The pathogenic role of lupus-specific autoantibodies and Interleukin-6 on demyelination of the brainstem and spinal cord in systemic lupus erythematosus.

OBJECTIVES: Demyelinating syndromes that result in brainstem and/or spinal cord lesions similar to those observed in neuromyelitis optica spectrum disorder (NMOSD) as neuropsychiatric syndromes in systemic lupus erythematosus (NPSLE) occasionally develop in patients with SLE. Cerebrospinal fluid (CSF) interleukin (IL)-6 is a known biomarker for NMOSD; however, its application in patients with SLE with brainstem and/or spinal cord lesions is unknown. Additionally, the breakdown of blood-brain barrier (BBB) integrity by autoantibodies is another mechanism of NMOSD; however, it is not elucidated in SLE. Therefore, this study was designed to clarify the use of CSF IL-6 and investigate whether autoantibodies contribute to BBB breaches and the development of brainstem and/or spinal cord lesions. METHODS: Data from patients with NPSLE who had NMOSD-like demyelinating lesions in the central nervous system (CNS), including brainstem and/or spinal cord lesions, were retrospectively analyzed. We retrospectively investigated the interval changes in CSF IL-6 and clinical and serological factors related to BBB permeability using CSF/serum albumin ratio (QAlb). RESULTS: Twelve patients with NPSLE who had demyelinating lesions in the brainstem and/or spinal cord were recruited. Before treatment, CSF IL-6 levels were 29.1 pg/mL and significantly decreased to 3.8 pg/mL by treatment (p = 0.008). Before treatment, CSF IL-6 was significantly correlated with the anti-dsDNA antibody titer (p = 0.027). Furthermore, before treatment, QAlb was significantly correlated with the serum anti-Smith antibody titer. In patients with atypical NMOSD who had specific lesions defined in the NMOSD diagnostic criteria but were negative for antiaquaporin four antibody, a significant correlation was observed between the serum anti-Smith antibody titer and CSF IL-6 (p = 0.025) and QAlb (p = 0.033) values before treatment. CONCLUSION: CSF IL-6 could be a surrogating marker for disease activity, and serum anti-Smith antibody permeabilizes the BBB in patients with NPSLE, supporting the development of NMOSD-like CNS lesions.

Real-world efficacy of belimumab in achieving remission or low-disease activity in systemic lupus erythematosus: A retrospective study.

OBJECTIVES: We investigated the effect of belimumab (BEL) on achieving low disease activity (LDA) and remission as an additive molecular-targeting agent to standard of care (SoC) in patients with SLE. METHODS: Clinical information was retrospectively collected from patients with SLE who received BEL additive to SoC (BEL+SoC), and from patients treated with SoC alone as a control arm. Disease activity was measured by SLE-disease activity score (SLE-DAS). The proportion of patients in LDA and remission at 12 months was compared after propensity score matching. The factors contributing to LDA and remission achievement was identified by Cox proportional hazard model. RESULTS: BEL+SoC significantly reduced SLE-DAS at 6 months, with a significantly higher proportion of patients achieving LDA and remission at 12 months compared to SoC alone. The presence of arthritis at baseline was significantly associated with achieving LDA and remission. Additionally, both treatment groups experienced a significant reduction in daily glucocorticoid dose. CONCLUSIONS: Adding BEL to SoC was beneficial for patients with arthritis, leading to higher proportion of achieving LDA and remission, while also reducing their glucocorticoid dose. Our results indicate the utility of BEL in a treat-to-target approach for SLE patients in a real-world setting.

The expanding role of synthetic nucleic acids for diagnosis and treatment.

PURPOSE OF REVIEW: The presence of autoantibodies is a characteristic and diagnostic index of systemic lupus erythematosus (SLE). Antidouble-stranded DNA (antids-DNA) antibodies are the most frequent autoantibodies found in SLE related to the diagnosis and disease activity of SLE, and are measured by established methods like ELISA as a polyclonal autoantibody. However, there is no reliable data on the relationship between the respective reactivity of these polyclonal antids-DNA antibodies against different epitopes generated from the original antigen and the disease phenotype. Of the complications in SLE, neuropsychiatric SLE (NPSLE) is a troublesome and frequent phenotype of the disease but no specific diagnostic autoantibodies in serum have been found. First in this review, the possibility of antids-DNA antibodies for identifying primary NPSLE in patients with SLE based on the reactivity of different synthetic nucleic acids is described as a diagnostic marker. The purpose of this review is to examine diagnostic and therapeutic opportunities to modulate autoimmune in the central nervous system (CNS) developing the CNS inflammatory disorders. RECENT FINDINGS: Khatri et al. investigated antids-DNA antibodies in order to develop a reliable method based on the application of synthetic nucleic acids and protein-based antigen arrays to characterize autoreactive antibodies specially for NPSLE. They found autoantibodies in three particular synthetic double stranded antigens and the antinuclear antibody patterns in ordinary lupus and NPSLE. These discoveries are leading to precision medicine in the CNS inflammatory disorders. SUMMARY: Verifying the similarity of antids-DNA obtained from patients with NPSLE can be useful as a diagnostic marker. mRNA vaccination can locally suppress autoimmunity in the CNS associated with critical steps for the develop of CNS autoinflammation. Synthetic nuclei acids may provide a diagnostic and therapeutic target in patients with autoimmune CNS inflammatory disorders.

Pathogenic neuropsychiatric effect of stress-induced microglial interleukin 12/23 axis in systemic lupus erythematosus.

OBJECTIVES: The central nervous system disorder in systemic lupus erythematosus (SLE), called neuropsychiatric lupus (NPSLE), is one of the most severe phenotypes with various clinical symptoms, including mood disorder, psychosis and delirium as diffuse neuropsychological manifestations (dNPSLE). Although stress is one of the aggravating factors for neuropsychiatric symptoms, its role in the pathogenesis of dNPSLE remains to be elucidated. We aimed to investigate stress effects on the neuropsychiatric pathophysiology in SLE using lupus-prone mice and patients' data. METHODS: Sleep disturbance stress (SDS) for 2 weeks was placed on 6-8-week-old female MRL/lpr and control mice. Behavioural phenotyping, histopathological analyses and gene and protein expression analyses were performed to assess SDS-induced neuroimmunological alterations. We also evaluated cytokines of the cerebrospinal fluid and brain regional volumes in patients with dNPSLE and patients with non-dNPSLE. RESULTS: SDS-subjected MRL/lpr mice exhibited less anxiety-like behaviour, whereas stressed control mice showed increased anxiety. Furthermore, stress strongly activated the medial prefrontal cortex (mPFC) in SDS-subjected MRL/lpr. A transcriptome analysis of the PFC revealed the upregulation of microglial activation-related genes, including Il12b. We confirmed that stress-induced microglial activation and the upregulation of interleukin (IL) 12/23p40 proteins and increased dendritic spines in the mPFC of stressed MRL/lpr mice. IL-12/23p40 neutralisation and tyrosine kinase 2 inhibition mitigated the stress-induced neuropsychiatric phenotypes of MRL/lpr mice. We also found a higher level of cerebrospinal fluid IL-12/23p40 and more atrophy in the mPFC of patients with dNPSLE than those with non-dNPSLE. CONCLUSIONS: The microglial IL-12/23 axis in the mPFC might be associated with the pathogenesis and a promising therapeutic target for dNPSLE.

What are the latest clinical findings regarding the association of neurotoxic brain antibodies found in the cerebrospinal fluid in patients with autoimmune disorders?

PURPOSE OF REVIEW: Recently, experiments show that the autoantibodies with direct access to neurons following blood brain barrier (BBB) disruption destroy neurons and lead to remodeling in damaged neurons. These are critical steps in autoantibody-mediated central nervous system disorder called neuropsychiatric syndromes in systemic lupus erythematosus (NPSLE). The purpose of this review is to examine therapeutic opportunities to repress neuronal remodeling by microglia after acute neuronal injury by autoantibodies. RECENT FINDINGS: Recent studies have demonstrated that BBB disruption is a critical step for developing NPSLE, and serum anti-Sm antibodies have been significantly associated with BBB breakdown. In addition, it has been reported that antiglucose regulated protein-78 in patients with SLE also disrupt the BBB. Experiments with anti-N-methyl-D-aspartate antibodies show that HMGB1 and C1q were essential to activate microglia which, in turn, remodel damaged neurons in vivo. Interestingly treatment with angiotensin-converting enzyme inhibitor inactivated microglia and blunted neuronal remodeling as well as positively affected behavioral abnormalities. SUMMARY: BBB disruption, acute neuronal damage and neuronal remodeling by activated microglia are all critical steps for NPSLE development, and each step will afford novel therapeutic targets.

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.

Antibodies and the brain: anti-N-methyl-D-aspartate receptor antibody and the clinical effects in patients with systemic lupus erythematosus.

PURPOSE OF REVIEW: Neuropsychiatric manifestations are one of the fatal complications in patients with systemic lupus erythematosus (SLE). However, the diagnosis and monitoring of that aspect of SLE is still challenging, as there are no reliable biomarkers linked to central nervous system (CNS) damage. This review emphasizes potential candidate autoantibodies that appear to be associated with development of behavioral and psychiatric manifestations in SLE patients. RECENT FINDINGS: Developments in the pathogenesis in SLE, not surprising for this immune disorder, point to specific, autoantibody toxicity. Namely, the discovery of an antibody which reacts with DNA and with the extracellular domain of N-methyl-D-aspartate (NMDA) receptor subunit GluN2A and 2B (anti-NMDA), an important receptor on neurons that is ubiquitous in the CNS, may lead to new insights into the behavioral and psychiatric manifestations in SLE. These anti-NMDA antibodies induce neuronal apoptosis and degeneration of surviving neurons in murine models. This functional antibody is also detected in SLE patients who have behavioral and psychiatric manifestations. The presence of anti-NMDA in cerebrospinal fluid but not in serum is associated significantly with overwhelming CNS abnormalities, suggesting importance of direct access of autoantibodies to brain dysfunction. SUMMARY: As anti-NMDA autoantibodies are present in patients who develop psychiatric manifestations in SLE, it is possible that novel therapeutic approaches will depend on altering the activity of these autoantibodies.

Antibodies as Mediators of Brain Pathology.

The brain is normally sequestered from antibody exposure by the blood brain barrier. However, antibodies can access the brain during fetal development before the barrier achieves full integrity, and in disease states when barrier integrity is compromised. Recent studies suggest that antibodies contribute to brain pathology associated with autoimmune diseases such as systemic lupus erythematosus and neuromyelitis optica, and can lead to transient or permanent behavioral or cognitive abnormalities. We review these findings here and examine the circumstances associated with antibody entry into the brain, the routes of access and the mechanisms that then effect pathology. Understanding these processes and the nature and specificity of neuronal autoantibodies may reveal therapeutic strategies toward alleviating or preventing the neurological pathologies and behavioral abnormalities associated with autoimmune disease.

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.

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.

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.

IgG4-related disease complicated with diffuse and chronic gastrointestinal inflammation leading to small intestinal perforation.

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a systemic inflammatory disease characterised by elevated serum IgG4, IgG4+ cell infiltration, storiform fibrosis, and obliterative phlebitis. While IgG4-RD can affect various organs, gastrointestinal tract involvement is less common. Here, we report a 70-year-old female with IgG4-RD complicated with diffuse and chronic gastrointestinal inflammation, which led to small intestinal perforation. She had been suffering from anorexia, abdominal pain, vomiting, and diarrhoea and hospitalised due to recurrent ileus. Consequently, she was referred due to small intestinal perforation required for surgical intervention. Pathology revealed acute and chronic inflammation with massive IgG4+ plasmacyte infiltration into mucosa of the small intestine and ischaemic change secondarily caused by chronic inflammation. Random biopsies from the mucosa of stomach, duodenum, ileum, and colon also revealed diffuse and massive IgG4+ plasmacyte infiltration in stomach, duodenum, small intestine, and colon. She was diagnosed with IgG4-RD based on the pathological findings and elevated serum IgG4 levels. Glucocorticoid rapidly ameliorated the symptoms. IgG4-RD may cause gastrointestinal manifestations, and histopathological assessment should be considered, even in the absence of specific characteristics of IgG4-RD.

A case of dupilumab combination therapy for exacerbation of atopic dermatitis in a patient with eosinophilic granulomatosis with polyangiitis treated with mepolizumab.

We report a 60-year-old male with eosinophilic granulomatosis with polyangiitis (EGPA) complicated with atopic dermatitis (AD). The patient was initially treated with prednisolone, cyclosporine A, and mepolizumab (MEPO). Due to worsening skin symptoms after prednisolone tapering, dupilumab (DUP) was added as an adjunctive therapy for AD confirmed by skin biopsy. The combination therapy of MEPO and DUP resulted in rapid improvement of skin symptoms, suggesting it may be an effective therapeutic option for patients with EGPA and AD. This case report emphasises the importance of a multidisciplinary approach in treating complex diseases such as EGPA and AD.

Involvement of the complement system in immune thrombocytopenia: review of the literature.

Immune thrombocytopenia (ITP) is a thrombocytopenic condition induced by autoimmune mechanisms and includes secondary ITP with underlying diseases such as connective tissue diseases (CTD). In recent years, it has been elucidated that the subsets of the ITP are associated with complement abnormalities but much remains unclear. To perform a literature review and identify the characteristics of complement abnormalities in ITP. PUBMED was used to collect the literature published up to June 2022 related to ITP and complement abnormalities. Primary and secondary ITP (CTD-related) were examined. Out of the collected articles, 17 were extracted. Eight articles were related to primary ITP (pITP) and 9 to CTD-related ITP. Analysis of the literature revealed that the ITP severity was inversely correlated with serum C3, C4 levels in both ITP subgroups. In pITP, a wide range of complement abnormalities was reported, including abnormalities of initial proteins, complement regulatory proteins, or the end products. In CTD-related ITP, reported complement abnormalities were limited to the initial proteins. Activation of the early complement system, mainly through activation of C3 and its precursor protein C4, was reported for both ITPs. On the other hand, more extensive complement activation has been reported in pITP.

Anti-ribosomal P protein antibodies in patients with systemic lupus erythematosus is associated with hyperferritinemia.

AIM: Anti-ribosomal P protein antibodies (anti-ribo P) have been reported as one of the specific autoantibodies in patients with systemic lupus erythematosus (SLE) and has been demonstrated to bind and activate macrophages in vitro. Clinically, hyperferritinemia has been known to be a biomarker for macrophage activation. The aim of this study is to clarify the relationship of anti-ribo P and clinical characteristics and biomarkers including serum ferritin in patients with SLE. METHODS: Clinical parameters and laboratory data were measured in patients with active SLE (N = 127) in our university hospital. The risk factors affected by anti-ribo P were retrospectively calculated by logistic regression analysis, and the correlation of anti-ribo P and clinical factors was demonstrated. RESULTS: Anti-ribo P was significantly elevated in active SLE compared to non-SLE diseases (P < .0001). Sensitivity and the specificity of anti-ribo P in patients with SLE were 32.0% and 99.3%, respectively. Patients positive for anti-ribo P had the highest risk for elevated serum ferritin (odds ratio: 8.432). Accordingly, anti-ribo P positive patients had significantly elevated serum ferritin compared to negative patients (P = .024). A significant positive correlation was observed between the anti-ribo P titer and the serum ferritin level (r2  = .07, t = 5.22, P = .0081), but not serum interleukin (IL)-6 in SLE patients. CONCLUSION: The presence of anti-ribo P is a risk factor for higher ferritin levels that is independent of systemic inflammation regulated by IL-6. We speculate that anti-ribo P could be directly associated with macrophage activation leading to hyperferritinemia in patients with SLE.