Toward Telemonitoring in Immune-Mediated Inflammatory Diseases: Protocol for a Mixed Attention Model Study.

BACKGROUND: Rheumatic and musculoskeletal diseases (RMDs) are chronic diseases that may alternate between asymptomatic periods and flares. These conditions require complex treatments and close monitoring by rheumatologists to mitigate their effects and improve the patient's quality of life. Often, delays in outpatient consultations or the patient's difficulties in keeping appointments make such close follow-up challenging. For this reason, it is very important to have open communication between patients and health professionals. In this context, implementing telemonitoring in the field of rheumatology has great potential, as it can facilitate the close monitoring of patients with RMDs. The use of these tools helps patients self-manage certain aspects of their disease. This could result in fewer visits to emergency departments and consultations, as well as enable better therapeutic compliance and identification of issues that would otherwise go unnoticed. OBJECTIVE: The main objective of this study is to evaluate the implementation of a hybrid care model called the mixed attention model (MAM) in clinical practice and determine whether its implementation improves clinical outcomes compared to conventional follow-up. METHODS: This is a multicenter prospective observational study involving 360 patients with rheumatoid arthritis (RA) and spondylarthritis (SpA) from 5 Spanish hospitals. The patients will be followed up by the MAM protocol, which is a care model that incorporates a digital tool consisting of a mobile app that patients can use at home and professionals can review asynchronously to detect incidents and follow patients' clinical evolution between face-to-face visits. Another group of patients, whose follow-up will be conducted in accordance with a traditional face-to-face care model, will be assessed as the control group. Sociodemographic characteristics, treatments, laboratory parameters, assessment of tender and swollen joints, visual analog scale for pain, and electronic patient-reported outcome (ePRO) reports will be collected for all participants. In the MAM group, these items will be self-assessed via both the mobile app and during face-to-face visits with the rheumatologist, who will do the same for patients included in the traditional care model. The patients will be able to report any incidence related to their disease or treatment through the mobile app. RESULTS: Participant recruitment began in March 2024 and will continue until December 2024. The follow-up period will be extended by 12 months for all patients. Data collection and analysis are scheduled for completion in December 2025. CONCLUSIONS: This paper aims to provide a detailed description of the development and implementation of a digital solution, specifically an MAM. The goal is to achieve significant economic and psychosocial impact within our health care system by enhancing control over RMDs. TRIAL REGISTRATION: ClinicalTrials.gov NCT06273306; https://clinicaltrials.gov/ct2/show/NCT06273306. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/55829.

Influence of rheumatoid factor on serum drug levels of TNF inhibitors with different structures in rheumatoid arthritis.

OBJECTIVES: Certolizumab pegol (CZP), an Fc-free antibody fragment, has shown stable serum levels and steady efficacy in the treatment of RA patients, irrespective of RF levels at baseline. Here, we examine, in clinical practice, the effect of baseline RF and ACPA levels on serum drug levels of IFX, ADL and CZP an Fc-free antibody fragment. METHODS: This is a retrospective study performed in real-world patients. We assessed 170 patients with RA: 90 (53%) received IFX, 48 (28%) ADL and 32 (19%) CZP. Demographic and clinical variables, RF and ACPA levels were obtained at the baseline visit (T0), and patients were stratified based on negative, low, medium, or high levels. After 6 months (T6) serum drug levels and anti-drug antibodies (ADAb), were computed. RESULTS: While CZP serum levels did not differ across RF groups at T6, high baseline RF was linked to lower serum drug levels compared to RF negative status in treatment with complete monoclonal antibodies IFX and ADL. No differences in disease activity measured by DAS28 at baseline were observed across RF quartiles in patients treated with IFX or ADL. ADAb was observed in 26 patients with IFX, 3 with ADL and 1 with CZP, following 6 months of treatment. Patients with high baseline RF levels dropped out more frequently by secondary non-response in IFX or ADL than CZP (80% vs. 75% vs. 33%, p=0.002). CONCLUSIONS: In this real word data evaluation, CZP serum levels were independent of RF levels in patients however patients with high baseline RF levels who obtained IFX or ADL had lower serum drug levels at 6 months than baseline RF-negative patients. In addition, secondary non-response was more frequent in patients with high RF levels treated with IFX and ADL.

Early monitoring of anti-infliximab antibodies by drug-tolerant assay predicts later immunogenicity and drug survival in rheumatic diseases.

OBJECTIVES: To investigate the appearance of anti-drug antibodies (ADA) against infliximab (IFX) determined by drug-sensitive and drug-tolerant assays and their relationship with drug levels and drug survival. METHODS: This longitudinal observational study included 45 patients with rheumatoid arthritis (RA) and 61 with spondyloarthritis (SpA). Serum samples were obtained at weeks 2, 6, 12, 24, and 52. Serum IFX levels were measured by a capture enzyme-linked immunosorbent assay (ELISA) and ADA by an in-house drug-sensitive two-site (bridging) enzyme-linked immunosorbent assay (bELISA) and a commercially available drug-tolerant ELISA (IDK, Immundiagnostik, Germany). RESULTS: Anti-drug antibodies were detected earlier by IDK than by bELISA. Once ADA appeared, positivity persisted throughout the study period. Patients who were bELISA ADA+ had higher IDK ADA levels (than bELISA ADA- patients). Circulating IFX levels were detected in all patients except those found to be bELISA ADA+. Serum IFX levels were lower in IDK ADA+ than in IDK ADA-patients.Most patients (64%) discontinued due to inefficacy. The early onset of immunogenicity was related to IFX survival. Both in RA and SpA, the median survival (years) was shorter in patients with earlier development of ADA (IDK+ before or at week 24) than those who became IDK+ later (after week 24) or never developed ADA. CONCLUSION: A drug-tolerant assay detects ADA during IFX therapy earlier and more frequently than a drug-sensitive assay. The onset of immunogenicity detected by drug-tolerant assays is related to the subsequent detection of ADA by drug-sensitive assays and drug survival.

Predicting anti-TNF treatment response in rheumatoid arthritis: An artificial intelligence-driven model using cytokine profile and routine clinical practice parameters.

Introduction: Rheumatoid arthritis (RA) is a heterogeneous disease in which therapeutic strategies used have evolved dramatically. Despite significant progress in treatment strategies such as the development of anti-TNF drugs, it is still not possible to differentiate those patients who will respond from who will not. This can lead to effective-treatment delays and unnecessary costs. The aim of this study was to utilize a profile of the patient's characteristics, clinical parameters, immune status (cytokine profile) and artificial intelligence to assess the feasibility of developing a tool that could allow us to predict which patients will respond to treatment with anti-TNF drugs. Methods: This study included 38 patients with RA from the RA-Paz cohort. Clinical activity was measured at baseline and after 6 months of treatment. The cytokines measured before the start of anti-TNF treatment were IL-1, IL-12, IL-10, IL-2, IL-4, IFNg, TNFa, and IL-6. Statistical analyses were performed using the Wilcoxon-Rank-Sum Test and the Benjamini-Hochberg method. The predictive model viability was explored using the 5-fold cross-validation scheme in order to train the logistic regression models. Results: Statistically significant differences were found in parameters such as IL-6, IL-2, CRP and DAS-ESR. The predictive model performed to an acceptable level in correctly classifying patients (ROC-AUC 0.804167 to 0.891667), suggesting that it would be possible to develop a clinical classification tool. Conclusions: Using a combination of parameters such as IL-6, IL-2, CRP and DAS-ESR, it was possible to develop a predictive model that can acceptably discriminate between remitters and non-remitters. However, this model needs to be replicated in a larger cohort to confirm these findings.

Patient and physician assessment in difficult-to-treat rheumatoid arthritis: patterns of subjective perception at early stages of b/tsDMARD treatment.

OBJECTIVES: To analyse the trajectories of Disease Activity Score 28 (DAS28), patient global assessment (PGA) and physician global assessment (PhGA) and to assess their predictive capabilities on difficult-to-treat rheumatoid arthritis (D2TRA) classification. METHODS: Longitudinal study of patients with rheumatoid arthritis (RA) from 2020 to 2022. Based on the D2TRA EULAR (European Alliance of Associations for Rheumatology) definition, patients were classified as D2TRA according to biological or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) failure due to inefficacy (D2TRA-inefficacy) or other reasons (D2TRA-other). Patients who did not fulfil the D2TRA criteria were classified as NoD2TRA. DAS28, PGA and PhGA scores collected every 6 months during the first 24 months of b/tsDMARD treatment were used to identify different trajectories using latent class mixed models (LCMM). RESULTS: The study population comprised 255 patients with RA, of whom 167 were NoD2TRA, 58 D2TRA-inefficacy and 30 D2TRA-other. LCMM stratified patients into two different trajectories for DAS28 and PhGA and three for PGA according to the most stable model. The most notable variation occurred during the first 6 months of treatment, thereafter remaining stable during the follow-up period. Most D2TRA-inefficacy patients fitted the trajectory, showing higher values of the studied parameters. NoD2TRA followed the trajectory with lower values, and D2TRA-other were distributed more homogeneously across all trajectories. CONCLUSIONS: The assessment of disease activity, together with patients' and physicians' perceptions, form a key element in the correct discrimination of patients who are going to develop D2TRA-inefficacy. However, identifying those patients who will be D2TRA-other remains challenging, whether by subjective or objective parameters.

Immune response after SARS-CoV-2 vaccination in patients with inflammatory immune-mediated diseases receiving immunosuppressive treatment.

BACKGROUND: Real world data on the response to the SARS-CoV-2 vaccine in patients with immunomediated diseases (IMIDs) treated with immunesuppressants is of great interest because vaccine response may be impaired. The main aim was to study the humoral and cellular immune response after SARS-CoV-2 vaccination in patients with IMIDs treated with immunosuppressants. The secondary aim was to describe the frequency of SARS-CoV-2 infections after vaccination in these patients. MATERIAL AND METHODS: This is an observational study including 86 patients with IMIDs. All patients were treated with biologic or targeted synthetic disease-modifying antirheumatic drugs [b/tsDMARDs: TNF inhibitors (TNFi), rituximab, anti-interleukin 6 receptor (anti-IL6R) or JAK inhibitors (JAKi)]. Demographic and clinical information were collected. After 4-6 weeks of 2nd and 3rd vaccine doses, humoral response was assessed using the Thermo Scientific ELiA SARS-CoV-2-Sp1 IgG Test. Also, in patients with serum SARS-CoV-2 antibody levels under 100UI/ml, cellular response was analyzed using the QuantiFERON SARS-CoV-2 Starter Pack. RESULTS: A total of 86 patients under b/tsDMARDs and 38 healthy controls were included. Most patients received TNFi (45 with TNFi, 31 with rituximab, 5 with anti-IL6R and 5 with JAKi). SARS-CoV-2 antibodies (Ab) were present in an 86% of patients with IMIDs and in 100% healthy controls (p = 0.017). However, 12 (14%) patients had undetectable SARS-CoV-2 Ab levels, all treated with rituximab. In addition, SARS-CoV-2 Ab (IU/ml) were statistically lower in patients (Mdn (IQR): 59.5 (17-163) in patients vs 625 (405-932) in controls, p < 0.001). Patients treated with rituximab had lower Ab levels than those treated with TNFi and controls (p < 0.001). The cellular response to SARS-CoV-2 vaccine was evaluated in 30 patients. Eleven patients had a positive cellular response, being more frequent in patients treated with rituximab (p = 0.03). SARS-CoV-2 infection was reported in 43% of patients and 34% of controls after vaccination. Only 6 (7%) patients required hospitalization, most of whom treated with rituximab (67%). CONCLUSION: SARS-CoV-2 antibody levels were lower in patients than in controls, especially in patients treated with rituximab. A cellular response can be detected despite having a poor humoral response. Severe infections in vaccinated patients with IMIDs are rare, and are observed mainly in patients treated with rituximab.

Ultrasonography in the diagnosis of suspected primary Sjögren's syndrome and concordance with salivary gland biopsy: a Spanish single-center study.

OBJECTIVE: The study aims to evaluate the utility of major salivary gland ultrasonography for diagnosis of primary Sjögren's syndrome (pSS) and to assess its concordance with minor salivary gland biopsy (MSGB). METHODS: A cross-sectional study of 72 patients with suspected pSS was performed. Demographic, clinical, and serological data were collected. MSGB was performed, as was ultrasonography. The ultrasound technician was blind to clinical, serological, and histological data. The validity of ultrasonography compared with MSGB, the American-European Consensus Group (AECG), and American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) criteria was assessed by calculating the percentage of agreement, sensitivity, specificity, positive and negative predictive values, and area under the curve (AUC). RESULTS: Based on MSGB as the gold standard, the percentage of agreement between both tests was 78% (AUC 0.75). Based on the ACR/EULAR criteria, the percentage of agreement was 83% (AUC 0.78) for ultrasonography and 81% (AUC 0.83) for biopsy. Sensitivity and specificity were 90% and 67%, respectively, for ultrasonography and 76% and 90% for biopsy. The results were similar with the AECG criteria. The intra- and inter-observer variability was good (κ > 0.7). Significant differences were observed for positive anti-Ro52 values and hypergammaglobulinemia in pathological ultrasound scans. CONCLUSION: Diagnostic ultrasonography is as useful as MSGB in pSS. Therefore, it could be included in the classification criteria. In this cohort, it proved more sensitive than MSGB and could be used as an initial test for patients suspected of having pSS. MSGB could be used in cases where clinical and serological results are inconclusive. Key Points • Major salivary gland ultrasonography adds diagnostic value similar to that of MSGB, thus potentially enabling this invasive procedure to be avoided. • Ultrasonography could be included in the classification criteria for primary Sjögren's syndrome. • Given that ultrasonography is more sensitive and less specific than MSGB, it could be used as an initial diagnostic test in patients with suspected Sjögren's syndrome. • Biopsy should be performed in those cases where ultrasonography, clinical, and serological data are inconclusive.

Difficult-to-treat rheumatoid arthritis (D2T RA): clinical issues at early stages of disease.

OBJECTIVES: Most studies on difficult-to-treat rheumatoid arthritis (D2T RA) have focused on established RA. Here, we analyse whether disease activity in the early stages of RA could influence progression to a D2T RA under real-life conditions. Other clinical and treatment-related factors were also analysed. METHODS: A longitudinal multicentre study of patients with RA was conducted from 2009 to 2018. Patients were followed up until January 2021. D2T RA was defined based on EULAR criteria (treatment failure, signs suggestive of currently active/progressive disease and management being perceived as problematic by the rheumatologist and/or patient). The main variable was disease activity in the early stages. The covariates were sociodemographic, clinical and treatment-related factors. We ran a multivariable logistic regression analysis to investigate risk factors associated with progression to D2T RA. RESULTS: The study population comprised 631 patients and 35 (5.87%) developed D2T RA. At the time of diagnosis, the D2T RA group were younger, with a higher disability, 28-joint Disease Activity Score (DAS28) score, tender joint count and pain scores. In our final model, DAS28 was not statistically significantly associated with D2T RA. No differences were found between groups for therapy. Disability was independently associated with D2T RA (OR: 1.89; p=0.01). CONCLUSIONS: In this cohort of patients newly diagnosed with RA, our results do not allow us to prove the influence of active disease according to DAS28. However, we did find that younger patients and those with elevated initial disability scores are more likely to develop D2T RA regardless of other factors.

A paradigm of difficult-to-treat rheumatoid arthritis: subtypes and early identification.

OBJECTIVES: Multiple failures to biologic or targeted specific disease-modifying anti-rheumatic drugs (b/tsDMARDs) that lead to difficult-to-treat rheumatoid arthritis (D2TRA) may be the result of multi-drug inefficacy or reflect treatment problems related to adverse events, comorbidities, and/or poor adherence. We aimed to characterise a cohort of D2TRA patients in clinical practice, to analyse the differences between D2TRA due to inefficacy versus D2TRA from other causes, and to compare them with non-D2TRA. METHODS: The D2TRA group included patients who were receiving ≥2b/tsDMARDs due to inefficacy (D2TRA-inef cacy) or because of adverse events, poor adherence, contraindications, comorbidities, drug-intolerance, etc. (D2TRA-other). Patients who achieved low disease activity or remission with the rst bDMARD were classified as non-D2TRA patients. For all patients, demographic, clinical characteristics and laboratory parameters were assessed prior to starting the rst b/tsDMARD. Descriptive analysis was performed and bivariate logistic regression models were assembled. RESULTS: In total, 253 patients were included: 131 non-D2TRA and 122 D2TRA [86 (70.5%) D2TRA-inefficacy and 36 (29.5%) D2TRA-other]. Comparison of the two groups of D2TRA patients: no differences in gender, age at start of b/tsDMARD or age at RA diagnosis were found; this was also true of socioeconomic status, frequency of anxiety-depression and other comorbidities. Patients categorised as D2TRA-other had less extra-articular manifestations than D2TRA-inef cacy, as well as lower values of DAS28 at the start of the rst b/tsDMARD. Comparisons of Non-D2TRA patients versus D2TRA-other resulted in the following observations: no differences in sociodemographic characteristics were evident nor were there any differences in terms of disease activity. CONCLUSIONS: Patients with D2TRA-other are indistinguishable from non-D2TRA patients at baseline, indicating the former cohort does not appear to have any predictive value during the early stages of b/tsDMARD treatment, unlike what occurs in patients with D2TRA-inefficacy.

Serum leptin concentration is associated with the attainment of clinical outcomes in patients with axial spondyloarthritis treated with TNF inhibitors.

OBJECTIVES: To analyse the influence of adipokines on attaining the clinical outcomes in patients with axial spondyloarthritis (axSpA) treated with TNF inhibitors (TNFi), and then, to investigate the association of patients' characteristics and adipokine concentrations. METHODS: This was a longitudinal study including 110 patients with axSpA who were initiated at TNFi and were followed-up for 6 months (m). Disease activity was assessed by Ankylosing Spondylitis Disease Activity Score (ASDAS) at baseline and at 6 m of treatment. Clinical outcomes at 6 m of treatment were defined as remission (ASDAS <1.3) and the attainment of low disease activity (LDA; ASDAS<2.1). Leptin and adiponectin concentrations were measured in serum samples collected at baseline and after 6 m. RESULTS: Both leptin and adiponectin were constitutively elevated in female axSpA patients. At time of TNFi initiation, leptin concentrations were higher in patients with high body mass index (overweight or obese). On the contrary, adiponectin was higher in normalweight patients. After 6 m of TNFi treatment, 24% of patients attained remission. They had significant lower leptin concentration at baseline compared with patients who did not attain remission. Furthermore, this difference remained significant after 6 m of treatment meaning that TNFi did not modify adipokine concentration. Similar results were found considering LDA as the clinical outcome, obtained in 48% of the patients. CONCLUSIONS: The present study showed that low leptin concentrations were associated with attaining clinical outcomes in axSpA patients treated with TNFi. In addition, since leptin secretion by white adipocytes is enhanced during obesity and considering that TNFi do not seem to modulate its expression, obese patients should be encouraged to decrease BMI to attain a successful therapy.

Effectiveness and safety of tocilizumab in monotherapy in biologic-naïve and non-naïve patients with rheumatoid arthritis in a real-world setting / Eficacia y seguridad de tocilizumab en monoterapia en pacientes con artritis reumatoide naive y no naive a biológicos en un entorno del mundo real

Objective: To evaluate the effectiveness and safety of tocilizumab (TCZ) monotherapy in biologic-naïve patients with rheumatoid arthritis (RA) versus patients with previous biologic exposure in a real-world setting. Materials and methods: Non-controlled clinical-trial, 32-week prospective multicenter study including RA patients with moderate-severe disease activity starting TCZ in monotherapy who had a prior inadequate response or were intolerant to methotrexate (MTX). Effectiveness according to EULAR response evaluated at 24-week and safety at 32-weekwere assessed. Results: Of the 93 were enrolled of whom 84 (90%) were eligible for the effectiveness analysis. Biologic-naïve patients (n=46, 54.8%) were younger (51.5 versus 57.9) with shorter disease duration (6.4 versus 13.3) but presented similar comorbidities in comparison with non-naïve patients. DAS28 remission was achieved in a higher percentage in the group of patients with prior biological treatment. 89 adverse events (AE) were recorded in 50 patients, most of them non-serious AE (non-SAE) (86.3%). Conclusions: In a real world setting, TCZ exhibit similar effectiveness and safety in monotherapy in patients with RA regardless previous exposure to other biologic therapies. This study provides additional and valuable real-world findings on the use of TCZ in patients with RA.(AU)

Objetivo: Evaluar la efectividad y seguridad de la monoterapia con tocilizumab (TCZ) en pacientes con artritis reumatoide (AR) sin tratamiento biológico en comparación con pacientes con exposición previa a biológico en un entorno real.Materiales y métodos: Ensayo clínico no controlado, estudio multicéntrico prospectivo de 32 semanas que incluyó pacientes con AR con actividad de la enfermedad moderada-grave que comenzaron con TCZ en monoterapia y que tuvieron una respuesta inadecuada previa o fueron intolerantes al metotrexato. La eficacia de acuerdo con la respuesta EULAR fue evaluada a las 24 semanas y la seguridad a las 32 semanas. Resultados: De los 93 pacientes seleccionados, 84 (90%) fueron elegibles para el análisis de efectividad. Los pacientes sin tratamiento biológico previo (n=46, 54,8%) eran más jóvenes (51,5 frente a 57,9 años), con una duración más corta de la enfermedad (6,4 frente a 13,3 años), pero presentaban comorbilidades similares en comparación con los pacientes con tratamiento previo. La remisión de DAS28 se logró en un mayor porcentaje en el grupo de pacientes con tratamiento biológico previo. Se registraron 89 eventos adversos en 50 pacientes, la mayoría de ellos no graves (86,3%). Conclusiones: En un entorno del mundo real, TCZ exhibe una eficacia y seguridad similares en monoterapia en pacientes con AR, independientemente de la exposición previa a otras terapias biológicas. Este estudio proporciona hallazgos adicionales y valiosos en el contexto del mundo real sobre el uso de TCZ en pacientes con AR.(UA)

Effectiveness and safety of tocilizumab in monotherapy in biologic-naïve and non-naïve patients with rheumatoid arthritis in a real-world setting.

OBJECTIVE: To evaluate the effectiveness and safety of tocilizumab (TCZ) monotherapy in biologic-naïve patients with rheumatoid arthritis (RA) versus patients with previous biologic exposure in a real-world setting. MATERIALS AND METHODS: Non-controlled clinical-trial, 32-week prospective multicenter study including RA patients with moderate-severe disease activity starting TCZ in monotherapy who had a prior inadequate response or were intolerant to methotrexate (MTX). Effectiveness according to EULAR response evaluated at 24-week and safety at 32-weekwere assessed. RESULTS: Of the 93 were enrolled of whom 84 (90%) were eligible for the effectiveness analysis. Biologic-naïve patients (n=46, 54.8%) were younger (51.5 versus 57.9) with shorter disease duration (6.4 versus 13.3) but presented similar comorbidities in comparison with non-naïve patients. DAS28 remission was achieved in a higher percentage in the group of patients with prior biological treatment. 89 adverse events (AE) were recorded in 50 patients, most of them non-serious AE (non-SAE) (86.3%). CONCLUSIONS: In a real world setting, TCZ exhibit similar effectiveness and safety in monotherapy in patients with RA regardless previous exposure to other biologic therapies. This study provides additional and valuable real-world findings on the use of TCZ in patients with RA.

Predictive model to identify multiple failure to biological therapy in patients with rheumatoid arthritis.

Background: Despite advances in the treatment of rheumatoid arthritis (RA) and the wide range of therapies available, there is a percentage of patients whose treatment presents a challenge for clinicians due to lack of response to multiple biologic and target-specific disease-modifying antirheumatic drugs (b/tsDMARDs). Objective: To develop and validate an algorithm to predict multiple failure to biological therapy in patients with RA. Design: Observational retrospective study involving subjects from a cohort of patients with RA receiving b/tsDMARDs. Methods: Based on the number of prior failures to b/tsDMARDs, patients were classified as either multi-refractory (MR) or non-refractory (NR). Patient characteristics were considered in the statistical analysis to design the predictive model, selecting those variables with a predictive capability. A decision algorithm known as 'classification and regression tree' (CART) was developed to create a prediction model of multi-drug resistance. Performance of the prediction algorithm was evaluated in an external independent cohort using area under the curve (AUC). Results: A total of 136 patients were included: 51 MR and 85 NR. The CART model was able to predict multiple failures to b/tsDMARDs using disease activity score-28 (DAS-28) values at 6 months after the start time of the initial b/tsDMARD, as well as DAS-28 improvement in the first 6 months and baseline DAS-28. The CART model showed a capability to correctly classify 94.1% NR and 87.5% MR patients with a sensitivity = 0.88, a specificity = 0.94, and an AUC = 0.89 (95% CI: 0.74-1.00). In the external validation cohort, 35 MR and 47 NR patients were included. The AUC value for the CART model in this cohort was 0.82 (95% CI: 0.73-0.9). Conclusion: Our model correctly classified NR and MR patients based on simple measurements available in routine clinical practice, which provides the possibility to characterize and individualize patient treatments during early stages.

Low Serum BAFF Concentration Is Associated with Response to TNF Inhibitors in Seropositive Patients with Rheumatoid Arthritis.

We investigated B-cell-activating factor (BAFF) in relation to response to treatment with TNF inhibitors (TNFis) in rheumatoid arthritis (RA). This was a longitudinal study including 158 patients with RA treated with TNFis and followed up for 6 months. Clinical response at 6 months of treatment was defined according to the EULAR criteria for good responders (GRs). BAFF concentration was measured in serum samples, collected at baseline and at 6 months. Associations with EULAR response were evaluated using univariable and multivariable logistic regression models. ROC analysis was performed to determine the optimal threshold of serum BAFF concentration associated with good EULAR response to treatment. After 6 months of TNFi treatment, 24% of patients were GRs. They had a lower BMI, lower baseline DAS28 and lower baseline serum BAFF concentration than non-responders. After 6 months of TNFi treatment, autoantibody-positive patients who attained GR had significantly lower serum BAFF concentrations compared with patients who did not. Serum BAFF < 968 pg/mL at 6 months represented the concentration likely to best discriminate between GR and non-GR at 6 months of TNFi treatment. Autoantibody-seropositive patients who had serum BAFF < 968 pg/mL at 6 months demonstrated a more than four-fold increased probability to be GRs compared with patients with higher BAFF concentrations. In conclusion, serum BAFF concentrations were associated with response to TNFis in seropositive RA patients, corroborating the importance of the B-cell compartment in RA.

Difficult-to-Treat Rheumatoid Arthritis in Older Adults: Implications of Ageing for Managing Patients.

Difficult-to-treat rheumatoid arthritis is a heterogeneous term in which patients may present with difficulties in their management for different reasons. This can ultimately lead to patients being exposed to multiple treatments because of inefficacy (resulting from mechanisms intrinsic to rheumatoid arthritis or from non-inflammatory causes such as chronic pain syndrome or structural damage, among others), toxicity or adverse effects that may be linked to comorbidities. One particular group in which such characteristics may be more patent is older patients. Increasing life expectancy, an ageing population and the late onset of rheumatoid arthritis have led to an increased interest in the particularities of treating older patients. This may pose a challenge for physicians, as ageing has implications for optimal patient treatment owing to the potential presence of comorbidities, the risk of adverse events and perceptions of disease status by both physicians and patients. All of these factors may have implications for classifying and managing patients aged > 65 years as difficult-to-treat rheumatoid arthritis, as these patients could be misclassified. This can occur when a significant proportion may still exhibit signs of active disease but not necessarily be difficult to treat because the treatment criterion has not been fulfilled. Alternatively, patients may be exposed to multiple biologic/targeted disease-modifying antirheumatic drugs because of contraindications and/or comorbid conditions. Treatment-to-target strategies and an adequate assessment of inflammatory rheumatoid arthritis activity in older patients should be undertaken, taking special care with associated comorbidities, polypharmacy and risk profiles. Such an approach can help to ensure appropriate treatment for older adults and avoid the misclassification of difficult-to-treat patients.

Achievement rate and predictive factors of the recommended therapeutical target in patients with axial spondyloarthritis who remain on biological therapy: a prospective cohort study in Spain.

OBJECTIVES: To determine the frequency of sustained remission (R) or low diseas activity (LDA) in patients with axial spondyloarthritis (axSpA) undergoing long-term biological therapy and to analyse predictive factors for achieving these outcomes. DESIGN: Prospective, observational cohort study. SETTING: Spanish hospital. PARTICIPANTS: Patients with axSpA who initiated biological treatment between 2003 and 2017. INTERVENTION: Assessment of demographic and clinical characteristics at the beginning of treatment and disease activity every 6 months up to a maximum of 2 years. MAIN OUTCOME MEASURES: Disease activity was measured by Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Disease Activity Index and C reactive protein (BASDAI&CRP). Sustained R was defined as ASDAS<1.3 and/or BASDAI <2 and normal CRP while sustained LDA was defined as ASDAS <2.1 and/or BASDAI <4 and normal CRP on at least three consecutive visits. RESULTS: In total 186 patients (66.1% men and 75.3% with radiographic sacroiliitis) were included. Overall, 76.8% of patients achieved ASDAS R/LDA (R53.2%/LDA23.6%) in at least one visit. Forty per cent (R17.6%/LDA22.4%) of the patients fulfilled the sustained ASDAS R/LDA state, whereas only 30.8% maintained this status (R14.8%/LDA15.9%) according to BASDAI&CRP. In the multivariate analysis, male sex (OR=4.01), younger age at the beginning of biological therapy (OR=0.96) and an HLA*B27 positive status (OR=4.30) were associated with achieving sustained ASDAS R/LDA. CONCLUSIONS: In clinical practice, around one-third of patients on biological disease-modifying antirheumatic drugs achieve a sustained R/LDA status, but these rates drop to less than one in five when targeting remission, preventing the use of the latter as a feasible target. Male sex, HLA*B27 positivity and younger age at the beginning of biological therapy are the main predictors for achieving sustained R/LDA.

Study of Plasma Anti-CD26 Autoantibody Levels in a Cohort of Treatment-Naïve Early Arthritis Patients.

In rheumatoid arthritis (RA), the identification of biomarkers to adjust treatment intensity and to correctly diagnose the disease in early stages still constitutes a challenge and, as such, novel biomarkers are needed. We proposed that autoantibodies (aAbs) against CD26 (DPP4) might have both etiological importance and clinical value. Here, we perform a prospective study of the potential diagnostic power of Anti-CD26 aAbs through their quantification in plasmas from 106 treatment-naïve early and undifferentiated AR. Clinical antibodies, Anti-CD26 aAbs, and other disease-related biomarkers were measured in plasmas obtained in the first visit from patients, which were later classified as RA and non-RA according to the American College of Rheumatology criteria. Two different isotype signatures were found among ten groups of patients, one for Anti-CD26 IgA and other for Anti-CD26 IgG and IgM isotypes, both converging in patients with arthritis (RA and Unresolved Undifferentiated Arthritis: UUA), who present elevated levels of all three isotypes. The four UUA patients, unresolved after two years, were ACPA and rheumatic factor (RF) negatives. In the whole cohort, 51.3% of ACPA/RF seronegatives were Anti-CD26 positives, and a similar frequency was observed in the seropositive RA patients. Only weak associations of the three isotypes with ESR, CRP and disease activity parameters were observed. Anti-CD26 aAbs are present in treatment-naïve early arthritis patients, including ACPA and RF seronegative individuals, suggestive of a potential pathogenic and/or biomarker role of Anti-CD26 aAbs in the development of rheumatic diseases.