Real-Life Comparison of Four JAK Inhibitors in Rheumatoid Arthritis (ELECTRA-i Study).

Background: Real-world evidence of the efficacy and adverse events of JAK inhibitor treatment (Tofacitinib, Baricitinib, Upadacitinib, and Filgotinib) in rheumatoid arthritis is still limited. Methods: We studied 115 patients from the Rheumatology Unit of S. Giovanni di Dio Hospital affected by D2T-RA, according to the 2010 EULAR criteria. Out of the 115 patients, 17 had been treated with Baricitinib 8 mg/daily, 32 with Filgotinib 200 mg/daily, 21 with Tofacitinib 10 mg/daily, and 45 with Upadacitinib 15 mg/daily. We evaluated the clinical response after 3, 6, and 12 months of treatment and the follow-up from September 2022 to September 2023. All patients were evaluated according to the number of tender joints (NTJs), number of swollen joints (NSJs), visual analog scale (VAS), global assessment (GA), health assessment questionnaire (HAQ), Disease Activity Score (DAS28), and CDAI. Furthermore, laboratory parameters of efficacy and tolerability were evaluated. Results: All treatments demonstrated a statistically significant decrease in the DAS28 and CDAI scores, tender and swollen joint counts, VAS, HAQ, and patient global assessment (PGA) after 3, 6, and 12 months of treatment. All treatments showed similar behavior, and statistically significant decreases in circulating calprotectin, TNFα, and IL-6 were observed for all drugs after 12 months of treatment. In addition, soluble urokinase plasminogen activator receptor (suPAR) values showed significant differences at baseline and after 12 months of treatment for Filgotinib: 4.87 ± 4.53 vs. 3.61 ± 0.9 (0.009) and Upadacitinib: 6.64 ± 7.12 vs. 4.06 ± 3.61 (0.0003), while no statistically significant differences were found for Baricitinib: 3.4 ± 0.1 vs. 3.78 ± 0.1 and Tofacitinib: 3.95 ± 1.77 vs. 2.58 ± 0.1. The TC/HDL-C ratio (atherogenic index) showed significant differences when comparing Baricitinib vs. Filgotinib (0.0012), Filgotinib vs. Tofacitinib (0.0095), and Filgotinib vs. Upadacitinib (0.0001); furthermore, the LDL-C/HDL-C ratio in the Filgotinib group did not change (2.37 ± 0.45 vs. 2.35 ± 2.13 (NS)) after 12 months of treatment. Venous Thrombotic Events (VTEs) and major adverse cardiovascular events (MACEs) accounted for 1% of adverse events after treatment with Baricitinib. Herpes zoster reactivation accounted for 1% of adverse events after treatment with Filgotinib and Tofacitinib, while non-melanoma skin cancer (NMSC) accounted for 1% of adverse events after Upadacitinib treatment. Conclusions: Our real-world data from patients with RA show differences in some laboratory parameters and in the impact of lipid metabolism in JAK inhibitor treatment.

ToRaRI (Tofacitinib in Rheumatoid Arthritis a Real-Life experience in Italy): Effectiveness, safety profile of tofacitinib and concordance between patient-reported outcomes and physician's global assessment of disease activity in a retrospective study in Central-Italy.

INTRODUCTION: The use of Janus Kinase Inhibitors (JAK-Is) in rheumatoid arthritis (RA) has entered in daily practice. In consideration of ORAL-Surveillance trial and the new EULAR recommendations, real-world data are needed to assess Jak-Is safety and effectiveness. The multicenter study presented here aimed to evaluate effectiveness and safety of tofacitinib in a real-life cohort. METHODS: A retrospective analysis was performed from September 2021 to December 2022. Data were collected when tofacitinib was started (T0) and after 3 (T3), 6 (T6) and 12 (T12) months of treatment. The primary objective was to analyze the efficacy and safety of tofacitinib. Safety was assessed by recording adverse events (AEs) with and without discontinuation. The secondary objective was to assess the difference between Patient-Reported Outcomes (PROs) and Physician's Global Assessment of disease activity (PhGA). RESULTS: 122 patients were included in the study from the following rheumatology Centers: Pisa, Ancona, Florence (two Centers), Siena, and Sardinia. A statistically significant improvement in DAS-28-CRP, CDAI and SDAI score was observed at T3, T6, compared to baseline (p < 0.001). Improvement was confirmed in patients who reach T12. Patients naïve to bDMARDs showed a shorter remission time and higher remission rates. There was also a statistically significant improvement in PROs compared to baseline (p < 0.001). The improvement was rapid and was consistent with PhGA. The 12-month retention rate for tofacitinib was 89.35%. Reasons to stop tofacitinib were: insufficient response (7), gastrointestinal symptoms (2), infection (1), malignancy (1), Zoster (1), pruritus sine materia (1). CONCLUSIONS: Tofacitinib is safe and effective in our RA cohort. It induces higher remission rates in patients naive to bDMARDs, suggesting that there may be a benefit using it as first-line therapy. Additionally, improvement in PROs was consistent with PhGA scores, demonstrating how tofacitinib affects both the objective and subjective components of disease activity. Key Points 1. JAK inhibitors are considered at a similar level as biologic agents in terms of effectiveness. 2. After ORAL-Surveillance results, real-world data are needed to assess the benefit/risk profile of Jaki. 3. Disagreement between patients and physicians has been previously reported with biologic therapy among patients with rheumatoid arthritis, with patients rating disease activity higher than physicians. 4. Jak inhibitors could reduce this discrepancy, due to their mechanism of action.

Management of psoriatic arthritis: a consensus opinion by expert rheumatologists.

Background: Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disease involving several articular and extra-articular structures. Despite the important progresses recently made in all of the aspects of this disease, its management is still burdened by unresolved issues. The aim of this exercise was to provide a set of statements that may be helpful for the management of PsA. Methods: A group of 38 Italian rheumatologists with recognized expertise in PsA selected and addressed the following four topics: "early PsA," "axial-PsA," "extra-articular manifestations and comorbidities," "therapeutic goals." Relevant articles from the literature (2016-2022) were selected by the experts based on a PubMed search. A number of statements for each topic were elaborated. Results: Ninety-four articles were selected and evaluated, 68 out of the 1,114 yielded by the literature search and 26 added by the Authors. Each of the four topic was subdivided in themes as follows: transition from psoriasis to PsA, imaging vs. CASPAR criteria in early diagnosis, early treatment for "early PsA"; axial-PsA vs. axialspondyloarthritis, diagnosis, clinical evaluation, treatment, standard radiography vs. magnetic resonance imaging for "axial PsA"; influence of inflammatory bowel disease on the therapeutic choice, cardiovascular comorbidity, bone damage, risk of infection for "comorbidities and extra-articular manifestations"; target and tools, treat-to-target strategy, role of imaging for "therapeutic goals." The final document consisted of 49 statements. Discussion: The final product of this exercise is a set of statements concerning the main issues of PsA management offering an expert opinion for some unmet needs of this complex disease.

Older Age, a High Titre of Neutralising Antibodies and Therapy with Conventional DMARDs Are Associated with Protection from Breakthrough Infection in Rheumatoid Arthritis Patients after the Booster Dose of Anti-SARS-CoV-2 Vaccine.

Objectives: We aimed to analyse the incidence and severity of breakthrough infections (BIs) in rheumatoid arthritis (RA) patients after a COronaVIrus Disease 2019 (COVID-19) vaccination booster dose. Methods: We enrolled 194 RA patients and 1002 healthcare workers (HCWs) as controls. Clinical, lifestyle and demographic factors were collected at the time of the third dose, and immunogenicity analyses were carried out in a subgroup of patients at 4-6 weeks after the third dose. Results: BIs were experienced by 42% patients (82/194) with a median time since the last vaccination of 176 days. Older age (>50 years; aHR 0.38, 95% CI: 0.20-0.74), receiving conventional synthetic disease modifying antirheumatic drugs (csDMARDs) (aHR 0.52, 95%CI: 0.30-0.90) and having a titre of neutralising antibodies >20 (aHR 0.36, 95% CI: 0.12-1.07) were identified as protective factors. Conversely, anti-IL6R treatment and anti-CD20 therapy increased BI probability. BIs were mostly pauci-symptomatic, but the hospitalisation incidence was significantly higher than in HCWs (8.5% vs. 0.19%); the main risk factor was anti-CD20 therapy. Conclusions: Being older than 50 years and receiving csDMARDs were shown to be protective factors for BI, whereas anti-IL6R or anti-CD20 therapy increased the risk. Higher neutralising antibody titres were associated with a lower probability of BI. If confirmed in a larger population, the identification of a protective cut-off would allow a personalised risk-benefit therapeutic management of RA patients.

Different Biomarkers of Response to Treatment with Selective Jak-1 Inhibitors in Rheumatoid Arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a systemic autoimmune disease that causes progressive joint damage. The Janus kinase (JAK) inhibitors (JAK-I) represent a new therapeutic option for RA patients, blocking the intracellular JAK-STAT pathway. Today, no studies have been conducted to determine whether new biomarkers could better reflect disease activity in patients treated with JAK-I than traditional disease activity indicators. Thus, the aim of our study was to determine additional disease activity biomarkers in RA patients receiving selective JAK-1 inhibitors. METHODS: we enrolled 57 patients with RA: 34 patients were treated with Upadacitinib (UPA) and 23 patients with Filgotinib (FIL). All patients were evaluated for clinimetry with DAS28 and Crohn's Disease Activity Index (CDAI), number of tender and swollen joints, Visual Analogic Scale (VAS), Physician Global Assessment (PhGA), and Health Assessment Questionnaire (HAQ), at baseline and at the 12th week of treatment. Lymphocyte subpopulations, complete blood count, erythrocyte sedimentation rate (ESR), C-Reactive Protein (CRP), anti-cyclic citrullinated peptide antibodies (APCA), rheumatoid factor (RF) IgM, interleukin 6 (IL-6), circulating calprotectin (cCLP), tumor necrosis factor α (TNFα), soluble urokinase Plasminogen Activator Receptor (suPAR), complement functional activity were measured at baseline and after the 12th week of treatment. RESULTS: in both groups of patients, we documented a significant reduction in the clinimetric parameters DAS28, CDAI, number of tender joints, number of swollen joints, VAS, PhGA, and HAQ. Moreover, significant differences were reported for laboratory parameters of ESR, CRP, IL-6, suPAR, cCLP, and PLT/L ratio in both groups. However, no difference was demonstrated between the two groups for changes in renal, hepatic, and lipid parameters. CONCLUSIONS: the suPAR and cCLP levels may lead towards a different therapeutic choice between UPA and FIL, with the expression of two different RA pathophenotypes directing FIL towards a lymphocyte-poor form and UPA towards a myeloid form of RA.

ReLiFiRa (Real Life Filgotinib in Rheumatoid Arthritis): Retrospective Study of Efficacy and Safety in Common Clinical Practice.

BACKGROUND: Filgotinib (FIL) is a selective JAK1 inhibitor with an affinity 30-fold higher than JAK2, approved to treat moderate to severe active rheumatoid arthritis (RA), in adults with inadequate response or intolerance to one or more disease-modifying antirheumatic drugs (DMARDs). METHODS: We conducted a retrospective, multicentric study in order to evaluate efficacy and safety of FIL 200 mg daily therapy, after 3 and 6 months, in 120 patients affected by RA, managed in Tuscany and Umbria rheumatological centers. The following clinical records were analyzed: demographical data, smoking status, previous presence of comorbidities (Herpes zoster -HZ- infection, venous thromboembolism -VTE-, major adverse cardiovascular events -MACE-, cancer, diabetes, and hypertension), disease duration, presence of anti-citrullinated protein antibodies (ACPA), rheumatoid factor (RF), number of biological failures, and prior csDMARDs utilized. At baseline, and after 3 (T3) and 6 (T6) months of FIL therapy, we evaluated mean steroid dosage, csDMARDs intake, clinimetric indexes (DAS28, CDAI, HAQ, patient and doctor PGA, VAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and body mass index (BMI). RESULTS: At baseline, the mean disease duration was 9.4 ± 7.5 years; the prevalence of previous HZ infection, VTE, MACE, and cancer was respectively 4.12%, 0%, 7.21%, and 0.83%, respectively. In total, 76.3% of patients failed one or more biologics (one biological failure, 20.6%; two biological failures, 27.8%; three biological failures, 16.5%; four biological failures, 10.3%; five biological failures, 1.1%). After 3 months of FIL therapy, all clinimetric index results significantly improved from baseline, as well as after 6 months. Also, ESR and CRP significatively decreased at T3 and T6. Two cases of HZ were recorded, while no new MACE, VTE, or cancer were recorded during the observation time. CONCLUSION: Despite the limitations of the retrospective study and of the observational period of only 6 months, real-life data on the treatment of RA patients with FIL demonstrate that this Jak inhibitor therapy is safe in terms of CV, VTE events, and occurrence of cancer, and is also effective in a population identified as "difficult to treat" due to failure of previous b-DMARD therapy.

Testing for isotypes does not help differentiating rheumatoid arthritis from other rheumatoid factor positive diseases.

Rheumatoid factors (RFs) are useful for diagnosis and classification of rheumatoid arthritis (RA). Nephelometric and turbidimetric techniques, which detect total RF but do not reveal the antibody isotype, are common diagnostic methods in clinical routine. Given the recent development of isotype-specific immunoassays, the detection of IgG, IgM, and IgA RFs represents an interesting challenge. The aim of the study was to evaluate whether specific RF tests performed as a second step after traditional nephelometry could help differentiating RA from other RF-positive diseases. We tested 117 consecutive serum samples that were RF-positive at nephelometry (BNII nephelometric analyzer, Siemens) for IgA, IgG, and IgM RF isotypes by a fluoroimmunoenzymatic assay (FEIA) on the Phadia 250 instrument (ThermoFisher). Fifty-five subjects had RA and 62 presented non-RA diagnoses. Eighteen sera (15.4%) were positive only by nephelometry, two were positive only for IgA RF, and the remaining 97 sera were all positive for IgM RF isotype (with or without IgG and IgA RF). Positive findings did not correlate with RA or non-RA diagnosis. Spearman rho correlation coefficient between nephelometric total RF and IgM isotype was moderate (0.657), and weak between total RF and IgA (0.396) and IgG (0.360) isotypes. Despite its low specificity, measurement of total RF by nephelometry still seems to be the method that performs best. As IgM, IgA, and IgG RF isotypes showed only a moderate correlation with total RF measurement, their diagnostic use as a second level test remains controversial.

Soluble Urokinase Plasminogen Activator Receptor (suPAR) in Autoimmune Rheumatic and Non Rheumatic Diseases.

The soluble urokinase plasminogen activator receptor (suPAR) is the bioactive form of uPAR, a membrane-bound glycoprotein, and it is primarily expressed on the surface of immunologically active cells. Mirroring local inflammation and immune activation, suPAR has gained interest as a potential prognostic biomarker in several inflammatory diseases. Indeed, in many diseases, including cancer, diabetes, cardiovascular diseases, kidney diseases, and inflammatory disorders, higher suPAR concentrations have been associated with disease severity, disease relapse, and mortality. Our review describes and discusses the supporting literature concerning the promising role of suPAR as a biomarker in different autoimmune rheumatic and non-rheumatic diseases.

Lack of comparability of immunoassays for rheumatoid factor isotypes.

OBJECTIVES: Rheumatoid arthritis (RA) is a systemic autoimmune disease characterised by the presence of autoantibodies that are used for classification of the disease. Though routine diagnostics is commonly restricted to measuring rheumatoid factor (RF) and anti-citrullinated protein antibodies, detection of RF IgM, IgG and IgA isotypes, may increase the power of RA serodiagnosis by reducing the number of seronegative patients as well as provide prognostic information. The agglutination-based RF assays, such as nephelometry or turbidimetry, are unable to differentiate isotypes. We compared three different immunoassays used in current laboratory practice to detect RF isotypes. METHODS: We tested 117 consecutive serum samples that were positive for total RF at nephelometry, from 55 RA and 62 non-RA subjects. IgA, IgG, and IgM isotypes of RF were tested by immunoenzymatic (ELISA, Technogenetics), fluoroenzymatic (FEIA, ThermoFisher) and chemiluminescence (CLIA, YHLO Biotech Co.) immunoassays. RESULTS: Diagnostic performance differed considerably between the assays, especially with regard to RF IgG isotype. Agreement among methods by Cohen's kappa ranged from 0.05 (RF IgG CLIA vs. FEIA) to 0.846 (RF IgM CLIA vs. FEIA). CONCLUSIONS: The poor agreement observed in this study indicates substantial lack of comparability among assays for RF isotypes. Harmonization of these tests requires further efforts before their measurement can be used in clinical practice.

The Third Dose of BNT162b2 COVID-19 Vaccine Does Not "Boost" Disease Flares and Adverse Events in Patients with Rheumatoid Arthritis.

Data on the risk of adverse events (AEs) and disease flares in autoimmune rheumatic diseases (ARDs) after the third dose of COVID-19 vaccine are scarce. The aim of this multicenter, prospective study is to analyze the clinical and immunological safety of BNT162b2 vaccine in a cohort of rheumatoid arthritis (RA) patients followed-up from the first vaccine cycle to the third dose. The vaccine showed an overall good safety profile with no patient reporting serious AEs, and a low percentage of total AEs at both doses (40/78 (51.3%) and 13/47 (27.7%) patients after the second and third dose, respectively (p < 0.002). Flares were observed in 10.3% of patients after the end of the vaccination cycle and 12.8% after the third dose. Being vaccinated for influenza was inversely associated with the onset of AEs after the second dose, at both univariable (p = 0.013) and multivariable analysis (p = 0.027). This result could allow identification of a predictive factor of vaccine tolerance, if confirmed in larger patient populations. A higher disease activity at baseline was not associated with a higher incidence of AEs or disease flares. Effectiveness was excellent after the second dose, with only 1/78 (1.3%) mild breakthrough infection (BI) and worsened after the third dose, with 9/47 (19.2%) BI (p < 0.002), as a probable expression of the higher capacity of the Omicron variants to escape vaccine recognition.

Correction: Benucci et al. Predicting Loss of Efficacy after Non-Medical Switching: Correlation between Circulating TNF-α Levels and SB4 in Etanercept to SB4 Switchers and Naïve Patients with Rheumatic Disease. J. Pers. Med. 2022, 12, 1174.

The authors wish to make the following correction to this paper [...].

Circulating Calprotectin (cCLP) in autoimmune diseases.

BACKGROUND AND AIM: Calprotectin (CLP) is a heterodimeric complex formed by two S100 proteins (S100A8/A9), which plays a pivotal role in innate immunity. Due to its intrinsic cytotoxic and proinflammatory properties, CLP controls cell differentiation, proliferation and NETosis and has been associated with a wide range of rheumatic diseases. Our review summarizes the widespread interest in circulating CLP (cCLP) as a biomarker of neutrophil-related inflammation, in autoimmune rheumatic disease (ARD) and non-ARD. METHODS: A thorough literature review was performed using PubMed and EMBASE databases searching for circulating calprotectin and synonyms S100A8/A9, myeloid-related protein 8/14 (MRP8/MRP14), calgranulin A/B and L1 protein in addition to specific ARDs and autoimmune non-rheumatic diseases. We selected only English-language articles and excluded abstracts without the main text. RESULTS: High cCLP serum levels are associated with worse structural outcomes in rheumatoid arthritis and to a lesser extent, in spondyloarthritis. In addition, cCLP can predict disease relapse in some autoimmune diseases including systemic lupus erythematosus (SLE), anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) and some severe manifestations of connective tissue diseases, such as glomerulonephritis in SLE, AAV, juvenile idiopathic arthritis, adult-onset Still's disease and lung fibrosis in systemic sclerosis. Therefore, cCLP levels enable the identification of patients who need an accurate and tight follow-up. The clinical usefulness of cCLP as an inflammatory marker has been suggested for inflammatory/autoimmune non-rheumatic diseases, and especially for the monitoring of the inflammatory bowel diseases patients. Currently, there are only a few studies that evaluated the cCLP efficacy as a clinical biomarker in inflammatory/autoimmune non-rheumatic diseases with controversial results. Future studies are warranted to better clarify the role of cCLP in relation to the disease severity in myasthenia gravis, multiple sclerosis, chronic inflammatory demyelinating polyneuropathy, Graves' orbitopathy, autoimmune bullous diseases and uveitis. CONCLUSION: Our literature review supports a relevant role of cCLP as potential prognostic biomarker mirroring local or systemic inflammation, especially in chronic inflammatory rheumatic diseases.

JAK inhibitors and autoimmune rheumatic diseases.

The four Janus kinase (JAK) proteins and the seven Signal Transducers of Activated Transcription (STAT) mediate intracellular signal transduction downstream of cytokine receptors, which are involved in the pathology of allergic, autoimmune, and inflammatory diseases. The development of targeted small-molecule treatments with diverse selective inhibitory profiles, such as JAK inhibitors (JAKi), has supported an important change in the treatment of multiple disorders. Indeed, JAKi inhibit intracellular signalling controlled by numerous cytokines implicated in the disease process of rheumatoid arthritis and several other inflammatory and immune diseases. Therefore, JAKi have the capacity to target multiple pathways of those diseases. Other autoimmune diseases treated with JAKi include systemic sclerosis, systemic lupus erythematosus, dermatomyositis, primary Sjogren's syndrome, and vasculitis. In all of these cases, innate immunity stimulation activates adaptive immunity, resulting in the production of autoreactive T cells as well as the stimulation and differentiation of B cells. Mechanism-based treatments that target JAK-STAT pathways have the possibility of improving outcomes by reducing the consumption of glucocorticoids and/or non-specific immunosuppressive drugs in the management of systemic immune-mediated inflammatory diseases.

Multiparametric autoantibody analysis: a new paradigm for the diagnosis of connective tissue diseases.

BACKGROUND: In patients affected by connective tissue diseases (CTDs), the identification of wide autoantibody profiles may prove useful in early diagnosis, in the evaluation of prognosis (risk stratification), and in predicting response to therapy. The aim of the present study was to evaluate the utility of multiparametric autoantibody analysis performed by a new fully automated particle-based multi-analyte technology (PMAT) digital system in a large multicenter cohort of CTD patients and controls. METHODS: Serum samples from 787 patients with CTD (166 systemic lupus erythematosus; 133 systemic sclerosis; 279 Sjögren's syndrome; 106 idiopathic inflammatory myopathies; 103 undifferentiated CTD), 339 patients with other disorders (disease controls) (118 infectious diseases, 110 organ-specific autoimmune diseases, 111 other rheumatic diseases), and 121 healthy subjects were collected in 13 rheumatologic centers of the FIRMA group. Sera were analyzed with the Aptiva-PMAT instrument (Inova Diagnostics) for a panel of 29 autoantibodies. RESULTS: Multiparametric logistic regression showed that enlarged antibody profiles have a higher diagnostic efficiency than that of individual antibodies or of antibodies that constitute classification criteria for a given disease and that probability of disease increases with multiple positive autoantibodies. CONCLUSIONS: This is the first study that analyzes the clinical and diagnostic impact of autoantibody profiling in CTD. The results obtained with the new Aptiva-PMAT method may open interesting perspectives in the diagnosis and sub-classification of patients with autoimmune rheumatic diseases.

The Association of uPA, uPAR, and suPAR System with Inflammation and Joint Damage in Rheumatoid Arthritis: suPAR as a Biomarker in the Light of a Personalized Medicine Perspective.

BACKGROUND: In recent years, the involvement of the soluble urokinase Plasminogen Activator Receptor (suPAR) in the pathophysiological modulation of Rheumatoid Arthritis (RA) has been documented, resulting in the activation of several intracellular inflammatory pathways. METHODS: We investigated the correlation of urokinase Plasminogen Activator (uPA)/urokinase Plasminogen Activator Receptor (uPAR) expression and suPAR with inflammation and joint damage in RA, evaluating their potential role in a precision medicine context. RESULTS: Currently, suPAR has been shown to be a potential biomarker for the monitoring of Systemic Chronic Inflammation (SCI) and COVID-19. However, the effects due to suPAR interaction in immune cells are also involved in both RA onset and progression. To date, the literature data on suPAR in RA endorse its potential application as a biomarker of inflammation and subsequent joint damage. CONCLUSION: Available evidence about suPAR utility in the RA field is promising, and future research should further investigate its use in clinical practice, resulting in a big step forward for precision medicine. As it is elevated in different types of inflammation, suPAR could potentially work as an adjunctive tool for the screening of RA patients. In addition, a suPAR system has been shown to be involved in RA pathogenesis, so new data about the therapeutic response to Jak inhibitors can represent a possible way to develop further studies.

Comparison of current methods for anti-dsDNA antibody detection and reshaping diagnostic strategies.

Anti-double-stranded DNA antibodies (anti-dsDNA) are considered a specific marker for systemic lupus erythematosus (SLE). Though the Farr technique was once the reference method for their detection, it has been almost entirely replaced by more recently developed assays. However, there is still no solid evidence of the commutability of these methods in terms of diagnostic accuracy and their correlation with the Crithidia luciliae immunofluorescence test (CLIFT). Anti-dsDNA antibody levels were measured in 80 subjects: 24 patients with SLE, 36 disease controls drawn from different autoimmune rheumatic diseases (14 systemic sclerosis, 10 Sjögren's syndrome, nine autoimmune myositis, three mixed connective tissue disease), 10 inflammatory arthritis and 10 apparently healthy blood donors by eight different methods: fluorescence enzyme immunoassay, microdot array, chemiluminescent immunoassay (two assays), multiplex flow immunoassay, particle multi-analyte technology immunoassay and two CLIFT. At the recommended manufacturer cut-off, the sensitivity varied from 67% to 92%, while the specificity ranged from 84% to 98%. Positive agreement among CLIFT and the other assays was higher than negative agreement. Mean agreement among methods assessed by the Cohen's kappa was 0.715, ranging from moderate (0.588) to almost perfect (0.888). Evaluation of the concordance among quantitative values by regression analysis showed a poor correlation index (mean r2, 0.66). The present study shows that current technologies for anti-dsDNA antibody detection are not fully comparable. In particular, their different correlation with CLIFT influences their positioning in the diagnostic algorithm for SLE (either in association or sequentially). Considering the high intermethod variability, harmonization and commutability of anti-dsDNA antibody testing remains an unachieved goal.

Booster dose of SARS-CoV-2 messenger RNA vaccines strengthens the specific immune response of patients with rheumatoid arthritis: A prospective multicenter longitudinal study.

OBJECTIVES: To characterize the kinetics of humoral and T-cell responses in rheumatoid arthritis (RA)-patients followed up to 4-6 weeks (T3) after the SARS-CoV-2 vaccine booster dose. METHODS: Health care workers (HCWs, n = 38) and patients with RA (n = 52) completing the messenger RNA vaccination schedule were enrolled at T3. In each cohort, 25 subjects were sampled after 5 weeks (T1) and 6 months (T2) from the first vaccine dose. The humoral response was assessed by measuring anti-receptor-binding domain (RBD) and neutralizing antibodies, the T-cell response by interferon-γ-release assay (IGRA), T cell cytokine production, and B cell phenotype at T3 by flow cytometry. RESULTS: Patients with RA showed a significant reduction of antibody titers from T1 to T2 and a significant increase at T3. T-cell response by IGRA persisted over time in patients with RA, whereas it increased in HCWs. Most patients with RA scored positive for anti-RBD, neutralizing antibody and T-cell responses, although the magnitude was lower than HCWs. The spike-specific-cytokine response was mainly clusters of differentiation (CD)4+ T cells restricted in both cohorts and significantly lower with reduced interleukin-2 response and CD4-antigen-responding naïve T cells in patients with RA. Unswitched memory B cells were reduced in patients with RA compared with HCWs independently of vaccination. CONCLUSION: COVID-19 vaccine booster strengthens the humoral immunity in patients with RA even with a reduced cytokine response.