Behçet's Disease Uveitis.

Uveitis in Behçet's disease (BD) is frequent (40% of cases) and is a major cause of morbidity. The age of onset of uveitis is between 20 and 30 years. Ocular involvement includes anterior, posterior, or panuveitis. Uveitis may be the first sign of the disease in 20% of cases or it may appear 2 or 3 years after the first symptoms. Panuveitis is the most common presentation and is more commonly found in men. Bilateralization usually occurs on average 2 years after the first symptoms. The estimated risk of blindness at 5 years is 10-15%. BD uveitis has several ophthalmological features that distinguish it from other uveitis. The main goals in the management of patients are the rapid resolution of intraocular inflammation, the prevention of recurrent attacks, the achievement of complete remission, and the preservation of vision. Biologic therapies have changed the management of intraocular inflammation. The aim of this review is to provide an update to a previous article by our team on pathogenesis, diagnostic approaches, and the therapeutic strategy of BD uveitis.

Prognostic Factors and Treatment Efficacy in Spinal Cord Sarcoidosis: An Observational Cohort With Long-term Follow-up.

BACKGROUND AND OBJECTIVES: Spinal cord sarcoidosis is a rare manifestation of sarcoidosis with a consequent risk of neurologic sequelae for the patient. We investigated prognostic factors and efficacy of immunosuppressive treatments in a longitudinal cohort. METHODS: We retrospectively studied patients with spinal cord sarcoidosis followed between 1995 and 2021 in 7 centers in France. Patients with definite, probable, or possible spinal cord sarcoidosis according to the Neurosarcoidosis Consortium Consensus Group criteria and with spinal cord involvement confirmed by MRI were included. We analyzed relapse or progression rate with a Poisson model, initial Rankin score with a linear model, and change in the Rankin score during follow-up with a logistic model. RESULTS: A total of 97 patients were followed for a median of 7.8 years. Overall mean relapse or progression rate was 0.17 per person-year and decreased over time. At last visit, 46 (47.4%) patients had a loss of autonomy (Rankin score ≥2). The main prognostic factors significantly associated with relapse or progression rate were gadolinium enhancement (relative rate [95% CI] 0.61 [0.4, 0.95]) or meningeal involvement (relative rate [95% CI] 2.05 [1.31, 3.19]) on spinal cord MRI and cell count (relative rate [95% CI] per 1 log increase 1.16 [1.01, 1.33]) on CSF analysis. Relapse or progression rate was not significantly associated with initial Rankin score or Expanded Disability Status Scale. Tumor necrosis factor-α (TNF-α) antagonists significantly decreased relapse or progression rate compared with corticosteroids alone (relative rate [95% CI] 0.33 [0.11, 0.98]). Azathioprine was significantly less effective than methotrexate on relapse or progression rate (relative rate [95% CI] 2.83 [1.04, 7.75]) and change in Rankin score (mean difference [95% CI] 0.65 [0.23, 1.08]). DISCUSSION: Regarding the relapse or progression rate, meningeal localization of sarcoidosis was associated with a worse prognosis, TNF-α antagonists resulted in a significant decrease compared to corticosteroids alone, and methotrexate was more effective than azathioprine. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that in individuals with spinal cord neurosarcoidosis, TNF-α antagonists were associated with decreased relapse or progression rate compared to corticosteroids alone, but other therapies showed no significant benefit.

Lower Relapses Rate With Infliximab Versus Adalimumab in Sight-Threatening Uveitis: A Multicenter Study of 330 Patients.

PURPOSE: To compare the relapse rate of sight-threatening noninfectious uveitis (NIU) in patients treated with infliximab (IFX) or adalimumab (ADA). DESIGN: Observational retrospective multicenter study. METHODS: A total of 330 patients (median age, 36 years; interquartile range, 27-54), 45.2% men) with sight-threatening NIU (ie, retinal vasculitis and/or macular edema) treated with anti-tumor necrosis factor [TNF]-α agents (IFX intravenously at 5 mg/kg at weeks 0, 2, 6, and every 4 to 6 weeks or ADA subcutaneously at 80 mg, then 40 mg every 2 weeks). Data were obtained retrospectively from patients' medical records. Main outcome measures were relapse rate, complete response of NIU, corticosteroid sparing effect, and safety. RESULTS: Main etiologies of uveitis included Behçet disease (27%), idiopathic juvenile arthritis (5.8%), and sarcoidosis (5.5%). The estimated relapse rate at 6 months after introduction of biological agents was 13% (95% CI = 0.009-0.16). IFX was associated with less relapse risk than ADA (hazard ratio [HR] = 0.52, 95% CI = 0.36- 0.77, P = .001). ADA and IFX were comparable in terms of complete response rate of NIU as well as corticosteroid-sparing effect. Behçet disease was associated with higher odds of complete response (HR = 2.04, 95% CI = 1.16 -3.60, P = .01] and lower relapse rate (HR = 0.53, 95% CI = 0.33-0.85, P = .009) than other causes of NIU with anti-TNF-α agents. CONCLUSIONS: In sight-threatening NIU, IFX seems to be associated with a lower relapse rate than ADA.

Mast cells drive pathologic vascular lesions in Takayasu arteritis.

BACKGROUND: Takayasu arteritis (TAK) is a large vessel vasculitis resulting in artery wall remodeling with segmental stenosis and/or aneurysm formation. Mast cells (MCs) are instrumental in bridging cell injury and inflammatory response. OBJECTIVES: This study sought to investigate the contribution of MCs on vessel permeability, angiogenesis, and fibrosis in patients with TAK. METHODS: MC activation and their tissue expression were assessed in sera and in aorta from patients with TAK and from healthy donors (HDs). In vivo permeability was assessed using a modified Miles assay. Subconfluent cultured human umbilic vein endothelial cells and fibroblasts were used in vitro to investigate the effects of MC mediators on angiogenesis and fibrogenesis. RESULTS: This study found increased levels of MC activation markers (histamine and indoleamine 2,3-dioxygenase) in sera of patients with TAK compared with in sera of HDs. Marked expression of MCs was shown in aortic lesions of patients with TAK compared with in those of noninflammatory aorta controls. Using Miles assay, this study showed that sera of patients with TAK significantly increased vascular permeability in vivo as compared with that of HDs. Vessel permeability was abrogated in MC-deficient mice. MCs stimulated by sera of patients with TAK supported neoangiogenesis (increased human umbilic vein endothelial cell proliferation and branches) and fibrosis by inducing increased production of fibronectin, type 1 collagen, and α-smooth muscle actin by fibroblasts as compared to MCs stimulated by sera of HD. CONCLUSIONS: MCs are a key regulator of vascular lesions in patients with TAK and may represent a new therapeutic target in large vessel vasculitis.

Prognosis Factors and Outcomes of Neuro-ophthalmologic Sarcoidosis.

BACKGROUND: Neuro-ophthalmologic manifestations are uncommon in sarcoidosis. We aim to assess the prognostic factors and outcome of neuro-ophthalmic sarcoidosis. METHODS: We conducted a multicenter retrospective study on patients with neuro-ophthalmic sarcoidosis. Response to therapy was based on visual acuity, visual field, and orbital MRI exam. Factors associated with remission and relapse were analyzed. RESULTS: Thirty-five patients [median (IQR) age of 37 years (26.5-53), 63% of women] were included. The diagnosis of sarcoidosis was concomitant of neuro-ophthalmologic symptoms in 63% of cases. Optic neuritis was the most common manifestation. All patients received corticosteroids and 34% had immunosuppressants. At 6 months, 61% improved, 30% were stable, and 9% worsened. Twenty percent of patients had severe visual deficiency at the end of follow-up. Nonresponders patients had significantly worse visual acuity at baseline (p = 0.01). Relapses were less frequent in patients with retro-bulbar optic neuropathy (p = 0.03). CONCLUSION: Prognosis of neuro-ophthalmic sarcoidosis is poor.

Anti-Tumor Necrosis Factor α versus Tocilizumab in the Treatment of Refractory Uveitic Macular Edema: A Multicenter Study from the French Uveitis Network.

PURPOSE: To analyze the factors associated with response (control of ocular inflammation and corticosteroid-sparing effect) to biologics (anti-tumor necrosis factor [TNF]-α agents and tocilizumab) in patients with refractory uveitic macular edema (ME). DESIGN: Multicenter, retrospective, observational study. PARTICIPANTS: Adult patients with uveitic ME refractory to systemic corticosteroids, disease-modifying antirheumatic drugs, or both. METHODS: Patients received anti-TNF-α agents (infliximab 5 mg/kg at week 0, 2, 6, and every 4-6 weeks [n = 69] and adalimumab 40 mg/2 weeks [n = 80]) and tocilizumab (8 mg/kg every 4 weeks intravenously [n = 39] and 162 mg/week subcutaneously [n = 16]). MAIN OUTCOME MEASURES: Analysis of complete and partial response rates, relapse rate, low vision (visual acuity in at least 1 eye of ≥ 1 logarithm of the minimum angle of resolution), corticosteroid-sparing effect, and adverse events at 6 months. RESULTS: Two hundred four patients (median age, 40 years [interquartile range, 28-58 years]; 42.2% men) were included. Main causes of uveitis included Behçet's disease (17.2%), birdshot chorioretinopathy (11.3%), and sarcoidosis (7.4%). The overall response rate at 6 months was 46.2% (21.8% of complete response) with anti-TNF-α agents and 58.5% (35.8% of complete response) with tocilizumab. In multivariate analysis, treatment with tocilizumab (odds ratio, 2.10; 95% confidence interval [CI], 1.06-4.06; P = 0.03) was associated independently with complete response of uveitic ME compared with anti-TNF-α agents. Anti-TNF-α agents and tocilizumab did not differ significantly in terms of relapse rate (hazard ratio, 1.00; 95% CI, 0.31-3.18; P = 0.99) or occurrence of low vision (odds ratio, 1.02; 95% CI, 0.51-2.07; P = 0.95) or corticosteroid-sparing effect (P = 0.29). Adverse events were reported in 20.6% of patients, including serious adverse events reported in 10.8% of patients. CONCLUSIONS: Tocilizumab seems to improve complete response of uveitic ME compared with anti-TNF-α agents.

Spectrum and Outcome of Noninfectious Aortitis.

OBJECTIVE: To assess the spectrum and long-term outcome of patients with noninfectious aortitis. METHODS: We performed a retrospective multicenter study of 353 patients (median age at diagnosis was 62 [IQR 46-71] yrs and 242 [68.6%] patients were women) with noninfectious aortitis. Factors associated with vascular complications were assessed in multivariate analysis. RESULTS: We included 136 patients with giant cell arteritis (GCA), 96 with Takayasu arteritis (TA), 73 with clinically isolated aortitis (CIA), and 48 with aortitis secondary to inflammatory diseases (including Behçet disease, relapsing polychondritis, IgG4-related disease, Cogan syndrome, ankylosing spondylitis). After a median follow-up of 52 months, vascular complications were observed in 32.3%, revascularizations in 30% of patients, and death in 7.6%. The 5-year cumulative incidence of vascular complications was 58% (95% CI 41-71), 20% (95% CI 13-29), and 19% (95% CI 11-28) in CIA, GCA, and TA, respectively. In multivariate analysis, male sex (HR 2.10, 95% CI 1.45-3.05, P < 0.0001) and CIA (HR 1.76, 95% CI 1.11-2.81, P = 0.02) were independently associated with vascular complications. CONCLUSION: Noninfectious aortitis accounts for significant morbidity and mortality. CIA seems to carry the highest rate of vascular complications.

Specific microbiome profile in Takayasu's arteritis and giant cell arteritis.

Recent studies have provided evidence of a close link between specific microbiota and inflammatory disorders. While the vessel wall microbiota has been recently described in large vessel vasculitis (LVV) and controls, the blood microbiome in these diseases has not been previously reported (LVV). We aimed to analyse the blood microbiome profile of LVV patients (Takayasu's arteritis [TAK], giant cell arteritis [GCA]) and healthy blood donors (HD). We studied the blood samples of 13 patients with TAK (20 samples), 9 patients with GCA (11 samples) and 15 HD patients. We assessed the blood microbiome profile by sequencing the 16S rDNA blood bacterial DNA. We used linear discriminant analysis (LDA) coupled with linear discriminant effect size measurement (LEfSe) to investigate the differences in the blood microbiome profile between TAK and GCA patients. An increase in the levels of Clostridia, Cytophagia and Deltaproteobacteria and a decrease in Bacilli at the class level were found in TAK patients compared with HD patients (LDA > 2, p < 0.05). Active TAK patients had significantly lower levels of Staphylococcus compared with inactive TAK patients. Samples of GCA patients had an increased abundance of Rhodococcus and an unidentified member of the Cytophagaceae family. Microbiota of TAK compared with GCA patients was found to show higher levels of Candidatus Aquiluna and Cloacibacterium (LDA > 2; p < 0.05). Differences highlighted in the blood microbiome were also associated with a shift of bacterial predicted metabolic functions in TAK in comparison with HD. Similar results were also found in patients with active versus inactive TAK. In conclusion, patients with TAK were found to present a specific blood microbiome profile in comparison with healthy donors and GCA subjects. Significant changes in the blood microbiome profiles of TAK patients were associated with specific metabolic functions.

Venous thrombosis and predictors of relapse in eosinophil-related diseases.

Eosinophils have widespread procoagulant effects. Eosinophilic cardiovascular toxicity mostly consists of endomyocardial damage or eosinophilic vasculitis, while reported cases of venous thrombosis (VT) are scarce. We aimed to report on the clinical features and treatment outcomes of patients with unexplained VT and eosinophilia, and to identify predictors of relapse. This retrospective, multicenter, observational study included patients aged over 15 years with VT, concomitant blood eosinophilia ≥ 1G/L and without any other moderate-to-strong contributing factors for VT. Fifty-four patients were included. VT was the initial manifestation of eosinophil-related disease in 29 (54%) patients and included pulmonary embolism (52%), deep venous thrombosis (37%), hepatic (11%) and portal vein (9%) thromboses. The median [IQR] absolute eosinophil count at VT onset was 3.3G/L [1.6-7.4]. Underlying eosinophil-related diseases included FIP1L1-PDGFRA-associated chronic myeloid neoplasm (n = 4), Eosinophilic Granulomatosis with Polyangiitis (n = 9), lymphocytic (n = 1) and idiopathic (n = 29) variants of hypereosinophilic syndrome. After a median [IQR] follow-up of 24 [10-62] months, 7 (13%) patients had a recurrence of VT. In multivariate analysis, persistent eosinophilia was the sole variable associated with a shorter time to VT relapse (HR 7.48; CI95% [1.94-29.47]; p = 0.015). Long-term normalization of eosinophil count could prevent the recurrence of VT in a subset of patients with unexplained VT and eosinophilia ≥ 1G/L.

French recommendations for the management of Behçet's disease.

Behçet's disease (BD) is a systemic variable vessel vasculitis that involves the skin, mucosa, joints, eyes, arteries, veins, nervous system and gastrointestinal system, presenting with remissions and exacerbations. It is a multifactorial disease, and several triggering factors including oral cavity infections and viruses may induce inflammatory attacks in genetically susceptible individuals. BD vasculitis involves different vessel types and sizes of the vascular tree with mixed-cellular perivascular infiltrates and is often complicated by recurrent thrombosis, particularly in the venous compartment. Several new therapeutic modalities with different mechanisms of action have been studied in patients with BD. A substantial amount of new data have been published on the management of BD, especially with biologics, over the last years. These important therapeutic advances in BD have led us to propose French recommendations for the management of Behçet's disease [Protocole National de Diagnostic et de Soins de la maladie de Behçet (PNDS)]. These recommendations are divided into two parts: (1) the diagnostic process and initial assessment; (2) the therapeutic management. Thirty key points summarize the essence of the recommendations. We highlighted the main differential diagnosis of BD according to the type of clinical involvement; the role of genetics is also discussed, and we indicate the clinical presentations that must lead to the search for a genetic cause.

Emerging Molecular Targets for the Treatment of Refractory Sarcoidosis.

Sarcoidosis is a multisystem granulomatous disease of unknown origin that has variable clinical course and can affect nearly any organ. It has a chronic course in about 25% of patients. Corticosteroids (CS) are the cornerstone of therapy but their long-term use is associated with cumulative toxicity. Commonly used CS-sparing agents include methotrexate, cyclophosphamide, azathioprine, and mycophenolate mofetil. Twenty to forty percentage of sarcoidosis patients are refractory to these therapies or develop severe adverse events. Therefore, additional and targeted CS-sparing agents are needed for chronic sarcoidosis. Macrophage activation, interferon response, and formation of the granuloma are mainly mediated by T helper-1 responses. Different pro-inflammatory cytokines such as interleukin (IL)-8, IL-12, IL-6, and tumor necrosis factor-alpha (TNF-α) have been shown to be highly expressed in sarcoidosis-affected tissues. As a result of increased production of these cytokines, Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling is constitutively active in sarcoidosis. Several studies of biological agents that target TNF-α have reported their efficacy and appear today as a second line option in refractory sarcoidosis. Some case series report a positive effect of tocilizumab an anti-IL-6 monoclonal antibody in this setting. More recently, JAK inhibition appears as a new promising strategy. This review highlights key advances on the management of chronic refractory sarcoidosis. Novel therapeutic strategies and treatment agents to manage the disease are described.

Biotherapies in Uveitis.

Non-infectious uveitis (NIU) represents one of the leading causes of blindness in developed countries. The therapeutic strategy aims to rapidly control intra-ocular inflammation, prevent irremediable ocular damage, allow corticosteroid sparing and save the vision, and has evolved over the last few years. Anterior NIU is mostly managed with topical treatment in adults. However, for intermediate, posterior and pan-uveitis, notably when both eyes are involved, systemic treatment is usually warranted. Biotherapies are recommended in case of inefficacy or non-tolerance of conventional immunosuppressive drugs in non-anterior NIU. Anti-tumor necrosis factor alpha (anti-TNF-α) agents are by far the most widely used, especially adalimumab (ADA) and infliximab (IFX). In case of sight-threatening uveitis in Behçet's disease or in case of risk of severe recurrences, respectively IFX and ADA may be recommended as first-line therapy. Many questions are left unanswered; how long to treat NIU, how to discontinue anti-TNF-α agents, what biologic to use in case of anti-TNF-α failure? The objective of this review is to present an updated overview of knowledge on the use of biological treatments in NIU.

Cardiac sarcoidosis: A long term follow up study.

BACKGROUND: Prognostic factors are lacking in cardiac sarcoidosis (CS), and the effects of immunosuppressive treatments are unclear. OBJECTIVES: To identify prognostic factors and to assess the effects of immunosuppressive drugs on relapse risk in patients presenting with CS. METHODS: From a cohort of 157 patients with CS with a median follow-up of 7 years, we analysed all cardiac and extra-cardiac data and treatments, and assessed relapse-free and overall survival. RESULTS: The 10-year survival rate was 90% (95% CI, 84-96). Baseline factors associated with mortality were the presence of high degree atrioventricular block (HR, 5.56, 95% CI 1.7-18.2, p = 0.005), left ventricular ejection fraction below 40% (HR, 4.88, 95% CI 1.26-18.9, p = 0.022), hypertension (HR, 4.79, 95% CI 1.06-21.7, p = 0.042), abnormal pulmonary function test (HR, 3.27, 95% CI 1.07-10.0, p = 0.038), areas of late gadolinium enhancement on cardiac magnetic resonance (HR, 2.26, 95% CI 0.25-20.4, p = 0.003), and older age (HR per 10 years 1.69, 95% CI 1.13-2.52, p = 0.01). The 10-year relapse-free survival rate for cardiac relapses was 53% (95% CI, 44-63). Baseline factors that were independently associated with cardiac relapse were kidney involvement (HR, 3.35, 95% CI 1.39-8.07, p = 0.007), wall motion abnormalities (HR, 2.30, 95% CI 1.22-4.32, p = 0.010), and left heart failure (HR 2.23, 95% CI 1.12-4.45, p = 0.023). After adjustment for cardiac involvement severity, treatment with intravenous cyclophosphamide was associated with a lower risk of cardiac relapse (HR 0.16, 95% CI 0.033-0.78, p = 0.024). CONCLUSIONS: Our study identifies putative factors affecting morbidity and mortality in cardiac sarcoidosis patients. Intravenous cyclophosphamide is associated with lower relapse rates.

Evolving spectrum of drug-induced uveitis at the era of immune checkpoint inhibitors results from the WHO's pharmacovigilance database.

PURPOSE: Drug-induced uveitis is a rare but sight-threatening condition. We seek to determine the spectrum of drug-induced uveitis at the era of immune checkpoint inhibitors (ICI). METHODS: Retrospective pharmacovigilance study based on adverse drug reactions reported within VigiBase, the WHO international pharmacovigilance database. We included deduplicated individual case safety reports (ICSRs) reported as 'uveitis' at Preferred Term level according to the Medical Dictionary for Drug Regulatory Activities between 1967 and 04/28/2019. We performed a case/non-case analysis to study if suspected drug-induced uveitis were differentially reported for each suspected treatment compared to the full database. We excluded drugs with potential indication bias. RESULTS: 1404 ICSRs corresponding to 37 drugs had a significant over-reporting signal with a median age of 57 [42-68] years and 45.7% of males. We identified five major groups of treatments: bisphosphonates (26.9%), non-antiviral anti-infectious drugs (25.4%), protein kinase inhibitors (15.5%), ICI (15.0%), and antiviral drugs (11.1%). Severe visual loss was reported in 12.1% of cases. ICI and protein kinase inhibitors were the most recently emerging signals. The time to onset between first infusion and uveitis was significantly different between groups ranging from 5 days [2-19] in the bisphosphonate group to 138.5 [47.25-263.75] in protein kinase inhibitors group (p < 0.0001). Anti-Programmed Cell death 1 represented more than 70% of ICI-induced uveitis. We identified Vogt-Koyanagi-Harada (VKH)-like syndrome as being associated with ICI use. CONCLUSIONS: The spectrum of drug-induced uveitis has changed with the evolution of pharmacopeia and the recent emergence of ICIs. VKH-like syndrome has been reported with ICI and protein kinase inhibitors therapy.

Immunomodulatory role of Interleukin-33 in large vessel vasculitis.

The mechanisms regulating inflammation in large vessels vasculitis (LVV) are poorly understood. Interleukin 33 (IL-33) has been shown to license innate and adaptive immunity by enhancing Th2 cytokines production. We aimed to examine the role of IL-33 in the immunomodulation of T cell activation in LVV. T cell homeostasis and cytokines production were determined in peripheral blood from 52 patients with giant cell arteritis (GCA) and 50 healthy donors (HD), using Luminex assay, flow cytometry, quantitative RT-PCR and by immunofluorescence analysis in inflammatory aorta lesions. We found increased level of IL-33 and its receptor ST2/IL-1R4 in the serum of patient with LVV. Endothelial cells were the main source of IL-33, whereas Th2 cells, Tregs and mast cells (MC) express ST2 in LVV vessels. IL-33 had a direct immunomodulatory impact by increasing Th2 and Tregs. IL-33 and MC further enhanced Th2 and regulatory responses by inducing a 6.1 fold increased proportion of Tregs (p = 0.008). Stimulation of MC by IL-33 increased indoleamine 2 3-dioxygenase (IDO) activity and IL-2 secretion. IL-33 mRNA expression was significantly correlated with the expression of IL-10 and TGF-ß within aorta inflammatory lesions. To conclude, our findings suggest that IL-33 may exert a critical immunoregulatory role in promoting Tregs and Th2 cells in LVV.

Targeting JAK/STAT pathway in Takayasu's arteritis.

OBJECTIVE: Takayasu's arteritis (TAK) is a large vessel vasculitis with important infiltration of proinflammatory T cells in the aorta and its main branches, but its aetiology is still unknown. Our work aims to explore the involvement of Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) signalling pathway in proinflammatory T cells differentiation and disease activity of TAK. METHODS: We analysed transcriptome and interferons gene signatures of fluorescence-activated cell sorting (FACS-sorted) CD4+ and CD8+ T cells from healthy donors (HD) and in 25 TAK (median age of 37.6 years including 21 active TAK with National Institutes of Health (NIH) score >1). Then we tested, in vitro and in vivo, the effects of JAK inhibitors (JAKinibs) in TAK. RESULTS: Transcriptome analysis showed 248 and 432 significantly dysregulated genes for CD4+ and CD8+ samples between HD and TAK, respectively. Among dysregulated genes, we highlighted a great enrichment for pathways linked to type I and type II interferons, JAK/STAT and cytokines/chemokines-related signalling in TAK. We confirmed by Real Time Reverse Transcription Polymerase Chain Reaction (RT-qPCR) the upregulation of type I interferons gene signature in TAK as compared with HD. JAKinibs induced both in vitro and in vivo a significant reduction of CD25 expression by CD4+ and CD8+ T cells, a significant decrease of type 1 helper T cells (Th1) and Th17 cells and an increase of Tregs cells in TAK. JAKinibs also decreased C reactive protein level, NIH score and corticosteroid dose in TAK patients. CONCLUSIONS: JAK/STAT signalling pathway is critical in the pathogenesis of TAK and JAKinibs may be a promising therapy.