Notch2 with retinoic acid license IL-23 expression by intestinal EpCAM+ DCIR2+ cDC2s in mice.

Despite the importance of IL-23 in mucosal host defense and disease pathogenesis, the mechanisms regulating the development of IL-23-producing mononuclear phagocytes remain poorly understood. Here, we employed an Il23aVenus reporter strain to investigate the developmental identity and functional regulation of IL-23-producing cells. We showed that flagellin stimulation or Citrobacter rodentium infection led to robust induction of IL-23-producing EpCAM+ DCIR2+ CD103- cDC2s, termed cDCIL23, which was confined to gut-associated lymphoid tissues, including the mesenteric lymph nodes, cryptopatches, and isolated lymphoid follicles. Furthermore, we demonstrated that Notch2 signaling was crucial for the development of EpCAM+ DCIR2+ cDC2s, and the combination of Notch2 signaling with retinoic acid signaling controlled their terminal differentiation into cDCIL23, supporting a two-step model for the development of gut cDCIL23. Our findings provide fundamental insights into the developmental pathways and cellular dynamics of IL-23-producing cDC2s at steady state and during pathogen infection.

A case of atypical IgG4-related disease presenting hypereosinophilia, polyneuropathy, and liver dysfunction.

Ig (immunoglobulin) G4-related disease (Ig4-RD) affects several organs, including salivary glands, lacrimal glands, pancreas, biliary ducts, and retroperitoneum. A 72-year-old woman was examined for hypereosinophilia, high levels of IgG4, polyneuropathy, liver dysfunction, enlargement of lymph nodes and lacrimal glands, and beaded dilation of the bile ducts. We diagnosed Ig4-RD based on biopsies of the lymph nodes, liver, and submandibular gland. The symptoms of the patient improved after glucocorticoid treatment. This was a novel and atypical case of Ig4-RD that was difficult to differentiate from other diseases, including eosinophilic granulomatosis with polyangiitis, idiopathic hypereosinophilic syndrome, and polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes syndrome. This case report highlights the importance of biopsies in differentiating Ig4-RD.

The clinical features of pulmonary artery involvement in Takayasu arteritis and its relationship with ischemic heart diseases and infection.

BACKGROUND: Pulmonary artery involvement (PAI) in Takayasu arteritis (TAK) can lead to severe complications, but the relationship between the two has not been fully clarified. METHODS: We retrospectively investigated 166 consecutive patients with TAK who attended Kyoto University Hospital from 1997 to 2018. The demographic data, clinical symptoms and signs, comorbidities, treatments, and imaging findings were compared between patients with and without PAI. TAK was diagnosed based on the American College of Rheumatology Classification Criteria (1990) or the Japanese Clinical Diagnostic Criteria (2008). PAI was identified using enhanced computed tomography, magnetic resonance imaging, or lung scintigraphy. RESULTS: PAI was detected in 14.6% (n = 24) of total TAK patients. Dyspnea (25.0% vs. 8.6%; p = 0.043), pulmonary arterial hypertension (PAH) (16.7% vs. 0.0%; p < 0.001), ischemic heart disease (IHD) (29% vs. 9.3%; p = 0.018), respiratory infection (25.0% vs. 6.0%; p = 0.009), and nontuberculous mycobacteria (NTM) infection (20.8% vs. 0.8%; p < 0.001) were significantly more frequent, and renal artery stenosis (0% vs. 17%; p = 0.007) was significantly less frequent in TAK patients with PAI than in those without PAI. PAI and biologics were risk factors for NTM. CONCLUSIONS: TAK patients with PAI more frequently have dyspnea, PAH, IHD, and respiratory infection, including NTM, than TAK patients without PAI.

Rapid Flow Cytometry-Based Assay for the Functional Classification of MEFV Variants.

PURPOSE: Pathogenic MEFV variants cause pyrin-associated autoinflammatory diseases (PAADs), which include familial Mediterranean fever (FMF), FMF-like disease, and pyrin-associated autoinflammation with neutrophilic dermatosis (PAAND). The diagnosis of PAADs is established by clinical phenotypic and genetic analyses. However, the pathogenicity of most MEFV variants remains controversial, as they have not been functionally evaluated. This study aimed to establish and validate a new functional assay to evaluate the pathogenicity of MEFV variants. METHODS: We transfected THP-1 monocytes with 32 MEFV variants and analyzed their effects on cell death with or without stimulation with Clostridium difficile toxin A (TcdA) or UCN-01. These variants were classified using hierarchical cluster analysis. Macrophages were obtained from three healthy controls and two patients with a novel homozygous MEFVP257L variant, for comparison of IL-1ß secretion using a cell-based assay and a novel THP-1-based assay. RESULTS: Disease-associated MEFV variants induced variable degrees of spontaneous or TcdA/UCN-01-induced cell death in THP-1. Cell death was caspase-1 dependent and was accompanied by ASC speck formation and IL-1ß secretion, indicating that pathogenic MEFV variants induced abnormal pyrin inflammasome activation and subsequent pyroptotic cell deaths in this assay. The MEFV variants (n = 32) exhibiting distinct response signatures were classified into 6 clusters, which showed a good correlation with the clinical phenotypes. Regarding the pathogenicity of MEFVP257L variants, the results were consistent between the cell-based assay and the THP-1-based assay. CONCLUSION: Our assay facilitates a rapid and comprehensive assessment of the pathogenicity of MEFV variants and contributes to a refined definition of PAAD subtypes.

Development of severe thrombocytopenia with TAFRO syndrome-like features in a patient with rheumatoid arthritis treated with a Janus kinase inhibitor: A case report.

RATIONALE: Thrombocytepenia, anasarca, fever, renal insufficiency, and organomegaly (TAFRO) syndrome is a novel disease entity characterized by a constellation of symptoms (thrombocytopenia, anasarca, fever, renal insufficiency, and organomegaly). Here, we describe the development of TAFRO syndrome-like features during the treatment of rheumatoid arthritis with a Janus kinase (JAK) inhibitor. PATIENT CONCERNS: In this report, a 74-year-old woman treated with a JAK inhibitor (tofacitinib) for rheumatoid arthritis was admitted because of fever and thrombocytopenia. DIAGNOSES: On laboratory examination, marked thrombocytopenia and elevated creatinine and C-reactive protein levels were present. A computed tomography scan revealed lymphadenopathy, hepato-splenomegaly, and anasarca. A left axillary lymph node biopsy revealed Castleman's disease-like features. These clinical features satisfied the proposed diagnostic criteria for TAFRO syndrome. Since autoimmune disorders should be excluded when diagnosing TAFRO syndrome, it is not strictly correct to diagnose her as TAFRO syndrome. Therefore, we diagnosed her as rheumatoid arthritis complicated by TAFRO syndrome-like features. INTERVENTIONS: The patient was treated with high-dose glucocorticoid, tacrolimus, eltrombopag, intravenous immunoglobulin, and rituximab. OUTCOMES: Her condition was refractory to the above-mentioned treatment, and she eventually died because of multi-organ failure 6 months after the first admission. LESSONS: TAFRO syndrome-like features can develop during treatment with a JAK inhibitor for rheumatoid arthritis. Patients with autoimmune diseases complicated by TAFRO syndrome-like features can follow a fatal clinical course, and thus, an intensive combined treatment is warranted for such patients, especially in cases refractory to glucocorticoid.

Initial high-dose corticosteroids and renal impairment are risk factors for early severe infections in elderly patients with antineutrophil cytoplasmic autoantibody-associated vasculitis: A retrospective observational study.

Recent large observational studies of antineutrophil cytoplasmic autoantibody-associated vasculitis (AAV) show that severe infection is a major cause of death and that the majority of infections occur during the early phase of initiating remission-induction therapy. Many risk factors for severe infection have been suggested, but these have been inconsistent. Nevertheless, infectious risk factors in elderly patients with AAV have not been adequately investigated in previous studies.In this retrospective observational study, we examined potential predictors of severe infection within 90 days (early severe infections) after remission-induction therapy in patients with AAV aged 65 years or older. We included 167 consecutive elderly patients with AAV admitted to our hospital. Data from medical history and remission-induction therapy were analyzed for predictive risk factors associated with early severe infections. The relationship between initial doses of corticosteroids and cumulative incidence of severe infections was also analyzed. A multivariate analysis of risk factors for early severe infections was performed using logistic regression analysis. The Kaplan-Meier method was used to estimate the overall survival, and the log-rank test was used to evaluate the differences between patients with and without early severe infections. Gray method was used to compare the cumulative incidence of severe infections in patients who did and did not receive initial high-dose corticosteroids.Logistic regression analysis showed that initial high-dose corticosteroid administration (prednisolone ≥0.8 mg/kg/d) (odds ratio [OR] 3.86, P = .030) and serum creatinine levels at diagnosis ≥1.5 mg/dL (OR 5.13, P = .003) were independent predictors of early severe infection although administration of cyclophosphamide or rituximab was not. The cumulative incidence of severe infections was also significantly higher in patients who received initial high-dose corticosteroids (P = .042), and patients with early severe infections exhibited a high mortality rate within 6 months (P < .001).Our findings suggest that initial high-dose corticosteroids and renal impairment at diagnosis are associated with a higher risk of early severe infections and early death in elderly patients with AAV.

Efficacy of Plasma Exchange in Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis.

We aimed to investigate the efficacy of plasma exchange on severe anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). Of 182 patients with AAV in our hospital, 12 patients with life-threatening organ damage (rapidly progressive glomerulonephritis and/or diffuse alveolar hemorrhage) underwent centrifuge-based therapeutic plasma exchange and immunosuppressive therapy. Twenty-four patients matched for age, serum creatinine, and severity of vasculitis, who received high-dose glucocorticoids with or without immunosuppressants, were included in the nonplasma exchange group. Renal survival rate at 2 years from induction treatment was not significantly different between the plasma and nonplasma exchange groups (P = 0.524). Mortality rate at 5 years from induction treatment was not significantly different between the plasma and nonplasma exchange groups (P = 0.631). In this retrospective study, we could not show the significant differences in the renal survival rate and survival rate between the two groups.