Seven-chain adaptive immune receptor repertoire analysis in rheumatoid arthritis reveals novel features associated with disease and clinically relevant phenotypes.

BACKGROUND: In rheumatoid arthritis (RA), the activation of T and B cell clones specific for self-antigens leads to the chronic inflammation of the synovium. Here, we perform an in-depth quantitative analysis of the seven chains that comprise the adaptive immune receptor repertoire (AIRR) in RA. RESULTS: In comparison to controls, we show that RA patients have multiple and strong differences in the B cell receptor repertoire including reduced diversity as well as altered isotype, chain, and segment frequencies. We demonstrate that therapeutic tumor necrosis factor inhibition partially restores this alteration but find a profound difference in the underlying biochemical reactivities between responders and non-responders. Combining the AIRR with HLA typing, we identify the specific T cell receptor repertoire associated with disease risk variants. Integrating these features, we further develop a molecular classifier that shows the utility of the AIRR as a diagnostic tool. CONCLUSIONS: Simultaneous sequencing of the seven chains of the human AIRR reveals novel features associated with the disease and clinically relevant phenotypes, including response to therapy. These findings show the unique potential of AIRR to address precision medicine in immune-related diseases.

Acroosteolysis and facial dysmorphia: a new case of Hajdu-Cheney syndrome.

Hajdu-Cheney syndrome or acro-dento-osteo-dysplasia syndrome is a rare disease characterized by band osteolysis of distal phalanges and facial dysmorphia, among other manifestations. We present the case of a 45-year-old male who consulted for mechanical joint pain of both hands, facial dysmorphism, cranio-facial alterations, and digital telescoping with acroosteolysis.

Humoral responses against HDL are linked to lipoprotein traits, atherosclerosis, inflammation and pathogenic pathways during early arthritis stages.

OBJECTIVE: Chronic inflammation and immune dysregulation are crucial mechanisms for atherosclerosis in RA. Recent evidence suggests a link via humoral responses against high-density lipoproteins (HDL). This study aimed to characterize the specificity, clinical relevance and emergence of humoral responses against HDL along disease course, especially during the earliest phases of arthritis. METHODS: IgG and IgM serum levels of antibodies against HDL (anti-HDL) and apolipoprotein A1 (anti-ApoA1) were measured in 82 early RA patients, 14 arthralgia individuals and 96 controls. Established RA patients (n = 42) were included for validation. Atherosclerosis and vascular stiffness were measured by Doppler ultrasound. Lipoprotein content, particle numbers and size were measured by H-NMR. Cytokines were measured by immunoassays. A cardiometabolic-related protein panel was evaluated using high-throughput targeted proteomics. RESULTS: Anti-HDL and anti-ApoA1 responses were increased in early RA compared with controls (both P < 0.001) and were comparable to established disease. Only anti-ApoA1 antibodies were increased in arthralgia. IgG anti-HDL and anti-ApoA1 were associated with unfavourable lipoprotein traits in RA and arthralgia, respectively. A similar picture was observed for inflammatory mediators. No associations with clinical features or risk factors were found. IgG anti-HDL were independently associated with atherosclerosis occurrence in early RA, and outperformed patient stratification over conventional algorithms (mSCORE) and their anti-ApoA1 counterparts. Anti-HDL antibodies correlated with proteins involved in immune activation, remodelling and lipid metabolism pathways in early RA. CONCLUSION: Humoral responses against HDL particles are an early event along the arthritis course, although quantitative and qualitative differences can be noticed among stages. These differences informed distinct capacities as biomarkers and underlying pathogenic circuits.

Longitudinal analysis of blood DNA methylation identifies mechanisms of response to tumor necrosis factor inhibitor therapy in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic, immune-mediated inflammatory disease of the joints that has been associated with variation in the peripheral blood methylome. In this study, we aim to identify epigenetic variation that is associated with the response to tumor necrosis factor inhibitor (TNFi) therapy. METHODS: Peripheral blood genome-wide DNA methylation profiles were analyzed in a discovery cohort of 62 RA patients at baseline and at week 12 of TNFi therapy. DNA methylation of individual CpG sites and enrichment of biological pathways were evaluated for their association with drug response. Using a novel cell deconvolution approach, altered DNA methylation associated with TNFi response was also tested in the six main immune cell types in blood. Validation of the results was performed in an independent longitudinal cohort of 60 RA patients. FINDINGS: Treatment with TNFi was associated with significant longitudinal peripheral blood methylation changes in biological pathways related to RA (FDR<0.05). 139 biological functions were modified by therapy, with methylation levels changing systematically towards a signature similar to that of healthy controls. Differences in the methylation profile of T cell activation and differentiation, GTPase-mediated signaling, and actin filament organization pathways were associated with the clinical response to therapy. Cell type deconvolution analysis identified CpG sites in CD4+T, NK, neutrophils and monocytes that were significantly associated with the response to TNFi. INTERPRETATION: Our results show that treatment with TNFi restores homeostatic blood methylation in RA. The clinical response to TNFi is associated to methylation variation in specific biological pathways, and it involves cells from both the innate and adaptive immune systems. FUNDING: The Instituto de Salud Carlos III.

Experts document on methotrexate use in combined therapy with biological or targeted synthetic disease modifying drugs in patients with rheumatoid arthritis.

OBJECTIVE: We aimed to develop recommendations for the management of methotrexate (MTX) when considering the combination with biological (b) or targeted synthetic (ts) disease modifying drugs (DMARDs) in rheumatoid arthritis (RA). METHODS: Eleven experts on RA were selected. Two coordinators formulated 13 questions about the combination therapy of MTX with bDMARDs or tsDMARDs. A systematic review was conducted to answer the questions. Inclusion and exclusion criteria were established as well as the search strategies (Medline, Embase and the Cochrane Library were searched up to January 2019). Two reviewers selected the articles and collected data. Simultaneously, EULAR and ACR meeting abstracts were evaluated. Based on this evidence, the coordinators proposed preliminary recommendations that the experts discussed and voted in a nominal group meeting. The level of evidence and grade of recommendation was established using the Oxford Center for Evidence Based Medicine and the level of agreement with a Delphi. Agreement was established if at least 80% of the experts voted 'yes' (yes/no). RESULTS: The systematic review retrieved 513 citations of which 61 were finally included. A total of 10 recommendations were generated, voted and accepted. The level of agreement was very high in all of them and it was achieved in the first Delphi round. Final recommendations cover aspects such as the optimal MTX dosage, tapering strategy or patients' risk management. CONCLUSIONS: This document is intended to help clinicians solve usual clinical questions and facilitate decision making when treating RA patients with MTX in combination with bDMARDs or tsDMARDs.

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.

Do NSAIDs Take Us Away From Treatment Goals in Axial Spondyloarthritis: A Story About Dysbiosis or Just a Matter of Bias?

Non-steroidal anti-inflammatory drugs (NSAIDs) remain the mainstay of treatment for spondyloarthritides (SpA), a group of entities with common clinical and pathophysiological aspects, but also with differential features. Although NSAIDs provide significant symptomatic relief, especially for joint pain and morning stiffness, their role in achieving and maintaining the treatment goals advocated by the treat to target strategy in SpA is not entirely clear. These agents can induce changes in the composition of the intestinal microbiota, also favoring an alteration of the barrier function in the gut epithelium. All of this, favored by a pre-disposing genetic background, could activate a specific type of aberrant immune response in the gut lamina propria, also known as type-3 immunity. This article offers a perspective on how NSAIDs, despite their undeniable value in the short-term SpA treatment, could hinder the achievement of medium and long-term treatment goals by compromising the barrier function of the gut mucosa and potentially altering the composition of the gut microbiota.

Profiling of Serum Oxylipins During the Earliest Stages of Rheumatoid Arthritis.

OBJECTIVE: Eicosanoids modulate inflammation via complex networks involving different pathways and downstream mediators, including oxylipins. Although altered eicosanoids are linked to rheumatoid arthritis (RA), suggesting that metabolization is enhanced, the role of oxylipins in disease stratification remains unexplored. This study was undertaken to characterize oxylipin networks during the earliest stages of RA and evaluate their associations with clinical features and treatment outcomes. METHODS: In total, 60 patients with early RA (according to the American College of Rheumatology/European League Against Rheumatism 2010 criteria), 11 individuals with clinically suspect arthralgia (CSA), and 28 healthy control subjects were recruited. Serum samples were collected at the time of onset. In the early RA group, 50 patients who had not been exposed to disease-modifying antirheumatic drug (DMARD) or glucocorticoid treatment at the time of recruitment were prospectively followed up at 6 and 12 months after having received conventional synthetic DMARDs. A total of 75 oxylipins, mostly derived from arachidonic, eicosapentanoic, and linoleic acids, were identified in the serum by liquid chromatography tandem mass spectrometry. RESULTS: Univariate analyses demonstrated differences in expression patterns of 14 oxylipins across the RA, CSA, and healthy control groups, with each exhibiting a different trajectory. Network analyses revealed a strong grouping pattern of oxylipins in RA patients, whereas in individuals with CSA, a fuzzy network of oxylipins with higher degree and closeness was found. Partial least-squares discriminant analyses yielded variable important projection scores of >1 for 22 oxylipins, which allowed the identification of 2 clusters. Cluster usage differed among the groups (P = 0.003), and showed associations with disease severity and low rates of remission at 6 and 12 months in RA patients who were initially treatment-naive. Pathway enrichment analyses revealed different precursors and pathways between the groups, highlighting the relevance of the arachidonic acid pathway in individuals with CSA and the lipooxygenase pathway in patients with early RA. In applying distinct oxylipin signatures, subsets of seropositive and seronegative RA could be identified. CONCLUSION: Oxylipin networks differ across stages during the earliest phases of RA. These distinct oxylipin networks could potentially elucidate pathways with clinical relevance for disease progression, clinical heterogeneity, and treatment response.

Experts document on methotrexate use in combined therapy with biological or targeted synthetic disease modifying drugs in patients with rheumatoid arthritis.

OBJECTIVE: We aimed to develop recommendations for the management of methotrexate (MTX) when considering the combination with biological (b) or targeted synthetic (ts) disease modifying drugs (DMARDs) in rheumatoid arthritis (RA). METHODS: Eleven experts on RA were selected. Two coordinators formulated 13 questions about the combination therapy of MTX with bDMARDs or tsDMARDs. A systematic review was conducted to answer the questions. Inclusion and exclusion criteria were established as well as the search strategies (Medline, Embase and the Cochrane Library were searched up to January 2019). Two reviewers selected the articles and collected data. Simultaneously, EULAR and ACR meeting abstracts were evaluated. Based on this evidence, the coordinators proposed preliminary recommendations that the experts discussed and voted in a nominal group meeting. The level of evidence and grade of recommendation was established using the Oxford Center for Evidence Based Medicine and the level of agreement with a Delphi. Agreement was established if at least 80% of the experts voted 'yes' (yes/no). RESULTS: The systematic review retrieved 513 citations of which 61 were finally included. A total of 10 recommendations were generated, voted and accepted. The level of agreement was very high in all of them and it was achieved in the first Delphi round. Final recommendations cover aspects such as the optimal MTX dosage, tapering strategy or patients' risk management. CONCLUSIONS: This document is intended to help clinicians solve usual clinical questions and facilitate decision making when treating RA patients with MTX in combination with bDMARDs or tsDMARDs.

GlycA Levels during the Earliest Stages of Rheumatoid Arthritis: Potential Use as a Biomarker of Subclinical Cardiovascular Disease.

This study aimed at evaluating the clinical relevance of glycoprotein profiles during the earliest phases of rheumatoid arthritis (RA) as biomarkers of cardiovascular (CV) risk and treatment response. Then, GlycA and GlycB serum levels were measured using 1H-nuclear magnetic resonance in 82 early RA patients, 14 clinically-suspect arthralgia (CSA), and 28 controls. Serum glycosyltransferase activity was assessed by a colorimetric assay. Subclinical CV disease was assessed by Doppler-ultrasound. We found that GlycA and GlycB serum levels were increased in RA (both p < 0.001), but not in CSA, independently of cardiometabolic risk factors. Increased serum glycosyltransferase activity paralleled GlycA (r = 0.405, p < 0.001) and GlycB levels (r = 0.327, p = 0.005) in RA. GlycA, but not GlycB, was associated with atherosclerosis occurrence (p = 0.012) and severity (p = 0.001). Adding GlycA to the mSCORE improved the identification of patients with atherosclerosis over mSCORE alone, increasing sensitivity (29.7 vs. 68.0%) and accuracy (55.8 vs. 76.6%) and allowing reclassification into more appropriate risk categories. GlycA-reclassification identified patients with impaired lipoprotein metabolism. Finally, baseline GlycA levels predicted poor clinical response upon anti-rheumatic treatment at 6 and 12 months in univariate and multivariate analysis. In sum, increased GlycA levels during the earliest stage of RA can be considered a powerful biomarker for CV risk stratification and treatment response.

Biological Dose Tapering in Daily Clinical Practice: A 10 Year Follow-up Study.

OBJECTIVE: To describe practice patterns, long-term outcome, and related factors, in relation to biological therapies tapering in rheumatoid arthritis (RA) patients in a well-controlled real-world setting. METHODS: An observational longitudinal retrospective 10-year study was conducted in all RA patients receiving biological agents in an RA clinic from May 2003 to October 2013. Biological treatment of patients with sustained DAS28<3.2 or SDAI<11 was tapered (dose down-titrated or interval widen) or discontinued as per practice protocol. Primary outcome of tapering was relapse, defined as an increase in DAS28≥1.2. Descriptive, survival analysis, and logistic regression analysis with first relapse as dependent variable were carried out. RESULTS: Of 193 RA patients on biological treatment (mean age 54±14 years, 81% women), tapering was applied in 106 (55%) and discontinuation in 34 (17.6%). During follow-up 38 patients relapsed (62%). Rate of relapse was 10% at 6 months, 19% at 12 months, 33.2% at 2 years and 50% after 5 years. Mean time in dose reduction was 4.5 years [95% confidence interval (95% CI): 3.7-5.3]. Six patients (15.7%) did not respond after reinstatement of full dose of biologic. In the multivariate analysis, pain [OR=1.26 (95% CI: 1.11-1.43); P<.001] and erythrocyte sedimentation rate (ESR) [OR=1.01 (95% CI: 1.00-1.03); P=.011] at baseline were associated with relapse after tapering. CONCLUSIONS: Tapering may be considered a long-term option in RA patients on biologics and low disease activity, especially if low ESR and pain scores are present at baseline; treatment reinstatement could be considered a safe option in case of relapse.

A Combined Transcriptomic and Genomic Analysis Identifies a Gene Signature Associated With the Response to Anti-TNF Therapy in Rheumatoid Arthritis.

Background: Rheumatoid arthritis (RA) is the most frequent autoimmune disease involving the joints. Although anti-TNF therapies have proven effective in the management of RA, approximately one third of patients do not show a significant clinical response. The objective of this study was to identify new genetic variation associated with the clinical response to anti-TNF therapy in RA. Methods: We performed a sequential multi-omic analysis integrating different sources of molecular information. First, we extracted the RNA from synovial biopsies of 11 RA patients starting anti-TNF therapy to identify gene coexpression modules (GCMs) in the RA synovium. Second, we analyzed the transcriptomic association between each GCM and the clinical response to anti-TNF therapy. The clinical response was determined at week 14 using the EULAR criteria. Third, we analyzed the association between the GCMs and anti-TNF response at the genetic level. For this objective, we used genome-wide data from a cohort of 348 anti-TNF treated patients from Spain. The GCMs that were significantly associated with the anti-TNF response were then tested for validation in an independent cohort of 2,706 anti-TNF treated patients. Finally, the functional implication of the validated GCMs was evaluated via pathway and cell type epigenetic enrichment analyses. Results: A total of 149 GCMs were identified in the RA synovium. From these, 13 GCMs were found to be significantly associated with anti-TNF response (P < 0.05). At the genetic level, we detected two of the 13 GCMs to be significantly associated with the response to adalimumab (P = 0.0015) and infliximab (P = 0.021) in the Spain cohort. Using the independent cohort of RA patients, we replicated the association of the GCM associated with the response to adalimumab (P = 0.0019). The validated module was found to be significantly enriched for genes involved in the nucleotide metabolism (P = 2.41e-5) and epigenetic marks from immune cells, including CD4+ regulatory T cells (P = 0.041). Conclusions: These findings show the existence of a drug-specific genetic basis for anti-TNF response, thereby supporting treatment stratification in the search for response biomarkers in RA.

Vitamin D Receptor Polymorphism and DHCR7 Contribute to the Abnormal Interplay Between Vitamin D and Lipid Profile in Rheumatoid Arthritis.

Emerging evidence suggests a role for 7-dehydrocholesterol reductase (DHCR7) in the crosstalk between cholesterol and vitamin D. Our aim was to evaluate the impact of vitamin D-related polymorphisms and DHCR7 levels in the association between vitamin D deficiency and altered lipid profile in rheumatoid arthritis (RA). Serum 25(OH)-vitamin D, DHCR7 levels and vitamin D-related polymorphisms (VDR-rs2228570, CYP27A1-rs933994, CYP2R1-rs10741657 and DHCR7-rs12785878) were analyzed in 211 RA patients,94 controls and in a prospective cohort of 13 RA patients undergoing TNFα-blockade. Vitamin D was decreased in RA (p < 0.001), correlated to HDL-cholesterol (r = 0.217, p < 0.001) and total-/HDL-cholesterol ratio (r = -0.227, p = 0.004). These correlations were restricted to the VDR-rs2228570 status. Vitamin D deficiency was associated with lower HDL-cholesterol (p = 0.028), higher tender (p = 0.005) and swollen (p = 0.002) joint counts, higher DAS28 (p = 0.018) and HAQ (p = 0.024) in AG/AA-patients but not in their GG-counterparts. The associations among DHCR7, vitamin D and lipid profile followed a seasonal pattern, decreased DHCR7 (p = 0.008) and vitamin D (p < 0.001) and increased total-cholesterol (p = 0.025) being found in winter/spring. Increasing vitamin D upon TNFα-blockade paralleled RA clinical improvement (r = -0.610, p = 0.027) and DHCR7 elevation (r = 0.766, p = 0.002). In conclusion, vitamin D-related polymorphisms and DHCR7 are pivotal to understand the complex, seasonal associations between vitamin D and lipid profile in RA.

Identification of a 3'-Untranslated Genetic Variant of RARB Associated With Carotid Intima-Media Thickness in Rheumatoid Arthritis: A Genome-Wide Association Study.

OBJECTIVE: To investigate the genetic background influencing the development of cardiovascular (CV) disease in patients with rheumatoid arthritis (RA). METHODS: We performed a genome-wide association study (GWAS) in which, after quality control and imputation, a total of 6,308,944 polymorphisms across the whole genome were analyzed in 2,989 RA patients of European origin. Data on subclinical atherosclerosis, obtained through assessment of carotid intima-media thickness (CIMT) and presence/absence of carotid plaques by carotid ultrasonography, were available for 1,355 individuals. RESULTS: A genetic variant of the RARB gene (rs116199914) was associated with CIMT values at the genome-wide level of significance (minor allele [G] ß coefficient 0.142, P = 1.86 × 10-8 ). Interestingly, rs116199914 overlapped with regulatory elements in tissues related to CV pathophysiology and immune cells. In addition, biologic pathway enrichment and predictive protein-protein relationship analyses, including suggestive GWAS signals of potential relevance, revealed a functional enrichment of the collagen biosynthesis network related to the presence/absence of carotid plaques (Gene Ontology no. 0032964; false discovery rate-adjusted P = 4.01 × 10-3 ). Furthermore, our data suggest potential influences of the previously described candidate CV risk loci NFKB1, MSRA, and ZC3HC1 (P = 8.12 × 10-4 , P = 5.94 × 10-4 , and P = 2.46 × 10-4 , respectively). CONCLUSION: The present findings strongly suggest that genetic variation within RARB contributes to the development of subclinical atherosclerosis in patients with RA.

Prevalence of comorbidities in rheumatoid arthritis and evaluation of their monitoring in clinical practice: the spanish cohort of the COMORA study.

OBJECTIVES: To describe the prevalence of comorbidities in patients with RA in Spain and discuss their management and implications using data from the Spanish cohort of the multinational study on COMOrbidities in Rheumatoid Arthritis (COMORA). METHODS: This is a national sub-analysis of the COMORA study. We studied the demographics and disease characteristics of 200 adults patients diagnosed with RA (1987 ACR), and routine practices for screening and preventing the following selected comorbidities: cardiovascular, infections, cancer, gastrointestinal, pulmonary, osteoporosis and depression. RESULTS: Patients had a mean age of 58 years and a mean RA duration of 10 years. Mean DAS28 score was 3.3 and approximately 25% of patients were in remission (DAS28 <2.6). Forty-four (22%) patients had ≥1 comorbidity, the most frequent being depression (27%) and obesity (26%). A history of myocardial infarction or stroke was observed in 5% and 1% of patients, respectively, and any solid tumor in 6%. Having a Framingham Risk Score >20% (51%), hypercholesterolemia (46%) or hypertension (41%) and smoking (25%) were the most common CV risk factors. For prostate, colon and skin cancers, only 9%, 10% and 18% of patients, respectively, were optimally monitored. Infections were also inadequately managed, with 7% and 17% of patients vaccinated against influenza and pneumococcal, respectively, as was osteoporosis, with 47% of patients supplemented with vitamin D and 56% with a bone densitometry performed. CONCLUSIONS: In Spain, the prevalence of comorbidities and CV risk factors in RA patients with established and advanced disease is relatively high, and their management in clinical daily practice remains suboptimal.

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.

Profiling of B-Cell Factors and Their Decoy Receptors in Rheumatoid Arthritis: Association With Clinical Features and Treatment Outcomes.

Introduction: B-cell activation is pivotal in rheumatoid arthritis (RA) pathogenesis and represents a relevant therapeutic target. The main aim of this study was to characterize the profiles of B-cell factors and their decoy receptors in RA and evaluate their clinical relevance. Methods: sBLyS, sAPRIL, sBCMA, sTACI, sBLyS-R, and several cytokines' serum levels were measured by immunoassays in 104 RA patients and 33 healthy controls (HC). An additional group of 42 systemic lupus erythematosus (SLE) patients were enrolled as disease controls. Whole blood IFI44, IFI44L, IFI6, and MX1 gene expression was measured and averaged into an IFN-score. BLyS membrane expression (mBLyS) was assessed on blood cell subsets by flow cytometry. Results: increased sAPRIL and sBCMA levels were found in RA, whereas BLyS was elevated in very early RA (VERA). No differences were observed for sTACI and sBLyS-R. An increased sBLyS/sBLyS-R ratio was associated with poor clinical outcome at 6 and 12 months in VERA, whereas a positive association with disease activity was observed in established disease. Increased mBLyS expression was found on monocytes, mDCs, neutrophils and B-cells in RA, to a similar extent that in SLE patients. Cluster analysis identified a specific B-cell factors profile overrepresented in RA and associated with autoantibodies, elevated proinflammatory cytokines (IFNα, MIP1α, TNFα, IL-37, and GM-CSF) and increased type-I IFN signature. Increasing sBCMA and sBLyS serum levels upon treatment and mBLyS expression at baseline on monocytes and mDCs, but not B-cells, were associated with poor clinical outcome upon TNFα-blockade. Conclusions: profound and complex alterations of soluble and membrane-bound B-cell factors are observed in RA associated with clinical outcomes, thus supporting its applicability to guide patient stratification along disease course.

IRF4 and IRGs Delineate Clinically Relevant Gene Expression Signatures in Systemic Lupus Erythematosus and Rheumatoid Arthritis.

Introduction: Overactivation of the type I interferon (IFN) signature has been observed in several systemic autoimmune conditions, such as Systemic Lupus Erythematosus (SLE) or Rheumatoid Arthritis (RA). Impaired control of Interferon-Responding Genes (IRGs) expression by their regulatory mechanisms, including Interferon Regulatory Factors (IRFs), may underlie these findings and it may explain the heterogeneity observed among these conditions. In the present study we aimed to evaluate the associations between IRF4 gene expression and those of IRGs in SLE and RA patients to gain insight about its links with the IFN signature as well as to explore the potential clinical relevance of these associations. Methods: The gene expression of IRF4 and IRGs (IFI44, IFI44L, IFI6, and MX1) in peripheral blood was analyzed in 75 SLE patients, 98 RA patients, and 28 healthy controls. A group of 13 biological-naïve RA patients was prospectively followed upon TNFα-blockade. The associations among IRF4 and IRGs were evaluated by principal component analyses (PCA), correlations and network analyses. Publicly available datasets were used for replication. Results: A broad activation of IRGs was observed in autoimmune patients, although certain heterogeneity can be distinguished, whereas IRF4 was only upregulated in RA. The differential expression of IRF4 in RA was then confirmed in publicly available gene expression datasets. PCA revealed different associations among IRF4 and IRGs in each condition, which was later confirmed by correlation and network analyses. Cluster analysis identified 3 gene expression signatures on the basis of IRF4 and IRGs expression which were differentially used by SLE and RA patients. Cluster III was associated with markers of disease severity in SLE patients. Cluster II, hallmarked by IRF4 upregulation, was linked to clinical stage and mild disease course in RA. TNFα-blockade led to changes in the association between IRF4 and IRGs, whereas increasing IRF4 expression was associated with a good clinical outcome in RA. Conclusions: The differential expression of IRF4 and IRGs observed in SLE and RA can delineate gene expression signatures associated with clinical features and treatment outcomes. These results support a clinically-relevant phenomenon of shaping of the IFN signature by IRF4 in autoimmune patients.

High triglycerides and low high-density lipoprotein cholesterol lipid profile in rheumatoid arthritis: A potential link among inflammation, oxidative status, and dysfunctional high-density lipoprotein.

BACKGROUND: The interactions between inflammation and lipid profile in rheumatoid arthritis (RA) are poorly understood. The lipid profile study in RA has been biased toward lipoprotein levels, whereas those of triglycerides (TGs) and lipoprotein functionality have been underestimated. OBJECTIVES: Since recent findings suggest a role for TG and TG-rich lipoproteins (TRL) on inflammation, we aimed to evaluate a combined lipid profile characterized by high TG and low high-density lipoprotein cholesterol levels (TGhighHDLlow) in RA. METHODS: Lipid profiles were analyzed in 113 RA patients, 113 healthy controls, and 27 dyslipemic subjects. Levels of inflammatory mediators, paraoxonase-1 (PON1) activity, and total antioxidant capacity were quantified in serum. PON1-rs662 status was evaluated by real-time polymerase chain reaction. RESULTS: The TGhighHDLlow profile was detected in 29/113 RA patients. Although no differences in prevalence compared with healthy controls or dyslipemic subjects were observed, this profile was associated with increased tumor necrosis factor α (P = .004), monocyte chemotactic protein (P = .004), interferon-gamma-inducible protein-10 (P = .018), and leptin (P < .001) serum levels in RA, where decreased PON1 activity and total antioxidant capacity were found. TGhighHDLlow prevalence was lower among anti-TNFα-treated patients (P = .004). When RA patients were stratified by PON1-rs662 status, these associations remained in the low-activity genotype (QQ). Finally, a poor clinical response on TNFα blockade was related to an increasing prevalence of the TGhighHDLlow profile over treatment (P = .021) and higher TRL levels at baseline (P = .042). CONCLUSIONS: The TGhighHDLlow profile is associated with systemic inflammation, decreased PON1 activity, and poor clinical outcome on TNFα blockade in RA, suggesting a role of TRL and HDL dysfunction as the missing link between inflammation and lipid profile.

Heterogeneity of the Type I Interferon Signature in Rheumatoid Arthritis: A Potential Limitation for Its Use As a Clinical Biomarker.

INTRODUCTION: An increased expression of interferon (IFN)-responding genes (IRGs), the so-called IFN signature, has been reported in rheumatoid arthritis (RA). However, some controversy exists concerning its clinical relevance. The main aim of this study is to evaluate whether quantitative and qualitative differences in the activation of the IFN pathway may account for these findings. METHODS: The expression of IFN-induced protein 44 (IFI44), IFN-induced protein 44 like (IFI44L), IFN alpha inducible protein 6, and MX dynamin-like GTPase 1 (MX1) was determined in peripheral blood in 98 RA patients (IFI6) and 28 controls. RA patients were classified into groups according to their clinical stage and treatments received: very early RA (VERA), biological disease-modifying antirheumatic drug (bDMARD) naive, and bDMARD. An additional group of 13 RA patients candidates for tumor necrosis factor alpha (TNFα) blockade was also recruited. The associations among IRGs were evaluated by network and principal component analyses. RESULTS: The expression of all IRGs was increased in RA to different levels. The IFN score was increased in all RA groups (VERA, bDMARD-naïve, and bDMARD), but important differences in their degree of activation and in the relationships among IRGs were observed. The IFN score correlated with the accumulated disease activity score 28-joints, and it was found to be a predictor of clinical outcome in VERA. No differences in the IFN score were observed between the bDMARD-naive and bDMARD groups, but opposite associations with the clinical parameters were noted. Interestingly, the correlations among IRGs delineate different pictures between these two groups. The IFN score at baseline predicted poor clinical outcome upon TNFα blockade. Although no absolute changes in the IFN score were found, TNFα-blockade shifted the associations among IRGs. CONCLUSION: A certain heterogeneity within the IFN signature can be recognized in RA, depending on the clinical stage. The structure of the IFN signature may be a potential explanation for the controversy in this field and must be considered to decipher its clinical relevancein RA.