Macrophage IL-1ß-positive microvesicles exhibit thrombo-inflammatory properties and are detectable in patients with active juvenile idiopathic arthritis.

Objective: IL-1ß is a leaderless cytokine with poorly known secretory mechanisms that is barely detectable in serum of patients, including those with an IL-1ß-mediated disease such as systemic juvenile idiopathic arthritis (sJIA). Leukocyte microvesicles (MVs) may be a mechanism of IL-1ß secretion. The first objective of our study was to characterize IL-1ß-positive MVs obtained from macrophage cell culture supernatants and to investigate their biological functions in vitro and in vivo. The second objective was to detect circulating IL-1ß-positive MVs in JIA patients. Methods: MVs were purified by serial centrifugations from PBMCs, or THP-1 differentiated into macrophages, then stimulated with LPS ± ATP. MV content was analyzed for the presence of IL-1ß, NLRP3 inflammasome, caspase-1, P2X7 receptor, and tissue factor (TF) using ELISA, Western blot, or flow cytometry. MV biological properties were studied in vitro by measuring VCAM-1, ICAM-1, and E-selectin expression after HUVEC co-culture and factor-Xa generation test was realized. In vivo, MVs' ability to recruit leukocytes in a murine model of peritonitis was evaluated. Plasmatic IL-1ß-positive MVs were studied ex vivo in 10 active JIA patients using flow cytometry. Results: THP-1-derived macrophages stimulated with LPS and ATP released MVs, which contained NLRP3, caspase-1, and the 33-kDa precursor and 17-kDa mature forms of IL-1ß and bioactive TF. IL-1ß-positive MVs expressed P2X7 receptor and released soluble IL-1ß in response to ATP stimulation in vitro. In mice, MVs induced a leukocyte peritoneal infiltrate, which was reduced by treatment with the IL-1 receptor antagonist. Finally, IL-1ß-positive MVs were detectable in plasma from 10 active JIA patients. Conclusion: MVs shed from activated macrophages contain IL-1ß, NLRP3 inflammasome components, and TF, and constitute thrombo-inflammatory vectors that can be detected in the plasma from active JIA patients.

Thoracic manifestations of IgG4-related disease.

Immunoglobulin G4-related disease (IgG4-RD) is a recently described rare systemic fibroinflammatory disease with an estimated incidence of less than 1 in 100,000 persons per year. The disease can affect virtually any organ and is characterized by unifying histopathological findings. Recently, four subgroups of patients have been characterized: hepatobiliary, head and neck, Mikulicz syndrome and retroperitoneal fibrosis, who illustrate the mainly abdominal and ENT tropism of the disease. Yet, thoracic involvement is not uncommon. It can be detected in up to 30% of patients with systemic IgG4-RD and is the exclusive manifestation of the disease in about 10% of cases. Clinical symptoms are nonspecific and may include dyspnoea, cough or chest pain. Chest CT findings are heterogeneous and primarily include peribronchovascular thickening, nodules, ground-glass opacities and lymphadenopathy. There is no specific diagnostic test for IgG4-RD thoracic involvement, which may mimic malignancy or vasculitis. Therefore, a cautious approach is needed to make an accurate diagnosis: a search for extra-thoracic manifestations, elevated serum IgG4 levels, circulating levels of plasmablasts and pathologic evidence of disease is warranted. Although very suggestive, neither the presence of a polyclonal IgG4 lymphoplasmacytic infiltrate, storiform fibrosis or obliterative phlebitis are sufficient to confirm the histological diagnosis. Steroids are recommended as first-line therapy. Rituximab or disease-modifying antirheumatic drugs may be used in relapsed or rare cases of steroid-refractory disease. In this review, we summarize current knowledge regarding the pathophysiology, epidemiology, diagnostic modalities (clinical-biological-imaging-histopathology) and treatment of IgG4-RD thoracic involvement.

Ocular Inflammation Induced by Immune Checkpoint Inhibitors.

Ocular immunotherapy-related adverse events (IRAEs), although rare, can be sight-threatening. Our objective was to analyze ocular IRAEs diagnosed in France from the marketing of immune checkpoint inhibitors (ICPIs) until June 2021 and to review the literature. We collected the cases of 28 patients (36 ocular IRAEs), occurring after an average of 17 weeks (±19). Forty-six percent of patients were treated for metastatic melanoma. Anti-PD1 agents were responsible for 57% of the IRAEs. Anterior uveitis was the most common (44%), followed by panuveitis (28%). Of 25 uveitis cases, 80% were bilateral and 60% were granulomatous. We found one case with complete Vogt-Koyanagi-Harada syndrome and one case of birdshot retinochoroidopathy. The other IRAEs were eight ocular surface disorders, one optic neuropathy, and one inflammatory orbitopathy. Seventy percent of the IRAEs were grade 3 according to the common terminology of AEs. ICPIs were discontinued in 60% of patients and 50% received local corticosteroids alone. The literature review included 230 uveitis cases, of which 7% were granulomatous. The distributions of ICPIs, cancer, and type of uveitis were similar to our cohort. Ocular IRAEs appeared to be easily controlled by local or systemic corticosteroids and did not require routine discontinuation of ICPIs. Further work is still warranted to define the optimal management of ocular IRAEs.

Acute severe hepatitis in adult-onset Still's disease: case report and comprehensive review of a life-threatening manifestation.

Acute severe hepatitis is a rare complication of adult-onset Still's disease (AOSD). This condition is poorly characterized. We performed a review of the medical literature to describe clinical, biological, pathological, and treatment characteristics from AOSD patients with acute severe hepatitis. Their characteristics were compared with AOSD patients without severe hepatitis. Twenty-one cases were collected including a new case reported here. Patients with severe hepatitis were mostly young adults with a median age of 28 years (range: 20 to 55 years). Overall, patients with severe hepatitis had less arthritis, macular rash, sore throat, lymphadenopathy, or splenomegaly than patients without severe hepatitis. Cytopenia was more frequent in case of severe hepatitis. Most patients were treated with steroids, and the use of biotherapies has increased over the last decade. Despite treatment, 49% of patients required liver transplantation and 24% died. Key Points • Acute severe hepatitis in adult-onset Still's disease (AOSD) is associated with liver transplantation and/or death in, respectively, 43% and 24% of cases. • Severe hepatitis is the inaugural manifestation of AOSD in half of cases. Diagnosis is difficult when extra-hepatic clinical manifestations are lacking. • The mechanism of hepatic necrosis in AOSD with severe hepatitis is unknown. Liver biopsy is not specific and should not delay treatment initiation.