Calcium pyrophosphate crystal arthritis associated with immune checkpoint inhibitor successfully treated with intra-articular glucocorticoid: A case report.

Immune checkpoint inhibitors (ICIs) sometimes induce immune-related adverse events (irAEs), and arthritis is one of the irAE symptoms. Recently, crystal-induced arthritis, such as calcium pyrophosphate (CPP) crystal deposition disease and gout, has been reported to occur after ICI administration. However, the distinction between ICI-associated crystal arthritis and ICI-induced non-crystal arthritis is difficult because their symptoms are similar. Besides, optimal treatment for ICI-associated crystal arthritis has not been established. Here, we report a patient who developed CPP crystal arthritis twice after pembrolizumab (ICI) administration and was successfully treated with intra-articular glucocorticoid injection. He suffered arthritis and acute interstitial nephritis simultaneously after ICI administration. Musculoskeletal ultrasound of his affected joint suggests that his arthritis was crystal-induced arthritis, and arthrocentesis detected CPP crystal in synovial fluid. Thus, we diagnosed his arthritis as ICI-associated cystal arthritis. Therefore, our case encourages the use of musculoskeletal ultrasound in patients with arthritis after treatment with ICI because it may distinguish between ICI-associated crystal arthritis and ICI-induced non-crystal arthritis. Besides, ICI-associated crystal arthritis could be treatable by intra-articular glucocorticoid injection.

Immunogenicity and influence on disease activity of recombinant zoster vaccine in patients with rheumatoid arthritis treated with DMARDs.

OBJECTIVES: This study aimed to determine the immunogenicity and the influence on disease activity of an adjuvanted recombinant varicella-zoster virus (VZV) subunit vaccine (RZV) in patients with rheumatoid arthritis (RA) treated with disease-modifying antirheumatic drugs (DMARDs). METHODS: This prospective longitudinal study enrolled 53 patients with RA (aged ≥50 years) treated with DMARDs (conventional synthetic (cs)DMARDs 20, biological (b)DMARDs 23 and targeted synthetic (ts)DMARDs 10) and 10 control individuals. The participants received two intramuscular RZV 2 months apart. VZV-specific CD4+ T cell responses (cell-mediated immunity; CMI) and IgG antibody responses (humoral immunity; HI) were assessed at 0 and 3 months after the first RZV administration using flow cytometry and enzyme immunoassay, respectively. Disease activity (Disease Activity Score 28-C reactive protein and Clinical Disease Activity Index), flares and adverse events were monitored for 6 months after the first vaccination. RESULTS: VZV-specific CMI and HI significantly increased in the three DMARDs-treated patients with RA after RZV administration compared with the corresponding prevaccination values (p<0.001-0.014), and the magnitudes and fold-increases of those responses were not significantly different among the three DMARDs-treated patients with RA. Furthermore, the vaccine response rates of CMI and HI were not significantly different between csDMARDs-treated patients and b-DMARDs or ts-DMARDs-treated patients. Meanwhile, no significant increases in disease activity indices or adverse events were observed in these patients during the 6-month follow-up period after the first vaccination. RZV-induced RA flares occurred in two patients (3.8%) but were mild and controllable. CONCLUSION: RZV is robustly immunogenic and has a clinically acceptable safety profile in elderly patients with RA receiving DMARDs.

Short-term and long-term outcomes of patients with anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis.

OBJECTIVES: Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a subtype of dermatomyositis characterized by frequent interstitial lung disease and reduced muscle involvement. This study aimed to determine the short-term and long-term outcomes of patients with MDA5-DM. METHODS: Information on baseline characteristics, treatments, and short-term and long-term outcomes of patients with MDA5-DM including survival, relapse, and the titer of anti-MDA5 antibody, was retrospectively collected. Descriptive statistics regarding clinical outcomes were calculated, and a comparison of clinical parameters between patients with and without relapse was performed. The short-term survival according to the use of Janus kinase inhibitors (JAKi) was also assessed. RESULTS: A total of 154 patients with MDA5-DM were included in the study. Forty patients (25.9%) died during the remission induction phase, with respiratory failure being the most common cause of mortality. Among the 114 patients who survived the remission induction phase, the 5-year cumulative survival and relapse-free survival rates were 96.8% and 77.4%, respectively, and 7.9% of patients achieved complete drug-free remission. Fifty-four patients achieved normalization of anti-MDA5 antibody titers and only two of them relapsed after normalization. In the severe patients, the 6-month survival rate became significantly higher after the emergence of the JAKi treatment compared with before its existence (p= 0.03). CONCLUSIONS: Although relapse often occurs, the long-term survival of MDA5-DM patients who survived the remission induction phase is generally favorable. The status of the anti-MDA5 antibody is associated with relapse. JAKi may improve the survival of refractory patients with severe MDA5-DM.

CCR4 predicts the efficacy of abatacept in rheumatoid arthritis patients through the estimation of Th17 and Treg cell abundance.

OBJECTIVE: Predicting the efficacy of biological disease-modifying anti-rhematic drugs (bDMARDs) is challenging. In this study, we aimed to explore markers that predict the efficacy of abatacept in rheumatoid arthritis (RA) patients. METHODS: Thirty RA patients receiving abatacept were recruited, and peripheral blood mononuclear cells (PBMCs) from the participants were subjected to DNA microarray analysis. The expression of CCR4, which was selected by the result of DNA microarray, was determined by flow cytometry in 16 newly diagnosed treatment-naïve RA patients. CCR4 expression on each helper T cell subset was also measured. RESULTS: CCR4 was upregulated in the abatacept responder. The expression levels of CCR4 were significantly correlated with the improvement of clinical disease activity index (CDAI). CCR4 expression was predominantly observed in CD4+ T cells in PBMCs. The percentage of CCR4-expressing CD4+ T cells was significantly higher in RA patients than in healthy individuals. Interestingly, Th17 and Treg cells expressed high levels of CCR4 compared to non-Th17-related helper T cells. CONCLUSION: CCR4 is a Th17- and Treg-related gene, and the high CCR4 expression in peripheral blood samples may predict the efficacy of abatacept in RA.

Early initiation of angiotensin-converting enzyme inhibitor in patients with scleroderma renal crisis: A nationwide inpatient database study.

OBJECTIVES: To evaluate the effectiveness of early initiation of angiotensin-converting enzyme inhibitor (ACEi) in patients with scleroderma renal crisis (SRC). METHODS: This was a retrospective cohort study using a nationwide inpatient database in Japan from July 2010 to March 2020. All hospitalized patients with SRC were divided into those who received ACEi within two days of admission (early ACEi group) and those who did not (control group). Propensity-score overlap weighting analysis was performed to adjust for confounding factors. The primary outcome was the composite of in-hospital mortality or hemodialysis dependence at discharge. RESULTS: Of the 475 eligible patients, 248 (52.2%) were in the early ACEi group and 227 (47.8%) were in the control group. After overlap weighting, the primary outcome was significantly lower in the early ACEi group than in the control group (40.1% vs. 49.0%; odds ratio, 0.69; 95% confidence interval, 0.48-1.00; P= 0.049). CONCLUSIONS: The present study showed that early initiation of ACEi was associated with lower composite outcome of in-hospital mortality or hemodialysis dependence at discharge in patients with SRC. Further prospective studies are warranted to verify the present findings.

Prognosis of spontaneous pneumomediastinum occurring in dermatomyositis or polymyositis patients with interstitial lung disease according to antimelanoma differentiation-associated gene 5 antibody status: a retrospective cohort study.

OBJECTIVES: Spontaneous pneumomediastinum (SPNM) historically has been considered a poor prognostic factor in dermatomyositis/polymyositis patients complicated with interstitial lung disease (ILD). However, there is a lack of actual data regarding the association between SPNM occurrence and mortality in dermatomyositis/polymyositis patients. This study aimed to assess the association between SPNM occurrence and mortality in myositis patients with ILD according to antimelanoma differentiation-associated gene 5 (MDA5) antibody status. METHODS: Dermatomyositis/polymyositis patients with ILD who were hospitalised at five Japanese hospitals from 2016 to 2020 were included in this retrospective observational study. We collected data about baseline characteristics including myositis-specific autoantibodies, treatments, SPNM and death within 1 year from therapy initiation or strengthening. Baseline characteristics and outcomes were compared between patients with and without SPNM (the SPNM group and the non-SPNM group, respectively). RESULTS: A total of 119 patients were analysed. SPNM occurred in 23 patients, and 15 patients died. Fifteen patients with SPNM were anti-MDA5 antibody positive. The mortality rate was significantly higher in the SPNM group (34.8%) than in the non-SPNM group (7.3%) (p=0.001). All deaths in the SPNM group occurred in anti-MDA5 antibody-positive patients (8/15), whereas none of the anti-MDA5 antibody-negative patients in the SPNM group died (0/8). In anti-MDA5 antibody-positive patients, the mortality rate was significantly higher in patients with SPNM occurrence (53.3%) than in those without SPNM occurrence (4.0%) (p=0.001). CONCLUSION: SPNM occurred more frequently in anti-MDA5 antibody-positive than in anti-MDA5 antibody-negative myositis patients. SPNM occurrence was associated with higher mortality risk, especially in anti-MDA5 antibody-positive patients.

Relationship of systemic type I interferon activity with clinical phenotypes, disease activity, and damage accrual in systemic lupus erythematosus in treatment-naive patients: a retrospective longitudinal analysis.

BACKGROUND: Systemic lupus erythematosus (SLE) is heterogeneous in organ involvement and disease severity, presenting a broad clinical phenotype. Systemic type I interferon (IFN) activity has been shown to be associated with lupus nephritis, autoantibodies, and disease activity in treated SLE patients; however, these relationships are unknown in treatment-naive patients. We aimed to determine the relationship of systemic IFN activity with clinical phenotypes, disease activity, and damage accrual in treatment-naive SLE patients before and after induction and maintenance therapy. METHODS: Forty treatment-naive SLE patients were enrolled for this retrospective longitudinal observational study to examine the relationship between serum IFN activity and clinical manifestations of EULAR/ACR-2019 criteria domains, disease activity measures, and damage accrual. As controls, 59 other treatment-naive rheumatic disease patients and 33 healthy individuals were recruited. Serum IFN activity was measured by WISH bioassay and presented as an IFN activity score. RESULTS: Treatment-naive SLE patients had significantly higher serum IFN activity than other rheumatic disease patients (score: 97.6 and 0.0, respectively, p < 0.001). High serum IFN activity was significantly associated with fever, hematologic disorders (leukopenia), and mucocutaneous manifestations (acute cutaneous lupus and oral ulcer) of EULAR/ACR-2019 criteria domains in treatment-naive SLE patients. Serum IFN activity at baseline significantly correlated with SLEDAI-2K scores and decreased along with a decrease in SLEDAI-2K scores after induction and maintenance therapy (R2 = 0.112, p = 0.034). SLE patients who developed organ damage (SDI ≥ 1) had higher serum IFN activity at baseline than those who did not (SDI = 0) (150.0 versus 57.3, p= 0.018), but the multivariate analysis did not detect its independent significance (p = 0.132). CONCLUSIONS: Serum IFN activity is characteristically high and is linked to fever, hematologic disorders, and mucocutaneous manifestations in treatment-naive SLE patients. Serum IFN activity at baseline correlates with disease activity and decreases in parallel with a decrease in disease activity after induction and maintenance therapy. Our results suggest that IFN plays an important role in the pathophysiology of SLE and that serum IFN activity at baseline may be a potential biomarker for the disease activity in treatment-naive SLE patients.

Prevalence and risk factors of osteonecrosis of the femoral head in patients with ANCA-associated vasculitis: a multicentre cohort study.

OBJECTIVE: We aimed to determine the prevalence and risk factors for osteonecrosis of the femoral head (ONFH) in a multicentre cohort of patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS: One hundred and eighty-six AAV patients who underwent radiographs and MRI screening of bilateral hip joints at more than 6 months after initial remission induction therapy (RIT) were retrospectively assessed for the presence of ONFH. RESULTS: Among 186 AAV patients, 33 (18%) were diagnosed with ONFH. Among the patients with ONFH, 55% were asymptomatic and 64% had bilateral ONFH. Seventy-six per cent of ONFH joints were in precollapse stages (stage ≤2), whereas 24% of ONFH joints were in collapse stages (stage ≥3). Moreover, 56% of the precollapse stage joints were already at risk of future collapse (type ≥C-1). Even in asymptomatic ONFH patients, 39% of the precollapse stage joints were type ≥C-1. Prednisolone dose of ≥20 mg/day on day 90 of RIT was an independent risk factor for ONFH in AAV patients (OR 1.072, 95% CI 1.017 to 1.130, p=0.009). Rituximab use was a significant beneficial factor against ONFH (p=0.019), but the multivariate analysis rejected its significance (p=0.257). CONCLUSION: Eighteen per cent of AAV patients developed ONFH, and two-thirds of the ONFH joints were already in collapse stages or at risk of future collapse. Prednisolone dose of ≥20 mg/day on day 90 of RIT was an independent risk factor for ONFH. A rapid reduction of glucocorticoids in RIT and early detection of precollapse ONFH by MRI may decrease and intervene ONFH development in AAV patients.

Efficacy and safety of dose escalation of tofacitinib in refractory anti-MDA5 antibody-positive dermatomyositis.

Anti-melanoma differentiation-associated protein 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is frequently complicated with rapidly progressive-interstitial lung disease (RP-ILD). The prognosis of MDA5-DM with RP-ILD is mostly poor despite intensive treatment with a combination of high-dose glucocorticoids and single conventional immunosuppressants. It was reported that the triple therapy (high-dose glucocorticoids, cyclophosphamide and tacrolimus) was more effective than a combination of high-dose glucocorticoids and stepwise addition of immunosuppressants. In addition, the efficacy of tofacitinib 10 mg/day for MDA5-DM with RP-ILD refractory to the triple therapy was suggested. However, the effect of those therapies was evaluated only in comparison to the historical control. Moreover, more importantly, there are still refractory patients even if treated with those therapies. In this case series, we report six MDA5-DM cases with RP-ILD in which the dose of tofacitinib was increased from 10 mg to 20 mg/day due to poor response to the triple therapy, followed by tofacitinib 10 mg/day. Four of six patients improved after dose escalation of tofacitinib, while two non-responders died. All six patients developed at least one infection including five cases of cytomegalovirus reactivation, one pulmonary aspergillosis, one herpes zoster and one herpes simplex keratitis. These cases suggest that the dose escalation of tofacitinib can be an option for MDA5-DM patients refractory to 10 mg/day of tofacitinib and other immunosuppressants although the risk of infection is a concern. The risk-benefit balance of the dose escalation of tofacitinib should be carefully assessed in each case.

Epithelial cell-derived cytokine TSLP activates regulatory T cells by enhancing fatty acid uptake.

Epithelial cells control a variety of immune cells by secreting cytokines to maintain tissue homeostasis on mucosal surfaces. Regulatory T (Treg) cells are essential for immune homeostasis and for preventing tissue inflammation; however, the precise molecular mechanisms by which epithelial cell-derived cytokines function on Treg cells in the epithelial tissues are not well understood. Here, we show that peripheral Treg cells preferentially respond to thymic stromal lymphoprotein (TSLP). Although TSLP does not affect thymic Treg differentiation, TSLP receptor-deficient induced Treg cells derived from naïve CD4+ T cells are less activated in an adoptive transfer model of colitis. Mechanistically, TSLP activates induced Treg cells partially through mTORC1 activation and fatty acid uptake. Thus, TSLP modulates the activation status of induced Treg through the enhanced uptake of fatty acids to maintain homeostasis in the large intestine.

Visceral disseminated varicella zoster virus infection during non-intensive maintenance therapy in a patient with systemic lupus erythematosus.

Visceral disseminated varicella zoster virus infection (VD-VZV) is a rare complication in immunocompromised patients. Although systemic lupus erythematosus (SLE) patients have a higher risk of VZV infection, only a few reports describe VD-VZV in SLE. Here, we report a 48-year-old woman with SLE who had received maintenance therapy. She was transferred to the hospital because of severe epigastric pain. There were no significant abnormalities in abdominal computed tomography and upper gastrointestinal endoscopy. On hospital day 4, she developed vesicular eruption on her face and abdomen. VZV antigen was detected in specimens obtained from skin lesions, and treatment with acyclovir was started. VZV DNA in blood turned out to be positive, and the epigastric pain was thought to be caused by VD-VZV. There is a risk of VD-VZV in patients with SLE, even in those receiving non-intensive maintenance therapy.

Antiphospholipid antibody positivity and the thrombotic risk in Japanese patients with anti-neutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVES: It has been reported that 21.0-51.7% of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) patients were antiphospholipid antibody (aPL)-positive. However, the clinical significance of aPL positivity in AAV is not fully understood. METHODS: We retrospectively assessed patients with AAV diagnosed from 2013 to 2020 at our hospital. Positivity of aPL was defined as positivity of anti-cardiolipin antibody, anti-cardiolipin ß2 glycoprotein 1 complex antibody, and/or lupus anticoagulant at least one time during the follow-up periods. The thrombotic risk of aPL positivity was examined by multivariate analyses with the Cox regression model. RESULTS: A total of 93 patients with a median age of 71.9 years were included in the study. The median follow-up period was 35.4 months. Thirty-one patients (33.3%) were aPL-positive. Twenty-two thrombotic events occurred in 17 patients (18.3%). Thrombotic events occurred more frequently in aPL-positive patients than in aPL-negative patients (P = 0.011). Multivariate analyses with two different models identified aPL positivity as a thrombotic risk factor (hazard ratios 4.302 and 5.956, 95% confidence intervals 1.546-11.968 and 1.940-18.281, respectively). CONCLUSIONS: The proportion of aPL-positive patients was 33.3%, and aPL positivity increased the thrombotic risk in Japanese patients with AAV.

Immunological features that associate with the strength of antibody responses to BNT162b2 mRNA vaccine against SARS-CoV-2.

Predictive clinical factors associated with favorable responses to BNT162b2 mRNA vaccine against SARS-CoV-2 have been reported in some studies; however, there is a subgroup with low antibodytiters without well-known clinical factors reducing antibody responses. To clarify the immunological backgrounds that underlie the difference in antibody responses, we analyzed peripheral blood mononuclear cells (PBMCs) of each 20 individuals with a high anti-SARS-CoV-2 antibody titer and a low antibody titer out of 1774 healthcare workers who received BNT162b2 mRNA vaccine. A higher percentage of B cells before vaccination was associated with a higher antibody titer. Among B cells, naïve and transitional B cell frequencies were positively correlated with a higher antibody titer, whereas the frequencies of late memory B cells and plasmablasts were associated with a lower antibody titer. Fold change in the frequency of activated CD8+ T cells upon vaccination was also correlated with high antibody titers.

Prognosis and Treatment of Myositis-Associated Severe Interstitial Lung Disease: A Descriptive Study Using a Nationwide Inpatient Database in Japan.

OBJECTIVE: The aim of this study was to determine the prognosis, clinical course, and current management of severe interstitial lung disease (ILD) associated with myositis in Japan. METHODS: We conducted a retrospective descriptive study using a nationwide database for inpatient care of acute illness in Japan. Among a total of ~66 million inpatient admissions, we identified patients with severe ILD associated with polymyositis (PM) or dermatomyositis (DM) who required mechanical ventilation and methylprednisolone pulse therapy (≥1 gm/day of methylprednisolone) from July 2010 to March 2018. RESULTS: We identified 155 patients with PM and 394 with DM who fulfilled the above criteria. The median age of patients was 65 years; DM patients were significantly younger than PM patients (64 versus 68 years; P < 0.001). The numbers of patients who were treated with calcineurin inhibitors, intravenous cyclophosphamide, and polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) were 403 (73.4%), 318 (57.9%), and 78 (14.2%), respectively. All these treatments were given significantly more frequently to the patients with DM compared with those with PM. The uses of other treatment options were much less frequent. The median periods after hospitalization when methylprednisolone pulse therapy, calcineurin inhibitors, mechanical ventilation, intravenous cyclophosphamide, and PMX-DHP were initiated and in-hospital death occurred among patients with DM were 2, 4, 7, 8, 17, and 36 days, respectively. In-hospital mortality was significantly higher in patients with DM than in those with PM (76.6% versus 56.8%; P < 0.001). CONCLUSION: The mortality of patients with myositis-associated severe ILD who require mechanical ventilation is extremely high despite aggressive and prompt interventions.

High Systemic Type I Interferon Activity Is Associated With Active Class III/IV Lupus Nephritis.

OBJECTIVE: Previous studies suggest a link between high serum type I interferon (IFN) and lupus nephritis (LN). We determined whether serum IFN activity is associated with subtypes of LN and studied renal tissues and cells to understand the effect of IFN in LN. METHODS: Two hundred and twenty-one patients with systemic lupus erythematosus were studied. Serum IFN activity was measured by WISH bioassay. mRNA in situ hybridization was used in renal tissue to measure expression of the representative IFN-induced gene, IFN-induced protein with tetratricopeptide repeats-1 (IFIT1), and the plasmacytoid dendritic cell (pDC) marker gene C-type lectin domain family-4 member C (CLEC4C). Podocyte cell line gene expression was measured by real-time PCR. RESULTS: Class III/IV LN prevalence was significantly increased in patients with high serum IFN compared with those with low IFN (odds ratio 5.40, P = 0.009). In multivariate regression models, type I IFN was a stronger predictor of class III/IV LN than complement C3 or anti-dsDNA antibody, and could account for the association of these variables with LN. IFIT1 expression was increased in all classes of LN, but most in the glomerular areas of active class III/IV LN kidneys. IFIT1 expression was not closely colocalized with pDCs. IFN directly activated podocyte cell lines to induce chemokines and proapoptotic molecules. CONCLUSION: Systemic high IFN is involved in the pathogenesis of severe LN. We did not find colocalization of pDCs with IFN signature in renal tissue, and instead observed the greatest intensity of the IFN signature in glomerular areas, which could suggest a blood source of IFN.

NF-κB1 Contributes to Imiquimod-Induced Psoriasis-Like Skin Inflammation by Inducing Vγ4+Vδ4+γδT17 Cells.

Recent studies have identified NF-κB1 as a new disease susceptibility gene for psoriasis. Although accumulating evidence has shown the importance of NF-κB signaling in various cell types in the pathogenesis of psoriasis, it remains unclear how NF-κB1 contributes to the pathogenesis of psoriasis. In this study, we examined psoriasis-like skin diseases induced by topical administration of imiquimod in Nf-κb1‒deficient (Nf-κb1-/-) mice and littermate wild-type (WT) mice. Compared with WT mice, Nf-κb1-/- mice exhibited attenuated skin inflammation. The numbers of Vγ4+Vδ4+γδT17 cells, which cause skin inflammation in this model, were significantly reduced in the skin and draining lymph nodes in imiquimod-treated Nf-κb1-/- mice. Nf-κb1 is preferentially phosphorylated in Vγ4+Vδ4+γδT17 cells in WT mice. In vitro proliferation of Vγ4+Vδ4+γδT17 cells but not conventional CD4+ T cells was significantly impaired in Nf-κb1-/- mice compared with that in WT mice. RNA-sequencing analyses revealed that the expression of E2 factor target genes was decreased in Vγ4+Vδ4+γδT cells by the absence of NF-κB1. Consistently, the cell cycle progression of Vγ4+Vδ4+γδT cells was reduced in Nf-κb1-/- mice compared with that in WT mice. These results suggest that Nf-κb1 plays a crucial role in the pathogenesis of imiquimod-induced psoriasis-like skin inflammation by promoting the proliferation of Vγ4+Vδ4+γδT17 cells.

Suppressor of cytokine signalling 3 (SOCS3) expressed in podocytes attenuates glomerulonephritis and suppresses autoantibody production in an imiquimod-induced lupus model.

OBJECTIVE: Recently, podocytes have been recognised not only as a physical barrier to prevent urinary protein loss but also as producers of proinflammatory cytokines. However, the roles of podocytes in the pathogenesis of lupus nephritis (LN) remain largely unknown. This study aims to determine the roles of suppressor of cytokine signalling (SOCS) family members expressed in glomeruli in the regulation of LN. METHODS: We investigated the expression of SOCS family members in glomeruli in murine lupus model induced by repeated epicutaneous administration of the TLR7/8 agonist imiquimod. We also investigated the roles of SOCS3 expressed in podocytes in the imiquimod-induced glomerulonephritis and systemic autoimmunity by using podocyte-specific SOCS3-deficient mice (podocin-Cre x SOCS3fl/fl mice (SOCS3-cKO mice)). Finally, we investigated the expression of proinflammatory cytokines and chemokines in SOCS3-deficient podocyte cell lines. RESULTS: qPCR analysis revealed that among SOCS family members, SOCS3 was preferentially induced in glomeruli on epicutaneous administration of imiquimod and that interleukin 6 (IL-6) induced SOCS3 expression in podocyte cell lines. SOCS3-cKO mice exhibited severe glomerulonephritis, high levels of serum creatinine and urine albumin and decreased survival rate compared with control SOCS3-WT mice. Levels of anti-double-strand DNA antibody, SOCS (GC) formation and the numbers of follicular helper T (Tfh) cells and GC B cells in the spleen were higher in SOCS3-cKO mice than those in SOCS3-WT mice. Serum IL-6 levels and expression of IL-6 mRNA in glomeruli were also elevated in SOCS3-cKO mice. IL-6-induced IL-6 expression was enhanced in SOCS3-deficient podocyte cell lines compared with that in SOCS3-sufficient podocyte cell lines. CONCLUSION: SOCS3 expressed in podocytes plays protective roles for the development of glomerulonephritis and inhibits autoantibody production in the imiquimod-induced lupus model presumably by suppressing IL-6 production of podocytes.

Associations of ultrasound-based inflammation patterns with peripheral innate lymphoid cell populations, serum cytokines/chemokines, and treatment response to methotrexate in rheumatoid arthritis and spondyloarthritis.

OBJECTIVES: We aimed to explore the associations of musculoskeletal inflammation patterns with peripheral blood innate lymphoid cell (ILC) populations, serum cytokines/chemokines, and treatment response to methotrexate in patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA). METHODS: We enrolled 100 patients with either RA or SpA and performed ultrasound to evaluate power Doppler signals for synovitis (52 joint regions), tenosynovitis (20 tendons), and enthesitis (44 sites). We performed clustering analysis using unsupervised random forest based on the multi-axis ultrasound information and classified the patients into groups. We identified and counted ILC1-3 populations in the peripheral blood by flow cytometry and also measured the serum levels of 20 cytokines/chemokines. We also determined ACR20 response at 3 months in 38 patients who began treatment with methotrexate after study assessment. RESULTS: Synovitis was more prevalent and severe in RA than in SpA, whereas tenosynovitis and enthesitis were comparable between RA and SpA. Patients were classified into two groups which represented synovitis-dominant and synovitis-nondominant inflammation patterns. While peripheral ILC counts were not significantly different between RA and SpA, they were significantly higher in the synovitis-nondominant group than in the synovitis-dominant group (ILC1-3: p = 0.0007, p = 0.0061, and p = 0.0002, respectively). On the other hand, clustering of patients based on serum cytokines/chemokines did not clearly correspond either to clinical diagnoses or to synovitis-dominant/nondominant patterns. The synovitis-dominant pattern was the most significant factor that predicted clinical response to methotrexate (p = 0.0065). CONCLUSIONS: Musculoskeletal inflammation patterns determined by ultrasound are associated with peripheral ILC counts and could predict treatment response to methotrexate.

Sox12 enhances Fbw7-mediated ubiquitination and degradation of GATA3 in Th2 cells.

Allergic asthma that is caused by inhalation of house dust mites (HDMs) is mainly mediated by Th2 cells. Recently, the roles of Sox (SRY-related high-mobility-group (HMG)-box) family members in various immune responses have been investigated. However, the roles of Sox12, a member of the SoxC group, in Th2 cell differentiation and allergic airway inflammation, remain unknown. We showed that Sox12 mRNA was significantly increased during Th2 cell differentiation. In vivo, HDM-induced eosinophil infiltration into the lung and Th2 cell differentiation were exacerbated in Sox12-/- mice compared with those in control Sox12+/- mice. In vitro, Sox12-/- CD4+ T cells that were cultured under Th2 conditions had increased production of Th2 cytokines and GATA3 protein compared with those of control Sox12+/- CD4+ T cells. Importantly, forced expression of Sox12 decreased the protein levels of GATA3 in CD4+ T cells under Th2 conditions without affecting mRNA expression. Furthermore, Sox12 induced degradation of GATA3 through the proteasome pathway in CD4+ T cells. Consistently, Sox12 enhanced ubiquitination of GATA3, which was mediated by the E3 ligase Fbw7. Finally, we found that Fbw7 knockdown partly abrogated Sox12-mediated GATA3 suppression in CD4+ T cells. Taken together, these results suggest that Sox12 suppresses Th2 cell differentiation by accelerating Fbw7-mediated GATA3 degradation, and attenuates HDM-induced allergic inflammation.

Update on eosinophilic granulomatosis with polyangiitis.

Eosinophilic granulomatosis with polyangiitis (EGPA) (formerly Churg-Strauss syndrome) is a rare form of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis characterized by eosinophil-rich granulomatous inflammation and small to medium-size vessel vasculitis associated with bronchial asthma and eosinophilia. Its rarity and unique features such as eosinophilic inflammation have delayed progress of research regarding EGPA for several years, compared to other forms of ANCA-associated vasculitis. However, recently, attention to EGPA as a research subject has been gradually increasing. To resolve problems in existing criteria for EGPA, new classification criteria for EGPA generated by a large international cohort will be launched and is being expected to accelerate future studies. Pathogenesis and roles of ANCA in EGPA are still largely unknown; however, it has been reported that glomerulonephritis is more frequent in ANCA-positive patients than in ANCA-negative patients, while heart failure is more frequent in ANCA-negative patients than in ANCA-positive patients. In addition, a recent genome-wide association study has suggested the presence of two genetically distinct subgroups of EGPA, which correspond to ANCA-positive and -negative subgroups. Although responses to glucocorticoids in EGPA are generally good, patients with EGPA often experience a relapse. Currently, there is no standard therapy for EGPA based on accumulation of clinical trial results. Recently, clinical benefits of mepolizumab for EGPA were proved by a randomized controlled trial and mepolizumab was approved for EGPA. In addition, various new drugs are under evaluation. To find optimal use of these drugs and to resolve unmet needs, such as relapse prevention, will be needed in future.