Ophthalmic vascular manifestations in eosinophil-associated diseases: a comprehensive analysis of 57 patients from the CEREO and EESG networks and a literature review.

Introduction: Eosinophils have widespread procoagulant effects. In daily practice, eosinophil-related cardiovascular toxicity consists of endomyocardial damage, eosinophilic vasculitis and arterial or venous thrombosis. Here we aim to report on the clinical features and treatment outcomes of patients with unexplained ophthalmic vascular manifestations and eosinophilia. Methods: We conducted a retrospective, multicenter, observational study and a literature review of patients with eosinophilia (≥0.5 x109/L) and concomitant ophthalmic vascular manifestations independent of the underlying eosinophilic disease but with no alternative cause for ophthalmic manifestations. Results: Fifty-seven patients were included (20 from the observational study and 37 from the literature review). Ophthalmic vascular features were the initial manifestation of eosinophil-related disease in 34 (59%) patients and consisted of 29 central retinal artery occlusions, six branch retinal artery occlusions, five central retinal vein occlusions, two branch retinal vein occlusions, seven retinal vasculitides, two retinal vasospasms, 12 Purtscher's retinopathies, 13 anterior ischemic optic neuropathies and two posterior ischemic optic neuropathies. The median [IQR] absolute eosinophil count at onset of ophthalmic vascular manifestations was 3.5 [1.7-7.8] x109/L. Underlying eosinophil-related diseases included eosinophilic granulomatosis with polyangiitis (n=32), clonal hypereosinophilic syndrome (HES) (n=1), idiopathic HES (n=13), lymphocytic HES (n=2), adverse drug reactions (n=3), parasitosis (n=2), polyarteritis nodosa (n=1), IgG4-related disease (n=1), eosinophilic fasciitis (n=1) and primary sclerosing cholangitis (n=1). Other extra-ophthalmologic arterial or venous thromboses related to eosinophilia were reported in four (7%) and nine (16%) patients, respectively. Visual prognosis was poor: only eight (10%) patients achieved full recovery of ophthalmologic symptoms. After a median follow-up of 10.5 [1-18] months, one patient (3%) had a recurrence of an ophthalmic vascular manifestation, and three patients (10%) had a recurrence of other vascular symptoms (deep vein thrombosis in two and pulmonary embolism in one patient). At the time of recurrence, absolute eosinophil counts were above 0.5 x109/L in all cases (n=4). Discussion: This study broadens the spectrum of vascular manifestations associated with hypereosinophilia by adding ophthalmic vascular manifestations. In patients with ophthalmological vascular manifestations and hypereosinophilia, aggressive treatment of the underlying pathology (and normalization of blood count) should be implemented.

Mepolizumab and benralizumab in patients with severe asthma and a history of eosinophilic granulomatosis with polyangiitis.

Introduction: Asthma associated with eosinophilic granulomatosis with polyangiitis (EGPA) is often severe and corticosteroid-dependent, leading to significant morbidity. Mepolizumab and benralizumab are humanized monoclonal antibodies targeting interleukin 5 (IL-5) and its receptor, respectively. They have been shown to be effective in steroid-sparing in patients with severe eosinophilic asthma. Objective: Our aim was to evaluate the efficacy and safety of mepolizumab and benralizumab prescribed for severe asthma in patients with EGPA under "real-world" conditions. Methods: This was a retrospective analysis of patients with EGPA and persistent asthma who received either mepolizumab 100 or 300 mg administered every 4 weeks, or benralizumab 30 mg administered every 4 weeks for the initial 3 injections and followed by an injection every 8 weeks thereafter, whilst combined with oral glucocorticoids. The follow-up every 6 ± 3 months included an assessment of clinical manifestations, pulmonary function tests and eosinophil cell count. The primary outcome was the proportion of patients at 12 months receiving a daily oral dose of prednisone or equivalent of 4 mg or less with a BVAS of 0. Results: Twenty-six patients were included. After 12 months of treatment with mepolizumab or benralizumab, 32% of patients met the primary outcome and were receiving less than 4 mg of prednisone per day with a BVAS of 0. The median dose of prednisone was 10 mg per day at baseline, 9 mg at 6 months, and 5 mg at 12 months (p ≤ 0.01). At 12 months, 23% of patients were weaned off corticosteroids, while an increase or no change in dose was observed in 27% of patients. The median eosinophil count was significantly reduced from 365 cells/mm3 to 55 cells/mm3 at 6 months and 70 cells/mm3 at 12 months, respectively. No significant change was observed in FEV1. After 12 months of treatment, 14% of patients had had an average of 1 exacerbation of asthma, compared with 52% of patients before baseline. The tolerability profile was favorable. Conclusion: In this real-world study in patients with severe asthma and a history of EGPA asthma, mepolizumab and benralizumab had a significant steroid-sparing effect and reduced asthma exacerbation, but no significant effect on lung function.

Targeted therapies for uveitis in spondyloarthritis: A narrative review.

Spondyloarthritis (SpA) encompasses a group of chronic inflammatory disorders of the joints frequently associated with uveitis in almost a quarter of cases. SpA-related uveitis typically affects the eye anterior chamber with sudden onset, causing pain, redness, photophobia, and blurred vision. Ophthalmologists will describe an acute anterior unilateral uveitis. Most patients present with episodic acute anterior non-granulomatous uveitis and retain excellent visual acuity. However, systemic treatments are recommended in the event of frequent relapses (2-3/year) or in rare cases of sight-threatening with ocular complications. The improved understanding of the pathogenesis of SpA has led to the management of this disease by biologics. Here, we review the main data regarding the opportunity to target specific components in inflammatory pathways for the treatment of SpA-related uveitis. These therapies are recommended for long-term control when uveitis relapses occur too frequently despite conventional systemic treatments. Significant benefits have been obtained with the tumor necrosis factor-α inhibitors (TNFis), particularly infliximab and adalimumab. Paradoxically, a high number of uveitis occurrences have been shown on etanercept. Mixed results have been demonstrated with interleukin-17 antagonists (secukinumab) and interleukin-12/interleukin-23 antagonists (ustekinumab) in cases of failure of TNFis. JAK inhibitors seem to be a valuable class of medications for these patients in the future. Although SpA-related uveitis is typically managed with conventional local and/or systemic treatments, these biological/targeted therapies may provide avenues to control both the underlying SpA and uveitis manifestations. Thus, a close collaboration between patients, rheumatologists, internists, and ophthalmologists is needed to optimally manage ocular inflammation in SpA.

Immune recovery uveitis in Whipple's disease: an unusual ocular presentation.

PURPOSE: To describe an unusual case of Whipple's disease (WD) complicated by uveitis, and subsequent paradoxical worsening after effective antibiotic treatment targeting Tropheryma whipplei (TW). METHODS: Case report. RESULTS: A 53-year-old male presented with bilateral knee arthritis, weight loss, chronic low-grade fever, and cognitive disorders. He was under treatment with tumor necrosis factor α inhibitors (TNFi) for seronegative spondyloarthritis. Given this unusual clinical presentation, further investigations were performed and revealed blood, saliva, stool, synovial fluid and cerebrospinal fluid positivity for TW, confirming the diagnosis of systemic WD. Ophthalmologic examination revealed bilateral posterior uveitis and an aqueous humor sample confirmed the presence of intraocular TW. TNFi were stopped, and the patient was subsequently treated with adequate antibiotics (ceftriaxone, followed by doxycycline and hydroxychloroquine), and subconjunctival corticosteroid injections. After a transient improvement of the ocular symptoms, he presented a recurrence of posterior segment inflammation, leading to repeated PCR testing for TW which were negative. Therefore, paradoxical worsening of the inflammation in the context of immune recovery uveitis (IRU) was thought to be the culprit. The patient was treated with systemic corticosteroid therapy, allowing for rapid improvement of the ocular findings. CONCLUSIONS: This case underlines the possibility of IRU complicating WD. Ophthalmologists, rheumatologists, and internists should be aware of this rare complication, particularly in the context of previous immunosuppressive therapy.

Hydroxychloroquine Therapy in Sarcoidosis-Associated Uveitis.

BACKGROUND/PURPOSE: To assess the efficacy and tolerance of hydroxychloroquine in sarcoidosis-associated uveitis. METHODS: Retrospective study on all patients with sarcoidosis-associated uveitis who were treated with hydroxychloroquine between 2003 and 2019 in a French university hospital. RESULTS: Twenty-seven patients with sarcoidosis-associated uveitis received hydroxychloroquine. The mean duration of treatment was 20.0 ± 10.9 months. At the end of the follow-up, hydroxychloroquine success was achieved in 15 (55.6%) patients. Four of them were also on oral corticosteroids, with a prednisone dose ≤5 mg/day. Under treatment, the median prednisone dose decreased from 20.0 (interquartile range (IQR), 7-25) to 5.0 (IQR, 3-6.5) mg/day (p = .02). The incidence rate of flare decreased from 204.6 to 63.8 per 100 person-years (p = .02). Hydroxychloroquine was discontinued in 12 (44.4%) patients during follow-up, including 8 (29.6%) for ineffectiveness, and three who experienced side effects. CONCLUSION: Hydroxychloroquine appears as an interesting option in sarcoidosis-associated uveitis.Abbreviations: AZA: Azathioprine; BAL: Bronchoalveolar Lavage; BCVA: Best-Corrected Visual Acuity; ENT: Ears, Nose and Throat; HCQ: Hydroxychloroquine; IOP: Intra-Ocular Pressure; IQR: interquartile range; MHC: Major Histocompatibility Complex; MMF: Mycophenolate Mofetil; MTX: Methotrexate; PMSI: Programme de Médicalisation du Système d'Information; SAU: Sarcoidosis-Associated Uveitis; SD: Standard Deviation; SUN: Standard Uveitis Nomenclature.

Value of Chest X-Ray and Chest Computed Tomography for Systemic Sarcoidosis Diagnosis in Undifferentiated Uveitis.

BACKGROUND: To evaluate the contribution of chest X-ray and chest CT for the diagnosis of sarcoid uveitis. METHODS: Retrospective study on consecutive patients with uveitis of unknown etiology, who underwent both chest X-ray and CT during uveitis diagnosis workup in a tertiary French university hospital. RESULTS: A total of 914 patients were included. Systemic sarcoidosis was identified in 23.1%. The probability of discordance between chest X-ray and CT increased with age at diagnosis (p < 0.001). In patients 30 years of age and younger, the probability of discordance was 5% or less, and 0.8% if the ACE level was normal. After 78.3 years of age, the probability of discordance was 20% or more. CONCLUSION: We recommend not to perform CT in patients under 30 years of age with a normal chest X ray and ACE level, and suggest performing chest CT first in the elderly.

Spatial Transcriptomics Reveals Signatures of Histopathological Changes in Muscular Sarcoidosis.

Sarcoidosis is a multisystemic disease characterized by non-caseating granuloma infiltrating various organs. The form with symptomatic muscular involvement is called muscular sarcoidosis. The impact of immune cells composing the granuloma on the skeletal muscle is misunderstood. Here, we investigated the granuloma-skeletal muscle interactions through spatial transcriptomics on two patients affected by muscular sarcoidosis. Five major transcriptomic clusters corresponding to perigranuloma, granuloma, and three successive muscle tissue areas (proximal, intermediate, and distal) around the granuloma were identified. Analyses revealed upregulated pathways in the granuloma corresponding to the activation of T-lymphocytes and monocytes/macrophages cytokines, the upregulation of extracellular matrix signatures, and the induction of the TGF-ß signaling in the perigranuloma. A comparison between the proximal and distal muscles to the granuloma revealed an inverse correlation between the distance to the granuloma and the upregulation of cellular response to interferon-γ/α, TNF-α, IL-1,4,6, fibroblast proliferation, epithelial to mesenchymal cell transition, and the downregulation of muscle gene expression. These data shed light on the intercommunications between granulomas and the muscle tissue and provide pathophysiological mechanisms by showing that granuloma immune cells have a direct impact on proximal muscle tissue by promoting its progressive replacement by fibrosis via the expression of pro-inflammatory and profibrosing signatures. These data could possibly explain the evolution towards a state of disability for some patients.

Etiological Diagnosis of Uveitis: Contribution of the of the Extra-Ophthalmological Clinical Examination.

PURPOSE: Determining uveitis etiology is a challenge. It is based primarily on demographic data and the characteristics of eye examination. It is not clear to what extent extraocular physical signs contribute to elucidating the etiology. This study aimed to establish the contribution of the clinical extra-ophthalmological features for the assessment of the underlying etiology of uveitis. METHODS: We retrospectively reviewed 1307 patients with uveitis referred to our tertiary center between 2003 and 2021. Uveitis was classified according to the Standardization of Uveitis Nomenclature. Clinical features were collected at diagnosis by internists before the etiological diagnosis was made. The main outcome description was the contribution of clinical features. RESULTS: Clinical extra-ophthalmological features contributed to the assessment of the underlying etiology of uveitis in 363 (27.8%) patients. The joint and the skin examinations were the most useful for etiological investigations, respectively in 12.3% and 11.8% of patients. Five etiologies of uveitis accounted for 80% of the cases: sarcoidosis, HLA-B27-related uveitis, Behçet's disease, multiple sclerosis, and Vogt-Koyanagi-Harada disease. Clinical extra-ophthalmological features were particularly important in the etiological diagnosis of acute bilateral anterior uveitis and panuveitis. CONCLUSION: This study suggests that clinical extra-ophthalmological features are essential for the etiological diagnosis of uveitis in more than a quarter of patients. It demonstrates once again the value of collaboration between ophthalmologists and other specialists experienced in performing extra-ophthalmological clinical examinations, particularly in patients with acute bilateral anterior uveitis and panuveitis.

Uveitis in Giant Cell Arteritis: A Retrospective Study of Seven Observational Cases and Literature Review.

PURPOSE: To describe the demographic and clinical characteristics of uveitis in patients with giant cell arteritis (GCA), their treatments, and evolution. METHODS: A national retrospective cohort study was performed. The inclusion criteria were as follows: patients with GCA fulfilling the 2022 ACR/EULAR criteria and a diagnostic of uveitis attested by an ophthalmologist. RESULTS: Seven women were included. The median age at diagnosis of uveitis was 71 years (64-84). All uveitis were diagnosed during active GCA (five at initial diagnosis, two at relapse). All uveitis were acute (100%), mostly anterior (86%) and bilateral (71%). Granulomatous features were less common (29%). All uveitis were treated with local and systemic corticosteroids. After a median follow-up of 30 (21-55) months, all patients achieved complete ophthalmic remission, with only one relapse at 2 years. GCA was also in complete remission. CONCLUSIONS: Uveitis could reveal GCA, and its presence correlated with disease activity of GCA. The most frequent clinical presentation of uveitis was acute and anterior; using local and systemic corticosteroids, the prognosis was favorable.

Diagnostic value of elevated serum angiotensin-converting enzyme and lymphopenia in patients with granulomatous hepatitis.

BACKGROUND AND AIM: Granulomatous hepatitis (GH) is associated with various aetiologies, especially inflammatory and infectious disorders. Sarcoidosis is a granulomatous disease in which the liver is the fourth most affected organ. Since epithelioid cell granulomas are not specific to sarcoidosis and since most patients with hepatic sarcoidosis are asymptomatic, valuable diagnostic biomarkers are needed to support the diagnosis of sarcoidosis. This study proposes to assess the diagnostic value of serum angiotensin converting enzyme (sACE) and lymphopenia in GH for sarcoidosis. METHODS: We retrospectively analyzed the records of 90 patients referred to the internal medicine or hepatogastroenterology departments of the Lyon University Hospital (Lyon, France) between March 2002 and January 2020 in a context of GH. RESULTS: In our tertiary center, 38 patients with sarcoidosis were identified among 73 patients with GH. Lymphopenia had a high specificity (85.7%), which increased when combined with elevated (97.0%). Interestingly, specificity increased in patients under 50 years old (100%). CONCLUSIONS: Those results suggests that lymphopenia and sACE may be valuable biomarkers for sarcoidosis diagnosis in GH when combined, especially in younger patients.

Health related quality of life, remission and low lupus disease activity state in patients with systemic lupus erythematosus.

OBJECTIVES: To measure the association between systemic lupus erythematosus (SLE) remission and scores of patients reported outcome measures (PRO). METHODS: We performed a prospective cohort study of SLE patients with a 2-year follow-up, recording LupusPRO, LupusQol, SLEQOL, and SF-36 questionnaires. Remission was defined as remission-off-treatment (ROFT) and remission-on-treatment (RONT) according to the DORIS consensus. Mixed models accounting for repeated measures were used to compare groups as follow: ROFT and RONT versus no remission, and Lupus Low Disease activity state (LLDAS) versus no LLDAS. RESULTS: A total of 1478 medical visits and 2547 PRO questionnaires were collected during the follow-up from the 336 recruited patients. A between-group difference in PRO scores reaching at least 5 points on a 0-100 scale was obtained in the following domains: "lupus symptoms" (LLDAS: +5 points on the 0-100 scale, RONT: +9 and ROFT: +5), "lupus medication" (LLDAS: +5, RONT: +8 and ROFT: +9), "pain vitality" (LLDAS: +6, RONT: +9 and ROFT: +6) of LupusPRO, "role emotional" (LLDAS: +5, RONT: +8), "role physical" (RONT: +7 and ROFT: +7), "bodily pain" (RONT: +6), "mental health" (RONT: +5) and "social functioning" (RONT: +6) of SF-36. In contrast, a between-group difference reaching at least 5 points was not achieved for any of the LupusQol and SLEQOL domains. CONCLUSIONS: RONT, ROFT, and LLDAS were associated with significant and clinically relevant higher quality of life in most PRO domains of LupusPRO (disease-specific) and SF-36 (generic) questionnaires, but not with LupusQol and SLEQOL disease-specific questionnaires.

H syndrome treated with Tocilizumab: two case reports and literature review.

H syndrome is a rare autosomal recessive genetic disorder characterized by the following clinical features: cutaneous hyperpigmentation, hypertrichosis, hepatosplenomegaly, heart anomalies, hearing loss, hypogonadism, short stature, hallux valgus, hyperglycemia, fixed flexion contractures of the toe joints, and the proximal interphalangeal joints. In rare cases, autoinflammatory and lymphoproliferative manifestations have also been reported. This disorder is due to loss-of-function mutations in SLC29A3 gene, which encode the equilibrative nucleoside transporter ENT3. This deficiency leads to abnormal function and proliferation of histiocytes. H syndrome is part of the R-group of histiocytosis. We report two different cases, one was diagnosed in adulthood and the other in childhood. The first case reported is a 37-year-old woman suffering from H syndrome with an autoinflammatory systemic disease that begins in adulthood (fever and diffuse organ's infiltration) and with cutaneous, articular, auditory, and endocrinological manifestations since childhood. The second case reported is a 2-year-old girl with autoinflammatory, endocrine, and cutaneous symptoms (fever, lymphadenopathy, organomegaly, growth delay, and cutaneous hyperpigmentation). Homozygous mutations in SLC29A3 confirmed the diagnosis of H syndrome in both cases. Each patient was treated with Tocilizumab with a significant improvement for lymphoproliferative, autoinflammatory, and cutaneous manifestations. Both cases were reported to show the multiple characteristics of this rare syndrome, which can be diagnosed either in childhood or in adulthood. In addition, an overview of the literature suggested Tocilizumab efficiency.

Long-Term Outcomes of Birdshot Chorioretinopathy Treated with Corticosteroids: A Case Reports.

PURPOSE: To report the progression of patients diagnosed with birdshot chorioretinopathy (BSCR) initially treated with corticosteroids. METHODS: We included 39 BSCR patients that were followed for ≥1 year. We analyzed their progression under treatment after 1, 3, 6 months, 1 year, and at the end of follow-up. In order to determine the efficiency of initial loading doses, patients were classified into two groups according to their initial treatment: methylprednisolone followed by prednisone (n = 28) and prednisone alone (n = 11). RESULTS: At the end of follow-up, 31/39 (79.5%) patients had reached inflammation control. Thirteen out of 28 (46.4%) and 6/11 (54.5%) patients were treated exclusively with corticosteroids, and 18/19 (94.7%) of them had reached inflammation control at the end of follow-up; their mean (range) corticosteroid dose was 3.5 (0-10) mg/day. CONCLUSIONS: We found that the prolonged corticosteroid therapy treatment strategy resulted in inflammation control in half of BSCR patients. This control was maintained with low doses of cortisone, usually <5 mg/day.

Diagnosis, Classification, and Assessment of the Underlying Etiology of Uveitis by Artificial Intelligence: A Systematic Review.

Recent years have seen the emergence and application of artificial intelligence (AI) in diagnostic decision support systems. There are approximately 80 etiologies that can underly uveitis, some very rare, and AI may lend itself to their detection. This synthesis of the literature selected articles that focused on the use of AI in determining the diagnosis, classification, and underlying etiology of uveitis. The AI-based systems demonstrated relatively good performance, with a classification accuracy of 93-99% and a sensitivity of at least 80% for identifying the two most probable etiologies underlying uveitis. However, there were limitations to the evidence. Firstly, most data were collected retrospectively with missing data. Secondly, ophthalmic, demographic, clinical, and ancillary tests were not reliably integrated into the algorithms' dataset. Thirdly, patient numbers were small, which is problematic when aiming to discriminate rare and complex diagnoses. In conclusion, the data indicate that AI has potential as a diagnostic decision support system, but clinical applicability is not yet established. Future studies and technologies need to incorporate more comprehensive clinical data and larger patient populations. In time, these should improve AI-based diagnostic tools and help clinicians diagnose, classify, and manage patients with uveitis.

Impact of Initial Management on Disease Evolution in Vogt-Koyanagi-Harada Syndrome: A Retrospective Cohort of 50 Patients.

PURPOSE: The study aims to determine the impact of initial management in Vogt-Koyanagi-Harada syndrome (VKHS). METHODS: Patients diagnosed with a VKHS between January 2001 and December 2020 in two French tertiary centers were included in a retrospective study. RESULTS: Fifty patients were included with a median duration of follow-up of 29.8 months. All patients received oral prednisone after methylprednisolone in all but four of them. Five patients received at least one associated immunosuppressive therapy (IST) within the first 6 months and 26 patients received IST during the entire follow-up period. Twenty-eight patients presented at least one relapse at a median of 5.4 months from diagnosis. Multivariate analyses demonstrated a significant association between relapse and delayed treatment (>26 days) (HR = 3.69, CI95% 1.30-10.47, p = .01), whereas no association was observed between relapse and the number of corticosteroid pulses at initial management. CONCLUSION: An early corticosteroid treatment within the first 26 days of symptoms decreased the relapse rate.

Sarcoidosis-Related Uveitis: A Review.

Sarcoidosis is an inflammatory disease that involves the eyes in 10-55% of cases, sometimes without systemic involvement. All eye structures can be affected, but uveitis is the most common ocular manifestation and causes vision loss. The typical ophthalmological appearance of these uveitis is granulomatous (in cases with anterior involvement), which are usually bilateral and with synechiae. Posterior involvement includes vitritis, vasculitis and choroidal lesions. Tuberculosis is a classic differential diagnosis to be wary of, especially in people who have spent time in endemic areas. The diagnosis is based on histology with the presence of non-caseating epithelioid granulomas. However, due to the technical difficulty and yield of biopsies, the diagnosis of ocular sarcoidosis is often based on clinico-radiological features. The international criteria for the diagnosis of ocular sarcoidosis have recently been revised. Corticosteroids remain the first-line treatment for sarcoidosis, but up to 30% of patients require high doses, justifying the use of corticosteroid-sparing treatments. In these cases, immunosuppressive treatments such as methotrexate may be introduced. More recent biotherapies such as anti-TNF are also very effective (as they are in other non-infectious uveitis etiologies).

Minor Salivary Gland Biopsy for the Diagnosis of Neurosarcoidosis.

INTRODUCTION: The definite diagnosis of neurosarcoidosis is challenging since it requires a compatible histology of the nervous system. When neurosarcoidosis is suspected, other systemic manifestations are investigated to confirm the diagnosis. A minor salivary gland biopsy (MSGB) is often performed since it is minimally invasive. The objective of the present study was to assess its performance for the diagnosis of neurosarcoidosis. METHODS: A retrospective single-center study included patients who underwent a MSGB in a tertiary neurological university hospital (Lyon, France) between 2015 and 2018. Clinical presentations unlikely to be compatible with neurosarcoidosis were excluded. Positive cases of neurosarcoidosis were defined as definite, probable, and possible cases, according to the latest international neurosarcoidosis diagnostic criteria from the Neurosarcoidosis Consortium Consensus Group. RESULTS: A total of 529 patients underwent a MSGB for clinical manifestations compatible with neurosarcoidosis. Among the 13 who fulfilled the criteria for neurosarcoidosis, only one had a positive MSGB. The sensitivity of MSGB was 7.7% (95% CI [0.2-36.0%]) and the specificity was 100.0% (95% CI [99.3-100%]). CONCLUSION: Considering the low sensitivity of MSGB for the diagnosis of NS, MSGB should be performed in selected indications, including a suspicion of spinal cord sarcoidosis, or when there is a strong clinical, laboratory, and radiological suspicion of NS. MSGB should rather not be performed when the chest CT-scan does not show signs of pulmonary or lymph node sarcoidosis.

Mutations in the B30.2 and the central helical scaffold domains of pyrin differentially affect inflammasome activation.

Familial Mediterranean Fever (FMF) is the most common monogenic autoinflammatory disorder. FMF is caused by mutations in the MEFV gene, encoding pyrin, an inflammasome sensor. The best characterized pathogenic mutations associated with FMF cluster in exon 10. Yet, mutations have been described along the whole MEFV coding sequence. Exon 10 encodes the B30.2 domain of the pyrin protein, but the function of this human-specific domain remains unclear. Pyrin is an inflammasome sensor detecting RhoA GTPase inhibition following exposure to bacterial toxins such as TcdA. Here, we demonstrate that the B30.2 domain is dispensable for pyrin inflammasome activation in response to this toxin. Deletion of the B30.2 domain mimics the most typical FMF-associated mutation and confers spontaneous inflammasome activation in response to pyrin dephosphorylation. Our results indicate that the B30.2 domain is a negative regulator of the pyrin inflammasome that acts independently from and downstream of pyrin dephosphorylation. In addition, we identify the central helical scaffold (CHS) domain of pyrin, which lies immediately upstream of the B30.2 domain as a second regulatory domain. Mutations affecting the CHS domain mimic pathogenic mutations in the B30.2 domain and render the pyrin inflammasome activation under the sole control of the dephosphorylation. In addition, specific mutations in the CHS domain strongly increase the cell susceptibility to steroid catabolites, recently described to activate pyrin, in both a cell line model and in monocytes from genotype-selected FMF patients. Taken together, our work reveals the existence of two distinct regulatory regions at the C-terminus of the pyrin protein, that act in a distinct manner to regulate positively or negatively inflammasome activation. Furthermore, our results indicate that different mutations in pyrin regulatory domains have different functional impacts on the pyrin inflammasome which could contribute to the diversity of pyrin-associated autoinflammatory diseases.