30). In five patients (17%) ATAs were detected; of these patients, four were nonresponders. The presence of ATAs was related to nonresponse to adalimumab (P = 0.006). ATIs were positive in 57% of patients (17/30) and serum levels were significantly increased in adalimumab nonresponders (P = 0.01).

CONCLUSION

Immunogenicity plays a role in adalimumab treatment because of the development of ATAs.

[The formation of infliximab and anti-infliximab immune complexes as an explanation for non-responding to infliximab treatment of rheumatoid arthritis: observational study in 4 patients]

OBJECTIVE

To investigate the in vivo mechanism of non-responding to infliximab treatment of patients with rheumatoid arthritis (RA) and the role of anti-infliximab antibodies by using radiolabeled infliximab.

DESIGN

Descriptive and comparative study.

METHOD

Two responding and two non-responding RA patients were infused with radiolabeled infliximab. Subsequently imaging investigations and serum analysis were performed at set times.

RESULTS

The scintigrams showed that the labelled infliximab was mainly present in the blood until 24 h after infusion. There was a trend of faster blood clearance and higher liver and spleen uptake of 99mTc-infliximab in one non-responding patient. Labelled infliximab was taken up by inflamed joints. The anti-infliximab level was high (1008 and 1641 U/ml) in the non-responders and low or not detectable in the responders. Sucrose gradients of serum revealed antibody complexes in both non-responders. Various sizes of antibody complexes, including very large ones, were observed in one non-responder who developed a serious infusion reaction.

CONCLUSION

Infliximab-anti-infliximab immune complexes were found to form in RA non-responders due to the presence of significant quantities of anti-infliximab. This finding may partly explain the failure of the infliximab treatment.

Preferential decrease in IgG4 anti-citrullinated protein antibodies during treatment with tumour necrosis factor blocking agents in patients with rheumatoid arthritis

Objective:

To investigate the dynamics of IgG1 and IgG4 anti-citrullinated protein antibody (ACPA) subclasses during anti-tumour necrosis factor (TNF) treatment in patients with rheumatoid arthritis (RA).

Methods:

IgG, IgG1 and IgG4 ACPA levels were determined by ELISA on anti-citrullinated fibrinogen (ACF) and IgG1 : IgG4 ACPA ratios were calculated. A pilot study was performed in 28 ACF-positive patients treated with infliximab for one year. Confirmation of the results was obtained using a cohort of 180 consecutive patients treated with adalimumab for 28 weeks.

Results:

The median reduction in ACF levels was 31% for total IgG, 29% for IgG1, 40% for IgG4 and 22% for the IgG4 : IgG1 ACF ratio in the infliximab cohort. In adalimumab-treated patients, ACF levels declined 14% for total IgG and IgG1, and 36% for IgG4 ACF; the IgG4 : IgG1 ratio was reduced by 24% (all percentage values p<0.05). The decrease in antibody levels was correlated with the clinical response; European League Against Rheumatism good responders had the greatest decline in antibody levels and this effect was most pronounced for IgG4 (48% reduction). The IgG4 : IgG1 ACF ratio preferentially decreased in patients with adequate therapeutic adalimumab levels.

Conclusion:

ACPA subclass distribution is modulated by effective anti-inflammatory treatment. The preferential decline of IgG4 ACPA, reflected by the decreased IgG4 : IgG1 ratio, suggests a beneficial effect of anti-TNF treatment on chronic antigenic stimulation by citrullinated proteins. This effect may be directly anti-TNF mediated or the result of effective dampening of the inflammation in the rheumatoid joint.

The role of the shared epitope in arthralgia with anti-cyclic citrullinated peptide antibodies (anti-CCP), and its effect on anti-CCP levels

OBJECTIVES

Patients presenting with both arthralgia and antibodies to cyclic citrullinated peptide (anti-CCP) have an increased risk of developing rheumatoid arthritis (RA). To further characterise this patient group and shed more light on its relationship with clinically manifest early arthritis and established RA, an immunogenetic and serological analysis was performed.

METHODS

In a group of 111 patients with anti-CCP-positive arthralgia, anti-CCP levels and shared epitope (SE) status were determined. Data were compared with 125 and 128 patients with anti-CCP-positive early arthritis and established RA respectively.

RESULTS

In patients with anti-CCP-positive arthralgia, the frequency of SE allele positivity is significantly lower when compared with anti-CCP-positive early arthritis and established RA (58% vs 80%, and 58% vs 92%, respectively, both p<0.001). Median anti-CCP levels were higher in the group of patients with SE-positive arthralgia compared with the group of patients with SE-negative arthralgia (p = 0.02). Median anti-CCP levels were similar in the groups of patients with SE-positive arthralgia and arthritis.

CONCLUSIONS

The lower frequency of SE positivity in patients with arthralgia compared with patients with RA indicates that, compared with patients who were SE positive, patients who were SE negative as a group go through a longer arthralgia phase, or alternatively have a lower risk for transition from anti-CCP positive arthralgia to RA. Furthermore, the present results suggest that in this early stage the effect of the SE on disease risk may be mediated through higher anti-CCP levels.

Immunogenicity does not influence treatment with etanercept in patients with ankylosing spondylitis

BACKGROUND

Immunogenicity, specifically the onset of antibodies against tumour necrosis factor (TNF) blocking agents, seems to play an important role in non-response to treatment with these drugs.

OBJECTIVES

To assess the relation of clinical response of ankylosing spondylitis (AS) to etanercept with etanercept levels, and the presence of antibodies to etanercept.

METHODS

Patients with AS were treated with etanercept 25 mg twice weekly, according to the international Assessment in Ankylosing Spondylitis (ASAS) working group consensus statement. Sera were collected at baseline and after 3 and 6 months of treatment. Clinical response was defined as a 50% improvement or as an absolute improvement of 2 points on a (0-10 scale) Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score. Functional etanercept levels were measured by a newly developed ELISA, measuring the binding of etanercept to TNF. Antibodies against etanercept were measured with a two-site assay and antigen binding test. Clinical data were used to correlate disease activity with serum etanercept levels.

RESULTS

In all, 53 consecutive patients were included. After 3 months of treatment 40 patients (76%) fulfilled the response criteria. Mean etanercept levels were 2.7 mg/litre and 3.0 mg/litre after 3 and 6 months respectively. Characteristics and etanercept levels of responders and non-responders were similar. No antibodies to etanercept were detected with any of the assays.

CONCLUSION

Etanercept levels of responders and non-responders were similar and no antibodies to etanercept were detected with any of the assays. This study indicates that etanercept is much less immunogenic compared with the other TNF-blocking agents.

The clinical response to infliximab in rheumatoid arthritis is in part dependent on pretreatment tumour necrosis factor alpha expression in the synovium

OBJECTIVE

To determine whether the heterogeneous clinical response to tumour necrosis factor (TNF)alpha blocking therapy in rheumatoid arthritis (RA) can be predicted by TNFalpha expression in the synovium before initiation of treatment.

METHODS

Prior to initiation of infliximab treatment, arthroscopic synovial tissue biopsies were obtained from 143 patients with active RA. At week 16, clinical response was evaluated using the 28-joint Disease Activity Score (DAS28). Immunohistochemistry was used to analyse the cell infiltrate as well as the expression of various cytokines, adhesion molecules and growth factors. Stained sections were evaluated by digital image analysis. Student t tests were used to compare responders (decrease in DAS28 > or =1.2) with non-responders (decrease in DAS28 <1.2) and multivariable regression was used to identify the independent predictors of clinical response.

RESULTS

Synovial tissue analysis confirmed our hypothesis that the baseline level of TNFalpha expression is a significant predictor of response to TNFalpha blocking therapy. TNFalpha expression in the intimal lining layer and synovial sublining were significantly higher in responders than in non-responders (p = 0.047 and p = 0.008, respectively). The numbers of macrophages, macrophage subsets and T cells (all able to produce TNFalpha) were also significantly higher in responders than in non-responders. The expression of interleukin (IL)1beta, IL6, IL18, IL10, E-selectin, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) was not associated with response to anti-TNFalpha treatment.

CONCLUSION

The effects of TNFalpha blockade are in part dependent on synovial TNFalpha expression and infiltration by TNFalpha producing inflammatory cells. Clinical response cannot be predicted completely, indicating involvement of other as yet unknown mechanisms.

Changes in lipid profile during infliximab and corticosteroid treatment in rheumatoid arthritis

OBJECTIVE

To evaluate the effects of infliximab and corticosteroid treatment on the lipid profile in patients with active rheumatoid arthritis (RA).

METHODS

Infliximab infusions were given at weeks 0, 2, 6 and then every 8 weeks. Before each infusion, disease activity parameters (Disease Activity Index 28-Joint Score (DAS28)) C reactive protein (CRP) and lipid levels (total cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides, apolipoprotein A1 (apo A1) and apolipoprotein B) were measured in 80 consecutive patients with RA, who completed the study period of 48 weeks. Longitudinal analyses were used to investigate (1) the course of lipid levels over a period of time and (2) the relationship between lipids, prednisone dose and disease activity.

RESULTS

Infliximab treatment causes a significant reduction in disease activity and a concomitant decrease in prednisone dose. Although they initially improved significantly, all lipid levels had returned to baseline levels after 48 weeks, except for apo A1. Longitudinal analyses revealed significant yet opposite associations between lipid levels and disease activity and between lipid levels and prednisone dose. DAS28 improvement by 1 point was associated with an increase of 0.016 mmol/l (0.618 mg/dl) total cholesterol and 0.045 mmol/l (1.737 mg/dl) HDL-cholesterol. Reduction of 10 mg prednisone was associated with a decrease of 0.04 mmol/l (1.544 mg/dl) total cholesterol and 0.16 mmol/l (6.177 mg/dl) HDL-cholesterol.

CONCLUSION

Overall, no changes in serum lipid levels were observed after 48 weeks of infliximab treatment. The initial beneficial effects of infliximab on the lipid profile, by means of a reduction of disease activity, are attenuated by a concomitant decrease in prednisone dose.

Rituximab treatment in patients with primary Sjögren's syndrome: An open-label phase II study

OBJECTIVE

To investigate the safety and efficacy of B cell depletion treatment of patients with active primary Sjögren's syndrome of short duration (early primary SS) and patients with primary SS and mucosa-associated lymphoid tissue (MALT)-type lymphoma (MALT/primary SS).

METHODS

Fifteen patients with primary SS were included in this phase II trial. Inclusion criteria for the early primary SS group were B cell hyperactivity (IgG >15 gm/liter), presence of autoantibodies (IgM rheumatoid factor, anti-SSA/SSB), and short disease duration (<4 years). Inclusion criteria for the MALT/primary SS group were primary SS and an associated MALT-type lymphoma (Ann Arbor stage IE) localized in the parotid gland. Patients were treated with 4 infusions of rituximab (375 mg/m2) given weekly after pretreatment with prednisone (25 mg) and clemastine. Patients were evaluated, using immunologic, salivary/lacrimal function, and subjective parameters, at baseline and at 5 and 12 weeks after the first infusion.

RESULTS

Significant improvement of subjective symptoms and an increase in salivary gland function was observed in patients with residual salivary gland function. Immunologic analysis showed a rapid decrease of peripheral B cells and stable levels of IgG. Human anti-chimeric antibodies (HACAs) developed in 4 of 15 patients (27%), all with early primary SS. Three of these patients developed a serum sickness-like disorder. Of the 7 patients with MALT/primary SS, complete remission was achieved in 3, and disease was stable in 3 and progressive in 1.

CONCLUSION

Findings of this phase II study suggest that rituximab is effective in the treatment of primary SS. The high incidence of HACAs and associated side effects observed in this study needs further evaluation.

Relationship between serum trough infliximab levels, pretreatment C reactive protein levels, and clinical response to infliximab treatment in patients with rheumatoid arthritis

OBJECTIVE

To investigate the relationship between serum trough infliximab levels and clinical response to infliximab treatment in patients with rheumatoid arthritis (RA).

METHODS

Disease activity and serum trough infliximab levels before and 2, 6, and 14 weeks after initiation of infliximab treatment at a dose of 3 mg/kg in a cohort of 105 patients with RA were assessed. Serum trough infliximab levels in responders and non-responders were compared. Additionally, the clinical responses of patients with high, intermediate, and low serum trough infliximab levels at 14 weeks were compared.

RESULTS

After 14 weeks of treatment non-responders had lower serum trough levels of infliximab than responders (median (interquartile range) 0.5 (0.2-2.2) v 3.6 (1.4-8.2) mg/l; p<0.01)). Patients with low serum trough infliximab levels at 14 weeks had significantly less improvement in the 28 joint count Disease Activity Score (DAS28) score than patients with intermediate or high serum trough infliximab levels at 14 weeks. Pretreatment C reactive protein (CRP) levels correlated negatively with serum trough infliximab levels at 14 weeks after the start of treatment (Spearman rank correlation r(s) = -0.43, p<0.001).

CONCLUSION

Serum trough levels of infliximab correlate with the clinical response to treatment with infliximab and pretreatment CRP levels. This study indicates that patients with high pretreatment CRP levels might benefit from higher dosages of infliximab or shorter dosing intervals.