Effectiveness and safety of filgotinib in rheumatoid arthritis patients: data from the GISEA registry.

OBJECTIVES: The aim of this study was to evaluate the effectiveness and safety profile of filgotinib, a JAK1 preferential inhibitor, in rheumatoid arthritis (RA) patients included in Italian GISEA (Group for the Study of Early Arthritis) registry. METHODS: Data from RA patients treated with filgotinib, recorded in the GISEA registry, were analysed. Disease activity scores and patient-reported outcomes (PROs) were assessed at baseline, as well as during 12-month follow-up. A difficult-to-treat (D2T) RA patient was defined according with EULAR criteria. Retention rate of filgotinib was estimated by the Kaplan-Meier method and factors influencing drug discontinuation were estimated by Cox regression models. RESULTS: 246 RA patients (female 89%, 57.6±12.2 years old) started filgotinib, mostly as second (22%) or further (43.9%) b/tsDMARDs line of treatment. At 3 and 12 months, 18.8% and 27.5% of patients achieved Clinical Diseases Activity Index based remission and 30.1% and 37.7% obtained a visual analogue scale of pain ≤20 (all p<0.01 vs. baseline). Filgotinib survival rate was 84.5% at the 6-month and 75.8% at 12-month follow-up, and was comparable either in monotherapy or combination therapy, and irrespective of glucocorticoid intake. b/tsDMARD naive patients had the lowest hazard ratio (HR) of filgotinib discontinuation (HR 0.29, 95%CI 0.14-0.64), while D2T-RA the highest (HR 1.82, 95%CI 1.01-3.3). Eight patients (3.3%) discontinued filgotinib due to adverse events. CONCLUSIONS: In an Italian real-life setting, filgotinib is confirmed to be safe and with a good effectiveness profile both in monotherapy and without glucocorticoids.

Comorbidities in the Spondyloarthritis GISEA Cohort: an average treatment effect analysis on patients treated with bDMARDs.

OBJECTIVES: We aimed to investigate the effectiveness of tumour necrosis factor inhibitors (TNFi), anti-interleukin-17 or interleukin-12/23 monoclonal antibodies (anti-IL) on comorbidities in a cohort of patients with spondyloarthritis (SpA), using an average treatment effect (ATE) analysis. METHODS: SpA patients from the multicentre Italian GISEA Registry were divided into groups according to pharmacological exposure: no treatment (G0), TNFi (G1) and non-responders to TNFi switched to anti-IL (G2). In each group, we recorded the prevalence and incidence of infectious, cardiopulmonary, endocrinological, gastrointestinal, oncologic, renal and neurologic comorbidities. Each comorbidity was then fitted for ATE and baseline features were evaluated for importance. RESULTS: The main findings of this study comprising 4458 SpA patients relate to cancer, other gastrointestinal diseases (OGID) and fibromyalgia. ATE showed no increased risk of solid cancer in G1 (0.42 95% CI 0.20-0.85) and G2 (0.26 95% CI 0.08-0.71) vs. G0, with significantly higher incidence in G0 (14.07/1000 patient-years, p=0.0001). Conversely, a significantly higher risk of OGID and fibromyalgia was found in G1 (1.56 95% CI 1.06-2.33; 1.69 95% CI 1.05-2.68, respectively) and G2 (1.91 95% CI 1.05-3.24; 2.13 95% CI 1.14-3.41, respectively) vs. G0. No treatment risk reduction was observed in haematological malignancies, cardiovascular events and endocrinological comorbidities. CONCLUSIONS: Overall, our study confirms the safety of TNFi and anti-IL in SpA patients, albeit with some caveats pertaining to solid cancers, OGID and fibromyalgia. Furthermore, taking into consideration causality with observational data may yield more reliable and relevant clinical information.

B-Cell Activation Biomarkers in Salivary Glands Are Related to Lymphomagenesis in Primary Sjögren's Disease: A Pilot Monocentric Exploratory Study.

Primary Sjögren's disease is primarily driven by B-cell activation and is associated with a high risk of developing non-Hodgkin's lymphoma (NHL). Over the last few decades, microRNA-155 (miR-155) has arisen as a key regulator of B-cells. Nevertheless, its role in primary Sjögren's disease remains elusive. Thus, the purpose of this study was (i) to explore miR-155, B-cell activating factor (BAFF)-receptor (BAFF-R), and Interleukin 6 receptor (IL-6R) expression in the labial salivary glands (LSG) of patients with primary Sjögren's disease, aiming to identify potential B-cell activation biomarkers related to NHL development. Twenty-four patients with primary Sjögren's disease, and with available tissue blocks from a LSG biopsy performed at diagnosis, were enrolled. Among them, five patients developed B-cell NHL during follow-up (7.3 ± 3.1 years). A comparison group of 20 individuals with sicca disease was included. Clinical and laboratory parameters were recorded and the LSG biopsies were evaluated to assess local inflammation in terms of miR-155/BAFF-R and IL-6R expression. Stratifying the primary Sjögren's disease cohort according to lymphomagenesis, miR-155 was upregulated in primary Sjögren's disease patients who experienced NHL, more so than those who did not experience NHL. Moreover, miR-155 expression correlated with the focus score (FS), as well as BAFF-R and IL-6R expression, which were increased in primary Sjögren's disease patients and in turn related to neoplastic evolution. In conclusion, epigenetic modulation may play a crucial role in the aberrant activation of B-cells in primary Sjögren's disease, profoundly impacting the risk of NHL development.

Stricter treat-to-target in RA does not result in less radiographic progression: a longitudinal analysis in RA BIODAM.

OBJECTIVES: To investigate whether meticulously following a treat-to-target (T2T)-strategy in daily clinical practice will lead to less radiographic progression in patients with active RA who start (new) DMARD-therapy. METHODS: Patients with RA from 10 countries starting/changing conventional synthetic or biologic DMARDs because of active RA, and in whom treatment intensification according to the T2T principle was pursued, were assessed for disease activity every 3 months for 2 years (RA-BIODAM cohort). The primary outcome was the change in Sharp-van der Heijde (SvdH) score, assessed every 6 months. Per 3-month interval DAS44-T2T could be followed zero, one or two times (in a total of two visits). The relation between T2T intensity and change in SvdH-score was modelled by generalized estimating equations. RESULTS: In total, 511 patients were included [mean (s.d.) age: 56 (13) years; 76% female]. Mean 2-year SvdH progression was 2.2 (4.1) units (median: 1 unit). A stricter application of T2T in a 3-month interval did not reduce progression in the same 6-month interval [parameter estimates (for yes vs no): +0.15 units (95% CI: -0.04, 0.33) for 2 vs 0 visits; and +0.08 units (-0.06; 0.22) for 1 vs 0 visits] nor did it reduce progression in the subsequent 6-month interval. CONCLUSIONS: In this daily practice cohort, following T2T principles more meticulously did not result in less radiographic progression than a somewhat more lenient attitude towards T2T. One possible interpretation of these results is that the intention to apply T2T already suffices and that a more stringent approach does not further improve outcome.

COVID-19 illness: Different comorbidities may require different immunological therapeutic targets.

BACKGROUND: The SARS-CoV-2 pandemic has led to more than 6,870.000 deaths worldwide. Despite recent therapeutic advances, deaths in Intensive Care Units still range between 34 and 72%, comprising substantial unmet need as we move to an endemic phase. The general agreement is that in the first few days of infection, antiviral drugs and neutralizing monoclonal antibodies should be adopted. When the patient is hospitalized and develops severe pneumonia, progressing to a systemic disease, immune modifying therapy with corticosteroids is indicated. Such interventions, however, are less effective in the context of comorbidities (e.g., diabetes, hypertension, heart failure, atrial fibrillation, obesity and central nervous system-CNS diseases) which are by themselves associated with poor outcomes. Such comorbidities comprise common and some distinct underlying inflammatory pathobiology regulated by differential cytokine taxonomy. METHODS: Searching in the PubMed database, literature pertaining to the biology underlying the different comorbidities, and the data from the studies related to various immunological treatments for the Covid-19 disease were carefully analyzed. RESULTS: Several experimental and clinical data have demonstrated that hypertension and atrial fibrillation present an IL-6 dependent signature, whereas diabetes, obesity, heart failure and CNS diseases may exhibit an IL-1a/b predominant signature. Distinct selective cytokine targeting may offer advantage in treating severe COVID-19 illness based on single or multiple associated comorbidities. When the patient does not immediately respond, a broader target range through JAKs pathway inhibitors may be indicated. CONCLUSIONS: Herein, we discuss the biological background associated with distinct comorbidities which might impact the SARS-CoV-2 infection course and how these should to be addressed to improve the current therapeutic outcome.

EULAR points to consider for the management of difficult-to-treat rheumatoid arthritis.

OBJECTIVE: To develop evidence-based European Alliance of Associations for Rheumatology (EULAR) points to consider (PtCs) for the management of difficult-to-treat rheumatoid arthritis (D2T RA). METHODS: An EULAR Task Force was established comprising 34 individuals: 26 rheumatologists, patient partners and rheumatology experienced health professionals. Two systematic literature reviews addressed clinical questions around diagnostic challenges, and pharmacological and non-pharmacological therapeutic strategies in D2T RA. PtCs were formulated based on the identified evidence and expert opinion. Strength of recommendations (SoR, scale A-D: A typically consistent level 1 studies and D level 5 evidence or inconsistent studies) and level of agreement (LoA, scale 0-10: 0 completely disagree and 10 completely agree) of the PtCs were determined by the Task Force members. RESULTS: Two overarching principles and 11 PtCs were defined concerning diagnostic confirmation of RA, evaluation of inflammatory disease activity, pharmacological and non-pharmacological interventions, treatment adherence, functional disability, pain, fatigue, goal setting and self-efficacy and the impact of comorbidities. The SoR varied from level C to level D. The mean LoA with the overarching principles and PtCs was generally high (8.4-9.6). CONCLUSIONS: These PtCs for D2T RA can serve as a clinical roadmap to support healthcare professionals and patients to deliver holistic management and more personalised pharmacological and non-pharmacological therapeutic strategies. High-quality evidence was scarce. A research agenda was created to guide future research.

EULAR definition of difficult-to-treat rheumatoid arthritis.

BACKGROUND: Despite treatment according to the current management recommendations, a significant proportion of patients with rheumatoid arthritis (RA) remain symptomatic. These patients can be considered to have 'difficult-to-treat RA'. However, uniform terminology and an appropriate definition are lacking. OBJECTIVE: The Task Force in charge of the "Development of EULAR recommendations for the comprehensive management of difficult-to-treat rheumatoid arthritis" aims to create recommendations for this underserved patient group. Herein, we present the definition of difficult-to-treat RA, as the first step. METHODS: The Steering Committee drafted a definition with suggested terminology based on an international survey among rheumatologists. This was discussed and amended by the Task Force, including rheumatologists, nurses, health professionals and patients, at a face-to-face meeting until sufficient agreement was reached (assessed through voting). RESULTS: The following three criteria were agreed by all Task Force members as mandatory elements of the definition of difficult-to-treat RA: (1) Treatment according to European League Against Rheumatism (EULAR) recommendation and failure of ≥2 biological disease-modifying antirheumatic drugs (DMARDs)/targeted synthetic DMARDs (with different mechanisms of action) after failing conventional synthetic DMARD therapy (unless contraindicated); (2) presence of at least one of the following: at least moderate disease activity; signs and/or symptoms suggestive of active disease; inability to taper glucocorticoid treatment; rapid radiographic progression; RA symptoms that are causing a reduction in quality of life; and (3) the management of signs and/or symptoms is perceived as problematic by the rheumatologist and/or the patient. CONCLUSIONS: The proposed EULAR definition for difficult-to-treat RA can be used in clinical practice, clinical trials and can form a basis for future research.

Comprehensive review on intravertebral intraspinal, intrajoint, and intradiscal vacuum phenomenon: From anatomy and physiology to pathology.

The term 'vacuum phenomenon' (VP), is characterized by gas-like density areas due to a rapid increase in the joint space volume ('acute VP') or represent a chronic gas collection. It can occur within a collapsed vertebral body, the spinal canal, joints but mainly the intervertebral disc. Studies support that VP is originated by a dynamic process involving the balance between tissues' liquid and gaseous components, influenced by the duration and the depth of mechanical and metabolic alterations, by the nature of neighboring tissues and the variability in both pressure and permeability of disc or vertebral or joint structures. Prevalence of VP in the general population is about 2%, reaching 20% in the elderly with disc degeneration. Although it's often a random finding in asymptomatic patients, VP is an eventually painful expression of disc degeneration, or disc or vertebral fracture, or bone lesions. In sporadic cases, intradiscal gas can be expelled (all-in-one or gradually), resulting in a gaseous cyst, causing pain and neurological symptoms. Considering that spontaneous resolution and recurrence after surgery are both possible, most of the authors recommend conservative treatment in patients with intradiscal and intravertebral VP; occasionally percutaneous CT(computed tomography) -guided aspiration or vertebral stabilization.

Checkpoint inhibitors (CPI) and autoimmune chronic inflammatory diseases (ACIDs): tolerance and loss of tolerance in the occurrence of immuno-rheumatologic manifestations.

Immune related adverse events (irAEs) have been observed with all checkpoint inhibitors and are very frequent. The evidences coming from experimental models of congenital or acquired deficiency of CTLA-4 or from PD-1 knock-out mice, provided all the informations to interpret the organ or systemic manifestations (endocrine, or systemic autoimmune chronic inflammatory diseases-ACIDs) observed in trials as well as in registries of cohorts treated with anti-CTLA-4 or anti-PD-1/PD-L1 inhibitors, or combination therapies. Finally the concern raised by cancers occurring in patients with autoimmune diseases (Systemic Lupus Erythematosus, Myositis, Rheumatoid Arthritis, Psoriatic Arthritis, Vasculitis, Scleroderma, Polymyalgia Rheumatica and others) and how to deal with immunotherapy was discussed. The biological knowledges acquired with the immunotherapy trials, have paved to way to better treat autoimmune diseases in patients developing cancer during the autoimmune illness. Immunotherapy without Autoimmunity is the unmet need within our reach in the future.

Measuring the T-cell down-regulation of TCR-zeta, ZAP-70 and CD28 in arthritis patients: An old tool for new biomarkers.

Low T-cell receptor (TCR)/CD28 signaling lymphocytes are expanded in arthritis. We asked whether the down-expression of TCR-related molecules correlates with specific arthritis characteristics and if it has clinical implications. TCR-ZETA, ZAP-70 and CD28 expression was measured by flow cytometry in synovial fluid (SF) and peripheral blood (PB)-derived T cells. In PB, ZETA-downregulation in CD4+ CD28+ and consequent CD4+ CD28lowZETAlow cell expansion correlate with CRP elevation, leukocyte recruitment into SF and, primarily, disease activity (DAS). In some patients, ZETA-downregulation extends to CD8+ CD28null and/or CD8+ CD28+ cells, and this correlates with enhanced leukocyte recruitment, multiple joint involvement, and disability index (HAQ). ZETA-downregulation in CD4+ CD28+ may also lead to CD4+ CD28+ ZETAnull cell expansion, which strongly correlates with HAQ. In SF, ZETA-downregulation in CD8+ CD28null and consequent CD8+ CD28nullZETAlow/null cell expansion correlate with CRP elevation and neutrophilic influx into SF, whereas ZAP-downregulation in CD8+ CD28+ and consequent CD8+ CD28lowZAPlow cell expansion strongly correlate with HAQ and DAS. ZETA-downregulation is preponderant in SF of seronegative arthritides, with seronegative rheumatoid arthritis showing significant down-regulation in CD8+ CD28null, and non-rheumatoid arthritides showing significant down-regulation in CD4+ CD28+ . Altogether, we identified new molecular and cellular biomarkers of arthritis-related T-cell inflammation, useful for assessing arthritis activity, predicting polyarticular progression and functional impairment, characterizing seronegative arthritides, and possibly tailoring immunotherapies.

Is treat-to-target really working in rheumatoid arthritis? a longitudinal analysis of a cohort of patients treated in daily practice (RA BIODAM).

OBJECTIVES: To investigate whether following a treat-to-target (T2T)-strategy in daily clinical practice leads to more patients with rheumatoid arthritis (RA) meeting the remission target. METHODS: RA patients from 10 countries starting/changing conventional synthetic or biological disease-modifying anti-rheumatic drugs were assessed for disease activity every 3 months for 2 years (RA BIODAM (BIOmarkers of joint DAMage) cohort). Per visit was decided whether a patient was treated according to a T2T-strategy with 44-joint disease activity score (DAS44) remission (DAS44 <1.6) as the target. Sustained T2T was defined as T2T followed in ≥2 consecutive visits. The main outcome was the achievement of DAS44 remission at the subsequent 3-month visit. Other outcomes were remission according to 28-joint disease activity score-erythrocyte sedimentation rate (DAS28-ESR), Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI) and American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) Boolean definitions. The association between T2T and remission was tested in generalised estimating equations models. RESULTS: In total 4356 visits of 571 patients (mean (SD) age: 56 (13) years, 78% female) were included. Appropriate application of T2T was found in 59% of the visits. T2T (vs no T2T) did not yield a higher likelihood of DAS44 remission 3 months later (OR (95% CI): 1.03 (0.92 to 1.16)), but sustained T2T resulted in an increased likelihood of achieving DAS44 remission (OR: 1.19 (1.03 to 1.39)). Similar results were seen with DAS28-ESR remission. For more stringent definitions (CDAI, SDAI and ACR/EULAR Boolean remission), T2T was consistently positively associated with remission (OR range: 1.16 to 1.29), and sustained T2T had a more pronounced effect on remission (OR range: 1.49 to 1.52). CONCLUSION: In daily clinical practice, the correct application of a T2T-strategy (especially sustained T2T) in patients with RA leads to higher rates of remission.

Basic immunology may lead to translational therapeutic rationale: SARS-CoV-2 and rheumatic diseases.

COVID-19 pandemia is a major concern for patients and healthcare systems. The fear of infection by patients with concomitant rheumatic diseases (either adult or children) and connective tissue diseases is arising worldwide, because of their immunological background and immunological therapies. Analysing the basic biology of single diseases, the data suggest that there is an "immunological umbrella" that seems to protect against the infection, through IFN type 1 and NK cell function. To date, reports from China, United States and Europe did not reveal an higher risk of infection, either for rheumatoid arthritis, juvenile idiopathic arthritis nor for lupus erythematosus. Antimalarials, anti-IL6-Anti-IL6 receptor, anti-IL1, anti-GM-CSF receptor and JAK1/2/3 inhibitors, are under investigation in COVID-dedicated clinical trials to control the inflammation raised by SARS-CoV-2 infection. Initial reports on the occurrence of autoimmune phenomena in the convalescence phase of SARS-CoV-2 infection suggests that the immunological consequences of the infection need to be strictly understood. Reporting of the study conforms to broad EQUATOR guidelines (Simera et al January 2010 issue of EJCI).

Gut microbiota analysis in systemic sclerosis according to disease characteristics and nutritional status.

OBJECTIVES: Systemic sclerosis (SSc) is a rare multi-organ disorder with a prominent gastrointestinal (GI) involvement. Altered gut microbiota is now considered a pivotal factor associated with the development of immune-mediated and inflammatory diseases. We performed a 16S ribosomal RNA (rRNA) gene-sequencing analysis of fecal microbiota in a cohort of SSc patients and matched healthy controls (HCs), with the aim to obtain some hints about a possible role of dysbiosis in the onset, progression, and severity of the disease. METHODS: We analysed stool samples from 63 SSc patients with different disease duration, phenotype, and nutritional status and from 17 HCs through 16S ribosomal RNA (rRNA) gene-sequencing. RESULTS: Microbial richness was lower for patients with long-standing disease. A similar observation was made for patients with diffuse cutaneous SSc (dsSSc) compared to those with limited variant (lcSSc) and for patients who reported a recent weight loss. Consistent with previous reports, we noted a deviation of the intestinal microbial composition in patients with SSc compared to HCs, with a greater expression of Lactobacillus and Streptococcus and a depletion of Sutterella. Nutritional status, assessed using BMI as a surrogate, appeared to have a marked impact on the gut microbiota, with overweight patients showing lower richness compared both to underweight and normal-BMI patients. CONCLUSIONS: Our findings expand the current knowledge of gut microbiota in SSc and could be useful to identify patients who would most benefit from treatments aimed at restoring the eu-biosis.

QT and QT dispersion intervals in long-standing and moderately active rheumatoid arthritis: results from a multicentre cross-sectional study.

OBJECTIVES: To define the prevalence of prolonged QT interval and QT dispersion (QTd) in rheumatoid arthritis (RA) patients and in a control population. METHODS: QT interval corrected by Bazett's formula (QTc) was calculated from standard 12-lead ECGs in 963 subjects free of previous cardiovascular events (646 RA patients and 317 controls strictly matched for age, sex and cardiovascular risk factors). RESULTS: RA patients (59.6±9.6 years, 68.1% females) had a long mean disease duration (10.6 years) and moderate disease activity (DAS28=3.68±1.23). QTc was 5 msec longer in RA patients than in controls (412±9 vs. 407±28 msec, p=0.013). However, the prevalence of QTc prolongation in RA patients and controls was not significantly different (5.3% vs. 6.3%, p=0.50). On the contrary, RA patients had a significantly greater QTd (42±26 vs. 35±18 msec, p<0.001) and a higher prevalence of increased QTd (33.3% vs. 18.3%, p<0.001) than controls. Furthermore, RA was independently associated to increased QTd [OR(95%CI)= 2.21(1.58-3.08), p=0.0001]. In the RA population, male gender and older age were independently associated with a higher prevalence of prolonged QTd. CONCLUSIONS: In this cohort of long-standing and moderately active RA patients, RA showed longer QTc but similar prevalence of prolonged QTc and an increased QTd with a 1.8-fold higher prevalence of increased QTd than the control population. Further studies in larger prospective cohorts are warranted to investigate whether QTd prolongation predicts sudden cardiac death and other adverse cardiovascular outcomes in RA.

European multicentre study validates enhanced liver fibrosis test as biomarker of fibrosis in systemic sclerosis.

Objectives: To validate enhanced liver fibrosis (ELF) test and its components-amino-terminal propeptide of procollagen type III (PIIINP), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and HA-as biomarkers of fibrosis in SSc in an independent, international, multicentre cohort. Methods: Two hundred and fifty-four SSc patients from six Rheumatology Centres were included. Sera were collected and stored according to EUSTAR biobanking recommendations and analysed through automated high throughput diagnostics. Statistical analysis was performed with SPSS software. Results: Two hundred and forty-seven SSc patients (mean age 55.7 ± 13.9 years, 202 F) were analysed. ELF score, TIMP-1 and PIIINP levels were higher in males (P = 0.0197, P = 0.0107, P = 0.0108 respectively) and in dcSSc (P = 0.001, P = 0.0008, P < 0.0001 respectively). ELF score and the single markers significantly correlated with modified Rodnan skin score (r = 0.37, P < 0.0001), disease activity and severity (P < 0.0001 for all markers, except for HA P = 0.0001) and inversely with forced vital capacity, (FVC) % (TIMP-1, r = -0.21, P = 0.0012; PIIINP, r = -0.26, P = 0.0001), TLC% (ELF score, r = -0.20, P = 0.0036; TIMP-1, r = -0.32, P < 0.0001; PIIINP, r = -0.28, P < 0.0001), diffusion capacity of the lung for carbon monoxide (DLCO) % (P < 0.0001 for all markers, except for HA P = 0.0115). Multivariate analysis indicated that age (P < 0.001), modified Rodnan skin score (P < 0.001) and DLCO% (P = 0.005) were independently associated with ELF score. Conclusion: Between the first and this validation studies, the value of the ELF score as independent marker of skin and lung involvement in SSc is confirmed in 457 patients. A longitudinal study is on-going to identify an SSc specific algorithm with predictive value for skin and lung progression.

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.

Rate of serious infections in spondyloarthropathy patients treated with anti-tumour necrosis factor drugs: a survey from the Italian registry GISEA.

OBJECTIVES: To determine the incidence of serious infections (SIs) among the spondyloarthropathy (SpA) patients from the "Gruppo Italiano per lo Studio delle Early Arthritis" (GISEA) registry and treated with tumour necrosis factor (TNF) inhibitors (TNFIs), and to identify the factors associated with the development of the infections. METHODS: This observational study on 3321 GISEA-registered SpA patients collected real-world demographic and clinical data relating to their biological drug treatments. The overall incidence of infections was analysed by type of SpA. RESULTS: A total of 3321 SpA patients (1731 males, 52.2%; mean age 47±13 years; median disease duration 3 years, interquartile range [IQR] 0-8) were eligible for inclusion in the analysis. Two hundred and fifty-nine patients experienced at least one of 391 microbiologically diagnosed SIs, 32% of which were recorded during the first 12 months of treatment. The overall incidence of SIs was 43.9/1000 patient-years of follow-up (95% confidence interval [CI] 39.6-48.4): 29.9/1000 (95% CI 23.1-38.1) among those treated with adalimumab (ADA); 36.1/1000 (95% CI 30.0-43.1) among those treated with etanercept (ETN); and 61.4/1000 (95% CI 53.3-70.5) among those treated with infliximab (INF). The highest incidence was observed among the patients with psoriatic arthritis (PsA), but the difference was statistically significant only in comparison with the patients with undifferentiated SpA (p=0.002), whose incidence of SIs was also lower than in the patients with ankylosing spondylitis (AS) (p=0.034). Multivariate models showed that the number of comorbidities (hazard ratio [HR] 1.29, 95%CI 1.2-1.4; p<0.001), age at the start of TNFi treatment (HR 0.99, 95%CI 0.97-0.99; p=0.030), steroid use (HR 1.40, 95%CI 1.1-1.8; p=0.012) and male sex (HR 0.72, 95%CI 0.5-0.9; p=0.012) were all statistically significant predictors of infection. The factors independently associated with a lower risk of SIs were the use of ETN (HR 0.52, 95%CI 0.4-0.7; p<0.001) or ADA (HR 0.59, 95%CI 0.4-0.8; p=0.002) rather than INF. CONCLUSIONS: The incidence of SIs was higher among patients with PsA or AS than among those with undifferentiated SpA, and among patients treated with INF than among those treated with ADA or ETN. Male sex, steroid use and the number of comorbidities were all factors predictive of SIs.