The complement system is linked to insulin resistance in patients with systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) patients more commonly have insulin resistance (IR) than control subjects. Recent studies have revealed that the complement (C) system is not only a mediator of the immune system but is also related to the pathogenesis of atherosclerosis in the general population. Given that the C alteration is a characteristic of SLE, in the present work we set out to analyse if there is a relationship between the C system and IR in patients with SLE. METHODS: New generation functional assays of the three pathways of the C system were performed in 225 non-diabetic patients with SLE. In addition, the serum levels of inactive (C1q, C2, C3, C4, factor D), activated (C3a) and regulators (C1 inhibitor and factor H) molecules of the C system were evaluated. Insulin and C-peptide serum levels were measured, and insulin resistance and indices of beta cell function were calculated using the homeostatic model assessment (HOMA). Metabolic syndrome criteria fulfillments were applied. Multivariable linear regression analysis was performed to assess the relationship between C system and IR indices and the presence of metabolic syndrome. RESULTS: After adjusting for covariates that included traditional cardiovascular risk factors associated with IR and prednisone, serum C3a and factor H levels were positively related to higher levels of the HOMA2-IR index. Besides, in the multivariable analysis, after adjustment for covariates, serum levels of C1q and C3 associated with a higher odds ratio for the presence of metabolic syndrome. CONCLUSIONS: IR and metabolic syndrome are positively and independently related to higher serum levels of some serum C elements in patients with SLE with a predominant role of the alternative pathway elements.

Red blood cell distribution width as a surrogate biomarker of damage and disease activity in patients with systemic lupus erythematosus.

OBJECTIVES: Red blood cell distribution width (RDW) is a measure of variability in mean corpuscular volume. Alterations in RDW can be observed in a variety of human disorders, including inflammatory, cardiovascular, and hepatic or renal diseases. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that can affect virtually any organ in the body. In this work, our objective was to analyse how a complete characterisation of disease characteristics in a large series of patients with SLE is related to RDW values. METHODS: 284 patients with SLE and 181 age- and sex-matched healthy controls were recruited. Complete blood count including RDW was assessed. Multivariable analysis was performed to analyse the relationship between RDW and SLE disease characteristics, including composite scores of disease activity and damage. RESULTS: After multivariable adjustment, RDW was higher in patients with SLE compared to controls (beta coefficient 0.8 [95% confidence interval: 0.3-1] %, p=0.003). Several disease characteristics, such as the presence of extractable nuclear antibodies and antiphospholipid syndrome, and the use of prednisone and azathioprine, were significantly associated with higher levels of RDW after adjustment for confounders. Of note, cumulative disease damage and disease activity scores were associated with higher RDW values after controlling for covariates. CONCLUSIONS: RDW may serve as a surrogate biomarker of accrual disease damage and activity in patients with SLE.

Agreement between local and central anti-synthetase antibodies detection: results from the Classification Criteria of Anti-Synthetase Syndrome project biobank.

OBJECTIVES: The CLASS (Classification Criteria of Anti-Synthetase Syndrome) project is a large international multicentre study that aims to create the first data-driven anti-synthetase syndrome (ASSD) classification criteria. Identifying anti-aminoacyl tRNA synthetase antibodies (anti-ARS) is crucial for diagnosis, and several commercial immunoassays are now available for this purpose. However, using these assays risks yielding false-positive or false-negative results, potentially leading to misdiagnosis. The established reference standard for detecting anti-ARS is immunoprecipitation (IP), typically employed in research rather than routine autoantibody testing. We gathered samples from participating centers and results from local anti-ARS testing. As an "ad-interim" study within the CLASS project, we aimed to assess how local immunoassays perform in real-world settings compared to our central definition of anti-ARS positivity. METHODS: We collected 787 serum samples from participating centres for the CLASS project and their local anti-ARS test results. These samples underwent initial central testing using RNA-IP. Following this, the specificity of ARS was reconfirmed centrally through ELISA, line-blot assay (LIA), and, in cases of conflicting results, protein-IP. The sensitivity, specificity, positive likelihood ratio and positive and negative predictive values were evaluated. We also calculated the inter-rater agreement between central and local results using a weighted κ co-efficient. RESULTS: Our analysis demonstrates that local, real-world detection of anti-Jo1 is reliable with high sensitivity and specificity with a very good level of agreement with our central definition of anti-Jo1 antibody positivity. However, the agreement between local immunoassay and central determination of anti-non-Jo1 antibodies varied, especially among results obtained using local LIA, ELISA and "other" methods. CONCLUSIONS: Our study evaluates the performance of real-world identification of anti-synthetase antibodies in a large cohort of multi-national patients with ASSD and controls. Our analysis reinforces the reliability of real-world anti-Jo1 detection methods. In contrast, challenges persist for anti-non-Jo1 identification, particularly anti-PL7 and rarer antibodies such as anti-OJ/KS. Clinicians should exercise caution when interpreting anti-synthetase antibodies, especially when commercial immunoassays test positive for non-anti-Jo1 antibodies.

Identification of new risk loci shared across systemic vasculitides points towards potential target genes for drug repurposing.

OBJECTIVES: The number of susceptibility loci currently associated with vasculitis is lower than in other immune-mediated diseases due in part to small cohort sizes, a consequence of the low prevalence of vasculitides. This study aimed to identify new genetic risk loci for the main systemic vasculitides through a comprehensive analysis of their genetic overlap. METHODS: Genome-wide data from 8467 patients with any of the main forms of vasculitis and 29 795 healthy controls were meta-analysed using ASSET. Pleiotropic variants were functionally annotated and linked to their target genes. Prioritised genes were queried in DrugBank to identify potentially repositionable drugs for the treatment of vasculitis. RESULTS: Sixteen variants were independently associated with two or more vasculitides, 15 of them representing new shared risk loci. Two of these pleiotropic signals, located close to CTLA4 and CPLX1, emerged as novel genetic risk loci in vasculitis. Most of these polymorphisms appeared to affect vasculitis by regulating gene expression. In this regard, for some of these common signals, potential causal genes were prioritised based on functional annotation, including CTLA4, RNF145, IL12B, IL5, IRF1, IFNGR1, PTK2B, TRIM35, EGR2 and ETS2, each of which has key roles in inflammation. In addition, drug repositioning analysis showed that several drugs, including abatacept and ustekinumab, could be potentially repurposed in the management of the analysed vasculitides. CONCLUSIONS: We identified new shared risk loci with functional impact in vasculitis and pinpointed potential causal genes, some of which could represent promising targets for the treatment of vasculitis.

Antibody predictors of mortality and lung function trends in myositis spectrum interstitial lung disease.

OBJECTIVES: The impact of autoantibody profiles on prognosis of idiopathic inflammatory myositis associated interstitial lung disease (IIM-ILD) and myositis spectrum ILD with Myositis Specific Antibodies (MSA) remains unclear. This retrospective cohort study examines whether serological profiles are associated with mortality and longitudinal lung function change. METHODS: Baseline clinical/demographic characteristics and follow-up lung function of consecutive adult patients with IIM-ILD or Interstitial Pneumonia with Autoimmune Features (IPAF) positive for MSAs were extracted from three hospitals. Univariate and multi-variate Cox-Proportional Hazards analyses were used to compare mortality between autoantibodies. Regression models were used to analyse lung function trends. RESULTS: Of 430 included patients, 81% met IIM criteria, 19% were IPAF-MSA. On univariate analysis, risk factors associated with mortality included higher age, Charlson Co-morbidity Index and CRP; and lower BMI, baseline TLCO% and FEV1%. Compared to anti-MDA5-negativity, anti-MDA5-positivity (MDA5+) was associated with high mortality in the first 3 months (HR 65.2. 95%CI 14.1, 302.0), while no significant difference was seen thereafter (HR 0.55, 95%CI 0.14, 2.28). On multi-variate analysis, combined anti-synthetase antibodies carried a reduced risk of mortality (HR 0.63), although individually, mortality was reduced in anti-Jo1 + (HR 0.61, 95%CI 0.4-0.87) and increased in anti-PL7+ patients (HR 2.07, 95%CI 1.44-2.99). Anti-MDA5+ was associated with slow improvement in %FVC over the first 3 years, while anti-PL7+ was linked with a slow decline from 12 months onwards. CONCLUSIONS: Among autoantibody profiles in myositis spectrum disorders, anti-MDA5+ and anti-PL7+ confer higher mortality risks. Survivors of an early peak of mortality in anti-MDA5+ disease appear to have a favourable prognosis.

Disease activity in patients with rheumatoid arthritis increases serum levels of apolipoprotein C-III.

OBJECTIVES: Rheumatoid arthritis (RA) has been unequivocally associated with an increased burden of accelerated atherosclerosis, which, at least in part, is a consequence of the inflammation present in the disease. Apolipoprotein C-III (ApoC3) is a key molecule in triglycerides metabolism that has been linked to cardiovascular (CV) disease. Our objective was to study how ApoC3 is related to the characteristics of RA, paying special attention to its relationship with the inflammatory activity of the disease. METHODS: Cross-sectional study that included 430 patients with RA. In these patients, data related to the disease, classic CV risk factors, complete lipid profile, and serum ApoC3 levels were evaluated. A multivariable regression analysis was performed to study the relationship of the characteristics of RA with ApoC3. RESULTS: Abdominal circumference, obesity, type 2 diabetes, and circulating triglycerides were significantly associated with higher ApoC3 serum levels. Furthermore, C-reactive protein and erythrocyte sedimentation rate, as well as the disease activity score -DAS28- were significantly related to a higher circulating ApoC3 after multivariable analysis. Patients included in the moderate or high disease activity groups had higher ApoC3 serum levels compared to those in remission (beta coefficient 1.28 [95% confidence interval 0.16-2.39] mg/dl, p=0.025) when adjusting for confounders. The use of prednisone, disease-modifying anti-rheumatic drugs and anti-tumour necrosis factor therapies was associated with lower values of ApoC3. CONCLUSIONS: The activity of the disease in patients with RA is independently associated with higher serum levels of ApoC3.

Alpha-Klotho protein in systemic lupus erythematosus.

OBJECTIVES: Alpha-Klotho protein (α-Klotho) is an essential component of endocrine fibroblast growth factor receptor complexes that governs multiple metabolic processes including aging-related disorders, diabetes, cancer, arteriosclerosis, and chronic kidney disease. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that can affect almost any organ in the body and in which multiple pathophysiological abnormalities are observed. In the present work, our objective was to study whether the serum levels of α-Klotho differ between patients with SLE and controls, and how this protein is related to the clinical and laboratory characteristics of the disease. METHODS: Cross-sectional study that included 364 women, 195 of them diagnosed with SLE and 169 sex- and age-matched controls. Circulating α-Klotho was analysed in SLE patients and controls. A multivariable analysis was performed to assess whether α-Klotho differs between patients and controls, and to study its relationship with SLE features. RESULTS: No differences were found in α-Klotho levels between SLE patients and controls, both in univariable and multivariable analyses. Disease-related data like SLE duration, acute phase reactants, activity, severity and damage indices, and autoantibodies profile were not significantly associated with serum levels of α-Klotho. However, the use of prednisone and the presence of musculoskeletal manifestations were significantly related to higher α-Klotho serum levels. CONCLUSIONS: α-Klotho protein serum levels do not differ between patients with SLE and controls. Nevertheless, SLE patients taking prednisone or those with musculoskeletal manifestations show significantly higher circulating levels of α-Klotho.

Circulating interleukin-6 and cardiovascular disease risk in patients with rheumatoid arthritis with low disease activity due to active therapy.

OBJECTIVES: Interleukin-6 (IL-6) has been implicated in the pathophysiology of rheumatoid arthritis (RA) and in the development of atherosclerosis in the general population. In the present work we aimed to study if IL-6 serum levels have an influence on factors associated with cardiovascular (CV) disease in a cohort of Spanish patients with RA. METHODS: Cross-sectional study that encompassed 407 patients with RA. Serum IL-6 levels were assessed. Multivariable analysis was performed to examine the relationship of IL-6 to subclinical carotid atherosclerosis and classic CV risk factors, including a comprehensive lipid molecule profile and indices of insulin resistance and beta-cell function. RESULTS: Circulating levels of IL-6 showed a correlation with acute phase reactants, disease activity, and other features of RA. However, classic CV risk factors, lipid profile and indices of insulin resistance, as well as subclinical carotid atherosclerosis, were not associated with serum IL-6 levels. CONCLUSIONS: Although a direct association between IL-6 levels and traditional CV risk factors and subclinical carotid atherosclerosis was not observed, circulating IL-6 was associated with disease activity and acute-phase reactants, which have been associated with an increased risk of CV in these patients.

Interleukin-6 serum levels are associated with disease features and cardiovascular risk in patients with systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc) is a chronic multisystem disease characterised by microcirculatory vascular dysfunction and progressive fibrosis of the skin and internal organs. Interleukin-6 (IL-6) is a proinflammatory cytokine that has been implicated in the pathogenesis of several autoimmune diseases and in the initiation and progression of the cardiovascular disease. In the present work we aimed to study the relationship of IL-6 with clinical manifestations and the cardiovascular risk in patients with SSc. METHODS: Cross-sectional study that included 53 individuals with SSc. A multivariate analysis was performed to study the relationship between IL-6 and disease characteristics and cardiovascular risk assessed by Systematic Coronary Risk Estimation (SCORE2) in SSc. RESULTS: The presence of digital ulcers, calcinosis, and anti-Scl70 antibody was associated with higher levels of IL-6. This was also the case for functional respiratory parameters where this association was found to be significant and negative after correction for covariates. In addition, the SCORE2 cardiovascular risk algorithm showed a positive and significant association with circulating IL-6. CONCLUSIONS: IL-6 levels are associated with disease manifestations and cardiovascular risk in patients with SSc.

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.

Optimisation of tocilizumab therapy in giant cell arteritis. A multicentre real-life study of 471 patients.

OBJECTIVES: Tocilizumab (TCZ) is the only biologic therapy approved for giant cell arteritis (GCA). There is general agreement on the initial/maintenance dose, duration of TCZ therapy is not well established. In GiACTA trial, after one year on TCZ, most patients had GCA relapse after withdrawal. The aim of this study is to assess the effectiveness and safety of TCZ therapy optimisation in a large unselected series of patients with GCA in a clinical practice scenario. METHODS: We carried out a multicentre study on 471 GCA patients treated with TCZ. Once prolonged remission was achieved (n=231) and based on a decision between patient and physician, TCZ was optimised (n=125). We compared optimised (TCZOPT) and not optimised (TCZNON-OPT) groups. Prolonged remission defined as normalisation of clinical and laboratory data for 6 months. Optimisation was carried out by decreasing TCZ dose and/or increasing dosing interval. RESULTS: We evaluated 231 GCA patients on TCZ in prolonged remission. At TCZ onset, no differences in demographic, clinical, or laboratory data were observed. First TCZ optimisation was performed after a median follow-up of 12[6-17] months. Intravenous TCZ was optimised from 8 to 4mg/kg/4weeks in 44% patients, while subcutaneous TCZ was optimised from 162mg/w to 162mg/every-other-week in 65% cases. At the end of follow-up, prolonged remission (78.2% vs. 84.2%; p=0.29) and relapses (5.6% vs. 10.4%, p=0.177) were similar in TCZOPT vs. TCZNON-OPT. Severe infections were more frequent in TCZNON-OPT (12.9% vs. 6.6%; p=0.009). CONCLUSIONS: TCZ optimisation may be done once complete remission is achieved by reducing dose or increasing dosing interval. This seems to be effective, safe and cost-effective therapeutic scheme.

Endothelin-1 as a Biomarker of Idiopathic Pulmonary Fibrosis and Interstitial Lung Disease Associated with Autoimmune Diseases.

The aim of this study was to determine the role of endothelin-1 (ET-1), a molecule involved in multiple vascular and fibrosing abnormalities, as a biomarker of interstitial lung disease (ILD), as well as its use for the differential diagnosis between idiopathic pulmonary fibrosis (IPF) and ILD associated with autoimmune diseases (AD-ILD), using a large and well-defined cohort of patients with ILD. A total of 112 patients with IPF, 91 patients with AD-ILD (28 rheumatoid arthritis (RA), 26 systemic sclerosis, 20 idiopathic inflammatory myositis and 17 interstitial pneumonia with autoimmune features) and 44 healthy controls were included. ET-1 serum levels were determined by enzyme-linked immunosorbent assay. A significant increase in ET-1 levels was found in patients with IPF compared to controls. Likewise, AD-ILD patients also showed higher ET-1 levels than controls when the whole cohort was stratified by the type of AD. Similar ET-1 levels were found in IPF and AD-ILD patients, regardless of the underlying AD. Interestingly, increased ET-1 levels were correlated with worse lung function in IPF and RA-ILD patients. Our study supports that serum ET-1 may be useful as a biomarker of ILD, although it could not help in the differential diagnosis between IPF and AD-ILD. Moreover, ET-1 levels may be associated with ILD severity.

Mucosal Immune Defence Gene Polymorphisms as Relevant Players in the Pathogenesis of IgA Vasculitis?

ITGAM-ITGAX (rs11150612, rs11574637), VAV3 rs17019602, CARD9 rs4077515, DEFA (rs2738048, rs10086568), and HORMAD2 rs2412971 are mucosal immune defence polymorphisms, that have an impact on IgA production, described as risk loci for IgA nephropathy (IgAN). Since IgAN and Immunoglobulin-A vasculitis (IgAV) share molecular mechanisms, with the aberrant deposit of IgA1 being the main pathophysiologic feature of both entities, we assessed the potential influence of the seven abovementioned polymorphisms on IgAV pathogenesis. These seven variants were genotyped in 381 Caucasian IgAV patients and 997 matched healthy controls. No statistically significant differences were observed in the genotype and allele frequencies of these seven polymorphisms when the whole cohort of IgAV patients and those with nephritis were compared to controls. Similar genotype and allele frequencies of all polymorphisms were disclosed when IgAV patients were stratified according to the age at disease onset or the presence/absence of gastrointestinal or renal manifestations. Likewise, no ITGAM-ITGAX and DEFA haplotype differences were observed when the whole cohort of IgAV patients, along with those with nephritis and controls, as well as IgAV patients, stratified according to the abovementioned clinical characteristics, were compared. Our results suggest that mucosal immune defence polymorphisms do not represent novel genetic risk factors for IgAV pathogenesis.

WISP-2 modulates the induction of inflammatory mediators and cartilage catabolism in chondrocytes.

Wnt-1 inducible signaling pathway protein 2 (WISP-2/CCN5) is a recently identified adipokine that has been described as an important mediator of canonical Wnt activation in adipogenic precursor cells. In osteoarthritis (OA), the most common form of arthritis, chondrocytes exhibit aberrant and increased production of pro-inflammatory mediators and matrix degrading enzymes such as IL-1ß and MMP-13. Although recent evidence suggests a role for Wnt signaling in OA physiopathology, little is known about the involvement of WISP-2 in cartilage degradation. In the present study, we determined the expression of WISP-2 in healthy and OA human chondrocytes. WISP-2 expression is modulated along chondrocyte differentiation and downregulated at the onset of hypertrophy by inflammatory mediators. We also investigated the effect of WISP-2 on cartilage catabolism and performed WISP-2 loss-of-function experiments using RNA interference technology in human T/C-28a2 immortalized chondrocytes. We demonstrated that recombinant human WISP-2 protein reduced IL-1ß-mediated chondrocyte catabolism, that IL-1ß and WNT/b-catenin signaling pathways are involved in rhWISP-2 protein and IL-1ß effects in human chondrocytes, and that WISP-2 has a regulatory role in attenuating the catabolic effects of IL-1ß in chondrocytes. Gene silencing of WISP-2 increased the induction of the catabolic markers MMP-13 and ADAMTS-5 and the inflammatory mediators IL-6 and IL-8 triggered by IL-1ß in human primary OA chondrocytes in a Wnt/ß-catenin dependent manner. In conclusion, here we have shown for the first time that WISP-2 may have relevant roles in modulating the turnover of extracellular matrix in the cartilage and that its downregulation may detrimentally alter the inflammatory environment in OA cartilage. We also proved the participation of Wnt/ß-catenin signaling pathway in these processes. Thus, targeting WISP-2 might represent a potential therapeutical approach for degenerative and/or inflammatory diseases of musculoskeletal system, such as osteoarthritis.

EULAR recommendations for cardiovascular risk management in rheumatic and musculoskeletal diseases, including systemic lupus erythematosus and antiphospholipid syndrome.

OBJECTIVE: To develop recommendations for cardiovascular risk (CVR) management in gout, vasculitis, systemic sclerosis (SSc), myositis, mixed connective tissue disease (MCTD), Sjögren's syndrome (SS), systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). METHODS: Following European League against Rheumatism (EULAR) standardised procedures, a multidisciplinary task force formulated recommendations for CVR prediction and management based on systematic literature reviews and expert opinion. RESULTS: Four overarching principles emphasising the need of regular screening and management of modifiable CVR factors and patient education were endorsed. Nineteen recommendations (eleven for gout, vasculitis, SSc, MCTD, myositis, SS; eight for SLE, APS) were developed covering three topics: (1) CVR prediction tools; (2) interventions on traditional CVR factors and (3) interventions on disease-related CVR factors. Several statements relied on expert opinion because high-quality evidence was lacking. Use of generic CVR prediction tools is recommended due to lack of validated rheumatic diseases-specific tools. Diuretics should be avoided in gout and beta-blockers in SSc, and a blood pressure target <130/80 mm Hg should be considered in SLE. Lipid management should follow general population guidelines, and antiplatelet use in SLE, APS and large-vessel vasculitis should follow prior EULAR recommendations. A serum uric acid level <0.36 mmol/L (<6 mg/dL) in gout, and disease activity control and glucocorticoid dose minimisation in SLE and vasculitis, are recommended. Hydroxychloroquine is recommended in SLE because it may also reduce CVR, while no particular immunosuppressive treatment in SLE or urate-lowering therapy in gout has been associated with CVR lowering. CONCLUSION: These recommendations can guide clinical practice and future research for improving CVR management in rheumatic and musculoskeletal diseases.

Biologic therapy in refractory neurobehçet's disease: a multicentre study of 41 patients and literature review.

OBJECTIVES: To assess efficacy and safety of biologic therapy (BT) in neurobehçet's disease (NBD) refractory to glucocorticoids and at least one conventional immunosuppressive drug. METHODS: Open-label, national, multicentre study. NBD diagnosis was based on the International Consensus Recommendation criteria. Outcome variables were efficacy and safety. Main efficacy outcome was clinical remission. Other outcome variables analysed were glucocorticoid-sparing effect and improvement in laboratory parameters. RESULTS: We studied 41 patients [21 women; age 40.6 (10.8) years]. Neurological damage was parenchymal (n = 33, 80.5%) and non-parenchymal (n = 17, 41.5%). First BTs used were infliximab (n = 19), adalimumab (n = 14), golimumab (n = 3), tocilizumab (n = 3) and etanercept (n = 2). After 6 months of BT, neurological remission was complete (n = 23, 56.1%), partial (n = 15, 37.6%) and no response (n = 3, 7.3%). In addition, median (IQR) dose of oral prednisone decreased from 60 (30-60) mg/day at the initial visit to 5 (3.8-10) mg/day after 6 months (P < 0.001). It was also the case for mean erythrocyte sedimentation rate [31.5 (25.6)-15.3 (11.9) mm/1st h, P = 0.011] and median (IQR) C-reactive protein [1.4 (0.2-12.8) to 0.3 (0.1-3) mg/dl, P = 0.001]. After a mean follow-up of 57.5 months, partial or complete neurological remission persisted in 37 patients (90.2%). BT was switched in 22 cases (53.6%) due to inefficacy (n = 16) or adverse events (AEs) (n = 6) and discontinued due to complete prolonged remission (n = 3) or severe AE (n = 1). Serious AEs were observed in two patients under infliximab treatment. CONCLUSIONS: BT appears to be effective and relatively safe in refractory NBD.

Apolipoprotein C3 and beta-cell dysfunction are linked in patients with systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) has been associated with insulin resistance and beta-cell dysfunction. Apolipoprotein C3 (ApoC3) is a component of very low-density lipoproteins. Since ApoC3 has been linked to beta-cell impairment in the general population, in this study we aimed to discover if this lipoprotein is related to glucose homeostasis disturbance in patients with SLE. METHODS: One hundred and forty non diabetic patients with SLE who had a glycaemia lower than 110 mg/dl were recruited. Insulin, C-peptide, and ApoC3 were assessed. Insulin resistance and beta-cell function were calculated using the Homeostasis Model Assessment (HOMA2) indices. A multivariable regression analysis was performed to study the relationship of ApoC3 to those molecules and indices adjusting for classical factors associated with insulin resistance that included glucocorticoids. RESULTS: In the multivariable regression analysis that included prednisone intake, a significant relation of ApoC3 to C-peptide was found (beta coef. 0.27 [95%CI 0.03-0.51) ng/ml, p=0.030). Similarly, ApoCa3 was associated with higher degree of beta-cell dysfunction (HOMA2-%B) although in this case statistical significance was not achieved (beta coef. 8 [95%CI-1-18], p=0.086). This relationship was not found with serum insulin levels or IR indices. Furthermore, in the univariable analysis, but not after multivariable adjustment, the disease damage score was found to significantly mediate the effect of ApoC3 on circulating C-peptide. and HOMA2-%B. CONCLUSIONS: Beta-cell dysfunction and ApoC3 are linked in patients with SLE.

Amylin serum levels are upregulated in patients with systemic lupus erythematosus.

OBJECTIVES: Amylin is a pancreatic hormone that participates in glucose homeostasis. We aimed to investigate how serum amylin levels are expressed in patients with systemic lupus erythematosus (SLE) compared to matched controls, and their possible relationship to disease-related characteristics, such as activity or damage. METHODS: 144 SLE patients and 96 non-diabetic sex- (female 96% vs. 91%, p=0.43) and age-matched controls (49±11 vs. 51±8 years, p=0.09) were included. Amylin, insulin and C-peptide serum levels, as well as insulin resistance indexes were assessed in both groups. Multivariable regression analysis was performed to compare amylin between groups and to explore its interrelations with SLE features. The analyses were adjusted for glucocorticoids intake and for insulin resistance classic risk factors. RESULTS: Patients with SLE exhibited significant higher serum levels of amylin when compared to controls after multivariable analysis (beta coef. 1.56 [95%CI 1.01-2.11], p=0.000). Moreover, SLE patients not on prednisone (beat coef. 1.54 [95%CI 0.98-2.10] ng/ml, p=0.000) and those on prednisone (beta coef. 1.51 [95%CI 0.96-2.07] ng/ml, p=0.000) disclosed higher amylin serum levels compared to controls in the fully multivariable analysis. Hyperamylinaemia in SLE patients remained significant even adjusting for differences in the insulin resistance and beta cell production rates between patients and controls. The damage produced by the disease and its severity were independently and positively associated with amylin serum levels. CONCLUSIOINS: Amylin is upregulated in SLE patients compared to controls, regardless of the insulin resistance that SLE may present. The damage produced by the disease and its severity independently explains this upregulation.

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.

Long-term survival of renal transplantation in patients with lupus nephritis: experience from a single university centre.

OBJECTIVES: Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE). Unfortunately, 10-20% of patients with LN develop end-stage renal disease (ESRD), and renal transplantation may be a therapeutic option. However, concerns about LN recurrence after transplant have been reported. We aimed to assess long-term post-transplant graft and patient survival in LN compared to patients with non-autoimmune nephropathy (polycystic kidney disease - PCKD). METHODS: We carried out a single-centre retrospective study of all patients who underwent renal transplantation due to LN in a referral unit between 1980 and 2018. This cohort was compared with a group of PCKD patients. The main outcome variables were graft and patient survival for up to 20 years, and the time-course of serum creatinine and proteinuria in the first 5 years after transplantation. Cumulative survival rates were estimated by the Kaplan-Meier method and compared using the log-rank test. RESULTS: We included 53 patients: LN group (n=21) and PCKD group (n=32). Baseline clinical characteristics were similar in both groups, except age at transplantation (39.8±11.3 years in the LN group and 46.6±5.0 years in the PCKD group; p=0.004). No significant differences were found regarding graft (p=0.59) or patient survival (p=0.087) at 20 years of follow-up. CONCLUSIONS: Despite concerns about LN recurrence after renal transplantation, this study shows that this procedure might be a safe alternative therapy for ESRD related to SLE and may provide long-term survival.