The challenge of standardizing CAR-T cell monitoring: A comparison of two flow-cytometry methods and correlation with qPCR technique.

Chimeric antigen receptor (CAR) T-cell therapy is a breakthrough in hematologic malignancies, such as acute B lymphoblastic leukemia (B-ALL). Monitoring this treatment is recommended, although standardized protocols have not been developed yet. This work compares two flow cytometry monitoring strategies and correlates this technique with qPCR method. CAR-T cells were detected by two different flow-cytometry protocols (A and B) in nine blood samples from one healthy donor and five B-ALL patients treated with Tisagenlecleucel (Kymriah®, USA). HIV-1 viral load allowed CAR detection by qPCR, using samples from seven healthy donors and nine B-ALL patients. CAR detection by protocol A and B did not yield statistically significant differences (1.9% vs. 11.8% CD3 + CAR+, p = 0.07). However, protocol B showed a better discrimination of the CD3 + CAR+ population. A strong correlation was observed between protocol B and qPCR (r = 0.7, p < 0.0001). CD3 + CAR+ cells were detected by flow cytometry only when HIV-1 viral load was above 104 copies/mL. In conclusion, protocol B was the most specific flow-cytometry procedure for the identification of CAR-T cells and showed a high correlation with qPCR. Further efforts are needed to achieve a standardized monitoring approach.

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.

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.

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.

Obesity and response to biological therapy in rheumatoid arthritis: the role of body mass index and adipose tissue cytokines.

OBJECTIVES: To analyse the role of body mass index (BMI) in the clinical response to biologic dis-ease-modifying anti-rheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA). To per-form an in-depth analysis of the pathophysiology of obesity by assessing serum adipokine levels and their potential changes according to treatment. METHODS: This study involved 105 patients with RA starting tumour necrosis factor inhibitors (TNFi) or tocilizumab (TCZ). Patients were classified ac-cording to BMI as normal-weight and overweight/obesity. The clinical response to treatment was as-sessed by Clinical Disease Activity Index (CDAI) 6 months after initiation of bDMARDs. Serum adi-pokines (leptin and adiponectin) were determined using a commercial immunoassay kit in samples ob-tained before initiation of bDMARDs and after 6 months of treatment. RESULTS: A correlation was observed between BMI and disease activity and between BMI and serum adipokines. Sixty percent of patients achieved low disease activity (LDA)/remission: 45 patients in TNFi group (64.2%) and 18 (51.4%) in TCZ group. In TNFi group, patients who did not attain LDA/remission had a higher BMI (kg/m2) ([28.7±5.1] vs. [24.5±4.6], p=0.001) and baseline CDAI (26.3 [17.4-33.9] vs. 19.8 [14.0-28.8], p<0.03). However, no differences in BMI or baseline CDAI were observed between patients who achieved LDA after 6 months in TCZ group. CONCLUSIONS: Obesity influences the extent of LDA/remission in patients treated with TNFi, but not in patients treated with TCZ, probably because of underlying pathophysiological mechanisms intrinsic to the production of proinflammatory adi-pokines. Therefore, therapeutic strategies with a mechanism of action other than TNF inhibition would be more suitable for obese patients.

Optimal concentration range of golimumab in patients with axial spondyloarthritis.

OBJECTIVES: To investigate the association between serum golimumab (GLM) trough levels, clinical disease activity and treatment response during the first year of therapy in patients with axial spondyloarthritis (axSpA), as well as determining an optimal concentration range of GLM in axSpA. METHODS: This was an observational prospective study including 49 patients with axSpA monitored during 52 weeks (W52). Serum GLM trough levels were measured by capture ELISA and antidrug antibodies by bridging ELISA at baseline, W24 and W52. Disease activity was assessed by the Ankylosing Spondylitis Disease Activity Score (ASDAS) and clinical improvement by ΔASDAS. The association between serum GLM trough levels and disease activity was assessed using univariable and multivariable regression. In case of drop-out or missing data before W52, the last observation carried forward (LOCF) was performed. ASDAS values and GLM levels at W24 were available for 42 patients and 38 patients at W52. RESULTS: In the univariable analyses, serum GLM trough levels were inversely associated with ASDAS at W24 (n=42, r =-0.445; p<0.01), at W52 (n=38, r=-0.330; p<0.05) and W52LOCF (n=49, r=-0.309; p<0.05). In the multivariable analysis, this significant association remained. Serum trough GLM levels above the 0.7-1.4mg/L range did not contribute to additional clinical improvement. CONCLUSIONS: In patients with axSpA, serum GLM trough levels are associated with disease activity during the first year of treatment. A concentration range of 0.7-1.4mg/L appears to be useful to achieve clinical response to GLM.

Immunogenicity of Therapeutic Antibodies: Monitoring Antidrug Antibodies in a Clinical Context.

One of the factors that may impact drug levels of therapeutic antibodies in patients is immunogenicity, with potential loss of efficacy. Nowadays, many immunogenicity assays are available for testing antidrug antibodies (ADA). In this article, we discuss different types of immunogenicity assays and their clinical relevance in terms of drug tolerance, relation with pharmacokinetics (PK), neutralizing antibodies, potential adverse events associated with ADA, and prediction of ADA production. Drug-tolerant assays can provide insight into the process of immunogenicity, but for clinical management, these assays do not necessarily outperform drug-sensitive assays. The usefulness of any ADA assay for clinical decision making will be larger when drug concentrations are also measured, and this is true, in particular, for drug-tolerant assays.

Antibodies to infliximab in Remicade-treated rheumatic patients show identical reactivity towards biosimilars.

OBJECTIVES: The aim of this study was to determine whether antibodies to infliximab (IFX) in Remicade-treated patients cross-react with the biosimilar CT-P13. METHODS: 250 consecutive patients with rheumatic diseases under Remicade and 77 controls were retrospectively selected for the study. Anti-IFX antibodies at drug through levels were measured in parallel with three different bridging ELISA assays: Promonitor-ANTI-IFX kit, which uses Remicade to detect antibodies, and two more assays that use either Inflectra or Remsima with the same format. Correlation and association between each assay was studied. RESULTS: 50.4% of patients were tested positive with Promonitor-ANTI-IFX. All were antibodies to IFX (ATI)-positive when either Inflectra or Remsima assays were used. In all comparisons positive and negative percentage agreements were 100%, and correlation coefficients were ≥0.995. No differences between rheumatoid arthritis and spondyloarthritis, or between concomitant immunosuppressives, were observed. CONCLUSIONS: Anti-IFX antibodies of Remicade-treated patients cross-react with either Inflectra or Remsima. Although additional epitopes may be present in the biosimilar, results suggest that epitopes influencing the immune response to IFX are also present in the biosimilar. Antibody-positive patients treated with Remicade should not be switched to the biosimilar, since antibodies will interact with the new drug and potentially lead to loss of response. This finding supports the utility for therapeutic drug monitoring before a switching strategy is considered.

Comparing a tapering strategy to the standard dosing regimen of TNF inhibitors in rheumatoid arthritis patients with low disease activity.

OBJECTIVES: The aim of this study is to compare clinical outcomes, incidence of flares and administered drug reduction between rheumatoid arthritis (RA) patients under TNF inhibitors (TNFi) tapering strategy and RA patients on standard regimen. METHODS: Two groups of RA patients on TNFi with DAS28<3.2 were compared: the tapering group (TG: 67 pts from Spain) and the control group with standard therapy regimen (CG: 77 pts from the Netherlands). DAS28 was measured at different time points: visit 0 (prior starting TNFi), visit 1 (prior to start tapering in TG and with DAS28<3.2 in TG and CG), visit 2 (6 months after visit 1), visit 3 (1 year after visit 1), visit 4 (the last visit available after visit 1) and visit-flare (visit with the worst flare between visit 1 and visit 4). RESULTS: Despite the reduction of administered drug at visit 4 in the TG (interval elongation of 32.8% in infliximab, 52.9% in adalimumab and 52.6% in etanercept), the DAS28 remained similar between groups at the end of the study (DAS28: 2.7±0.9 in TG vs. 2.5±1 in CG, p=0.1). No differences were seen in the number of patients with flares [26/67 (38.9%) in the TG vs. 30/77 (39%) in the CG, p=0.324] and only nineteen out of 136 patients (14%) had anti-drug antibodies at the end of the study. CONCLUSIONS: The tapering strategy of TNFi in RA patients result in a reduction of the drug administered, while the disease control is not worse than patients on the standard regimen.

Influence of rheumatoid factor levels and TNF inhibitor structure on secondary nonresponse in rheumatoid arthritis patients.

Background: The EXXELERATE study revealed poorer clinical outcomes in patients treated with adalimumab (ADL) and baseline rheumatoid factor (RF) above 203 IU/mL. However, responses were similar in patients treated with certolizumab pegol (CZP) regardless of RF levels. Objectives: This study investigated the impact of RF levels >203 IU/mL on TNF inhibitors (TNFi) serum levels and the association with secondary nonresponse in RA patients treated with TNFi. Methods: We performed an observational ambispective study with RA patients treated with infliximab (IFX), ADL, or CZP. Patients were stratified according to baseline RF levels: ≤ or >203 IU/mL. After 6 months, serum drug levels and antidrug antibodies were measured, and reasons for discontinuation were collected. Results: We included 170 RA patients: 90 (53%) received IFX, 48 (28%) ADL, and 32 (19%) CZP. While CZP serum levels did not differ between RF groups at 6 months (p = 0.6), RF levels >203 IU/mL were linked to lower serum drug levels in patients treated with IFX (p = 0.09) or ADL (p = 0.02). Secondary nonresponse was 3.6 times higher in patients with high versus low RF levels in patients under IFX or ADL. However, the reasons for withdrawal were not affected by RF levels in patients treated with CZP. Conclusion: Baseline RF above 203 IU/mL is associated with lower serum drug levels and an increased risk of discontinuation due to secondary nonresponse in patients treated with IFX or ADL. In contrast, drug levels and clinical outcomes are not significantly impacted by baseline RF levels in patients under CZP.

Exploring the influence of baseline rheumatoid factor levels on TNF inhibitor retention rate in patients with rheumatoid arthritis: a multicentre and retrospective study.

OBJECTIVE: To assess whether the retention rate of certolizumab pegol (CZP) was longer than that of other tumour necrosis factor inhibitors (TNFi) based on baseline rheumatoid factor (RF) levels. METHODS: Longitudinal, retrospective and multicentre study including patients with RA who were treated with any TNFi (monoclonal antibodies (mAB), etanercept (ETA) or CZP). Log-rank test and Cox regressions were conducted to evaluate the retention rate in the three groups according to the level of RF, with the third quartile of the baseline levels used as cut-off: <200 (

Exploring candidate biomarkers for rheumatoid arthritis through cardiovascular and cardiometabolic serum proteome profiling.

Introduction: RA patients are at higher risk of cardiovascular disease, influenced by therapies. Studying their cardiovascular and cardiometabolic proteome can unveil biomarkers and insights into related biological pathways. Methods: This study included two cohorts of RA patients: newly diagnosed individuals (n=25) and those with established RA (disease duration >25 years, n=25). Both cohorts were age and sex-matched with a control group (n=25). Additionally, a longitudinal investigation was conducted on a cohort of 25 RA patients treated with methotrexate and another cohort of 25 RA patients treated with tofacitinib for 6 months. Clinical and analytical variables were recorded, and serum profiling of 184 proteins was performed using the Olink technology platform. Results: RA patients exhibited elevated levels of 75 proteins that might be associated with cardiovascular disease. In addition, 24 proteins were increased in RA patients with established disease. Twenty proteins were commonly altered in both cohorts of RA patients. Among these, elevated levels of CTSL1, SORT1, SAA4, TNFRSF10A, ST6GAL1 and CCL18 discriminated RA patients and HDs with high specificity and sensitivity. Methotrexate treatment significantly reduced the levels of 13 proteins, while tofacitinib therapy modulated the expression of 10 proteins. These reductions were associated with a decrease in DAS28. Baseline levels of SAA4 and high levels of BNP were associated to the non-response to methotrexate. Changes in IL6 levels were specifically linked to the response to methotrexate. Regarding tofacitinib, differences in baseline levels of LOX1 and CNDP1 were noted between non-responder and responder RA patients. In addition, response to tofacitinib correlated with changes in SAA4 and TIMD4 levels. Conclusion: In summary, this study pinpoints molecular changes linked to cardiovascular disease in RA and proposes candidate protein biomarkers for distinguishing RA patients from healthy individuals. It also highlights how methotrexate and tofacitinib impact these proteins, with distinct alterations corresponding to each drug's response, identifying potential candidates, as SAA4, for the response to these therapies.

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.

Identifying biomarkers of treatment response to ciclosporin in atopic dermatitis through multiomic predictive modelling: DERMATOMICS study protocol.

INTRODUCTION: There is a need to optimise the management of atopic dermatitis (AD), improving the efficacy of treatments and reducing the toxicity associated with them. Although the efficacy of ciclosporine (CsA) in the treatment of AD has been thoroughly documented in the literature, the optimal dose has not been yet established. The use of multiomic predictive models of treatment response could optimise CsA therapy in AD. METHODS AND ANALYSIS: The study is a low-intervention phase 4 trial to optimise the treatment of patients with moderate-severe AD requiring systemic treatment. The primary objectives are to identify biomarkers that could allow for the selection of responders and non-responders to first-line treatment with CsA and to develop a response prediction model to optimise the CsA dose and treatment regimen in responding patients based on these biomarkers. The study is divided into two cohorts: the first comprised of patients starting treatment with CsA (cohort 1), and the second, of patients already receiving or who have received CsA therapy (cohort 2). ETHICS AND DISSEMINATION: The study activities began following authorisation by the Spanish Regulatory Agency (AEMPS) and the Clinical Research Ethics Committee of La Paz University Hospital approval. Trial results will be submitted for publication in an open access peer-reviewed medical speciality-specific publication.Trial registration of this study can be located at the EU Clinical Trials Register, available from https://euclinicaltrials.eu/search-for-clinical-trials/?lang=en. Our clinical trial was registered in the website before the enrolment of the first patient complying with European regulations. EU Clinical Trials Register is a primary registry according the WHO. Once our trial was included in a primary and official registry, in order to extend the accessibility to our research, we also registered it retrospectively in clinicaltrials.gov; however, this is not mandatory as per our regulation. TRIAL REGISTRATION NUMBER: NCT05692843.

Detection of specific RBD+ IgG+ memory B cells by flow cytometry in healthcare workers and patients with inborn errors of immunity after BNT162b2 m RNA COVID-19 vaccination.

Introduction: Inborn errors of immunity (IEI) are a heterogeneous group of diseases caused by intrinsic defects of the immune system. Estimating the immune competence of immunocompromised patients for an infection risk assessment or after SARS-CoV-2 vaccination constituted a challenge. Methods: The aim of this study was to determine the humoral responses of patients with IEI through a comprehensive analysis of specific receptor-binding domain-positive (RBD+) IgG+ memory B cells (MBCs) by flow cytometry, together with routine S-specific IgG antibodies and QuantiFERON SARS-CoV-2 (T-cell response), before the vaccine and 3 weeks after a second dose. Results and discussion: We first analyzed the percentage of specific RBD+ IgG+ MBCs in healthy healthcare workers. Within the control group, there was an increase in the percentage of specific IgG+ RBD+ MBCs 21 days after the second dose, which was consistent with S-specific IgG antibodies.Thirty-one patients with IEI were included for the pre- and post-vaccination study; IgG+ RBD+ MBCs were not evaluated in 6 patients due to an absence of B cells in peripheral blood. We detected various patterns among the patients with IEI with circulating B cells (25, 81%): an adequate humoral response was observed in 12/25, consider by the detection of positive S-specific IgG antibodies and the presence of specific IgG+ RBD+ MBCs, presenting a positive T-cell response; in 4/25, very low S-specific IgG antibody counts correlated with undetectable events in the IgG+ RBD+ MBC compartment but with positive cellular response. Despite the presence of S-specific IgG antibodies, we were unable to detect a relevant percentage of IgG+ RBD+ MBCs in 5/25; however, all presented positive T-cell response. Lastly, we observed a profound failure of B and T-cell response in 3 (10%) patients with IEI, with no assessment of S-specific IgG antibodies, IgG+ RBD+ MBCs, and negative cellular response. The identification of specific IgG+ RBD+ MBCs by flow cytometry provides information on different humoral immune response outcomes in patients with IEI and aids the assessment of immune competence status after SARS-CoV-2 mRNA vaccine (BNT162b2), together with S-specific IgG antibodies and T-cell responses.

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.

Pathogenic mechanisms involving the interplay between adipose tissue and auto-antibodies in rheumatoid arthritis.

We aimed to evaluate the association between adipose tissue (AT) dysfunction, autoimmunity, and disease activity in rheumatoid arthritis (RA). A cross-sectional study including 150 RA patients and 50 healthy donors and longitudinal study with 122 RA patients treated with anti-tumor necrosis factor (TNF)-α, anti-interleukin 6 receptor (IL6R) or anti-CD20 therapies for 6 months were carried out. In vitro experiments with human AT and adipocyte and macrophage cell lines were performed. A collagen-induced arthritis mouse model was developed. The insulin resistance and the altered adipocytokine profile were associated with disease activity, the presence of anti-citrullinated proteins anti-bodies (ACPAs), and worse response to therapy in RA. AT in the context of arthritis is characterized by an inflammatory state alongside the infiltration of macrophages and B/plasmatic cells, where ACPAs can have a direct impact, inducing inflammation and insulin resistance in macrophages and promoting a defective adipocyte differentiation, partially restored by biologicals.

Methotrexate Reduces the Probability of Discontinuation of TNF Inhibitors in Seropositive Patients With Rheumatoid Arthritis. A Real-World Data Analysis.

Tumor necrosis factor inhibitors (TNFi) are widely used for the treatment of patients with rheumatoid arthritis (RA), however a considerable percentage of patients discontinued the therapy. The aim of this study is to explore real-world TNFi survival, stratified for seropositivity, and to determine the factors that may influence it. This is a retrospective, observational and longitudinal study, using real-world data of patients, who started their first TNFi therapy between 1999 and 2018 from the RA-PAZ cohort. Patients were considered seropositive if they showed positive serum levels of either RF, ACPA, or both. Treatment survival was analyzed using Kaplan-Meier curves, and Cox proportional hazards models were used to compare the risks of TNFi discontinuation for seronegative and seropositive patients. Of the included 250 patients, 213 (85%) were seropositive. Results showed that TNFi survival did not depend on seropositivity status. However, median survival time was significant longer for seropositive patients who received concomitant MTX compared to patients who did not receive it (median [95% CI]: 3.3 yr. [2.3-4.2] vs. 2.6 yr. [1.7-3.6], respectively; p = 0.008). Furthermore, seropositive patients who received concomitant MTX were 49% less likely to discontinue TNFi therapy than patients who did not receive it (HR: 0.51; 95% CI: 0.35-0.74). In addition, we found that in seropositive patients, the use of prednisone throughout the TNFi treatment was associated with a higher likelihood of therapy discontinuation (OR: 2.30; 95% CI: 1.01-5.23). In conclusion, these data provide evidence to support the use of concomitant MTX in seropositive patients to prolong the effectiveness and the survival of the TNFi therapy. Moreover, the co-administration of prednisone in seropositive patients receiving TNFi was highly associated with TNFi discontinuation.