Effect of high mobility group box 1 on Toll-like receptor 9 in B cells in myeloperoxidase-ANCA-associated vasculitis

Abstract

High mobility group box 1 (HMGB1) played pathogenic role in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Recent findings demonstrated that Toll-like receptor 9 (TLR9) was involved in B cell tolerance breaking of autoimmune disease, including AAV. Here, we investigated the effect of HMGB1 on TLR9 in B cells of AAV. In the present work, patients with myeloperoxidase (MPO)-AAV in active stage were recruited. Intracellular TLR9 expression in various B cell subpopulations of the whole blood was detected by flow cytometry and the correlation with clinical data was analysed. Our results showed that intracellular TLR9 expression in B cells, memory B cells and plasmablasts correlated with erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP). In particular, TLR9 expression in plasma cells correlated with ESR, CRP, serum creatinine, eGFR, and Birmingham Vasculitis Activity Score. To further explore the effect of HMGB1 on B cell, peripheral blood mononuclear cells (PBMCs) from AAV patients were isolated. After stimulated with HMGB1, TLR9 expression in various B cell subpopulations and proliferation ratio of live B cells were analysed by flow cytometry. We found that TLR9 expression in plasma cells and the proliferation ratio of live B cells by HMGB1 stimulation were significantly upregulated compared with the control group. Therefore, TLR9 expression in plasma cells was associated with disease activity of MPO-AAV. HMGB1 could enhance TLR9 expression in plasma cells and B cell proliferation. These indicated a role of HMGB1 on TLR9 in B cells in MPO-AAV, which would provide potential clues for intervention strategies.     

Vascularites à ANCA précédées d’une atteinte articulaire isolée. À propos de deux cas et revue de la littérature

IntroductionJoint manifestations of ANCA (antineutrophil cytoplasmic antibody) associated vasculitis (AAV) are extremely common in the progression of systemic damages. However, the joint involvement is rarely isolated. The diagnosis and the treatment are difficult in this particular situation and few data are available on the topic.Case reportWe have observed two cases of joint manifestation revealing AAV we are going to describe here. The evolution toward a more severe disease raises the question of the treatment managing. The place of the ANCA research in relation to other immune tests is also discussed.ConclusionIsolated joint manifestations of ANCA vasculitis are rare but can lead to a delay in diagnosis. ANCA vasculitis should be considered in seronegative symmetrical polyarthritis by looking for ANCA in a second line biological test. Methotrexate is the first treatment option to be considered. In case of insufficient response or failure, rituximab seems an interesting option in this context.     

Ulcérations des extrémités : une manifestation inhabituelle de la maladie de Behçet

Background

Although cutaneous and mucosal involvement is a major manifestation in Behçet's disease, ulcerated lesions of the extremities are exceptional and poorly known.

Hemorrhagic occlusive retinal vasculitis leading to the diagnosis of ciliary body melanoma

Hemorrhagic occlusive retinal vasculitis (HORV) is a condition associated with intraocular vancomycin during surgical intervention, most frequently following bilateral sequential cataract surgery. Because of the high rate of ophthalmic vascular complications in this condition, gonioscopic evaluation for identification of neovascularization of the angle and iris is essential. Careful examination can reveal previously asymptomatic and unassociated lesions of the iris or ciliary body. We present the case of a 71-year-old female who was diagnosed with a ciliary body melanoma secondary to complete ophthalmic examination associated with HORV. She reported decreased vision to light perception in the left eye (OS) following sequential, bilateral cataract surgery. Fundus examination OS demonstrated diffuse retinal vasculitis, retinal ischemia, and extensive hemorrhage. Evaluation included inflammatory and coagulopathy laboratory evaluation, carotid ultrasonography and magnetic resonance imaging (MRI) of the brain and orbits, all of which proved unrevealing, except for an enhancing mass OS on MRI. Further evaluation revealed a pigmented mass with features of melanoma in the anterior chamber angle extending into the ciliary body. Fine needle aspiration biopsy revealed high risk cytogenetic characteristics, and plaque radiotherapy was successfully employed.     

IgG4‐related disease with hypergammaglobulinemic hyperviscosity and retinopathy

Immunoglobulin G4‐related disease (IgG4‐RD) is a recently described entity with protean manifestations. We describe a novel case of IgG4‐RD with hypergammaglobulinemic hyperviscosity responsive to fludarabine and rituximab. A 33‐year‐old Asian man developed bilateral lacrimal gland and submandibular salivary gland swelling with cervical lymphadenopathy. Biopsies of the affected tissues revealed reactive follicular hyperplasia. Seven years later, he presented with bilateral retinal hemorrhages due to hyperviscosity syndrome from profound polyclonal increase in IgG, including marked IgG4 elevation. Despite plasmapheresis, overproduction of IgG continued and he was refractory to systemic steroids, azathioprine, interferon alpha, and cyclophosphamide. IgG4‐RD was suspected following a myocardial infarction and detection of aneurysmal coronary arteries indicating large vessel vasculitis. Review of the cervical lymph node and lacrimal gland biopsies with immunohistochemical staining for IgG4‐positive plasma cells confirmed IgG4‐RD. B‐cell depletion with rituximab produced a partial response, but clinical symptoms and elevated protein levels persisted. Fludarabine was added to rituximab to suppress T‐cell activity, and this resulted in an excellent clinical and biochemical response. Combination therapy with fludarabine and rituximab in IgG4‐RD has not previously been reported and can be considered in patients with severe refractory disease.     

Ficolin-1 is up-regulated in leukocytes and glomeruli from microscopic polyangiitis patients

Abstract

Microscopic polyangiitis (MPA) is a systemic autoimmune disease that often has a fatal outcome. Although delineating the molecular pathogenesis is essential for its remedy, an understanding of its molecular mechanism has remained elusive. To search for new markers of active lesions that might help better understand the molecular basis of MPA and aid in its diagnosis, we here performed DNA microarray analysis with peripheral blood mononuclear cells (PBMCs). Compared to normal control, several genes were up- or down-regulated in MPA patients, including up-regulation of the mRNA level of ficolin-1 (FCN1 or M-ficolin), an innate pattern recognition complement molecule. The amount of ficolin-1, as detected by immunohistochemistry, was higher in the glomeruli of another group of MPA patients than in the glomeruli of control patients who harbored almost normal glomeruli. Many of the ficolin-1 dots were also positive for CD68, suggesting that the ficolin-1–positive cells were monocytes, such as macrophages or dendritic cells. This is not due to the difference in the number of neutrophil or monocytes in the blood samples of MPA and control patients. Taken together, we conclude that increased ficolin-1 expression could serve as a new marker for the characterization of MPA, especially when it is associated with local active lesions.