Osteochondral Tissue-On-a-Chip: A Novel Model for Osteoarthritis Research.

The existing in vitro and in vivo models for studying osteoarthritis have significant limitations in replicating the complexity of joint tissues. This research aims to validate a Tissue-On-a-Chip system for osteoarthritis research. Osteochondral tissues obtained from knee replacement surgeries of patients with osteoarthritis were cultured in an Organ-On-a-Chip system. This system was designed to supply oxygen and glucose to the cartilage from the bone. The distribution of oxygen and glucose was evaluated by fluorescence using Image-iT Green Hypoxia and 2-NBDG, respectively. Cytotoxicity was measured using lactate dehydrogenase (LDH) levels in chip cultures compared to plate cultures (12 tissues per method). Glycosaminoglycans (GAGs), alkaline phosphatase (ALP), Coll2-1, and procollagen type II N-terminal propeptide (PIINP) were measured in the perfused medium of the Tissue-On-a-Chip over a period of 70 days. Fluorescence of Image-iT Green Hypoxia was observed only in the cartilage area, while 2-NBDG was distributed throughout the tissue. An increase in LDH levels was noted in the plate cultures on day 24 and in the Tissue-On-a-Chip cultures on day 63. Compared to the start of the culture, GAG content increased on day 52, while ALP showed variations. A notable increase in GAG, ALP, and Coll2-1 levels was observed on day 59. PIINP levels remained stable throughout the experiment. The validated osteochondral Tissue-On-a-Chip system can replicate the joint microenvironment, with hypoxic conditions in cartilage and normoxic conditions in bone. Tissue survival and component stability were maintained for approximately two months. This platform is a useful tool for evaluating new drugs and represents a viable alternative to animal models.

Dietary habits in patients with fibromyalgia: a cross-sectional study.

OBJECTIVES: To the scarce information on dietary habits in fibromyalgia (FM), it is added that there are no comparative studies with other rheumatic diseases. The objective of this study was to characterise the dietary habits of patients with FM by comparing, for the first time, with healthy controls (HC) and rheumatoid arthritis (RA). METHODS: This cross-sectional, observational study was based on data obtained from the Dietfibrom project for FM and from the IMID Consortium for RA and HC. All participants completed a food frequency questionnaire evaluating their weekly dietary intake of main food groups. The three cohorts were compared using a multiple logistic regression model adjusted for age, sex, and body mass index. RESULTS: After quality control, n=287 FM, n=1,983 HC and n=1,942 RA patients were analysed. We found that FM had a profound impact in the diet compared to HC, reducing the consumption of dairy (OR=0.32, p<0.0001), bread and/or whole grain cereals (OR=0.59, p=0.0006), fresh fruit (OR=0.66, P=0.008), and fish (OR=0.64, p=0.002). These same four food groups were also significantly reduced in FM patients in comparison to RA patients (p<0.0005 in all cases). Additionally, a lower consumption of pasta, rice and/or potatoes was also observed in FM compared to RA (OR=0.72, p=0.028). CONCLUSIONS: The present cross-sectional study shows that FM is associated to a significant change in the normal dietary patterns. These results underscore the importance of diet in this prevalent disease and are a warning of the potential long-range effects of a deficient nutritional status.

Risk factors for hospital admissions related to COVID-19 in patients with autoimmune inflammatory rheumatic diseases.

OBJECTIVES: To describe patients with autoimmune inflammatory rheumatic diseases (AIRD) who had COVID-19 disease; to compare patients who required hospital admission with those who did not and assess risk factors for hospital admission related to COVID-19. METHODS: An observational longitudinal study was conducted during the pandemic peak of severe acute respiratory syndrome coronavirus 2 (1 March 2020 to 24 April). All patients attended at the rheumatology outpatient clinic of a tertiary hospital in Madrid, Spain with a medical diagnosis of AIRD and with symptomatic COVID-19 were included. The main outcome was hospital admission related to COVID-19. The covariates were sociodemographic, clinical and treatments. We ran a multivariable logistic regression model to assess risk factors for the hospital admission. RESULTS: The study population included 123 patients with AIRD and COVID-19. Of these, 54 patients required hospital admission related to COVID-19. The mean age on admission was 69.7 (15.7) years, and the median time from onset of symptoms to hospital admission was 5 (3-10) days. The median length of stay was 9 (6-14) days. A total of 12 patients died (22%) during admission. Compared with outpatients, the factors independently associated with hospital admission were older age (OR: 1.08; p=0.00) and autoimmune systemic condition (vs chronic inflammatory arthritis) (OR: 3.55; p=0.01). No statistically significant findings for exposure to disease-modifying antirheumatic drugs were found in the final model. CONCLUSION: Our results suggest that age and having a systemic autoimmune condition increased the risk of hospital admission, whereas disease-modifying antirheumatic drugs were not associated with hospital admission.

Prevalence of hospital PCR-confirmed COVID-19 cases in patients with chronic inflammatory and autoimmune rheumatic diseases.

BACKGROUND: The susceptibility of patients with rheumatic diseases and the risks or benefits of immunosuppressive therapies for COVID-19 are unknown. METHODS: We performed a retrospective study with patients under follow-up in rheumatology departments from seven hospitals in Spain. We matched updated databases of rheumatology patients with severe acute respiratory syndrome coronavirus 2-positive PCR tests performed in the hospital to the same reference populations. Rates of PCR+ confirmed COVID-19 were compared among groups. RESULTS: Patients with chronic inflammatory diseases had 1.32-fold higher prevalence of hospital PCR+ COVID-19 than the reference population (0.76% vs 0.58%). Patients with systemic autoimmune or immune-mediated disease (AI/IMID) showed a significant increase, whereas patients with inflammatory arthritis (IA) or systemic lupus erythematosus did not. COVID-19 cases in some but not all diagnostic groups had older ages than cases in the reference population. Patients with IA on targeted-synthetic or biological disease-modifying antirheumatic drugs (DMARDs), but not those on conventional-synthetic DMARDs, had a greater prevalence despite a similar age distribution. CONCLUSION: Patients with AI/IMID show a variable risk of hospital-diagnosed COVID-19. Interplay of ageing, therapies and disease-specific factors seem to contribute. These data provide a basis to improve preventive recommendations to rheumatic patients and to analyse the specific factors involved in COVID-19 susceptibility.

Genetic variation at the glycosaminoglycan metabolism pathway contributes to the risk of psoriatic arthritis but not psoriasis.

OBJECTIVE: Psoriatic arthritis (PsA) is a chronic inflammatory arthritis affecting up to 30% of patients with psoriasis (Ps). To date, most of the known risk loci for PsA are shared with Ps, and identifying disease-specific variation has proven very challenging. The objective of the present study was to identify genetic variation specific for PsA. METHODS: We performed a genome-wide association study in a cohort of 835 patients with PsA and 1558 controls from Spain. Genetic association was tested at the single marker level and at the pathway level. Meta-analysis was performed with a case-control cohort of 2847 individuals from North America. To confirm the specificity of the genetic associations with PsA, we tested the associated variation using a purely cutaneous psoriasis cohort (PsC, n=614) and a rheumatoid arthritis cohort (RA, n=1191). Using network and drug-repurposing analyses, we further investigated the potential of the PsA-specific associations to guide the development of new drugs in PsA. RESULTS: We identified a new PsA risk single-nucleotide polymorphism at B3GNT2 locus (p=1.10e-08). At the pathway level, we found 14 genetic pathways significantly associated with PsA (pFDR<0.05). From these, the glycosaminoglycan (GAG) metabolism pathway was confirmed to be disease-specific after comparing the PsA cohort with the cohorts of patients with PsC and RA. Finally, we identified candidate drug targets in the GAG metabolism pathway as well as new PsA indications for approved drugs. CONCLUSION: These findings provide insights into the biological mechanisms that are specific for PsA and could contribute to develop more effective therapies.

Hyperlipoproteinaemia(a) in patients with spondyloarthritis: results of the Cardiovascular in Rheumatology (CARMA) project.

OBJECTIVES: Cardiovascular (CV) disease is one of the main causes of morbi-mortality in spondyloarthritis (SpA), partially explained by traditional CV risk factors. Information on lipoprotein(a) [Lp(a)], a non-conventional risk factor, in SpA is scarce. In this study we assessed the prevalence of hyperlipoproteinaemia(a) in SpA patients and analysed the possible related factors. METHODS: A baseline analysis was made of ankylosing spondylitis (AS) and psoriatic arthritis (PsA) patients and controls included in the CARMA project (CARdiovascular in RheuMAtology), a 10-year prospective study evaluating the risk of CV events in chronic inflammatory rheumatic diseases. A multivariate logistic regression model was performed using hyperlipoproteinaemia(a) (Lp(a) >50 mg/dl) as a dependent variable and adjusting for confounding factors. RESULTS: 19.2% (95% CI: 16.80-22.05) of the SpA patients [20.7% (95% CI: 16.91-24.82) of those with AS and 17.7% (95% CI: 14.15-21.75) of those with PsA] and 16.7% (95% CI: 13.23-20.86) of the controls had hyperlipoproteinaemia(a) (p=0.326). Adjusting for age and sex, SpA patients were more likely to have hyperlipoproteinaemia(a) than controls (OR: 1.43, 95%CI: 1.00-2.04; p=0.05), especially those with AS (OR: 1.81, 95%CI: 1.18-2.77; p=0.007). In the adjusted model, apolipoprotein B in all patients, non-steroidal anti-inflammatory drugs in AS, and female sex in PsA, were associated with hyperlipoproteinaemia(a). No disease-specific factors associated with hyperlipoproteinaemia(a) were identified. CONCLUSIONS: SpA patients show a moderately increased risk of hyperlipoproteinaemia(a) compared to controls, especially those with AS. Lp(a) determination may be of interest to improve the CV risk assessment in SpA patients.

Treatment with methotrexate and risk of relapses in patients with giant cell arteritis in clinical practice.

OBJECTIVES: To assess the incidence and the risk of relapses in giant cell arteritis (GCA) patients treated with and without methotrexate (MTX) in clinical practice. Other associated factors were also investigated. METHODS: An inception cohort of GCA was assembled in the out-patient clinic at Hospital Clínico San Carlos, including patients from the date of diagnosis (Jan-1991 until Sept-2013), and followed-up until lost of follow up or Sept-2014. MAIN OUTCOME: relapse defined as recurrence of symptoms or signs of GCA with high ESR and the need to increase glucocorticoids at least 10mg over the previous dose. The independent variable was exposure to MTX over time. Covariables: Sociodemographic, clinical, and treatment. Incidence rates of relapses (IR) per 100 patient-year with their 95% confidence intervals [CI] were estimated using survival techniques. MTX influence on relapses was analysed by Cox models. RESULTS: 168 patients were included (675 patient-year). 31% of patients had relapses (IR of 12 [9.6-14.9]), and the median number of relapses was 1[1-2]. 65% of the patients were on MTX, (mean dose: 10mg). In the bivariate analysis, the risk of relapses in patients with and without MTX did not achieve statistical signification (p=0.1). After adjusting in the multivariate analysis, exposure to MTX had 72% less risk of relapse compared to those without MTX (p<0.05). Other variables included in the final model were: visual alterations and malaise at clinical presentation of GCA. CONCLUSIONS: The use of MTX seems to decrease the risk of recurrences. We also found other factors influencing on relapses.

Disease Remission in Children and Adolescents with Intermediate Uveitis: A Survival Analysis.

PURPOSE: To report the incidence rate (IR) of remission in pediatric noninfectious intermediate uveitis (IU). METHODS: Longitudinal retrospective cohort study, including 19 patients (32 eyes) between 1985 and 2014, followed-up until loss or January 2016. Remission was defined following the Standardization of Uveitis Nomenclature workshop criteria, prolonged remission as a remission spanning 12 months and until the end of follow-up, and relapse as recurrence of inflammatory activity in an eye in remission. RESULTS: Median follow-up time was 6.3 years. IRs (95% confidence interval) for remission, relapse, and prolonged remission were 18.6 (13.1-26.5), 32.3 (20.6-50.7), and 6.7 (3.8-11.9) episodes per 100 eye-years, respectively. 48% of eyes relapsed in the first year following remission. 25 and 50% of eyes achieved prolonged remission after 5 and 10 years of follow-up, respectively. CONCLUSIONS: Inflammatory relapses may be frequent in noninfectious IU affecting children and adolescents, appearing early after remission. Also, prolonged remission seems infrequent, being achieved late during follow-up.

Exploring the remission concept in rheumatoid arthritis with patients and rheumatologists: time for a new approach?

OBJECTIVES: To explore the remission concept in rheumatoid arthritis (RA) and to compare remission definitions and related concepts between rheumatologists and patients with the purpose of identifying similarities and disparities to comprehend the different perspectives of the disease. METHODS: This was a qualitative study of discourse and content analysis through focus groups, conducted from February to March 2016. Four focus groups were set up, each one with different interests: rheumatologists involved in basic research (BR), rheumatologists with high specialisation in imaging techniques (IR), clinical rheumatologists (CR), and patients (PA). RESULTS: There is no consensus in a remission definition in RA; differences exist between-groups, rheumatologists and patients value remission differently, and there are discrepancies within the group of rheumatologists. Rheumatologists highlight quantifiable objective parameters, in contrast, patients did not consider objective measures as the best instruments, and they prefer subjective measures of remission. The data confirmed the existence of two sources of knowledge of the disease, technical (physicians) and experiential (patients). These sources of knowledge should concur in order to establish new remission criteria well-adjusted to reality. CONCLUSIONS: The lack of consensus between key groups implicated in defining remission and remission criteria suggests a new strategy for its operational definition. Our group proposes that subjects with a balance between experiential and technical knowledge, should be the ones in charge of this assignment.

The rs3771863 single nucleotide polymorphism of the TACR1 gene is associated to a lower risk of sicca syndrome in fibromyalgia patients.

OBJECTIVES: Fibromyalgia (FM) has been associated with affective spectrum disorders and other chronic pain disorders, which tend to co-occur in individuals and co-aggregate among families. The objective of our study was to investigate the genetic risk factors associated with the presence of related symptoms and with disease severity in subjects affected with FM. METHODS: Two independent cohorts of subjects diagnosed with FM according to the 1990 ACR criteria were studied. A genetic array composed of 320 single nucleotide polymorphisms (SNPs) was analysed in a discovery cohort comprised by 564 patients, and the most suggestive variants were genotyped in a replication cohort, comprised by 397 subjects. The associated conditions and related symptoms analysed were: the presence of depression, sleep disorders, headache, myofascial syndrome, irritable bowel syndrome, chronic fatigue syndrome, vertiginous syndrome, chronic cystitis, and sicca syndrome. FM severity was assessed by the Fibromyalgia Impact Questionnaire and the Hospital Anxiety and Depression Scale. Analyses were adjusted by elapsed time from pain onset, and a meta-analysis was performed to pool the results. RESULTS: Minor allele of the rs3771863 SNP from the TACR1 gene showed a significant association with a lower risk of sicca syndrome (pooled and adjusted OR 0.56, [95%CI 0.42-0.76], p=0.00022). CONCLUSIONS: Our findings indicate a role of the TACR1 gene in the development of sicca syndrome in subjects affected with FM.

Signature of microRNA expression during osteogenic differentiation of bone marrow MSCs reveals a putative role of miR-335-5p in osteoarthritis.

BACKGROUND: The aim of this study was to evaluate, the existence of a signature of differentially expressed microRNAs (miRNAs) during osteogenic differentiation of bone marrow MSCs from OA and healthy donors and to describe their possible implication in joint regeneration through modulation of molecular mechanisms involved in homeostatic control in OA pathophysiology. METHODS: Following phenotypic assessment of BM-MSCs obtained from OA diagnosed patients (n = 10) and non-OA (n = 10), total small RNA was isolated after osteogenic induction for 1, 10 and 21 days, miRNA profiles were generated using a commercial expression array of 754 well-characterized miRNAs. MiRNAs, with consistent differential expression were selected for further validation by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis. RESULTS: A total of 246 miRNAs were differentially expressed (fold change ≥ ± 2, P ≤0.05) between OA and non-OA BM-MSC samples; these miRNAs showed variable interactions depending on the cell and differentiation status. Two miRNAs, hsa-miR-210 and hsa-miR-335-5p out of 21 used for validation showed a significant downregulated expression during induced osteogenesis. In particular hsa-miR-335-5p, a critical regulator in bone homeostasis, was further studied. hsa-miR-335-5p downregulation in OA-MSCs, as well as their host coding gene, MEST, were also assessed. CONCLUSIONS: To our knowledge, this study represents the most comprehensive assessment to date of miRNA expression profiling in BM-MSCs from OA patients and their role during osteogenic differentiation. We describe the existence of a correlation between miR-335-5p expression and OA indicating the putative role of this miRNA in OA features. These findings, may contribute to our understanding of the molecular mechanisms involved in MSCs mediated homeostatic control in OA pathophysiology that could be applicable in future therapeutic approaches.

Selected reaction monitoring assays in mesenchymal stem cells from osteoarthritis patients.

Osteoarthritis (OA) is considered the most prevalent form of arthritis. The aim of this study was to verify potential protein OA biomarkers by applying Selected Reaction Monitoring (SRM) assays to protein extracts obtained from Bone Marrow-Mesenchymal Stem Cells (BM-MSCs) isolated from OA patients. BM aspirates were obtained from the femoral channel of OA patients at the time of surgery and from the femoral channel of hip fracture subjects without OA during hip joint replacement surgery for the treatment of subcapital fracture. SRM results verified the differential expression of several protein biomarkers in BM-MSCs from OA patients.

Lack of association between ABO, PPAP2B, ADAMST7, PIK3CG, and EDNRA and carotid intima-media thickness, carotid plaques, and cardiovascular disease in patients with rheumatoid arthritis.

INTRODUCTION: Rheumatoid arthritis (RA) is a polygenic disease associated with accelerated atherosclerosis and increased cardiovascular (CV) mortality. Recent studies have identified the ABO rs579459, PPAP2B rs17114036, and ADAMTS7 rs3825807 polymorphisms as genetic variants associated with coronary artery disease and the PIK3CG rs17398575 and EDNRA rs1878406 polymorphisms as the most significant signals related to the presence of carotid plaque in nonrheumatic Caucasian individuals. Accordingly, we evaluated the potential relationship between these 5 polymorphisms and subclinical atherosclerosis (assessed by carotid intima-media thickness (cIMT) and presence/absence of carotid plaques) and CV disease in RA. MATERIAL AND METHODS: 2140 Spanish RA patients were genotyped for the 5 polymorphisms by TaqMan assays. Subclinical atherosclerosis was evaluated in 620 of these patients by carotid ultrasonography technology. RESULTS: No statistically significant differences were found when each polymorphism was assessed according to cIMT values and presence/absence of carotid plaques in RA, after adjusting the results for potential confounders. Moreover, no significant differences were obtained when RA patients were stratified according to the presence/absence of CV disease after adjusting for potential confounders. CONCLUSION: Our results do not confirm association between ABO rs579459, PPAP2B rs17114036, ADAMTS7 rs3825807, PIK3CG rs17398575, and EDNRA rs1878406 and subclinical atherosclerosis and CV disease in RA.

Effect of combined treatment with prednisone and methotrexate versus prednisone alone over laboratory parameters in giant cell arteritis.

OBJECTIVE: To compare the effect of combined treatment with prednisone and methotrexate (MTX) versus prednisone alone over laboratory parameters in giant cell arteritis (GCA). PATIENTS AND METHODS: We performed a double-blind, placebo-controlled, randomized clinical trial about usefulness of treatment with prednisone and MTX versus prednisone and placebo in GCA (Ann Intern Med 2001;134:106-114). As a part of follow-up of patients (n=42), we performed laboratory analysis in 20 time points during the two-year period of follow-up. To analyze differences, we calculated the area under the curve (AUC) for erythrocyte sedimentation rate (ESR), hemoglobin, and platelets, and compared the results in both groups adjusting by time of follow-up, existence of relapses and dose of prednisone. RESULTS: A total of 724 laboratory measurements were done. Median value of ESR was 33 [18-56] in patients with placebo and 26 [15-44] in patients with MTX (P=0.0002). No significant differences were observed in ESR during relapses. The mean ESR value followed a parallel course in both groups, but was lower in the group with MTX than in the group with placebo in 18 of 20 time points of follow-up. The AUC of ESR by time of follow-up was 28,461.7±12,326 in the group with placebo and 19,598.4±8,117 in the group with MTX (mean difference 8,863, 95% CI 1.542-16.184; P=0.019). The course of other laboratory parameters paralleled, without statistical significance, those observed for ESR. CONCLUSIONS: These data, along with clinical data, suggest that MTX might play a role as a disease-modifying agent in the treatment of GCA.

Dysregulation of Glypicans and Notum in Osteoarthritis: Plasma Levels, Bone Marrow Mesenchymal Stromal Cells and Osteoblasts.

In this study of the alterations of Glypicans 1 to 6 (GPCs) and Notum in plasma, bone marrow mesenchymal stromal cells (BM-MSCs) and osteoblasts in Osteoarthritis (OA), the levels of GPCs and Notum in the plasma of 25 patients and 24 healthy subjects were measured. In addition, BM-MSCs from eight OA patients and eight healthy donors were cultured over a period of 21 days using both a culture medium and an osteogenic medium. Protein and gene expression levels of GPCs and Notum were determined using ELISA and qPCR at 0, 7, 14 and 21 days. GPC5 and Notum levels decreased in the plasma of OA patients, while the BM-MSCs of OA patients showed downexpression of GPC6 and upregulation of Notum. A decrease in GPC5 and Notum proteins and an increase in GPC3 were found. During osteogenic differentiation, elevated GPCs 2, 4, 5, 6 and Notum mRNA levels and decreased GPC3 were observed in patients with OA. Furthermore, the protein levels of GPC2, GPC5 and Notum decreased, while the levels of GPC3 increased. Glypicans and Notum were altered in BM-MSCs and during osteogenic differentiation from patients with OA. The alterations found point to GPC5 and Notum as new candidate biomarkers of OA pathology.

The potential role of fatigue in difficult-to-treat rheumatoid arthritis.

OBJECTIVES: A subset of patients with rheumatoid arthritis (RA) who remains symptomatic after failing to multiple drugs are deemed to have "difficult-to-treat RA" (D2T RA). Fatigue is a burdensome symptom for RA patients, hindering their improvement. Our purpose was to evaluate the role of fatigue in D2T RA. METHODS: This cross-sectional study included rheumatoid arthritis (RA) patients between 2018 and 2022, treated with biological agents or targeted synthetic disease-modifying antirheumatic drugs. D2T RA was defined attending EULAR criteria. Independent variable was fatigue (dimensions and impact) assessed by the Bristol Rheumatoid Arthritis Fatigue Multidimensional Questionnaire and Numerical Rating Scales. Covariables: sociodemographic, clinical and treatment. To identify factors independently associated to D2T RA, multivariable logistic regression was run. RESULTS: The study included 145 patients and 38 (26.21%) developed D2T RA. D2T RA group were older, with more comorbidity and disability. D2T RA patients scored higher for global fatigue (p = 0.003), and almost for all their dimensions except for cognitive fatigue (p = 0.06) and fatigue coping (p = 0.07). Females with D2T RA showed more fatigue than those with non-D2T RA. In the adjusted models, all fatigue dimensions were associated with D2T RA: global fatigue RA (OR: 1.03; p = 0.007), physical (OR: 1.09; p = 0.008), living (OR: 1.09; p = 0.016), cognitive (OR: 1.1; p = 0.046) and emotional (OR: 1.18; p = 0.012). CONCLUSIONS: Despite the absence of an explicit mention of fatigue in the definition of D2T RA, it appears to be associated to this outcome. Fatigue should be evaluated in a multidimensional perspective, and gender-specific differences should be considered.

Switching related to inefficacy in biologics and targeted synthetic therapies for psoriatic arthritis: a comparative real-life study.

Background: Switching between therapies is a recommended strategy for psoriatic arthritis (PsA) patients who experience treatment failure; however, studies including real-life data are scarce. Objectives: To assess the incidence rate (IR) of switching between biologics and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) due to inefficacy in PsA, and to compare the risk of switching due to inefficacy across different b/tsDMARDs groups. Design: A longitudinal retrospective study, spanning from 2007 to 2022, was conducted on patients with PsA treated with b/tsDMARDs at an outpatient rheumatology clinic. Methods: The primary outcome was switching between b/tsDMARDs due to inefficacy. The independent variable was the exposure to b/tsDMARDs during follow-up. As covariates, clinical, treatment-related, and sociodemographic variables were considered. Survival techniques were run to estimate the IR of switching due to inefficacy per 100 patients*year and confidence interval at 95% (95% CI). Cox multivariate regression analyses were run to assess the risk of b/tsDMARDs switching due to inefficacy, expressed as hazard ratio (HR) and 95% CI. Results: In all, 141 patients were included, with 893.09 patients*year follow-ups. 52.48% of them were females in their fifties. In total, 262 courses of treatment were recorded. During the study period, 56 patients presented 121 switches and 103 related to inefficacy (IR: 11.53 (9.51-13.98)). Tumor necrosis factor-alpha inhibitors (TNFi) showed the lowest IR. In the bivariate analysis, all b/tsDMARDs had more risk of switching compared to TNFi (HR: anti-lL-17 vs TNFi: 2.26 (1.17-4.36); others vs TNFi: 3.21 (1.59-6.45)); however, this statistical significance was no longer present in the multivariate analysis once adjustments were made for the covariates. Still, the final model achieved statistical significance in the following variables: gender, clinical symptoms, prescription year, therapy courses, glucocorticoids, and sulfasalazine. Conclusion: In this study, we did not find differences in the rate of switching due to inefficacy among different groups of b/tsDMARDs. Other concomitant treatments, sociodemographic, and clinical variables were identified as risk factors for switching due to inefficacy.

METHODS: We included patients from 2007 to 2022 in which their consultant rheumatologist had decided to commence them on biologic therapy. We studied the changes due to drug failure, we also included sociodemographic, clinical and treatments information. RESULTS: The study comprised 141 patients. 52% were women in their fifties. We found that 56 patients change drugs 121 times, with 103 of those changes due to failure drug. This means about 11 out of every 100 patients change their biologic therapy each year. There was no difference in the risk of change between the different studied biologic therapies. Women, those with inflammatory back pain, and those who had tried many different drugs were more likely to change due to drug failure. Using additional therapies like glucocorticoids and sulfasalazine also increased the probability of biologic therapy change. CONCLUSION: Our work did not find differences in the risk of change due to drug failure among different biologic therapies.

Changes due to drug failure between biologic therapies: a real-life study in psoriatic arthritis patients Introduction: We wanted to evaluate how often patients with psoriatic arthritis change between different drugs because the drugs weren't working well enough. Additionally, we evaluated which factors could influence the change due to drug failure. The studied drugs are biological therapies that are arthritis-modifying drugs designed early in the last decade to prevent or reduce inflammation caused by the disease.

Alternative splicing and proteolytic rupture contribute to the generation of soluble IL-6 receptors (sIL-6R) in rheumatoid arthritis.

OBJECTIVE: To describe the relationship between the two mechanisms involved in sIL6R generation in rheumatoid arthritis (RA). METHOD: RA patients were selected from a group of subjects genotyped for the rs8192284 SNP, located at the proteolytic cleavage site of IL-6R. sIL6R and protease levels (ADAM17) were measured and the contribution of alternative splicing in the generation of sIL-6R was evaluated through qRT-PCR. RESULT: Increased sIL-6R plasma levels and expression of spliced isoform generating sIL-6R are genotype dependent. ADAM17 concentrations were independent of the genotype studied. CONCLUSION: Alternative splicing and proteolytic cleavage participate in sIL-6R generation in RA. The rs8192284 polymorphism determines the sIL-6R plasma level through differential proteolytic rupture controlled by ADAM17.