Recommendations for the management of the vascular involvement in Behçet's disease by the Japanese National Research Committee for Behçet's disease-secondary publication.

OBJECTIVES: This study aimed to develop clinical guidelines for the management of vascular Behçet's disease (BD) by the Behçet's Disease Research Committee of the Ministry of Health, Labour and Welfare of the Japanese Government. METHODS: A task force proposed clinical questions (CQs) concerning vascular BD based on a literature search. After screening, draft recommendations were developed for each CQ and brushed up in three blinded Delphi rounds, leading to the final recommendations. RESULTS: This study provides recommendations for 17 CQs concerning diagnosis and differential diagnoses, assessment of disease activity, and treatment. The guidelines recommend immunosuppressive treatments, for both arterial and venous involvement with active inflammation. Anticoagulation is also recommended for deep vein thrombosis except in high-risk patients. Surgical and endovascular therapies can be optional, particularly in patients with urgent arterial lesions undergoing immunosuppression. In addition, two sets of algorithms for diagnosis and treatment are shown for arterial and venous involvement. CONCLUSIONS: These recommendations are expected to serve as useful tools in the daily clinical practice of BD. This content has already been published in Japanese in the Guideline for the Management of Behçet's Disease 2020 and is submitted with permission from both the primary and secondary publishers.

Enhanced expression of mRNA for transforming growth factor ß activated kinase 1 in CD34+ cells of the bone marrow in rheumatoid arthritis.

OBJECTIVES: Transforming growth factor ß activated kinase 1 (TAK1) has been found to mediate maladaptive tumour necrosis factor (TNF) signalling, leading to hyperactive downstream nuclear factor Kappa ß (NF-κB) signalling. We explored the expression of TAK1 mRNA in bone marrow CD34+ cells in rheumatoid arthritis (RA) to delineate the mechanism for their abnormal response to TNF-α and differentiate into fibroblast-like cells. METHODS: CD34+ cells were purified from bone marrow samples obtained from 47 RA patients and 27 osteoarthritis (OA) patients during joint operations via aspiration from the iliac crest. The expression of mRNAs for TAK1 and NFκB1 was examined by quantitative RT-PCR. RESULTS: TAK1 mRNA expression in bone marrow CD34+ cells was significantly higher in RA than in OA (TAK1/ß-actin: [11.980 ± 2.380] x 10-3 and [5.593±1.307] x 10-3 [mean ± SEM], respectively; p=0.0238). TAk1 mRNA expression was not different depending on the type of operated joints or on the severity type of RA. Nor was it correlated with serum CRP or rheumatoid factor or with administration of methotrexate, other conventional synthetic disease-modifying anti-rheumatic drugs or oral glucocorticoid. TAK1 mRNA expression was significantly correlated with NFκB1 mRNA expression in RA bone marrow CD34+ cells. CONCLUSIONS: These results indicate that TAK1 mRNA expression is enhanced in bone marrow CD34+ cells independently of the clinimetrics or treatment in RA. It is also suggested that the upregulation of TAK1 mRNA expression might lead to the enhanced expression of NFκB1 mRNA in bone marrow CD34+ cells, but possibly not vice versa, resulting in their abnormal response to TNF-α.

Histopathology of pulmonary thromboembolism in a patient with Behçet's disease.

Pulmonary involvement in vascular Behçet's disease (BD) (VBD) is a serious manifestation. Among the pulmonary manifestations, pulmonary embolism is considered a rare manifestation because deep vein thrombosis (DVT) has been thought to detach from the vessel wall, whereas pulmonary thrombus has been suggested to result from in situ pulmonary arteritis.In this case report, we present histopathological evidence of pulmonary embolism derived from DVT in an autopsy case of VBD. This observation emphasises that DVT causes pulmonary embolism in BD, indicating that anticoagulants are required for its prevention.

Clinical features of Behçet's disease patients with joint symptoms in Japan: A national multicenter study.

OBJECTIVES: Approximately 30-60% of Behçet's disease patients exhibit joint symptoms. The aim of this study was to determine the clinical characteristics of such patients in Japan. METHODS: This study retrospectively analyzed 151 Behçet's disease patients with joint symptoms who had been treated at seven cooperative medical institutions from 2007 to 2017. We investigated their clinical characteristics and treatments. RESULTS: The most commonly affected joints were the knee, ankle, and proximal interphalangeal joints. Of the cases with pain and swelling, 18 of 293 joints (11 cases) displayed narrowing of the cleft or deformity by X-ray analysis. Improvement in their arthritis was observed in 80% of the patients who received steroids as initial treatment; however, the rate of improvement was lower in patients who had received prednisolone (PSL) at <10 mg/day. The recurrence of joint symptoms was significantly less common in the colchicine group than in the PSL group. CONCLUSIONS: These results suggest that PSL is effective for remission induction for the treatment of joint symptoms of Behçet's disease. Additionally, colchicine is effective in preventing the recurrence of joint symptoms in Behçet's disease. Furthermore, joint damages like joint space narrowing or with any deformity can often be observed in Behçet's disease.

Association of functional (GA)n microsatellite polymorphism in the FLI1 gene with susceptibility to human systemic sclerosis.

OBJECTIVE: Susceptibility genes that can account for characteristic features of SSc such as fibrosis, vasculopathy and autoimmunity remain to be determined. In mice, deficiency of Friend leukaemia integration 1 transcription factor (Fli1) causes SSc-like disease with these features. The human FLI1 gene contains (GA)n microsatellite, which has been shown to be associated with expression level. Because microsatellite polymorphisms are difficult to capture by genome-wide association studies, we directly genotyped FLI1 (GA)n microsatellite and examined its association with SSc. METHODS: Genomic DNA from 639 Japanese SSc patients and 851 healthy controls was genotyped for (GA)n microsatellite using the fragment assay. The cut-off repeat number for susceptibility to SSc was determined by receiver operating characteristics (ROC) analysis. Association with susceptibility and clinical characteristics was examined using logistic regression analysis. FLI1 mRNA levels were determined using quantitative RT-PCR. RESULTS: Based on the ROC analysis, (GA)n alleles with ≥22 repeats were collectively defined as L alleles and alleles with ≤21 repeats as S alleles. (GA)n L alleles were significantly associated with susceptibility to SSc (P = 5.0e-04, odds ratio 1.34, additive model). Significant association was observed both in diffuse cutaneous and limited cutaneous SSc. Among the SSc, (GA)n L alleles were significantly enriched in the patients with a modified Rodnan total skin thickness score ≥10 compared with those with a score <10. FLI1 mRNA levels were significantly decreased in healthy controls carrying (GA)n L alleles as compared with non-carriers. CONCLUSION: Extended repeat alleles of FLI1 (GA)n microsatellite may be associated with lower FLI1 mRNA levels and susceptibility to human SSc.

Anti-ribosomal P protein antibodies influence mortality of patients with diffuse psychiatric/neuropsychological syndromes in systemic lupus erythematous involving a severe form of the disease.

Objectives: The aim of this study is to clarify the effect of various autoantibodies on overall mortality in patients with diffuse psychiatric/neuropsychological syndromes in SLE (diffuse NPSLE). Methods: Fifty-five patients with diffuse NPSLE admitted from 1992 to 2017 had met inclusion criteria and were recruited for this study. The relationship of various serum autoantibodies with mortality was retrospectively analyzed based on the medical charts. Results: Of 55 patients, 14 patients [25.5%] had died during the observation period (2728 [22-8842] days (median [range])). The 5-year, 10-year, 15-year and 20-year mortality rates were 18.8%, 21.9%, 36.9% and 47.4%, respectively. Among various serum autoantibodies at the onset of diffuse NPSLE, only the presence of anti-ribosomal P protein antibodies (anti-ribo P) significantly increased the risk for death (relative risk 2.262, 95% confidence interval 1.276-4.417, p = 0.005). Of 14 fatal patients, 10 patients had died within 1 y after the onset of diffuse NPSLE. Remarkably, 7 of 10 patients with positive anti-ribo P had died of the severe complication primarily attributed to SLE except for one patient. Conclusions: The presence of anti-ribo P is a significant risk factor for overall poor prognosis in patients with diffuse NPSLE, involving a fatal complication by SLE.

Nurse-like cells in rheumatoid arthritis: Formation of survival niches cooperating between the cell types.

Nurse-like cells (NLCs) established from bone marrow and synovial tissue of rheumatoid arthritis (RA) patients were found to promote maturation and differentiation of B lineage cells as well as T cells. In co-culture of RA-NLCs and B cells, tight physical interactions (pseudoemperipolesis) developed, which resulted in activation of both cell types. RA-NLCs also supported myeloid cell maturation, promoting their differentiation into tartrate-resistant acid phosphatase-positive mononuclear cells, which are precursor cells of osteoclasts. In RA synovial tissue, the characteristic dendritic-shaped cells (the DCs) were electron microscopically found to form direct physical interactions with adjacent plasma cells (PCs) suspecting to be pseudoemperipolesis. The numbers of PCs accumulating in various areas tended to correlate with the numbers of the DCs, which appeared to have RA-NLC functions forming survival niches for PCs. Immunohistochemical staining analysis indicated that CD14+ cells including the DCs formed survival niches for CD138+ PCs by RA-NLC functions. Quantitative dual immunofluorescence staining studies of these areas indicated that the majority of CD14+ cells were of myeloid lineage. These survival niches promoted by RA-NLCs appear to play important roles in supporting immunological functions in RA bone marrow and synovial tissues.

The expression of mRNA for peptidylarginine deiminase type 2 and type 4 in bone marrow CD34+ cells in rheumatoid arthritis.

OBJECTIVES: Antibodies directed to citrullinated proteins are highly specific for rheumatoid arthritis (RA). Citrullination is catalyzed by peptidylarginine deiminase (PAD) enzymes. The current study examined the mRNA expression of PADI2 and PADI4 in bone marrow (BM) CD34+ cells from RA patients. METHODS: CD34+ cells were purified from BM samples obtained from 48 RA patients and from 30 osteoarthritis (OA) patients during joint operations via aspiration from the iliac crest. The expression of mRNAs for PADI2, PADI4 and Sp1 was examined by quantitative reverse transcription PCR. RESULTS: The expression of mRNA for PADI2 was significantly higher in RA BM CD34+ cells than OA BM CD34+ cells. The expression of mRNAs for PADI4 and Sp1 in RA BM CD34+ cells appeared to be increased compared to OA BM CD34+ cells, although it did not reach the statistical significance. The levels of mRNAs for PADI2, PADI4 and Sp1 were not correlated with serum C-reactive protein or with the administration of methotrexate or oral steroids. Finally, the level of PADI2 mRNA as well as that of PADI4 mRNA was significantly correlated with the level of Sp1 mRNA in RA BM CD34+ cells. CONCLUSIONS: These results indicate that the mRNA expression of PADI2, PADI4 and Sp1 is upregulated in RA BM CD34+ cells independently of the systemic inflammation or treatment regimen. Moreover, the data suggest that the enhanced mRNA expression of PADI2 and PADI4 in BM CD34+ cells might be a result of the enhanced expression of Sp1 gene in RA BM CD34+ cells.

Role of serum autoantibodies in blood brain barrier damages in neuropsychiatric systemic lupus erythematosus.

OBJECTIVES: The present study was carried out to elucidate the roles of serum autoantibodies in the development of blood-brain barrier (BBB) damages in neuropsychiatric systemic lupus erythematosus (NPSLE). METHODS: Paired serum and CSF samples were obtained from 101 SLE patients when they presented active neuropsychiatric manifestations (69 patients with diffuse psychiatric/neuropsychological syndromes [diffuse NPSLE] and 32 patients with neurologic syndromes or peripheral neuropathy [focal NPSLE]). IgG anti-NR2 subunit of NMDA receptor (anti-NR2), anti-Sm, anti-ribosomal P and IgG anti-cardiolipin in sera and albumin in CSF and sera were measured by ELISA. Blood-brain barrier (BBB) function was evaluated by Q albumin (CSF/serum albumin quotient x 1,000). RESULTS: Q albumin was significantly higher in acute confusional state (ACS) than in non-ACS diffuse NPSLE (anxiety disorder, cognitive dysfunction, mood disorder and psychosis) or in focal NPSLE. Anti-Sm, but not anti-NR2, anti-P or anticardiolipin, was significantly elevated in ACS compared with the other 2 groups of NPSLE, although serum anti-NR2 was significantly higher in ACS than that in focal NPSLE. Multiple regression analysis confirmed the significant contribution of anti-Sm (p=0.0040), but not anti-NR2 (p=0.5023), anti-P (p=0.2651), or anti-cardiolipin (p=0.6769) in the elevation of Q albumin. CONCLUSIONS: The data demonstrate that serum anti-Sm antibodies play a most important role in the disruption of BBB in NPSLE.

Differential influences of Fc gamma receptor blocking on the effects of certolizumab pegol and infliximab on human monocytes.

OBJECTIVES: To compare the effects of certolizumab pegol (CZP) and infliximab (IFX) on human monocytes. METHODS: Highly purified monocytes from healthy donors were cultured with CZP, IFX, control IgG1, or polyethylene glycol (PEG) at pharmacological attainable concentrations in culture medium with 10% autologous normal human serum (NHS) or with fetal bovine serum (FBS) for 24 h, after which the supernatants were replaced by fresh culture medium containing LPS. After additional 24 h of incubation, the supernatants were assayed for TNF-α and IL-6. In some experiments, the cells were harvested after 1 h of stimulation with LPS for analysis of mRNA for TNF-α by quantitative PCR. RESULTS: Pre-incubation of monocytes with CZP or IFX reduced the production of TNF-α in subsequent cultures stimulated by LPS in a dose-dependent manner. The suppressive effects of IFX on the TNF-α production were significantly diminished, but those of CZP were rather enhanced, in cultures with autologous NHS compared with in cultures with FBS. Addition of IgG, but not IgG F(ab')2 fragments, significantly inhibited the suppressive effects of IFX on the production of TNF-α and IL-6, whereas either IgG or IgG F(ab')2 fragments had no significant influences on the suppressive effects of CZP. Furthermore, pre-incubation with CZP or IFX significantly inhibited the expression of mRNA for TNF-α and IL-6 in monocytes compared with PEG or IgG. CONCLUSION: These results indicate that the mechanism of action of CZP is different from that of IFX. Thus, CZP suppresses the production of proinflammatory cytokines independently of Fc receptors, whereas the suppressive effects of IFX on human monocytes are almost totally dependent on the interaction with Fc receptors.

Brain MRI in patients with acute confusional state of diffuse psychiatric/neuropsychological syndromes in systemic lupus erythematosus.

OBJECTIVE: The objective of this study is to explore the characteristics of brain MRI abnormalities in acute confusional state (ACS) in neuropsychiatric systemic lupus erythematosus (NPSLE). METHODS: Thirty-six patients with ACS admitted to our institutions from 1992 to 2015 were exhaustively enrolled. Their medical charts and brain MRI scans were reviewed. RESULTS: Eighteen of 36 ACS patients had MRI abnormalities, mostly high-intensity lesions of various sizes in the cerebral white matter. MRI abnormalities improved after treatment in 12 of 14 patients in follow-up studies. MRI abnormalities were not correlated with ages at the onset of ACS, disease durations of SLE, the presence of anti-DNA, anti-phospholipid or anti-ribosomal P antibodies, or IL-6 levels in sera or cerebrospinal fluid. Notably, MRI abnormalities were significantly associated with the presence of serum anti-Sm antibodies (p = 0.0067). Finally, eight of the 18 patients with MRI abnormalities, but none of the other 18 patients without MRI abnormalities, died from active SLE. Thus, MRI abnormalities significantly increased the mortality in ACS (p = 0.0013, HR =10.36 [95% CI: 2.487-43.19]). CONCLUSION: These results demonstrate that patients with ACS with MRI abnormalities have more severe diseases, resulting in poorer prognoses. The data also indicate that anti-Sm is involved in the development of MRI abnormalities in ACS.

Differential activation mechanisms of serum C5a in lupus nephritis and neuropsychiatric systemic lupus erythematosus.

OBJECTIVE: To explore the role of C5a in the pathogenesis of neuropsychiatric systemic lupus erythematosus (NPSLE) and lupus nephritis (LN). METHODS: Sera were obtained from 29 patients with NPSLE, 25 with LN, 26 without NPSLE or LN [SLE alone], and 21 healthy donors. Cerebrospinal fluid (CSF) was obtained from 29 NPSLE patients. C5a and C5 were measured by ELISA. Blood-brain barrier (BBB) function was evaluated by Q albumin ([CSF albumin/serum albumin] × 103). RESULTS: Serum C5a, but not C5, was significantly increased in SLE compared with healthy control. Serum C5a, but not C5, was significantly higher in NPSLE and in LN than in SLE alone. Serum C4, but not C3, was lower in LN than in NPSLE. Q albumin was significantly higher in diffuse NPSLE than in focal NPSLE, whereas there were no significant differences in CSF or serum C5a between both groups. Notably, CSF C5 and C5a were significantly correlated with Q albumin, whereas serum C5a, but not C5, appeared to be inversely correlated with Q albumin. CONCLUSION: These results disclosed that serum C5a was elevated not only in NPSLE but also in LN through different mechanisms. Moreover, it is suggested that C5a might be consumed during BBB damages.

Differential effects of IL-6 blockade tocilizumab and TNF inhibitors on angiogenesis in synovial tissues from patients with rheumatoid arthritis.

OBJECTIVE: To compare the influences of tocilizumab (TCZ) and TNF inhibitors (TNFi) on the angiogenesis in synovial tissues of rheumatoid arthritis (RA). METHODS: Synovial tissues were obtained during joint operations from 13 RA patients treated with TCZ for at least 4 months with or without previous use of TNFi, from 13 RA patients with TNFi alone and from 10 RA patients with only conventional synthetic DMARDs (csDMARDs). Synovial tissues were evaluated by hematoxylin and eosin stain as well as by immunohistological staining with anti-CD31 in which the microvessel densities (MVD) were quantitated. Synovial histopathology was scored for various components. RESULTS: The most remarkable change in the synovium with TCZ was reduced angiogenesis as well as degeneration of lining layers irrespective of the previous use of TNFi. Thus, MVD in patients treated with TCZ with or without previous TNFi were significantly decreased compared with those in patients with TNFi alone or with csDMARDs. Moreover, MVD was significantly correlated with lining layer proliferation, but not with synovial stromal proliferation or inflammatory changes. CONCLUSIONS: These results demonstrated that inhibition of angiogenesis is a unique action of TCZ. Moreover, the data also suggest that lining layers proliferation might be closely associated with angiogenesis.

Association of antibodies to the NR1 subunit of N-methyl-D-aspartate receptors with neuropsychiatric systemic lupus erythematosus.

OBJECTIVE: To determine epitope reactivity of autoantibodies to N-methyl-D-aspartate (NMDA) receptor NR1 subunit and their association with neuropsychiatric systemic lupus erythematosus (NPSLE). METHODS: Paired serum and CSF specimens were obtained from 41 patients with NPSLE (22 with diffuse psychiatric/neuropsychological syndromes [diffuse NPSLE] and 19 with neurologic syndromes or polyneuropathy [focal NPSLE]), 21 patients with various rheumatic diseases other than SLE (non-SLERD). Sera were also obtained from 27 SLE patients without neuropsychiatric manifestations (non-CNS SLE). Antibodies to murine NR1 (mNR1) or to 4 different preparations of synthetic 25-amino-acid (AA) peptides of human NR1 were measured by enzyme-linked immune sorbent assay (ELISA). RESULTS: Serum anti-mNR1 levels were significantly higher in NPSLE than in non-SLERD. Sera from NPSLE patients bound efficiently to the AA residues 19-44 from the N-terminus of NR1 (NR1-A) or 56-81 (NR1-C). Accordingly, serum anti-NR1-A and anti-NR1-C were also elevated in NPSLE compared with non-SLERD. Of note, anti-NR1-A as well as anti-NR1-C levels in CSF, but not in sera, were significantly elevated in diffuse NPSLE compared with focal NPSLE or with non-SLERD. CONCLUSION: These results suggest that autoantibodies to NMDA receptor NR1, especially to the AA residues 19-44 and 56-81 from the N-terminus play a pivotal role in the pathogenesis of diffuse NPSLE.

Transverse myelitis extended to disseminated encephalitis in systemic lupus erythematosus: Histological evidence for vasculitis.

A 42-year-old woman was admitted due to systemic lupus erythematosus complicated with glomerulonephritis and pulmonary hypertension. During the treatment for these complications, she presented motor paresis and sensory loss caused by transverse myelitis. In spite of methyl prednisolone pulse therapy, she further developed acute confusional state due to disseminated encephalitis and fell into respiratory arrest. On laboratory examination, elevation of anti-NR2 antibodies in serum as well as in cerebrospinal fluid was noted. Although she recovered from the disseminated encephalitis after extensive treatment with high doses of corticosteroid and intravenous cyclophosphamide, she suddenly died of pulmonary hypertension. Autopsy findings confirmed the presence of liquefaction necrosis in the entire circumference of the whole spinal cord along with intimal hyperplasia and obliteration of the small arteries, accompanied by mononuclear cell infiltration and disruption of internal elastic lamina. It is therefore most likely that our patient developed longitudinal transverse myelitis through spinal cord vasculitis, which extended to brainstem and brain parenchyma, leading to the development of disseminated encephalitis.

Hypertrophic pachymeningitis: significance of myeloperoxidase anti-neutrophil cytoplasmic antibody.

The aim of this study was to elucidate the characteristics, pathogenesis and treatment strategy of hypertrophic pachymeningitis that is associated with myeloperoxidase anti-neutrophil cytoplasmic antibody (ANCA). We retrospectively investigated clinical, radiological, immunological and pathological profiles of 36 patients with immune-mediated or idiopathic hypertrophic pachymeningitis, including 17 patients with myeloperoxidase-ANCA, four patients with proteinase 3-ANCA, six patients with other immune-mediated disorders, and nine patients with 'idiopathic' variety. Myeloperoxidase-ANCA-positive hypertrophic pachymeningitis was characterized by: (i) an elderly female predominance; (ii) 82% of patients diagnosed with granulomatosis with polyangiitis (previously known as Wegener's granulomatosis) according to Watts' algorithm; (iii) a high frequency of patients with lesions limited to the dura mater and upper airways, developing headaches, chronic sinusitis, otitis media or mastoiditis; (iv) a low frequency of patients with the 'classical or generalized form' of granulomatosis with polyangiitis involving the entire upper and lower airways and kidney, or progressing to generalized disease, in contrast to proteinase 3-ANCA-positive hypertrophic pachymeningitis; (v) less severe neurological damage according to the modified Rankin Scale and low disease activity according to the Birmingham Vasculitis Activity Score compared with proteinase 3-ANCA-positive hypertrophic pachymeningitis; (vi) increased levels of CXCL10, CXCL8 and interleukin 6 in cerebrospinal fluids, and increased numbers of T cells, neutrophils, eosinophils, plasma cells and monocytes/macrophages in autopsied or biopsied dura mater with pachymeningitis, suggesting TH1-predominant granulomatous lesions in hypertrophic pachymeningitis, as previously reported in pulmonary or renal lesions of granulomatosis with polyangiitis; and (vii) greater efficacy of combination therapy with prednisolone and cyclophosphamide compared with monotherapy with prednisolone. Proteinase 3-ANCA may be considered a marker for more severe neurological damage, higher disease activity and a higher frequency of the generalized form compared with myeloperoxidase-ANCA-positive hypertrophic pachymeningitis. However, categorization into 'granulomatosis with polyangiitis' according to Watts' algorithm and immunological or pathological features were common in both proteinase 3- and myeloperoxidase-ANCA-positive hypertrophic pachymeningitis. These data indicate that most patients with myeloperoxidase-ANCA-positive hypertrophic pachymeningitis should be categorized as having the central nervous system-limited form of ANCA-associated vasculitis, consistent with the concept of ophthalmic-, pulmonary- or renal-limited vasculitis.

Effects of anti-IL-6 receptor antibody on human monocytes.

OBJECTIVE: To explore the effects of anti-IL-6 receptor antibody, tocilizumab on function of human monocytes. METHODS: Monocytes from healthy donors were cultured in the presence of staphylococcal enterotoxin B (SEB) with pharmacologically attainable concentrations of tocilizumab or control IgG. The expression of IL-6 mRNA was determined using quantitative RT-PCR. The expression of CD80 and CD86 and the induction of apoptosis of monocytes were measured using flow cytometry. RESULTS: Tocilizumab promoted apoptosis of SEB-stimulated monocytes. The induction of apoptosis of monocytes by tocilizumab were reversed by addition of IgG, but not IgG F(ab')2 fragments. Tocilizumab significantly suppressed the expression of CD80, but not that of CD86, on SEB- stimulated monocytes. Finally, tocilizumab significantly suppressed the expression of mRNA for IL-6 of monocytes stimulated with SEB. CONCLUSIONS: These results demonstrate that one of the mechanism of action of tocilizumab involves the induction of apoptosis of monocytes, which requires interaction with Fc receptor on monocytes. Moreover, the data also indicate that tocilizumab inhibit IL-6 production of monocytes at mRNA levels.

IgG anti-NR2 glutamate receptor autoantibodies from patients with systemic lupus erythematosus activate endothelial cells.

OBJECTIVE: To investigate the possibility that IgG anti-NR2 glutamate receptor antibodies (anti-NR2) derived from patients with systemic lupus erythematosus (SLE) cause an immunologic interaction with endothelial cells (ECs) in the blood-brain barrier, resulting in inflammation of the blood-brain barrier, allowing the entrance of these autoantibodies into the cerebrospinal fluid. METHODS: Purified IgG anti-NR2 antibodies from 14 patients with SLE were tested for their ability to bind to double-stranded DNA (dsDNA) and ECs, to modulate endothelial adhesion molecule expression and cytokine production by ECs, and to activate the NF-κB pathways in the ECs. Purified IgG from 5 normal subjects was used as a negative control. RESULTS: Purified IgG anti-NR2 antibodies bound to dsDNA in an IgG-dose-dependent manner. This interaction up-regulated the expression of endothelial leukocyte adhesion molecule 1, vascular cell adhesion molecule 1, and intercellular adhesion molecule 1 on the EC surface and increased the production of interleukin-6 (IL-6) and IL-8, but not tumor necrosis factor α or IL-1ß, by ECs. Purified IgG anti-NR2 also activated the degradation of cytoplasmic IκB, indicating the activation of NF-κB in the ECs. CONCLUSION: EC activation through the NF-κB signaling pathway induced by IgG anti-NR2 antibodies in the central nervous system of SLE patients may lead to inflammation of the blood-brain barrier, initiating the pathogenesis of neuropsychiatric SLE.