No clear influence of treatment escalation on flare prevention in serologically active clinically quiescent patients with systemic lupus erythematosus: a retrospective cohort study.

This study aimed to clarify the efficacy and safety of treatment escalation by initiating therapeutic agents in serologically active clinically quiescent (SACQ) patients with systemic lupus erythematosus (SLE). We retrospectively evaluated SACQ patients with SLE for ≥ 180 days, with the introduction of a therapeutic agent for SLE defined as exposure. The efficacy endpoints included the time to flare and time to remission, whereas the safety endpoint was the incidence of adverse events. The efficacy endpoints were assessed via Cox proportional hazards model with time-dependent covariates, which included exposure, serological activity, and prednisolone dose. Among 109 SACQ patients, 24 were initiated on the following therapeutic agents for SLE: hydroxychloroquine (10 patients), belimumab (6 patients), and immunosuppressive agents (8 patients). A total of 37 patients experienced a flare (8 and 29 patients during exposure and nonexposure periods, respectively). The time to flare was comparable between the exposure and control groups. Among 68 patients who were not in remission at the start of observation, 27 patients achieved remission (5 and 22 patients during exposure and nonexposure periods, respectively). Although both groups had a similar time to remission, the exposure group treated with belimumab had a significantly higher rate of remission than the control group. The adverse events were more frequent during the exposure period than during the nonexposure period. Thus, this study did not reveal a clear influence of treatment escalation on flare prevention and remission achievement.

Determination of the factors associated with antigen-specific CD4+ T-cell responses to BNT162b2 in patients with rheumatoid arthritis.

OBJECTIVES: Understanding interpatient variation in CD4+T-cell responses is the bases for understanding the pathogenesis and management of rheumatoid arthritis (RA). We examined immune responses to SARS-CoV-2 vaccine in a cohort of patients with RA and determined factors associated with the responses. METHODS: Four hundred and thirty-one patients with RA having received two doses of BNT162b2, a messenger RNA-based vaccine for SARS-CoV-2, were included. Vaccine antigen-specific IgG was detected by ELISA, and antigen-specific CD4+T cells were detected by CD154 expression in response to antigenic stimulation. Expression of cytokines was concomitantly detected by intracellular staining. Associations among background variables, antigen-specific antibody production and the CD4+T-cell responses were analysed. Unsupervised hierarchical clustering was performed based on the profiles of antigen-specific cytokine production by CD4+T cells to stratify patients with RA. RESULTS: Multivariate analysis indicated that ageing negatively affects CD4+T-cell response as well as antibody production. No association was detected between the presence or the levels of rheumatoid factor/anti-cyclic citrullinated peptide antibody and anti-vaccine immune responses. Methotrexate and prednisolone reduced B cell but not T-cell responses. Conventional immunophenotyping by the expression of chemokine receptors was not associated with the actual CD4+T-cell response, except for T helper cells (Th1). Functional immunophenotyping based on the profiles of antigen-specific cytokine production of CD4+T cells stratified patients with RA into three clusters, among which Th1-dominant type less frequently underwent joint surgery. CONCLUSIONS: Clinical and immunological variables that are associated with antigen-specific CD4 T-cell responses in patients with RA were determined by analysing immune responses against SARS-CoV-2 vaccine.

Streptococcal Toxic Shock Syndrome due to Streptococcus dysgalactiae subsp. equisimilis from Retroperitoneal Panniculitis during the treatment with anti-IL-6 receptor antibody: A Case Report.

A 53-year-old man with adult-onset Still's disease developed severe streptococcal toxic shock syndrome (STSS) due to Streptococcus dysgalactiae subsp. equisimilis (SDSE), following retroperitoneal panniculitis. He was receiving tocilizumab (TCZ), an interleukin-6 receptor inhibitor. The modifying effect of TCZ on the immune response and the pathophysiology of SDSE infection may have led to retroperitoneal panniculitis and atypical STSS with delayed shock and flare of soft tissue inflammation.

Relationships between Type 1 interferon signatures and clinical features of the new-onset lupus patients in Japan.

OBJECTIVES: The objective of the study is to investigate the relationships between Type 1 interferon (T1-IFN) signatures and clinical characteristics of lupus patients. METHODS: We examined 49 new-onset lupus patients who were diagnosed between 1999 and 2017. The patients treated with >10 mg of prednisolone or hydroxychloroquine were excluded from this study. Serum T1-IFN signatures were revealed by a functional reporter assay and standardized by recombinant IFN-α. Patient backgrounds, clinical findings, and treatments were retrospectively extracted from their electrical medical records. Clinical data were also available, including SLE Disease Activity Index of SLE patients on admission. RESULTS: T1-IFN signatures of lupus patients closely correlated with lupus disease activities, such as SLE Disease Activity Index-2K, white blood cell, C3 levels, and the titre of double-strand DNA antibody. We found fever and acute lupus dermatitis closely associated with T1-IFN signature. CONCLUSIONS: In lupus patients, fever and acute lupus dermatitis are good indicators of a strong T1-IFN signature.

Immunosuppressive therapy and humoral response to third mRNA COVID-19 vaccination with a six-month interval in rheumatic disease patients.

OBJECTIVES: To evaluate the long-term impact of immunosuppressive therapeutic agents on antibody response to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) mRNA vaccination in patients with autoimmune rheumatic diseases (AIRD) in order to propose a strategy for annual vaccination. METHODS: This prospective multicentre cohort study evaluated the humoral response to second and third BNT162b2 and/or mRNA-1273 vaccines in 382 Japanese AIRD patients classified into 12 different medication groups and in 326 healthy controls (HCs). The third vaccination was administered six months after the second vaccination. Antibody titres were measured using the Elecsys Anti-SARS-CoV-2 S assay. RESULTS: The seroconversion rate and antibody titres were lower in AIRD patients than in HCs 3-6 weeks after the second vaccination and 3-6 weeks after the third vaccination. Seroconversion rates were <90% after the third vaccination in patients receiving mycophenolate mofetil and rituximab. Antibody levels after the third vaccination were significantly lower in the groups prescribed TNF inhibitor with or without methotrexate, abatacept and rituximab or cyclophosphamide than those of HCs in a multivariate analysis adjusting for age, sex, and glucocorticoid dosage. The third vaccination induced an adequate humoral response in patients treated with sulfasalazine, bucillamine, methotrexate monotherapy, iguratimod, interleukin-6 inhibitors or calcineurin inhibitors including tacrolimus. CONCLUSIONS: Repeated vaccinations in many immunosuppressed patients produced antibody responses similar to those observed in HCs. In contrast, annual vaccination in patients receiving TNF inhibitors, abatacept, mycophenolate mofetil and rituximab may require caution.

Recent advances in the treatment strategy for AAV improved outcomes with intensive GC tapering.

OBJECTIVE: To evaluate trends in results of care and management for antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). METHODS: We employed multicenter cohort data collected during 2011-2021, recruiting 43 patients with granulomatosis with polyangiitis (GPA) and 91 with microscopic polyangiitis (MPA). According to the median registration date of September 2015, patients have split into two groups: an early group and a late group (both of them, n = 67). To prevent bias, a propensity score according to numerous baseline characteristics variables was calculated; 50 matching members of each group were statistically extracted. Their treatments and clinical outcomes were examined at 6, 12, and 24 months after initial remission therapy. RESULTS: Statistics demonstrated that the baseline characteristics were similar. The late group used rituximab (RTX) more often for both remission induction and maintenance therapy, compared with the early group. The mean daily PSL doses of the late group were significantly lower than those of early group at each time point. The late group discontinued PSL 14.0% at 12 months and 23.3% at 24 months. Despite their intensive glucocorticoids (GC) tapering, the remission rates and the relapse rates were significantly fairer in the late group. The Vasculitis Damage Index (VDI) and VDI due to GC at each time point were lower in the late group, and those differences had become wider over time. CONCLUSION: Recent developments in AAV treatment have allowed efficient remission and prevention of relapses, which in turn enabled extensive GC tapering causing fewer sequelae.

Association of HLA-class II alleles with risk of relapse in myeloperoxidase-antineutrophil cytoplasmic antibody positive vasculitis in the Japanese population.

Background: Disease relapse remains a major problem in the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). In European populations, HLA-DPB1*04:01 is associated with both susceptibility and relapse risk in proteinase 3-ANCA positive AAV. In a Japanese population, we previously reported an association between HLA-DRB1*09:01 and DQB1*03:03 with susceptibility to, and DRB1*13:02 with protection from, myeloperoxidase-ANCA positive AAV (MPO-AAV). Subsequently, the association of DQA1*03:02, which is in strong linkage disequilibrium with DRB1*09:01 and DQB1*03:03, with MPO-AAV susceptibility was reported in a Chinese population. However, an association between these alleles and risk of relapse has not yet been reported. Here, we examined whether HLA-class II is associated with the risk of relapse in MPO-AAV. Methods: First, the association of HLA-DQA1*03:02 with susceptibility to MPO-AAV and microscopic polyangiitis (MPA) and its relationship with previously reported DRB1*09:01 and DQB1*03:03 were examined in 440 Japanese patients and 779 healthy controls. Next, the association with risk of relapse was analyzed in 199 MPO-ANCA positive, PR3-ANCA negative patients enrolled in previously reported cohort studies on remission induction therapy. Uncorrected P values (Puncorr) were corrected for multiple comparisons in each analysis using the false discovery rate method. Results: The association of DQA1*03:02 with susceptibility to MPO-AAV and MPA was confirmed in a Japanese population (MPO-AAV: Puncorr=5.8x10-7, odds ratio [OR] 1.74, 95% confidence interval [CI] 1.40-2.16, MPA: Puncorr=1.1x10-5, OR 1.71, 95%CI 1.34-2.17). DQA1*03:02 was in strong linkage disequilibrium with DRB1*09:01 and DQB1*03:03, and the causal allele could not be determined using conditional logistic regression analysis. Relapse-free survival was shorter with nominal significance in carriers of DRB1*09:01 (Puncorr=0.049, Q=0.42, hazard ratio [HR]:1.87), DQA1*03:02 (Puncorr=0.020, Q=0.22, HR:2.11) and DQB1*03:03 (Puncorr=0.043, Q=0.48, HR:1.91) than in non-carriers in the log-rank test. Conversely, serine carriers at position 13 of HLA-DRß1 (HLA-DRß1_13S), including DRB1*13:02 carriers, showed longer relapse-free survival with nominal significance (Puncorr=0.010, Q=0.42, HR:0.31). By combining DQA1*03:02 and HLA-DRß1_13S, a significant difference was detected between groups with the highest and lowest risk for relapse (Puncorr=0.0055, Q=0.033, HR:4.02). Conclusion: HLA-class II is associated not only with susceptibility to MPO-AAV but also with risk of relapse in the Japanese population.

Anti-dsDNA IgE induces IL-4 production from basophils, potentially involved in B-cell differentiation in systemic lupus erythematosus.

OBJECTIVES: Recently, the involvement of basophils and IgE-type autoantibodies in the pathogenesis of SLE has been elucidated using mouse models; however, few studies have been conducted in humans. In this study, the role of basophils and anti-double-stranded DNA (dsDNA) IgE in SLE was examined using human samples. METHODS: The correlation between disease activity and serum levels of anti-dsDNA IgE in SLE was evaluated using enzyme-linked immunosorbent assay. Cytokines produced by IgE-stimulated basophils from healthy subjects were assessed using RNA sequences. The interaction of basophils and B cells to promote B cell differentiation was investigated using a co-culture system. The ability of basophils from patients with SLE with anti-dsDNA IgE to create cytokines that may be involved in B cell differentiation in response to dsDNA was examined using real-time PCR. RESULTS: Anti-dsDNA IgE levels in the serum of patients with SLE correlated with disease activity. Healthy donor basophils produced IL-3, IL-4 and TGF-ß1 after anti-IgE stimulation. Co-culture of B cells with anti-IgE-stimulated basophils increased plasmablasts which were cancelled by neutralizing IL-4. After encountering the antigen, basophils released IL-4 more quickly than follicular helper T cells. Basophils isolated from patients with anti-dsDNA IgE promoted IL-4 expression by adding dsDNA. CONCLUSIONS: These results suggest that basophils contribute to the pathogenesis of SLE by promoting B cell differentiation via dsDNA-specific IgE in patients similar to the process described in mouse models.

Antibody response to SARS-CoV-2 mRNA vaccines in patients with rheumatic diseases in Japan: Interim analysis of a multicentre cohort study.

OBJECTIVES: To evaluate the impact of medication on antibody response to severe acute respiratory syndrome coronavirus-2 mRNA vaccines in Japanese patients with rheumatic diseases. METHODS: This prospective multicentre cohort study evaluated the humoral response in 12 different medication groups. Antibody levels before the first vaccination and 3-6 weeks after the second vaccination were measured using the Elecsys Anti-SARS-CoV-2 S assay. Statistical analysis included comparing antibody titres among the different medication groups using the Kruskal-Wallis test followed by the Bonferroni-Dunn test and multiple linear regression analysis. RESULTS: 295 patients were analysed. The seroconversion rate was 92.2% and the median antibody titre was 255 U/ml (interquartile range, 34.1-685) after the second mRNA vaccination. Antibody levels were significantly lower in the groups treated with Tumour necrosis factor inhibitor with methotrexate, abatacept, mycophenolate mofetil (MMF), MMF or mizoribine combined with calcineurin inhibitor, and rituximab or cyclophosphamide compared with those treated with sulfasalazine and/or bucillamine or calcineurin inhibitor (p < 0.01). The correlation between antibody titre and treatment was significant after adjusting for age, gender, and glucocorticoid dose (p < 0.01). CONCLUSIONS: Additional early vaccination is required in patients treated with Tumour necrosis factor inhibitor and methotrexate, abatacept, MMF, MMF or mizoribine combined with calcineurin inhibitor and rituximab or cyclophosphamide.

Safety and efficacy of switching immunosuppressive drugs for maintenance treatment in patients with systemic lupus erythematosus: A retrospective cohort study.

OBJECTIVES: We aim to clarify the efficacy and safety of switching immunosuppressive drugs and to identify the predictive factors for treatment failure after switching in patients with systemic lupus erythematosus (SLE). METHODS: We retrospectively evaluated patients with SLE who switched immunosuppressive drugs for any reason in our hospital between 2015 and 2020. The efficacy endpoints were the change in SLE Disease Activity Index 2000 score, prednisolone dose, and disease status over 12 months, as well as treatment continuation rates. The safety endpoint was the frequency of adverse events over 1 year before and after switching. Cox hazard regression analyses were used to identify the predictive factors for treatment failure. RESULTS: Thirty-nine patients (age, 41.5 ± 12.6 years; 35 women and 4 men) were analysed. The SLE Disease Activity Index score and prednisolone dose were significantly reduced after switching, with few disease exacerbations over 12 months. The 1- and 2-year continuation rates were 71.4% and 62.3%, respectively. The frequency of adverse events was similar in the year before and after switching the drug. Drug switching due to inadequate efficacy was a predictive factor of less likely treatment failure. CONCLUSIONS: Immunosuppressive drug switching led to reduced disease activity and decreased glucocorticoid dose without disease exacerbations and severe adverse events.

CEACAM 1, 3, 5 and 6 -positive classical monocytes correlate with interstitial lung disease in early systemic sclerosis.

Background: Systemic sclerosis (SSc) is a multiple-organ disease characterized by vascular damage, autoimmunity, and tissue fibrosis. Organ injuries such as interstitial lung diseases (ILD), resulting from inflammatory and fibrosis processes, lead to poor prognosis. Although autoantibodies are detected in the serum of patients with SSc, the mechanisms by which immune cells are involved in tissue inflammation and fibrosis is not fully understood. Recent studies have revealed carcinoembryonic antigen related cell adhesion molecule (CEACAM)-positive monocytes are involved in murine bleomycin-induced lung fibrosis. We investigated CEACAM-positive monocytes in patients with SSc to clarify the role of monocytes in the pathogenesis of SSc. Methods: The proportion of of CEACAM-positive classical monocytes in healthy controls (HCs) and patients with rheumatoid arthritis (RA) and SSc was evaluated using flow cytometry. The correlation between the proportion of CEACAM-positive monocytes and clinical parameters was analyzed in patients with SSc. Gene expression microarrays were performed in CEACAM-positive and negative monocytes in patients with SSc. Infiltration of CEACAM-positive monocytes into scleroderma skin was evaluated by immunohistochemical staining. Results: The proportion of CEACAM-positive classical monocytes was increased in patients with early SSc within 2 years after diagnosis, which positively correlated with ESR, serum IgG, and serum KL-6 and negatively correlated with %forced vital capacity. The percentage of CEACAM-positive monocytes decreased after immunosuppressive therapy. CEACAM6-positive cells among classical monocytes were significantly increased in patients with SSc compared with HCs and patients with rheumatoid arthritis. SSc serum induced CEACAM6 expression on monocytes from HCs. Functionally, CEACAM-positive monocytes produced higher levels of TNF-α and IL-1ß compared to CEACAM-negative cells and showed activation of the NF-κB pathway. Furthermore, CEACAM6-positive monocytes infiltrated the dermis of SSc. Conclusions: CEACAM-positive monocytes showed inflammatory phenotypes and may be involved in the tissue inflammation and fibrosis in early SSc. CEACAM-positive monocytes may be one of biomarkers to detect patients with progressive ILD, requiring therapeutic intervention.

Comparative efficacy and safety of mizoribine and mycophenolate mofetil for treating systemic lupus erythematosus: a retrospective cohort study.

Background: Mizoribine (MZR) is an immunosuppressive agent that selectively inhibits inosine monophosphate dehydrogenase; its actions are considerably similar to those of mycophenolate mofetil (MMF). This study aimed to clarify whether MZR can be a good treatment option for systemic lupus erythematosus (SLE) and to compare the efficacy and safety of MZR and MMF in patients with active SLE. Methods: We retrospectively compared the efficacy, continuation rate, and safety of MZR (52 patients) and MMF (31 patients) after adjusting for stabilized inverse probability of treatment weighting based on propensity scores. The efficacy endpoints were as follows: cumulative incidence of lupus low disease activity state (LLDAS) or remission attainment and flares and change in prednisolone dose over 2 years. Drug continuation rates were defined as the time from drug initiation to discontinuation for any cause, owing to the lack of efficacy, or owing to adverse events. The safety endpoint was the frequency of adverse events. Results: Overall, 25 (48.1%) and 13 (25.0%) patients in the MZR group and 18 (58.1%) and 15 (48.3%) in the MMF group achieved LLDAS and remission during the follow-up period, respectively; thus, the cumulative incidence of LLDAS and remission attainment of the two groups was similar after adjustment. Prednisolone dose was steadily reduced in both the groups, and the change in prednisolone dose was nearly identical between the two groups. Drug discontinuation rate due to adverse events and the frequency of all adverse events and infections were higher in the MMF group than in the MZR group, albeit without significance after adjustment. Conclusion: MZR is as effective as MMF in controlling SLE activity. The adverse events of MZR, whose profile differs from MMF, are comparable to or less than those of MMF. MZR may be a valuable option as an immunosuppressive agent for SLE, as well as MMF.

TNFR2 Signaling Enhances Suppressive Abilities of Human Circulating T Follicular Regulatory Cells.

T follicular regulatory (Tfr) cells are a subset of CD4+ T cells that express CXCR5 and migrate into germinal centers (GCs). They regulate GC reactions by communicating with T follicular helper (Tfh) and B cells. TNF inhibitors are used in inflammatory diseases; however, the generation of autoantibodies or anti-drug Abs sometimes causes problems. Because TNFR2 signaling is important for suppressive functions of regulatory T cells, we investigated the role of TNFR2 on human Tfr cells. Tfr cells stimulated with MR2-1 (an anti-TNFR2 agonistic Ab) were analyzed for cell proliferation, Foxp3 expression, and surface molecules. Tfh/B cell proliferation, IgM production, and differentiation in cocultures with MR2-1-stimulated Tfr cells were examined. Tfr cells express a high level of TNFR2. MR2-1 stimulation altered the gene expression profile of Tfr cells. Cell proliferation and Foxp3 expression of Tfr cells were enhanced by MR2-1. MR2-1-stimulated Tfr cells expressed ICOS and Programmed cell death protein 1 and significantly suppressed Tfh/B cell proliferation, IgM production, and B cell differentiation. TNFR2-stimulated Tfr cells retained the migration function according to the CXCL13 gradient. In conclusion, we showed that TNFR2-stiumulated Tfr cells can regulate Tfh and B cells. Aberrant antibody production during TNF inhibitor treatment might be, at least in part, associated with TNFR2 signaling inhibition in Tfr cells. In addition, expansion and maturation of Tfr cells via TNFR2 stimulation in vitro may be useful for a cell-based therapy in inflammatory and autoimmune diseases to control GC reactions.

Successful transition from intravenous epoprostenol to oral selexipag and inhaled iloprost in a case of severe pulmonary arterial hypertension associated with systemic lupus erythematosus.

A 25-year-old woman was admitted to our hospital with severe pulmonary arterial hypertension associated with systemic lupus erythematosus (SLE-PAH). Her mean pulmonary arterial pressure was 56 mmHg, and her SLE Disease Activity Index-2 K score was 14 on admission. In addition to a strong immunosuppressive regimen, which included steroid pulse therapy followed by high-dose oral prednisolone (1 mg/kg) and intravenous cyclophosphamide, an upfront combination of vasodilator therapy, including oral tadalafil, macitentan, and intravenous epoprostenol, was administered in the early phase. Two months later, her mean pulmonary arterial pressure was 29 mmHg, and her other haemodynamic markers showed significant improvement. She refused to start life-long intravenous epoprostenol therapy and so was switched to oral selexipag and inhaled iloprost. The transition was successful, and she has experienced no exacerbations of SLE-PAH during the 10 months since the onset of pulmonary arterial hypertension. To the best of our knowledge, this is the first report of intravenous epoprostenol being switched to alternative oral and inhaled therapy in a patient with SLE-PAH. In combination with adequate immunosuppressive therapy, it is probably easier to make this transition in patients with SLE-PAH than in those with pulmonary arterial hypertension of a different aetiology. Continuous infusion of epoprostenol can have potentially life-threatening complications and a detrimental effect on the quality of life. Our alternative treatment strategy was successful, and we hope that it will prove beneficial in other cases.

Hydroxychloroquine versus tacrolimus for the treatment of persistently active systemic lupus erythematosus.

OBJECTIVES: We aimed to reveal the effectiveness of hydroxychloroquine (HCQ) compared with tacrolimus (TAC), an immunosuppressive agent, in patients with systemic lupus erythematosus (SLE) with persistent activity on standard treatment. METHODS: We retrospectively compared the efficacy and safety of the treatment between 18 patients receiving HCQ and 27 patients receiving TAC. None of the patients were in the lupus low disease activity state (LLDAS) at the beginning of this study. The efficacy end points were the cumulative incidence of LLDAS attainment without additional immunosuppressive agents, drug continuation rate, and treatment failure-free survival. The safety end point was the frequency of adverse events. RESULTS: Eight (44.4%) patients in the HCQ group and 10 (37.0%) patients in the TAC group achieved LLDAS during the follow-up period; thus, the cumulative incidences of LLDAS attainment of the two treatments were nearly identical. The drug continuation and treatment failure-free survival rates were also not different between the two groups. The frequency of adverse events showed no clear differences between the two groups. CONCLUSIONS: The efficacy and safety of an add-on treatment with HCQ are similar to those with TAC. Patients with persistently active SLE can benefit from HCQ in efforts to achieve at least low disease activity.

HLA-B52 allele in giant cell arteritis may indicate diffuse large-vessel vasculitis formation: a retrospective study.

BACKGROUND: This study aimed to identify new characteristics of elderly onset large-vessel vasculitis (EOLVV) by focusing on human leucocyte antigen (HLA) genotype, polymyalgia rheumatica (PMR), and affected vascular lesions observed on positron emission tomography/computed tomography (PET/CT) imaging. METHODS: We retrospectively studied 65 consecutive Japanese patients with large-vessel vasculitis (LVV) who had extracranial vasculitis lesions and underwent PET/CT imaging. PET/CT images were assessed using the semi-quantitative PET visual score of each affected vessel, and the PET vascular activity score (PETVAS) and number of affected vessels were calculated. Subjects were subsequently grouped based on age at onset, superficial temporal artery (STA) involvement, and presence of PMR and compared each group according to HLA genotype. Unsupervised hierarchical cluster analysis was used to identify the patients with similar characteristics in terms of affected vascular lesions detected through PET/CT imaging. The clinical characteristics and PET/CT findings of the population newly identified in this study were examined. RESULTS: Twenty-seven patients with EOLVV did not meet the American College of Rheumatology 1990 criteria for giant cell arteritis (GCA) and Takayasu arteritis and were considered as unclassified EOLVV (UEOLVV). The unsupervised hierarchical cluster analysis revealed that UEOLVV with PMR and large-vessel GCA (LV-GCA) formed a cluster of LVV with GCA features (i.e., PMR and/or STA involvement) when restricted to patients who were HLA-B52-positive. Patients who were HLA-B52-positive with LVV and GCA features had similar clinical characteristics and patterns of affected vessels and presented with diffuse LVV lesions. HLA-B52-positive patients who had LVV with GCA features also presented with higher PETVAS, more affected vessels, and lower rates of biologics usage and relapse compared to HLA-B52-positive patients with TAK. CONCLUSIONS: Patients who had UEOLVV with PMR had similar characteristics to patients with LV-GCA. Patients who were HLA-B52-positive and had LVV with GCA features presented with diffuse vascular lesions and may comprise a core population of Japanese patients with EOLVV. The findings of HLA-B52 positivity and diffusely affected vessels in patients with EOLVV can be considered as suspicious findings of LV-GCA.

Increased Proportion of CD226+ B Cells Is Associated With the Disease Activity and Prognosis of Systemic Lupus Erythematosus.

Background: CD226, an activating receptor expressed on the surface of natural killer (NK) cells and T cells, is also seen on B cells and CD226 polymorphism is associated with systemic lupus erythematosus (SLE). Because the specific roles of CD226+ B cells in SLE are still unknown, we investigated the association of CD226+ B cells with SLE. Methods: We measured CD226 expression on B cells and its subsets using flow cytometry in 48 SLE patients and 24 healthy controls (HCs). We assessed the relationships between CD226+ B cells and SLE Disease Activity Index 2000 (SLEDAI-2K), clinical manifestations, laboratory data, and prognosis after 12 months. Results: The proportions of CD226+ cells in whole B cells and all its subsets were significantly higher in SLE patients than HCs. In SLE patients, the proportions of CD226+ B cells and CD226+ switched-memory (SM) B cells were significantly correlated with SLEDAI-2K scores and anti-dsDNA antibody titers, and negatively correlated with serum complement levels. Moreover, basal percentages of CD226+ B cells and CD226+ SM B cells were low in patients who were in Lupus Low Disease Activity State after 12 months. In patients with renal involvement, the proportion of CD226+ B cells increased. Additionally, the proportion of CD226+ B cells was higher in patients who were not in complete renal remission after 12 months. Conclusions: Increased proportion of CD226+ B cells was associated with disease activity and prognosis of SLE. CD226+ B cells may be a useful biomarker for the management of SLE.

Association of elevated serum soluble CD226 levels with the disease activity and flares of systemic lupus erythematosus.

CD226 is an activating receptor expressed on the cell surface of natural killer cells and T cells. Although CD226 polymorphism is known to be involved in systemic lupus erythematosus (SLE), the involvement of soluble CD226 (sCD226) in SLE is still unknown. In the present study, we measured serum sCD226 levels using an enzyme-linked immunosorbent assay in 58 SLE patients and 33 healthy controls (HCs) and evaluated their associations with SLE Disease Activity Index 2000 (SLEDAI-2K), clinical manifestations, laboratory data, and the cumulative probability of flare. Serum sCD226 levels showed no significant differences between SLE patients and HCs. However, sCD226 levels were significantly elevated in active SLE patients with a SLEDAI-2K score of ≥ 20 compared with HCs. In SLE patients, sCD226 levels were significantly correlated with SLEDAI-2K scores and anti-dsDNA antibody titers. Moreover, the cumulative probability of flare was markedly higher in patients with high sCD226 than in those with low sCD226. In patients with neuropsychiatric involvement, sCD226 levels were elevated and reflected neuropsychiatric disease activity. These findings indicate that serum sCD226 levels are associated with disease activity and flares of SLE. Thus, it may be a useful biomarker for SLE, and its monitoring allows for more precise SLE management.

Human PD-1hiCD8+ T Cells Are a Cellular Source of IL-21 in Rheumatoid Arthritis.

Background: Rheumatoid arthritis (RA) is a prototypical autoantibody-driven autoimmune disease in which T-B interactions play a critical role. Recent comprehensive analysis suggests that PD-1+CD8+ T cells as well as two distinct IL-21-producing PD-1+CD4+ T cell subsets, follicular helper T (Tfh) and peripheral helper T (Tph) cells, are involved in the pathogenesis of RA. Herein, we aimed to clarify a generation mechanism of IL-21-producing CD8+ T cells in humans, and to characterize this novel subset in patients with RA. Methods: CD8+ T cells in the peripheral blood (PB) and synovial fluid (SF) of healthy control (HC) and patients with RA were subject to the analysis of IL-21 mRNA and protein. We evaluated the surface marker, cytokine and transcription profiles of IL-21-producing CD8+ T cells in HCPB, RAPB and RASF. Results: IL-21-producing CD8+ T cells were enriched in the CD45RA-(memory) PD-1+, especially PD-1hi subpopulation, and IL-12 and IL-21 synergistically induced IL-21 production by naïve CD8+ T cells. Memory PD-1hiCD8+ T cells in HCPB facilitated plasmablast differentiation and IgG production in an IL-21-dependent manner. In addition, PD-1hiCD8+ T cells in RASF and RAPB produced large amounts of IL-21 and were characterized by high levels of CD28, ICOS, CD69, HLA-DR, and CCR2 but not CXCR5. Furthermore, PD-1hiCD8+ T cells expressed high levels of transcripts of MAF and PRDM1, a feature observed in Tph cells. Conclusions: Identification of IL-21-producing PD-1hiCD8+ T cells expands our knowledge of T cell subsets with B helper functions in RA. Selective targeting of these subsets could pave an avenue for the development of novel treatment strategies for this disease.

IgG4-related disease presenting as a paraneoplastic syndrome: report of two cases and literature review.

An association between immunoglobulin G4-related disease (IgG4-RD) and malignancy has been suggested. We report two cases of IgG4-RD with suspected paraneoplastic syndrome. In both patients, malignancy was observed immediately after diagnosis of IgG4-RD, and surgical resection resulted in spontaneous regression of IgG4-RD. We review the reports on IgG4-RD associated with malignancy, including these two cases, and discuss their relevance.