Hepatitis B vaccination associated with low response in patients with rheumatic diseases treated with biologics.

BACKGROUND: Hepatitis B virus (HBV) vaccination is recommended for non-immunised patients with rheumatic diseases starting biological disease-modifying antirheumatic drugs (bDMARDs). There is some evidence that HBV vaccination is effective in patients under conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), but it is currently unclear whether this also applies to bDMARDs. OBJECTIVES: To assess the efficacy and safety of HBV vaccination in patients with inflammatory arthritides treated with bDMARDs. METHODS: A prospective cohort with inflammatory arthritides treated with bDMARDs, negative for anti-HBs and anti-HBc and never vaccinated for HBV was recruited. Engerix B was administered at 0, 1 and 6 months and anti-HBs was reassessed ≥1 month after last dose. Response was defined as anti-HBs≥10 IU/L and compared against vaccinated healthy controls. Disease flare, serious adverse events and immune-related disorders not previously present were recorded. RESULTS: 62 patients, most treated with TNF inhibitors (TNFi), and 38 controls were recruited. Most patients were taking csDMARDs (67.7%) and were in remission/low disease activity (59.4%). Only 20/62 patients (32.3%) had a positive response to vaccination, in comparison to 36/38 age-matched controls (94.7%, p<0.001). Response was seen in 19/51 patients treated with TNFi (37.3%) and in 1/11 (9.1%) patients treated with non-TNFi (p=0.07), including 1/6 treated with tocilizumab (16.7%). Among TNFi, response rates ranged from 4/22 (18.2%) for infliximab to 8/14 (57.1%) for etanercept. No relevant safety issues were identified. CONCLUSIONS: HBV vaccination response in patients with rheumatic diseases treated with bDMARDs was poorer than expected. Our data reinforce the recommendation for vaccination prior to starting bDMARDs.

Secukinumab-induced systemic lupus erythematosus in psoriatic arthritis.

CASE REPORT: A 68-year-old male treated with secukinumab for psoriatic arthritis suspended treatment for three months due to COVID pandemic. Upon secukinumab reintroduction, anorexia and weight loss ensued and four months later he had an abrupt onset of low-grade fever, fatigue, flu-like symptoms, dyspnoea and widespread inflammatory arthralgias. Laboratory investigations showed de novo anaemia, leukopenia, lymphopenia, cytocholestasis, elevated acute phase reactants, C3 complement consumption, proteinuria (1630mg/24h), active urine sediment, positive antinuclear (1:1280) and anti-double-stranded DNA (212.3 IU/mL) antibodies. Chest imaging showed peripheral pulmonary embolism, lobar pneumonia, and a small bilateral pleural effusion. Drug-induced lupus erythematosus (DILE) was suspected, and the patient was hospitalised. Secukinumab was discontinued and treatment with enoxaparin, antibiotics, enalapril, hydroxychloroquine and prednisolone 0.5mg/kg qd was started. Clinical and laboratorial remission ensued after one month except for proteinuria (decreased to 653mg/24h). Proliferative lupus nephritis was assumed and mycophenolate mofetil was introduced, with sustained complete remission over a 33-month follow-up. DISCUSSION: This is the second reported case of systemic secukinumab-associated DILE, and the first with renal involvement. Clinical and laboratory features of DILE are reviewed and compared with previously described cases.

Can numerical rating scales of disease impact be used as targets for patient-centred management in rheumatoid arthritis?

OBJECTIVES: Patient centred care is an increasingly important paradigm. Applying a treat-to-target strategy to the impact of the disease in patients' lives seems a very promising tool to serve this purpose. We aimed to evaluate if maximum acceptable impact scores (target-values) defined at the population level provide an appropriate representation for most individual patients. To determine if the individually established target values of impact are consistent enough to be used in a treat-to-target strategy. METHODS: Consecutive patients with rheumatoid arthritis were asked to indicate, in two consecutive visits, the maximum severity of impact they considered acceptable to live with for the rest of their lives, in the seven domains of Rheumatoid Arthritis Impact of Disease score. The individual adequacy of population-based reference values was assessed by measures of dispersion. Stability of individual target-values were evaluated through intraclass correlation coefficient. Socio-demographic, clinical and psychological features were tested as co-factors of stability. RESULTS: 299 patients were included. The dispersion of targets was wide (CV>0.68), thus limiting the use of any population-based single values as targets for the individual patients. Although the mean target values were very similar in both visits for all domains, reliability was poor in all cases (ICCs: 0.37-0.47). Only 25-30% of the patients selected the same target value in the 2 visits. No explanatory factors for (non-)stability were identified. CONCLUSIONS: Quantified impact targets defined at population level are not appropriate for individual patient care. Research on alternative tools to support patient-centred, target-oriented management strategies is warranted.

Sex differences in axial spondyloarthritis: data from a Portuguese spondyloarthritis cohort.

BACKGROUND: Axial spondyloarthritis (axSpA), particularly ankylosing spondylitis was historically considered a male's disease and has been under-recognized in women. Emerging evidence reveals sex differences in pathophysiology, disease presentation and therapeutic efficacy. OBJECTIVE: To identify differences between sexes in a Portuguese cohort of patients with axSpA regarding clinical manifestations, disease activity, functional capacity, patient related outcomes and presence of sacroiliitis on x-ray or magnetic resonance imaging. METHODS: Patients with ≥18 years fulfilling the ASAS- Assessment of Spondyloarthritis International Society classification criteria for axSpA registered in the electronic Rheumatic Diseases Portuguese Register (Reuma.pt) were included in this multicentric cross-sectional study. Sociodemographic data, clinical features and imaging were collected from the first record in Reuma.pt. These variables were compared between sexes using Mann-Whitney test and Chi-Square test. Variables with a significant association with variable sex were considered in the multiple variable analysis to adjust the sex effect on the outcome variables. Statistical analysis was performed with R version 4.0.2 and p <0.05 was considered statistically significant. RESULTS: A total of 1995 patients were included, 1114 (55.9%) men and 881 (44.1%) women. Men had an earlier disease onset (25.1 vs 28.4, p <0.001), were younger at diagnosis (26.9 vs 30.4, p<0.001) and were more frequently smokers (32.1% vs 15.7%, p <0.001). Comparing to women, men had worse Bath Ankylosing Spondylitis Metrological Index scores (4.0 vs 3.4, p<0.001), higher levels of C-Reactive Protein (10.5 vs 6.9 mg/L, p <0.001) and were more often Human Leukocyte Antigen-B27 positive (67.8% vs 54%, p <0.001). In contrast, women more frequently had inflammatory bowel disease (8.8% vs 4.9%, p =0.004), higher levels of erythrocyte sedimentation rate (25.0 vs 21.0mm/h, p=0.003) and worse patient-related outcomes- Bath Ankylosing Spondylitis Disease Activity Index (5.7 vs 4.5, p<0.001), Patient Global Assessment (60.0 vs 50.0, p <0.001) and fatigue (6.2 vs 5.0, p <0.001). DISCUSSION: In this large multicentric study from a Portuguese axSpA cohort, we confirmed sex differences in patients with axSpA. This work brings awareness to these differences, resulting in less underdiagnosis and misdiagnosis, optimizing treatment strategies, and improving outcomes in axSpA.

The impact of a csDMARD in combination with a TNF inhibitor on drug retention and clinical remission in axial spondyloarthritis.

OBJECTIVES: Many axial spondylarthritis (axSpA) patients receive a conventional synthetic DMARD (csDMARD) in combination with a TNF inhibitor (TNFi). However, the value of this co-therapy remains unclear. The objectives were to describe the characteristics of axSpA patients initiating a first TNFi as monotherapy compared with co-therapy with csDMARD, to compare one-year TNFi retention and remission rates, and to explore the impact of peripheral arthritis. METHODS: Data was collected from 13 European registries. One-year outcomes included TNFi retention and hazard ratios (HR) for discontinuation with 95% CIs. Logistic regression was performed with adjusted odds ratios (OR) of achieving remission (Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP < 1.3 and/or BASDAI < 2) and stratified by treatment. Inter-registry heterogeneity was assessed using random-effect meta-analyses, combined results were presented when heterogeneity was not significant. Peripheral arthritis was defined as ≥1 swollen joint at baseline (=TNFi start). RESULTS: Amongst 24 171 axSpA patients, 32% received csDMARD co-therapy (range across countries: 13.5% to 71.2%). The co-therapy group had more baseline peripheral arthritis and higher CRP than the monotherapy group. One-year TNFi-retention rates (95% CI): 79% (78, 79%) for TNFi monotherapy vs 82% (81, 83%) with co-therapy (P < 0.001). Remission was obtained in 20% on monotherapy and 22% on co-therapy (P < 0.001); adjusted OR of 1.16 (1.07, 1.25). Remission rates at 12 months were similar in patients with/without peripheral arthritis. CONCLUSION: This large European study of axial SpA patients showed similar one-year treatment outcomes for TNFi monotherapy and csDMARD co-therapy, although considerable heterogeneity across countries limited the identification of certain subgroups (e.g. peripheral arthritis) that may benefit from co-therapy.

Identification of Human Blood and Tissue T Follicular Regulatory (Tfr) Cells by Flow Cytometry.

T follicular helper (Tfh) cells and T follicular regulatory (Tfr) cells are crucially involved in the regulation of germinal center reactions. Thus, as key players, the assessment of these cell subsets is necessary for a better understanding of the humoral immune response. Flow cytometry (FC) is one of the most used techniques to perform immunophenotypic analysis, allowing the simultaneous study of different proteins by using multicolor fluorescent panels. Here, we describe an approach to identify Tfr cells from human blood and tissues, namely tonsil and lymph node, by flow cytometry.

Effectiveness and treatment retention of TNF inhibitors when used as monotherapy versus comedication with csDMARDs in 15 332 patients with psoriatic arthritis. Data from the EuroSpA collaboration.

BACKGROUND: Comedication with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) during treatment with tumour necrosis factor inhibitors (TNFi) is extensively used in psoriatic arthritis (PsA), although the additive benefit remains unclear. We aimed to compare treatment outcomes in patients with PsA treated with TNFi and csDMARD comedication versus TNFi monotherapy. METHODS: Patients with PsA from 13 European countries who initiated a first TNFi in 2006-2017 were included. Country-specific comparisons of 1 year TNFi retention were performed by csDMARD comedication status, together with HRs for TNFi discontinuation (comedication vs monotherapy), adjusted for age, sex, calendar year, disease duration and Disease Activity Score with 28 joints (DAS28). Adjusted ORs of clinical remission (based on DAS28) at 12 months were calculated. Between-country heterogeneity was assessed using random-effect meta-analyses, combined results were presented when heterogeneity was not significant. Secondary analyses stratified according to TNFi subtype (adalimumab/infliximab/etanercept) and restricted to methotrexate as comedication were performed. RESULTS: In total, 15 332 patients were included (62% comedication, 38% monotherapy). TNFi retention varied across countries, with significant heterogeneity precluding a combined estimate. Comedication was associated with better remission rates, pooled OR 1.25 (1.12-1.41). Methotrexate comedication was associated with improved remission for adalimumab (OR 1.45 (1.23-1.72)) and infliximab (OR 1.55 (1.21-1.98)) and improved retention for infliximab. No effect of comedication was demonstrated for etanercept. CONCLUSION: This large observational study suggests that, as used in clinical practice, csDMARD and TNFi comedication are associated with improved remission rates, and specifically, comedication with methotrexate increases remission rates for both adalimumab and infliximab.

GO-DACT: a phase 3b randomised, double-blind, placebo-controlled trial of GOlimumab plus methotrexate (MTX) versus placebo plus MTX in improving DACTylitis in MTX-naive patients with psoriatic arthritis.

OBJECTIVES: To assess the efficacy of golimumab in combination with methotrexate (MTX) versus MTX monotherapy in psoriatic arthritis (PsA) dactylitis. METHODS: Multicentre, investigator-initiated, randomised, double-blind, placebo-controlled, parallel-design phase 3b trial in 11 Portuguese rheumatology centres. Patients with PsA along with active dactylitis and naive to MTX and biologic disease-modifying antirheumatic drugs (bDMARDs) were randomly assigned to golimumab or placebo, both in combination with MTX. The primary endpoint was Dactylitis Severity Score (DSS) change from baseline to week 24. Key secondary endpoints included DSS and Leeds Dactylitis Index (LDI) response, and changes from baseline in the LDI and MRI dactylitis score. Analysis was by intention-to-treat for the primary endpoint. RESULTS: Twenty-one patients received golimumab plus MTX and 23 MTX monotherapy for 24 weeks. One patient from each arm discontinued. Patient inclusion was halted at 50% planned recruitment due to a favourable interim analysis. Median baseline DSS was 6 in both arms. By week 24, patients treated with golimumab plus MTX exhibited significantly greater improvements in DSS relative to MTX monotherapy (median change of 5 vs 2 points, respectively; p=0.026). In the golimumab plus MTX arm, significantly higher proportions of patients achieved at least 50% or 70% improvement in DSS and 20%, 50% or 70% improvement in LDI in comparison to MTX monotherapy. CONCLUSIONS: The combination of golimumab and MTX as first-line bDMARD therapy is superior to MTX monotherapy for the treatment of PsA dactylitis. TRIAL REGISTRATION NUMBER: NCT02065713.

Real-world Longterm Effectiveness of Tumor Necrosis Factor Inhibitors in Psoriatic Arthritis Patients from the Rheumatic Diseases Portuguese Register.

OBJECTIVE: To assess longterm effectiveness of tumor necrosis factor inhibitors (TNFi) in patients with psoriatic arthritis (PsA) registered in the Rheumatic Diseases Portuguese Register, exposed to at least 1 TNFi, prospectively followed between 2001 and 2017. METHODS: Kaplan-Meier analysis was performed for first-, second-, and third-line TNFi. Responses included European League Against Rheumatism (EULAR) criteria, Disease Activity Index for Psoriatic Arthritis (DAPSA), minimal disease activity (MDA), and Ankylosing Spondylitis Disease Activity Score (ASDAS) at 3 and 6 months. Baseline predictors of discontinuation and response were studied using Cox and multivariable multinomial/logistic regression models. RESULTS: The 750 patients with PsA showed drug retention of 4.1 ± 3.4 years (followup 5.8 ± 3.8 yrs) for first TNFi. Switching to a second (189 patients) or third (50 patients) TNFi further decreased survival by 1.1 years. Female sex, higher baseline 28-joint count Disease Activity Score, and infliximab were predictors of first TNFi discontinuation. After 6 months of the first TNFi, 48.7% of patients achieved a good EULAR criteria response and 20.9% were in DAPSA remission. There were 11.4% in MDA, and 56.4% had a good ASDAS. Responses to the second TNFi were significantly inferior compared to responses to the first TNFi. Female sex and higher baseline Health Assessment Questionnaire-Disability Index were negatively associated with good EULAR response at 3 months, and obesity decreased the chance of response at 6 months. CONCLUSION: In this study, switching to a second or third TNFi was associated with significantly lower drug survival and response rates for patients with axial and peripheral PsA subtypes. More successful therapeutic approaches will require considering the effect of sex and obesity on TNFi effectiveness.

The GO-DACT protocol: a multicentre, randomized, double-blind, parallel-group study to compare the efficacy of golimumab in combination with methotrexate (MTX) versus MTX monotherapy.

The GO-DACT is an investigator-initiated, national, multicentric randomized placebo-controlled double-blinded trial, that assesses dactylitis as primary endpoint. Psoriatic arthritis patients naïve to methotrexate and biologic disease modifying anti-rheumatic drugs, with at least one active dactylitis, were assigned to golimumab in combination with methotrexate or placebo in combination with methotrexate, for 24 weeks. Both clinical (dactylitis severity score and the Leeds dactylitis index) and imaging (high resolution magnetic resonance imaging), among others, were assessed as outcomes. The main objective of GO-DACT is to provide evidence to improve the treatment algorithm and care of psoriatic arthritis patients with active dactylitis. In this manuscript we describe the GO-DACT protocol and general concepts of the methodology of this trial.

The Experience with Biosimilars of Infliximab in Inflammatory Bowel Disease.

BACKGROUND: biosimilars are similar versions of existing innovator biologic agents but with distinct manufacturing processes. They were approved in inflammatory bowel disease (IBD) by extrapolation of indication from rheumatic diseases. As regulatory requirements for biosimilar approval focus on pre-clinical evidence of similarity rather than clinical data on efficacy, safety and immunogenicity, it is critical to review clinical evidence supporting their use in IBD in order to overcome reluctance from patients and clinicians alike. OBJECTIVE: to review clinical studies using infliximab (IFX) biosimilars in IBD. METHOD: we reviewed PubMed for original articles published up to July 1st 2017, reporting data on efficacy and/or safety of IFX biosimilars in IBD. RESULTS: 23 observational studies were found, 12 of them assessing switch from IFX originator to biosimilar and 17 assessing induction therapy with IFX biosimilar. Efficacy, safety and immunogenicity were compared, generally yielding similar results for originator and biosimilar IFX. So far only one randomized controlled trial assessed switching from originator to biosimilar IFX and it was not powered to show similarity in IBD. Ongoing trials are comparing IFX biosimilar and originator head to head in patients in remission, as well as switch versus reverse-switch. Current IBD clinical guidelines are discussed as well as future perspectives for biosimilars in IBD. CONCLUSION: observational studies seem to confirm biosimilarity in a real-world clinical setting. Current trials are expected to elucidate the remaining doubts about clinical biosimilarity.

Portuguese recommendations for the use of biological therapies in patients with axial spondyloarthritis - 2016 update.

OBJECTIVE: To update the recommendations for the treatment of axial spondyloarthritis (axSpA) with biological therapies, endorsed by the Portuguese Society of Rheumatology. METHODS: These treatment recommendations were formulated by Portuguese rheumatologists based on literature evidence and consensus opinion. At a national meeting, the 7 recommendations included in this document were discussed and updated. A draft of the full text of the recommendations was then circulated and suggestions were incorporated. A final version was again circulated before publication and the level of agreement among Portuguese Rheumatologists was anonymously assessed using an online survey. RESULTS: A consensus was achieved regarding the initiation, assessment of response and switching of biological therapies in patients with axSpA. In total, seven recommendations were produced. The first recommendation is a general statement indicating that biological therapy is not a first-line drug treatment option and should only be used after conventional treatment has failed. The second recommendation is also a general statement about the broad concept of axSpA adopted by these recommendations that includes both non-radiographic and radiographic axSpA. Recommendations 3 to 7 deal with the definition of active disease (including the recommended threshold of 2.1 for the Ankylosing Spondylitis Disease Activity Score [ASDAS] or the threshold of 4 [0-10 scale] for the Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]), conventional treatment failure (nonsteroidal anti-inflammatory drugs being the first-line drug treatment), assessment of response to treatment (based on an ASDAS improvement  of at least 1.1 units or a BASDAI improvement of at least 2 units [0-10 scale] or at least 50%), and strategy in the presence of an inadequate response (where switching is recommended) or in the presence of long-term remission (where a process of biological therapy optimization can be considered, either a gradual increase in the interval between doses or a decrease of each dose of the biological therapy). CONCLUSION: These recommendations may be used for guidance in deciding which patients with axSpA should be treated with biological therapies. They cover a rapidly evolving area of therapeutic intervention. As more evidence becomes available and more biological therapies are licensed, these recommendations will have to be updated.

Psychometric properties of sleep and coping numeric rating scales in rheumatoid arthritis: a subanalysis of an etanercept trial.

OBJECTIVES: In rheumatoid arthritis, quality of sleep and ability to cope are important for patients; however their usefulness as outcome measures is not well established. METHODS: Post-hoc analysis of an open-label 12-week trial of etanercept in biologic-naïve rheumatoid arthritis patients with visits at screening, baseline and over 12 weeks. Outcomes measured included Disease Activity Score 28 erythrocyte sedimentation rate (DAS28), numeric rating scales for sleep, coping, patient and physician-global assessment, pain and fatigue, and modified-HAQ. Reliability between screening and baseline visits by intra-class correlation, and responsiveness between baseline and 12 weeks by standardised response means were assessed for each outcome. RESULTS: In 108 patients, mean age 54 (standard deviation (SD) 13) years, mean disease duration 8 (SD 7) years, 75% women; disease activity was high at baseline: mean DAS28 5.5 (SD 0.8). Reliability intra-class correlation was 0.83[95% confidence interval: 0.77;0.88] for sleep, 0.81[0.74;0.87] for modified-HAQ, 0.80[0.71;0.86] for fatigue, 0.72[0.62;0.80] for physician-global assessment, 0.66[0.54;076] for coping, 0.65[0.53;0.75] for pain and 0.63[0.50;0.73] for patient-global assessment. Responsiveness standardised response means was 1.65[1.32;2.10] for physician-global assessment, 1.37[1.09;1.73] for pain, 1.36[1.08;1.73] for patient-global assessment, 1.15[0.95;1.41] for fatigue, 0.96[0.70;1.28] for coping, 0.92[0.73;1.15] for sleep and 0.86[0.69;1.07] for modified-HAQ. CONCLUSIONS: Numeric rating scales assessing sleep and coping were found to be generally as reliable as 'usual' outcomes in rheumatoid arthritis. Responsiveness was less high, indicating these domains of health may be less accessible to biologic treatment. When assessing the patient's perspective on treatment, it is feasible and valid to measure sleep and coping by numeric rating scales.

Effectiveness of early adalimumab therapy in psoriatic arthritis patients from Reuma.pt - EARLY PsA.

Objective To compare outcomes in psoriatic arthritis (PsA) patients initiating adalimumab (ADA), with short- and long-term disease duration and to evaluate the potential effect of concomitant conventional synthetic disease-modifying antirheumatic drugs (csDMARD) or glucocorticoids. Methods Analyses included adult PsA patients registered in the Rheumatic Diseases Portuguese Register (Reuma.pt) between June 2008-June 2016 who received ADA for ≥3 months. Psoriatic Arthritis Response Criteria (PsARC) response, tender and swollen joint count, inflammatory parameters, patient (PtGA) and physician global assessment (PhGA), Disease Activity Score-28 joints (DAS28), and Health Assessment Questionnaire Disability Index (HAQ-DI) were compared between patients with <5 years of disease (early PsA) and those with ≥5 years of disease duration (late PsA). Time to achieving PsARC response was estimated using the Kaplan-Meier method. Results Of 135 PsA patients treated with ADA, 126 had information on disease duration (earlyPsA, n=41). PsARC response was achieved by 72.9% of the patients (88.0% early PsA vs 62.2% late PsA; P=0.022) after 3 months and by 85.4% after 24 months (100% early PsA vs 75.9% late PsA; P=0.044). Early PsA patients achieved significantly less painful joints (2.7 vs 6.7, p=0.006), lower mean C-reactive protein (0.5 mg/dL vs 1.3 mg/dL; P=0.011), and PhGA (18.3 vs 28.1; P=0.020) at 3 months. In the long term, early PsA patients also had fewer swollen joints (0.3 vs 1.7; P=0.030) and lower PhGA (6.3 vs 21.9; P<0.001), C-reactive protein (0.4 mg/dL vs 1.0 mg/dL; P=0.026), and DAS28 (2.2 vs 3.2; P=0.030). HAQ-DI decreased in both groups reaching a mean value at 24 months of 0.4 and 0.8 (P=ns) in early and late PsA, respectively. Early PsA patients obtained PsARC response more rapidly than late PsA (3.8 and 7.4 months, respectively; P=0.008). Concomitant csDMARDs showed clinical benefit (2-year PsARC response, 88.3% vs 60.0%; P=0.044). Concomitant glucocorticoids had no effect on PsARC response over 2 years of follow-up. Persistence on ADA was similar in both groups. Conclusion Early PsA patients had a greater chance of improvement after ADA therapy and better functional outcome, and achieved PsARC response more rapidly than late PsA. In this cohort, comedication with csDMARDs was beneficial over 2 years.

Predictors of response to TNF blockers in patients with polyarticular psoriatic arthritis.

Psoriatic arthritis (PsA) is a chronic inflammatory rheumatic disease with a broad clinical spectrum. PsA can affect the axial skeleton, peripheral joints, entheses, synovial sheaths of tendons, skin, nails and extra-articular organs. Tumour necrosis factor alpha blockers (TNF blockers) were a breakthrough development in the treatment of PsA. Identifying predictors of response to biological therapies in patients with PsA is of utmost importance, especially in view of the costs and potential side effects of these agents. The aims of the present study were to determine baseline predictive factors of response to biological therapies, at 3 and 6 months, in PsA patients with polyarticular involvement (with or without axial involvement). Data were collected from the Rheumatic Diseases Portuguese Register (Reuma.pt). Eligible patients had to be anti-TNF-naive at baseline and to have at least 3 months of follow-up after the beginning of TNF blocker therapy. Only patients with information on at least one of the response measures (at 3 or 6 months of follow-up) were included in the analysis. Univariable logistic regression analysis of potential baseline predictors of European League Against Rheumatism (EULAR) good clinical response, EULAR good/moderate response, 28-joint Disease Activity Score with three variables including the erythrocyte sedimentation rate (DAS28-3V-ESR) remission and Health Assessment Questionnaire (HAQ) response were performed. Multivariable logistic regression using a forward selection procedure was used until the best-fit model was obtained, taking confounding effects into account. A total of 180 patients were eligible for the study (mean age 52 years, 54% women). In multivariable analysis at 3 months, females were less likely to attain a good EULAR response [OR=0.082 (95% CI=0.024, 0.278)], a DAS28-3V-ESR remission [OR=0.083 (95% CI=0.017, 0.416)], a moderate or good EULAR response [OR=0.091 (95% CI=0.011, 0.091)] and a HAQ response [OR=0.074 (95% CI=0.009, 0.608)]. At 6 months, female gender was also less likely to achieve a good EULAR response [OR=0.060 (95% CI=0.011, 0.325)], DAS28-3V-ESR remission [OR=0.060 (95% CI=0.012, 0.297)], and a HAQ response [OR=0.138 (95% CI= 0.029, 0.654)]. In this study we found that gender was the most consistent predictor of response to TNF blocker therapy in patients with polyarticular PsA, with females having a lower probability of response compared to males. These findings suggest that gender-related biochemical, hormonal and psychological factors could play an important role in the response to TNF blocker therapy in PsA.