Comparison of ELISA with automated ECLIA for IL-6 determination in COVID-19 patients: An Italian real-life experience.

Objectives: Coronavirus disease 2019 (COVID-19) has a wide spectrum of clinical severity. A cytokine storm is associated with COVID-19 severity. Of these, IL-6 is significantly associated with higher mortality and is also a marker for predicting disease prognosis. IL-6 may act as a target for therapeutics and, a blockade of IL-6 function by Tocilizumab has been described as a treatment of the inflammatory process COVID-19-related. This study aims to describe our experience comparing two different methods, in detail Human IL-6 Instant ELISA and the Elecsys IL-6 based on ECLIA, for the IL-6 assessment. Design and methods: IL-6 levels from serum samples of 104 COVID-19 patients, admitted to the AOU Careggi (Hospital in Florence -Italy), were assessed by using the two above-mentioned methods, and the results were analysed through Passing-Bablok regression fit and Bland-Altman plot. Results: The regression exhibited a linear relation between the methods with a regression equation (y = - 0.13 + 0.63 x; 95 % C.I. intercept = - 0.13 to 4.55; 95 % C.I. slope = 1.03 to 1.26 with R2 = 0.89, p > 0.05), showing a positive slope. The agreement of the two methods reported a bias of -25.0 pg/mL. Thus, the two methods correlate but do not agree in terms of numeric results. Conclusions: The two assays showed good comparability. However, because of the extremely wide linear range of the ECLIA, its throughput and its capacity for immune profiling, it represents an interesting emerging technology in the immunology field.

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.

Adopting the International Consensus on ANA Patterns (ICAP) classification for reporting: the experience of Italian clinical laboratories.

The indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA) is still considered the reference method to detect anti-nuclear antibodies (ANA) because of its high sensitivity and represents a relevant tool for the diagnosis of autoimmune rheumatic diseases. During the last decade, the International Consensus on ANA Patterns (ICAP) initiative promoted harmonization and understanding of HEp-2 IFA staining pattern nomenclature, as well as promoting their use in patient care by providing interpretation for HEp-2 IFA test results. In conjunction with a nationwide survey on the evolution of autoantibody diagnostics in autoimmune rheumatic diseases, we focused on the adherence of the Italian laboratories to the ICAP nomenclature analyzing its lights and shadows. The recent ICAP-oriented report, largely used today among Italian laboratories, also represents a further step in harmonizing and improving communication with the clinicians, adding value to laboratory findings and helping with critical clinical decisions.

Harmonization of ANA testing challenge: quantification strategy to accurately predict end-point titers avoiding serial dilution.

Despite the advantages of automated systems for antinuclear antibody (ANA) analysis, the prediction of end-point titers avoiding serial dilutions is still in progress. The aims of this study were to set a conversion table providing discriminant ranges of fluorescence signal intensity values (FI) corresponding to the end-point titers and validate this tool in a real-life laboratory setting. Eight hundred ninety-four serum samples were analyzed for ANA using Image Navigator System. In order to classify FI into non-overlapping groups corresponding to conventional end-point titers, statistical discriminant analysis was used. Validation study was performed calculating agreement and error rates between visual readings and conversion table of 1119 routine ANA positive samples. Setting of FI ranges corresponding to the end-point titers for different staining patterns was computed. For samples showing single pattern, the overall agreement between visual readings and conversion table was 98.4% for all titers ranging from 1:160 to 1:2560, of which 68.0% had the same titer and 30.4% were within ± one titer difference. Concordance rates according to ANA patterns were as follows: (1) nuclear 98.4%, of which 67.0% had the same titer and 31.4% ± one titer; (2) cytoplasmic 100%, of which 72.7% had the same titer and 27.3% than ± one titer; (3) mitotic 66.6%, of which 33.3% had more ± one titer. Our study developed a quantification method for autoantibodies titers assessment based on just one single sample dilution instead of traditional serial dilution approach, providing significant advantages in routine laboratory in terms of reduction in hand-on time and harmonization of results.

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.

Autoantibody status according to multiparametric assay accurately estimates connective tissue disease classification and identifies clinically relevant disease clusters.

OBJECTIVE: Assessment of circulating autoantibodies represents one of the earliest diagnostic procedures in patients with suspected connective tissue disease (CTD), providing important information for disease diagnosis, identification and prediction of potential clinical manifestations. The purpose of this study was to evaluate the ability of multiparametric assay to correctly classify patients with multiple CTDs and healthy controls (HC), independent of clinical features, and to evaluate whether serological status could identify clusters of patients with similar clinical features. METHODS: Patients with systemic lupus erythematosus (SLE), systemic sclerosis (SSc), Sjogren's syndrome (SjS), undifferentiated connective tissue disease (UCTD), idiopathic inflammatory myopathies (IIM) and HC were enrolled. Serum was tested for 29 autoantibodies. An XGBoost model, exclusively based on autoantibody titres was built and classification accuracy was evaluated. A hierarchical clustering model was subsequently developed and clinical/laboratory features compared among clusters. RESULTS: 908 subjects were enrolled. The classification model showed a mean accuracy of 60.84±4.05% and a mean area under the receiver operator characteristic curve of 88.99±2.50%, with significant discrepancies among groups. Cluster analysis identified four clusters (CL). CL1 included patients with typical features of SLE. CL2 included most patients with SjS, along with some SLE and UCTD patients with SjS-like features. CL4 included anti-Jo1 patients only. CL3 was the largest and most heterogeneous, including all the remaining subjects, overall characterised by low titre or lower-prevalence autoantibodies. CONCLUSION: Extended multiparametric autoantibody assay allowed an accurate classification of CTD patients, independently of clinical features. Clustering according to autoantibody titres is able to identify clusters of CTD subjects with similar clinical features, independently of their final diagnosis.

Rheumatoid factor isotypes in rheumatoid arthritis diagnosis and prognosis: a systematic review and meta-analysis.

OBJECTIVE: The first biomarker associated with the rheumatoid arthritis is rheumatoid factor (RF) and since the earliest reports a role has been proposed in the diagnosis and in the prediction of clinical features and outcome. The study of RF isotypes has further attempted to improve diagnostic accuracy and identify specific subgroups of patients. The main objective of this study is to provide an analysis of the literature on the role of RF isotypes in the diagnosis and prognosis of rheumatoid arthritis (RA). METHODS: We performed a systematic literature review and meta-analysis on the role of RF isotypes in RA (only in English, from PubMed, search terms: "rheumatoid factor isotypes", "diagnosis", "prognosis" and "rheumatoid arthritis", last search 31 July 2022, two independent assessment of quality and biases, results included in tables and in the meta-analysis). RESULTS: Thirty-six articles were examined (7517 patients). Testing all RF isotypes with latex test or nephelometry allows for the highest sensitivity (68.6%, 95% CI 66.2% to 71.0%); nonetheless, the determination of IgA isotype provides the highest specificity (91.4%, 95% CI 90.8% to 92.0%) and the highest positive likelihood ratio (7.7, 95% CI 5.7 to 10.4). When testing IgM isotype the highest diagnostic OR (21.7, 95% CI 16.1 to 29.3) is reached. When analysing anti-citrullinated protein antibodies, RF isotype determination increases diagnostic accuracy. On the other hand, these do not provide relevant prognostic information, as results are conflicting. CONCLUSIONS: Testing RF allows the highest sensitivity, while IgA isotype the highest specificity and positive likelihood ratio for RA diagnosis. On the other hand, determination of RF isotypes dose not allow prognostic information, as data are limited and heterogeneous.

Immunogenicity after two and three doses of mRNA vaccine in patients with cancer treated with exclusive radiotherapy.

BACKGROUND AND PURPOSE: Data on immunoresponse after SARS-CoV-2 vaccines for patients treated with exclusive radiotherapy (RT) are scarce. Since RT may affect the immune system, we conducted the MORA trial (Antibody response and cell-mediated immunity of MOderna mRNA-1273 vaccine in patients treated with RAdiotherapy). MATERIALS AND METHODS: Data regarding humoral and cellular immune response of patients treated with RT were prospectively collected after the second and third dose of mRNA vaccines. RESULTS: Ninety-two patients were enrolled. With a median of 147 days after the second dose, the median SARS-CoV-2 IgG titer was 300 BAU/mL: six patients were seronegative (Spike IgG titer ≤ 40 BAU/mL), whereas 24, 46 and 16 were poor responders (Spike IgG titer:41-200 BAU/mL), responders (Spike IgG titer:201-800 BAU/mL) and ultraresponders (Spike IgG titer > 800 BAU/mL), respectively. Among seronegative patients, two patients were negative also for cell mediated response, as tested with IFN-γ release Assay (IGRA) test. With a median of 85 days after the third dose, the median SARS-CoV-2 IgG titer was 1632 BAU/mL in 81 patients: only two patients were seronegative, whereas 16 and 63 patients were responders and ultraresponders, respectively. Among the 2 persistently seronegative patients, IGRA test was negative in one who had previously received anti-CD20 therapy. Documented paucisymptomatic (n = 3) or asymptomatic (n = 4) infection occurred after the third dose, during the Omicron wave. CONCLUSION: In patients treated with exclusive RT, even during the Omicron breakthrough, robust humoral response and clinical protection from severe SARS-CoV-2 disease were achievable with three doses of mRNA vaccine.

An Italian nationwide survey on the evolution of autoantibody diagnostics in autoimmune rheumatic diseases.

OBJECTIVES: The advent of new technologies and the discovery of new antigenic targets of autoantibodies has led to significant changes in autoimmune diagnostics worldwide. To address the extent to which autoimmunology laboratories adhere to such innovation in testing and reporting practices, the Italian Society of Clinical Pathology and Laboratory Medicine launched a national survey to assess the current status of autoimmune diagnostics and to provide direction for further harmonisation. METHODS: A questionnaire covering topics related to the diagnosis of autoimmune systemic rheumatic diseases was distributed to 152 Italian autoimmunology laboratories. The 59 closed-answer questions were subdivided into four main sections: 1. the setting (university, hospital or private laboratory) and the number of tests carried out; 2. the technologies used and their level of automation; 3. the analytical phase (antibody tests and methods), including awareness of the International Consensus on ANA Patterns (ICAP) initiative; 4. reporting of results and clinician relations. RESULTS: A total of 121 laboratories (79.6%) responded to the survey (15% universities, 70 hospitals, and 15% private laboratories). Indirect immunofluorescence is used by 94.8% of respondents, chemiluminescence by 78.4%, fluoro-immuno-enzymatic assays by 67.5%, immunodot by 52.6%, line-immunoassay by 47.4%, addressable laser bead immunoassay by 10.3% and radioimmunological methods by 10.2%. The great majority of respondents implemented complete automation of the listed methodologies. 65% of participants state that they add an interpretative comment in the report. 45% of participants enjoy a collaborative relationship with clinicians; counselling activities are provided by almost half of participants. CONCLUSIONS: Survey results indicated that almost all respondent laboratories have broadened their antibody panel and that high-throughput technologies have been widely introduced. Gaps identified by the survey include a still incomplete compliance with guidelines in antibody profiles (e.g. in antiphospholipid syndrome and rheumatoid arthritis and reporting of test results. Awareness of these differences provides insights that may further contribute to achieving harmonisation in autoimmune diagnostics.

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.

Detection of antinuclear antibodies: recommendations from EFLM, EASI and ICAP.

OBJECTIVES: Antinuclear antibodies (ANA) are important for the diagnosis of various autoimmune diseases. ANA are usually detected by indirect immunofluorescence assay (IFA) using HEp-2 cells (HEp-2 IFA). There are many variables influencing HEp-2 IFA results, such as subjective visual reading, serum screening dilution, substrate manufacturing, microscope components and conjugate. Newer developments on ANA testing that offer novel features adopted by some clinical laboratories include automated computer-assisted diagnosis (CAD) systems and solid phase assays (SPA). METHODS: A group of experts reviewed current literature and established recommendations on methodological aspects of ANA testing. This process was supported by a two round Delphi exercise. International expert groups that participated in this initiative included (i) the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group "Autoimmunity Testing"; (ii) the European Autoimmune Standardization Initiative (EASI); and (iii) the International Consensus on ANA Patterns (ICAP). RESULTS: In total, 35 recommendations/statements related to (i) ANA testing and reporting by HEp-2 IFA; (ii) HEp-2 IFA methodological aspects including substrate/conjugate selection and the application of CAD systems; (iii) quality assurance; (iv) HEp-2 IFA validation/verification approaches and (v) SPA were formulated. Globally, 95% of all submitted scores in the final Delphi round were above 6 (moderately agree, agree or strongly agree) and 85% above 7 (agree and strongly agree), indicating strong international support for the proposed recommendations. CONCLUSIONS: These recommendations are an important step to achieve high quality ANA testing.

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.