[Development of coronary artery disease in a young adult with Takayasu's arteritis: the lesser, the better]. / Sviluppo di malattia coronarica in giovane paziente affetto da arterite di Takayasu: the lesser, the better.

Large vessel vasculitis, such as Takayasu's arteritis (TA), is a rare inflammatory disease affecting multiple vascular districts including the coronary arteries, producing either stenosis and/or aneurysms: these lesions can be found in the same patient and also in the same vessel, with potentially devastating effects. Moreover, TA often affects young people, in the midst of their work and social activity. Ischemic heart disease is the leading cause of cardiovascular mortality in Western countries and is mainly due to coronary atherosclerosis, whose etiopathogenesis is multifactorial and is closely related to the concomitant presence of classic cardiovascular risk factors and inflammation of the vessel wall. We report the case of a young, physically active adult with multivessel coronary artery disease developed in the context of a TA bursted 7 years before and currently in clinical remission. This complex case required a careful literature review and a multidisciplinary approach, since the best treatment option for coronary lesions induced by TA has not been established: a "watchful waiting" strategy was eventually adopted, considering the poor outcome of both percutaneous and surgical revascularization in this group of patients.

COVID-19 presenting as a non-arteritic anterior ischemic optic neuropathy.

We present a case of a 61-year-old woman with an atypical non-arteritic anterior ischemic optic neuropathy (NA-AION) as a unique manifestation of COVID-19. Furthermore, the patient worsened after Pfizer-BioNTech COVID-19 vaccine administration. Our findings suggest that NA-AION could result from microangiopathic/thrombotic events that may occur during SARS-CoV-2 infection and/or vaccination against COVID-19. This report sheds light on possible ophthalmologic complications of COVID-19.

ANCA-negative microscopic polyangiitis with neuromuscular involvement: When pathology could make the difference.

Microscopic polyangiitis (MPA) is a necrotizing small vessel vasculitis with little or absent immune deposits (pauci-immune vasculitis), usually associated with the presence of antineutrophil cytoplasmic autoantibodies (ANCA) and a wide spectrum of organ manifestations. In our report we describe the case of a 74-year-old Asian man, who rapidly developed lower limb weakness and impaired renal and pulmonary functions. ANCA detection remained borderline throughout the disease course. Electrophysiological and instrumental studies revealed a picture of neuromuscular involvement; renal and muscle biopsies disclosed a small vessel vasculitis. He was started on a targeted immunosuppressive combination therapy and his clinical status progressively improved. In the framework of a multi-organ disease, microscopic polyangiitis should be considered as a differential diagnosis in case of acute/subacute onset of muscle weakness, even in the absence of ANCA detection.

Patterns of Anti-Inflammatory and Immunomodulating Drug Usage and Microvascular Endothelial Function in Rheumatoid Arthritis.

Objectives: Specific anti-inflammatory and/or immunomodulating drugs (AIDs) can influence endothelial function which is often impaired in patients with rheumatoid arthritis (RA). We sought to determine whether overall patterns of AID usage are similarly associated with endothelial function. Methods: The reactive hyperaemia index (RHI), a marker of microvascular endothelial function, was measured in 868 RA patients reporting their intake of seven AIDs known to affect endothelial function. Latent class analysis (LCA) was performed to characterise patterns of AID usage. Models for 2-6 classes were compared using the AIC and BIC statistics and Lo-Mendell-Rubin likelihood ratio tests. Associations between the classes and RHI were adjusted for age, gender, body mass index, diabetes, HDL-cholesterol, LDL-cholesterol, family history of ischaemic heart disease, smoking status, RA duration, DAS28 score, steroid dose, existing hypertension, and C-reactive protein. Results: LCA identified five distinct AID usage classes: Class 1, generally low medication usage; Class 2, using either sulfasalazine or non-tumour necrosis factor (TNF) inhibitors; Class 3, methotrexate users; Class 4, TNF-inhibitor users; and Class 5, hydroxychloroquine users. The geometric mean for the RHI for subjects in classes 1 to 5 was 1.92, 1.81, 1.94, 2.10, and 2.07, respectively, with subjects in classes 4 and 5 having better endothelial function than subjects in class 2 (p = 0.003 for each). The glucocorticoid dosage did not influence the classes formed or the association between the classes and the RHI in sensitivity analyses. Conclusion: There were five broad patterns (classes) of AID usage in RA patients. The RHI was relatively lower in users of either sulfasalazine or non-TNF inhibitors. TNF inhibitors or hydroxychloroquine may counteract the negative effects of RA on endothelial function.

Anti-TNF-Related Leukocytoclastic Vasculitis in Ulcerative Colitis: A Case Report.

BACKGROUND: The development of drugs directed against tumor necrosis factor (TNF)-α has dramatically modified the therapeutic approach to inflammatory bowel diseases: a larger use of such drugs has also led to a major knowledge about their adverse effects, especially on skin. The aim of this report was to describe a rare steroid-dependent form of leukocytoclastic vasculitis induced by an anti-TNF-α agent in a young woman with ulcerative colitis. CASE PRESENTATION: A young girl with ulcerative colitis developed a form of leukocytoclastic vasculitis induced by an anti-TNF-α agent. Recurrent palpable purpuric lesions on her legs were the main cutaneous manifestation. Skin lesions were steroid-dependent, but improved after withdrawal of the anti-TNF-α agent and second-line immunosuppressant therapy. CONCLUSIONS: The need to develop specific recommendations to guide the use of medications for managing skin reactions induced by anti-TNF-α drugs is herein emphasized.

Inclusion of Synovial Tissue-Derived Characteristics in a Nomogram for the Prediction of Treatment Response in Treatment-Naive Rheumatoid Arthritis Patients.

OBJECTIVE: This study applied a synovitis score obtained during routine care from ultrasound (US)-guided biopsies of synovial tissue (ST) in patients with rheumatoid arthritis (RA) and patients with other inflammatory and noninflammatory joint diseases to identify pretreatment synovial biomarkers associated with disease characteristics, and to integrate the findings into a multiparameter nomogram for use in baseline prediction of diagnosis and treatment response in treatment-naive rheumatoid arthritis (RA) patients. METHODS: The study enrolled a total of 1,015 patients with various autoimmune diseases (545 patients with RA, 167 patients with psoriatic arthritis [PsA], 199 patients with undifferentiated peripheral inflammatory arthritis [UPIA], 18 patients with crystal-induced arthritis, 26 patients with connective tissue diseases, and 60 patients with osteoarthritis [OA] [as part of the SYNGem cohort]). All patients underwent a US-guided ST biopsy at baseline, and patients were then stratified according to disease phase. The KSS, along with disease characteristics and clinical outcomes, were incorporated into a nomogram for prediction of achievement of clinical remission in RA patients who were previously naive to treatment. In patients in whom a treat-to-target strategy was applied, remission was defined as change in the Disease Activity Score in 28 joints (DAS28) at 6 months after treatment initiation. RESULTS: The KSS significantly differed among RA patients, as well as PsA patients and UPIA patients, when compared to OA patients. In RA, the KSS directly correlated with the DAS28 and was related to autoantibody positivity in treatment-naive RA patients. Moreover, at baseline, treatment-naive RA patients achieving 6-month remission according to DAS28 had a lower KSS, shorter duration of symptoms (very early RA [VERA]), and lower disease activity than treatment-naive RA patients not achieving remission according to DAS28. Results of logistic regression analysis identified the following synergistic predictive factors of achievement of DAS28-based disease remission at 6 months: having a short disease duration (VERA), not having high disease activity, and having a KSS of <5 at baseline. A nomogram integrating these baseline clinical and histologic characteristics in treatment-naive RA patients yielded an up to 81.7% probability of achieving 6-month remission according to the DAS28. CONCLUSION: The KSS is a reliable tool for synovitis assessment on US-guided ST biopsy, contingent on the phase of the disease and the autoimmune profile of each patient. This tool could be integrated within a therapeutic response-predictive nomogram for the prediction of treatment response in RA patients who were previously naive to treatment.

Systemic Bone Density at Disease Onset Is Associated With Joint Erosion Progression in Early Naive to Treatment Rheumatoid Arthritis: A Prospective 12-Month Follow-Up Open-Label Study.

Objectives: Osteoporosis and bone erosions are hallmarks of rheumatoid arthritis (RA) since disease onset is underpinned by the inflammatory burden. In this observational study, we aimed to dissect the putative RA-related parameters and bone-derived biomarkers associated with systemic and focal bone loss at disease onset and with their progression. Methods: One-hundred twenty-eight patients with early rheumatoid arthritis (ERA) were recruited at disease onset. At study entry, demographic, clinical, and immunological parameters were recorded. Each ERA patient underwent plain X-rays of the hands and feet at study entry and after 12 months to assess the presence of erosions. After enrollment, each patient was treated according to the recommendations for RA management and followed up based on a treat-to-target (T2T) strategy. At baseline, blood samples for soluble biomarkers were collected from each patient, and plasma levels of osteoprotegerin (OPG), receptor activator of nuclear factor κB ligand (RANKL), Dickkopf-1 (DKK1), and interleukin 6 (IL-6) were assessed by enzyme-linked immunosorbent assay (ELISA). Seventy-one ERA patients underwent bone mineral density (BMD) measurement at the left femoral neck and second to fourth lumbar spine vertebrae (L2-L4) by dual-energy X-ray absorptiometry (DXA). Results: Among the whole cohort, 34 (26.6%) ERA patients with bone erosions at study entry had a higher disease activity (p = 0.02) and IL-6 plasma levels (p = 0.03) than non-erosive ones. Moreover, at DXA, 33 (46.5%) ERA patients had osteopenia, and 16 (22.5%) had osteoporosis; patients with baseline bone erosions were more likely osteopenic/osteoporotic than non-erosive ones (p = 0.03), regardless of OPG, RANKL, and DKK1 plasma levels. Obese ERA patients were less likely osteopenic/osteoporotic than normal weight ones (p = 0.002), whereas anti-citrullinated protein antibodies (ACPA) positive ERA patients were more likely osteopenic/osteoporotic than ACPA negative ones (p = 0.034). At logistic regression analysis, baseline Disease Activity Score measured on 44 joints (DAS44) [OR: 2.46 (1.11-5.44)] and osteopenic/osteoporosis status [OR: 7.13 (1.27-39.94)] arose as independent factors of erosiveness. Baseline osteopenic/osteoporotic status and ACPA positivity were associated with bone damage progression during the follow-up. Conclusions: Bone erosions presence is associated with systemic bone loss since the earliest phases of RA, suggesting that the inflammatory burden and autoimmune biology, underpinning RA, represent crucial enhancers of bone remodeling either locally as at systemic level.

Postural control and disability in patients with early rheumatoid arthritis.

OBJECTIVES: Rheumatoid arthritis (RA) may affect the postural control through abnormal sensory inputs and impaired motor responses. Sensory Organization Test (SOT) objectively evaluates contribution of different sensorial afferences in postural control. The aim of the study is to assess mechanisms of postural instability and their relations with disability and disease characteristics in an early RA(ERA) cohort. METHODS: The equilibrium scores were assessed in 30 ERA patients and 30 age- and sex-matched controls. The somatosensory (SOM), visual (VIS) and vestibular (VEST) ratios were computed to assess the use of different sensory and the composite equilibrium score (CES) as a measure of global balance performance. RESULTS: ERA patients had lower CES (78.4±6.0% vs. 83.4±5.0%, p=0.002), SOM ratio (98.5±1.8% vs. 99.6±2.1%, p=0.035), VIS ratio (85.2±7.6% vs. 91.5±6.0%, p=0.001) and VEST ratio (70.8±10.0% vs. 80.3±7.8%, p<0.001) compared to controls. The presence of ankle arthritis correlated negatively to both SOM (r=-0.369, p=0.045) and VIS ratio (r=0.470, p=0.009), pain severity to CES (r=-0.389, p=0.045) and VIS ratio (r=-0.385, p=0.048) and HAQ-DI to CES (r=-0.591, p=0.001), SOM (r=-0.510, p=0.004) and VIS ratio (r=-0.390, p=0.033.). Patients-reported postural instability was associated with lower CES (75.4±5.4% vs. 80.7±5.5%, p=0.016) and VEST ratios (66.5±10.1% vs. 74.1±8.8%, p=0.036). SOT outcomes did not differ according to acute phase reactants, disease activity or autoantibody positivity. CONCLUSIONS: RA patients showed an early impairment of postural control related to the degree of disability and subjective postural instability. Our data suggest that the lack of balance could result from both impaired motor response and abnormal sensory organisation.

Sarilumab use in severe SARS-CoV-2 pneumonia.

BACKGROUND: Interleukin-6 signal blockade showed preliminary beneficial effects in treating inflammatory response against SARS-CoV-2 leading to severe respiratory distress. Herein we describe the outcomes of off-label intravenous use of Sarilumab in severe SARS-CoV-2-related pneumonia. METHODS: 53 patients with SARS-CoV-2 severe pneumonia received intravenous Sarilumab; pulmonary function improvement or Intensive Care Unit (ICU) admission rate in medical wards, live discharge rate in ICU treated patients and safety profile were recorded. Sarilumab 400 mg was administered intravenously on day 1, with eventual additional infusion based on clinical judgement, and patients were followed for at least 14 days, unless previously discharged or dead. FINDINGS: Of the 53 SARS-CoV-2pos patients receiving Sarilumab, 39(73·6%) were treated in medical wards [66·7% with a single infusion; median PaO2/FiO2:146(IQR:120-212)] while 14(26·4%) in ICU [92·6% with a second infusion; median PaO2/FiO2: 112(IQR:100-141.5)].Within the medical wards, 7(17·9%) required ICU admission, 4 of whom were re-admitted to the ward within 5-8 days. At 19 days median follow-up, 89·7% of medical inpatients significantly improved (46·1% after 24 h, 61·5% after 3 days), 70·6% were discharged from the hospital and 85·7% no longer needed oxygen therapy. Within patients receiving Sarilumab in ICU, 64·2% were discharged from ICU to the ward and 35·8% were still alive at the last follow-up. Overall mortality rate was 5·7%. INTERPRETATION: IL-6R inhibition appears to be a potential treatment strategy for severe SARS-CoV-2 pneumonia and intravenous Sarilumab seems a promising treatment approach showing, in the short term, an important clinical outcome and good safety.

Distinct synovial tissue macrophage subsets regulate inflammation and remission in rheumatoid arthritis.

Immune-regulatory mechanisms of drug-free remission in rheumatoid arthritis (RA) are unknown. We hypothesized that synovial tissue macrophages (STM), which persist in remission, contribute to joint homeostasis. We used single-cell transcriptomics to profile 32,000 STMs and identified phenotypic changes in patients with early/active RA, treatment-refractory/active RA and RA in sustained remission. Each clinical state was characterized by different frequencies of nine discrete phenotypic clusters within four distinct STM subpopulations with diverse homeostatic, regulatory and inflammatory functions. This cellular atlas, combined with deep-phenotypic, spatial and functional analyses of synovial biopsy fluorescent activated cell sorted STMs, revealed two STM subpopulations (MerTKposTREM2high and MerTKposLYVE1pos) with unique remission transcriptomic signatures enriched in negative regulators of inflammation. These STMs were potent producers of inflammation-resolving lipid mediators and induced the repair response of synovial fibroblasts in vitro. A low proportion of MerTKpos STMs in remission was associated with increased risk of disease flare after treatment cessation. Therapeutic modulation of MerTKpos STM subpopulations could therefore be a potential treatment strategy for RA.

Safety of Abatacept in Italian Patients with Rheumatoid Arthritis and Interstitial Lung Disease: A Multicenter Retrospective Study.

BACKGROUND: Treatment of rheumatoid arthritis (RA)-related interstitial lung disease (ILD) is challenging, and many conventional and biologic disease-modifying anti-rheumatic drugs (DMARDs) have been associated with ILD development or progression. The aim of this multicentric retrospective study was to analyze the evolution of ILD in Italian RA-ILD patients treated with abatacept (ABA). METHODS: All RA-ILD patients treated with ABA for at least six months were retrospectively evaluated. Serology, previous and concurrent therapies, chest high-resolution computer tomography (HRCT), forced vital capacity (FVC), and lung diffusion of carbon monoxide (CO, DLCO) were collected. RESULTS: Forty-four patients were included; HRCT, FVC, and DLCO were analyzed at baseline, at one year, and at the end of follow-up. A remission or a low disease activity of RA was reached in 41/44 patients. Overall, FVC and DLCO remained stable or increased in 86.1% and 91.7% of patients, respectively, while HRCT was stable or improved in 81.4% of them. Previous and concurrent treatments, in particular, methotrexate, serology, age, sex, joint and lung disease duration were not associated with the outcome at univariate analysis. CONCLUSION: The management of RA-ILD patients remains a critical unmet medical need. Waiting for prospective controlled studies, ABA has shown a good safety profile in our cohort of Italian RA-ILD patients.

Laboratory Monitoring of Biological Therapies in Rheumatology: The Role of Immunogenicity.

Biological drugs, such as proteins and immunogens, are increasingly used to treat various diseases, including tumors and autoimmune diseases, and biological molecules have almost completely replaced synthetic drugs in rheumatology. Although biological treatments such as anti-tumor necrosis factor (TNF) drugs seem to be quite safe, they cause some undesirable effects, such as the onset of infections due to weakening of the immune system. Given the biological nature of these drugs, they might be recognized as extraneous; this would induce an immune reaction that neutralizes their effectiveness or lead to more serious consequences. Laboratories play a pivotal role in appropriate therapeutic management. The aim of this review was to underline the production of anti-drug antibodies during treatment with biological drugs and highlight the role of laboratories in ensuring appropriate use of these drugs.

The B side of rheumatoid arthritis pathogenesis.

In the last years, a dramatic amount of research has been performedincreasing the knowledge about the biological mechanism underpinning Rheumatoid Arthritis (RA) inflammation, putting B lymphocytes in the center of RA pathogenesis. Nowadays, B cell phenotypes and autoantibodies positivity arose as important biomarkers in early and long-standing disease. Moreover, comparative analysis of peripheral blood and synovial tissue compartments enables the identification of novel physiopathological mechanisms promoting inflammation. In this narrative review we will discuss the biological relevance of B cell derived autoimmunity and in RA course, from disease onset to remission achievement.

Overweight/obesity affects histological features and inflammatory gene signature of synovial membrane of Rheumatoid Arthritis.

Overweight/obesity influence disease burden and clinical outcome of Rheumatoid Arthritis (RA). The impact of overweight/obesity on synovial tissue (ST) inflammation is largely unknown. Here, we investigated the histological and transcriptional signature of ST obtained from RA in different disease phases (disease onset, failure to first-line conventional DMARDs and in sustained clinical and ultrasound remission) finding that overweight/obese DMARDs naive RA showed higher likelihood of follicular synovitis, higher IHC scores for sublining inflammatory cells (CD68+, CD21+ and CD20+) and higher IL-1RA plasma levels than normal weight RA. Regardless to the synovitis pattern, overweight/obese DMARDs naive RA showed a worse clinical response to "Treat-to-target" (T2T) than normal weight RA at 6 and 12 months follow-up. Conversely, MTX-IR RA did not show significant differences in synovial inflammation based on BMI category. Overweight/obese RA in stable clinical and US remission showed higher degree of residual synovitis in terms of sublining CD68+, CD20+ cells and lining and sublining CD3+ compared to normal weight RA. Finally, gene expression profile analysis revealed that ST of overweight/obese DMARDs naive RA is enriched by CCL3 and MyD88 compared to normal weight RA in sustained disease remission, the latter correlating with BMI and IHC scores for synovial CD68+ cells. These findings suggest that indeed overweight/obese RA show higher degree of synovitis at disease onset and after remission achievement that influences the response rate to T2T and should be considered within the management of patients with RA.

Differential synovial tissue biomarkers among psoriatic arthritis and rheumatoid factor/anti-citrulline antibody-negative rheumatoid arthritis.

BACKGROUND: Differential diagnosis among psoriatic arthritis (PsA) and seronegative rheumatoid arthritis (Abneg RA) can be challenging particularly in the clinical setting of peripheral phenotype and autoantibodies seronegativity. The aim of the study was to identify synovial tissue (ST) biomarkers differentially expressed in PsA and Abneg RA and test their predictive value of therapeutic response. METHODS: Thirty-four PsA patients [12 DMARD naive and 22 non-responder to methotrexate (MTX-IR)] with peripheral joint involvement and 55 Abneg RA (27 DMARD naive and 28 MTX-IR) underwent US-guided ST biopsy and immunohistochemistry (IHC) for CD68+, CD3+, CD20+, CD21+, CD117+, and CD138+ cells. After study entry, each DMARD-naive patient started MTX therapy and was followed in an outpatient setting for at least 6 months to define the achievement of Minimal Disease Activity (PsA) and DAS remission (Abneg RA) status respectively. Each IR-MTX patient was treated according to EULAR recommendations. RESULTS: At study entry, IHC analysis revealed that PsA patients had comparable levels of lining and sublining CD68+ and sublining CD21+, CD20+, and CD3+ cells than Abneg RA, despite the therapeutic regimen. Moreover, regardless of the therapeutic scheme, PsA patients showed higher IHC score of CD117+ cells (p = 0.0004 and p = 0.0005 for naive and MTX-IR patients respectively) compared to Abneg RA patients. Conversely, Abneg RA patients showed higher IHC score of CD138+ cells, irrespective to the therapeutic scheme (p = 0.04 and p = 0.002 for naive and MTX-IR patients respectively). Analyzing the response rate to the therapeutic scheme, naive PsA patients reaching MDA status at 6 months follow-up, showed, at the study entry, lower IHC score of CD3+ cells compared to PsA patients not reaching this outcome (p = 0.02); conversely, naive Abneg RA patients reaching DAS remission status at 6 months follow-up, showed, at the study entry, lower IHC score of sublining CD68+ cells compared to Abneg RA patients not reaching this outcome (p < 0.001). CONCLUSIONS: CD117+ and CD138+ cells are differentially distributed among PsA and Abneg RA. Histological analysis of ST may help to solve the clinical overlap between the two diseases and provides prognostic data about the therapy success.

Chemerin and PEDF Are Metaflammation-Related Biomarkers of Disease Activity and Obesity in Rheumatoid Arthritis.

Objective: Obesity is a risk factor for Rheumatoid Arthritis (RA) being associated to low grade inflammation. This study aimed to determine whether PEDF and Chemerin are biomarkers of inflammation related to fat accumulation in RA and to investigate whether weight loss associates with clinical disease improvement through the modification of fat-related biomarkers in overweight/obese RA with low-moderate disease. Participants and Methods: Two-hundred and thirty RA patients were enrolled, of whom 176 at disease onset treated according to a treat-to-target strategy (T2T) and 54 overweight/obese RA in stable therapy and low-moderate disease activity. Gene expression of adipokines, interleukin-6 and their receptors were examined in adipose tissue from obese RA. Obese RA with low-moderate disease activity underwent low-calories diet aiming to Body Mass Index (BMI) reduction >5%, maintaining RA therapy unchanged. Chemerin, PEDF and Interleukin-6 plasma values were assessed by ELISA and disease activity was evaluated. Results: At RA onset, PEDF and Chemerin plasma values correlated with BMI (p < 0.001) but only Chemerin plasma values correlated with disease activity (p < 0.001). After adopting a T2T strategy, Chemerin arose as an independent factor associated with remission in early RA [OR(95%CIs):0.49(0.25-0.97)]. Moreover, after low-calories diet, RA with low-moderate disease activity reaching BMI reduction ≥5% (62.6%) at 6 months had significant decrease of PEDF (p < 0.05) and Chemerin (p < 0.05) plasma values, in parallel with the improvement in disease activity. Conclusions: PEDF and Chemerin arose as biomarkers of obesity and metaflammation respectively, providing a link between chronic inflammation and excess of body weight in RA. Therefore, BMI reduction of at least 5% in obese RA allowed better disease control without modifying RA treatment.

Prevalence and Determinants of Peripheral Microvascular Endothelial Dysfunction in Rheumatoid Arthritis Patients: A Multicenter Cross-Sectional Study.

OBJECTIVES: To define the prevalence and determinants of peripheral microvascular endothelial dysfunction (ED) in a large series of rheumatoid arthritis (RA) patients free of previous cardiovascular events. MATERIALS AND METHODS: Data from 874 RA patients enrolled in the EDRA study (Endothelial Dysfunction Evaluation for Coronary Heart Disease Risk Estimation in Rheumatoid Arthritis-ClinicalTrials.gov: NCT02341066) were analyzed. Log-transformed reactive hyperemia index (Ln-RHI) was evaluated by peripheral arterial tonometry (PAT) using the EndoPAT2000 device: values of Ln-RHI < 0.51 were considered indicative of peripheral ED. RESULTS: Peripheral microvascular ED was documented in one-third of RA patients (33.5%); in multiple logistic regression analysis, ACPA negativity and higher triglycerides concentrations were independently associated with the presence of peripheral ED [OR (95% CI) = 1.708 (1.218-2.396), p < 0.01 and OR (95% CI) = 1.005 (1.002-1.009), p < 0.01, respectively]. Multiple regression analysis showed a positive correlation between Ln-RHI values and systolic blood pressure and HDL cholesterol levels; furthermore, higher values of Ln-RHI were associated with ACPA positivity, while smoking habit was associated with lower Ln-RHI values. CONCLUSIONS: This study demonstrates for the first time a high prevalence of peripheral microvascular ED in patients with RA free of previous cardiovascular events that appear to be only partially driven by traditional cardiovascular risk factors. The association between ACPA negativity and ED warrants further exploration.