The 2023 revised diagnostic criteria for IgG4-related dacryoadenitis and sialadenitis.

OBJECTIVES: For the diagnosis of IgG4-related dacryoadenitis and sialadenitis, either revised comprehensive diagnostic criteria or organ-specific diagnostic criteria for IgG4-related dacryoadenitis and sialadenitis in 2008 were applied; however, the collected knowledge for IgG4-related dacryoadenitis and sialadenitis required us to revise the criteria for IgG4-related dacryoadenitis and sialadenitis. METHODS: The board member of Japanese Study Group for IgG4-related Dacryoadenitis and Sialadenitis revised the diagnostic criteria for IgG4-related dacryoadenitis and sialadenitis. We collected the clinical questions to be revised and performed a review of the literature. When the data were insufficient, additional data collection was performed. After the revision, public comments were collected. RESULTS: The three major points were revised. 1. Asymmetric or under two pairs of dacryoadenitis and sialoadenitis were included as IgG4-related dacryoadenitis and sialadenitis. 2. The thresholds of IgG4-positive cell infiltration were adjusted to an IgG4+/IgG+ ratio >0.4 and IgG4+ cells >10 per high power field. 3. The labial salivary gland biopsy was allowed to diagnose IgG4-related dacryoadenitis and sialadenitis. CONCLUSIONS: The revised diagnostic criteria for IgG4-related dacryoadenitis and sialadenitis solved several issues with the previous criteria. It will improve the early diagnosis of IgG4-related dacryoadenitis and sialadenitis, especially in situations without enough resources for a biopsy.

Interleukin 9 mediates T follicular helper cell activation to promote antibody responses.

Antigen-specific humoral responses are orchestrated through complex interactions among immune cells in lymphoid tissues, including the collaboration between B cells and T follicular helper (Tfh) cells. Accumulating evidence indicates a crucial role for interleukin-9 (IL-9) in the formation of germinal centers (GCs), enhancing the generation of class-switched high-affinity antibodies. However, the exact function of IL-9 in Tfh cell regulation remains unclear. In this study, we examined the humoral immune responses of CD4Cre/+Il9rafl/fl mice, which lack an IL-9-specific receptor in Tfh cells. Upon intraperitoneal immunization with sheep red blood cells (SRBCs), CD4Cre/+Il9rafl/fl mice displayed diminished levels of SRBC-specific IgG antibodies in their sera, along with reduced levels of GC B cells and plasma cells. Notably, Il9ra-deficient Tfh cells in the spleen exhibited decreased expression of their signature molecules such as B-cell lymphoma 6, C-X-C chemokine receptor 5, IL-4, and IL-21 compared to control mice. In models of allergic asthma induced by house dust mite (HDM) inhalation, CD4Cre/+Il9rafl/fl mice failed to elevate serum levels of HDM-specific IgE and IgG. This was accompanied by reductions in Tfh cells, GC B cells, and plasma cells in mediastinal lymph nodes. Furthermore, group 2 innate lymphoid cells (ILC2s) were identified as producers of IL-9 under immunizing conditions, possibly induced by leukotrienes released by activated IgD+ B cells around the T-B border. These observations may indicate the critical role of IL-9 receptor signaling in the activation of Tfh cells, with ILC2s potentially capable of supplying IL-9 in organized lymphoid tissues.

Submandibular gland tissue RNAseq and spatial transcriptome analyses in IgG4-related disease.

OBJECTIVE: To identify genes that could provide clues leading to the discovery of drugs to treat IgG4-related disease (IgG4-RD). METHODS: Submandibular gland tissue bulk RNAseq analysis of 45 cases with a definite diagnosis of IgG4-RD was integrated with Visium spatial transcriptome analysis of 2 cases to identify pathogenic genes expressed in tertiary lymphoid tissues. RESULTS: Bulk RNAseq and pathway analyses showed upregulation of cell cycle and T cell-related signals in IgG4-RD. Spatial transcriptome analysis identified the cluster corresponding to germinal centers and the top 38 common genes that showed significant variations in expression compared with other clusters. The top 20 genes were extracted by comparing the bulk RNAseq data. Network analysis identified CDK1 as the ge most strongly associated of the top 20 genes. CONCLUSION: The CDK1 gene may be a regulator of the pathogenesis of IgG4-RD and provide clues for drug discovery.

Bob1 maintains T follicular helper cells for long-term humoral immunity.

Humoral immunity is vital for host protection, yet aberrant antibody responses can trigger harmful inflammation and immune-related disorders. T follicular helper (Tfh) cells, central to humoral immunity, have garnered significant attention for unraveling immune mechanisms. This study shows the role of B-cell Oct-binding protein 1 (Bob1), a transcriptional coactivator, in Tfh cell regulation. Our investigation, utilizing conditional Bob1-deficient mice, suggests that Bob1 plays a critical role in modulating inducible T-cell costimulator expression and cellular respiration in Tfh cells. This regulation maintains the long-term functionality of Tfh cells, enabling their reactivation from central memory T cells to produce antibodies during recall responses. In a bronchial asthma model induced by house dust mite (HDM) inhalation, Bob1 is observed to enhance HDM-specific antibodies, including IgE, highlighting its pivotal function in Tfh cell regulation. Further exploration of Bob1-dependent mechanisms in Tfh cells holds promise for governing protective immunity and addressing immune-related disorders.

Extraction of characteristic serum microRNAs and prediction of target genes in IgG4-related dacryoadenitis and sialadenitis.

OBJECTIVES: To identify the specific microRNAs (miRNAs) in IgG4-related dacryoadenitis and sialadenitis (IgG4-DS) and predict the targeted genes. METHODS: miRNAs in the serum of nine patients with IgG4-DS, three patients with primary Sjögren's syndrome, and three healthy controls were analysed using the human miRNA chip, and miRNAs that exhibited significant fluctuation in expression in IgG4-DS patients were extracted. The respective target genes were predicted using an existing database, and expression of the target genes was evaluated in actual submandibular gland tissues affected by IgG4-DS. RESULTS: Serum miR-125a-3p and miR-125b-1-3p levels were elevated in IgG4-DS. Six candidate target genes (glypican 4, forkhead box C1, protein tyrosine phosphatase non-receptor type 3, hydroxycarboxylic acid receptor 1, major facilitator superfamily domain containing 11, and tumour-associated calcium signal transducer 2) were downregulated in the affected submandibular gland tissue. CONCLUSION: Overexpression of miR-125a-3p and miR-125b-1-3p is a hallmark of IgG4-DS. These miRNAs appear to be involved in the pathogenesis of IgG4-DS.

CD4+CD8+ T follicular helper cells regulate humoral immunity in chronic inflammatory lesions.

T follicular helper (Tfh) cells drive humoral immunity by facilitating B cell responses at the initial and recall phases. Recent studies have indicated the possible involvement of Tfh cells in the process of chronic inflammation. However, the functional role of Tfh cells in persistent immune settings remains unclear. Here, we report that CD4+CD8+ (double-positive, DP; CD3+CD4+CD8+CXCR5hiPD-1hi) Tfh cells, a subset of germinal-center-type Tfh cells, were abundantly present in the fibroinflammatory lesions of patients with immunoglobulin G4-related disease (IgG4-RD). Transcriptome analyses showed that these DP-Tfh cells in the lesions of IgG4-RD preferentially expressed signature genes characteristic of cytotoxic CD8+ T cells, such as Eomes, CRTAM, GPR56, and granzymes, in addition to CD70. Scatter diagram analyses to examine the relationships between tissue-resident lymphocytes and various clinical parameters revealed that the levels of DP-Tfh cells were inversely correlated to the levels of serum IgG4 and local IgG4-expressing (IgG4+) memory B cells (CD19+CD27+IgD-) in patients with IgG4-RD. Cell culture experiments using autologous tonsillar lymphocytes further suggested that DP-Tfh cells possess a poor B-cell helper function and instead regulate memory B cells. Since CD4+ (single positive, SP; CD3+CD4+CD8-CXCR5hiPD-1hi) Tfh cells differentiated into DP-Tfh cells under stimulation with IL-2 and IL-7 as assessed by in vitro experiments, these data imply that SP-Tfh cells are a possible origin of DP-Tfh cells under persistent inflammation. These findings highlight the potential feedback loop mechanism of Tfh cells in immune tolerance under chronic inflammatory conditions. Further studies on DP-Tfh cells may facilitate control of unresolved humoral responses in IgG4-RD pathological inflammation.

The differential diagnosis of IgG4-related disease based on machine learning.

INTRODUCTION: To eliminate the disparity and maldistribution of physicians and medical specialty services, the development of diagnostic support for rare diseases using artificial intelligence is being promoted. Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a rare disorder often requiring special knowledge and experience to diagnose. In this study, we investigated the possibility of differential diagnosis of IgG4-RD based on basic patient characteristics and blood test findings using machine learning. METHODS: Six hundred and two patients with IgG4-RD and 204 patients with non-IgG4-RD that needed to be differentiated who visited the participating institutions were included in the study. Ten percent of the subjects were randomly excluded as a validation sample. Among the remaining cases, 80% were used as training samples, and the remaining 20% were used as test samples. Finally, validation was performed on the validation sample. The analysis was performed using a decision tree and a random forest model. Furthermore, a comparison was made between conditions with and without the serum IgG4 concentration. Accuracy was evaluated using the area under the receiver-operating characteristic (AUROC) curve. RESULTS: In diagnosing IgG4-RD, the AUROC curve values of the decision tree and the random forest method were 0.906 and 0.974, respectively, when serum IgG4 levels were included in the analysis. Excluding serum IgG4 levels, the AUROC curve value of the analysis by the random forest method was 0.925. CONCLUSION: Based on machine learning in a multicenter collaboration, with or without serum IgG4 data, basic patient characteristics and blood test findings alone were sufficient to differentiate IgG4-RD from non-IgG4-RD.

HDAC inhibitors suppress the proliferation, migration and invasiveness of human head and neck squamous cell carcinoma cells via p63­mediated tight junction molecules and p21­mediated growth arrest.

In human head and neck squamous cell carcinoma (HNSCC), the invasion and metastatic properties of cancer cells are promoted by junctional adhesion molecule­A (JAM­A) and claudin­1; these are epithelial tight junction molecules regulated by histone deacetylases (HDACs) and transcription factor p63. HDAC expression is reportedly upregulated in HNSCC, and HDAC inhibitors suppress cancer cell proliferation by initiating proliferative arrest or apoptosis. However, little is known of the anti­cancer mechanisms of HDAC inhibitors in HNSCC. Thus, in the present study, the HNSCC Detroit 562 cell line and primary cultured HNSCC cells were treated with HDAC inhibitors to investigate their effects in HNSCC. Higher expression of p63, HDAC1, JAM­A and claudin­1 was observed in HNSCC tissues compared with the adjacent dysplastic regions. In Detroit 562 cells, treatment with trichostatin A (TSA), an inhibitor of HDAC1 and 6, downregulated the expression of p63, JAM­A and claudin­1, and upregulated that of acetylated tubulin; conversely, p63 knockdown resulted in the downregulation of JAM­A and claudin­1. Collectively, inhibiting HDAC suppressed the migration and invasiveness of cancer cells. In addition, treatment with TSA suppressed cancer cell proliferation via G2/M arrest, as well as upregulating p21 and downregulating cyclin D1 expression. TSA also downregulated the expression of epidermal growth factor receptor (EGFR) and phospho­ERK1/2. p63 knockdown and treatment with an EGFR inhibitor induced G1 arrest and downregulated EGFR and phospho­ERK1/2 levels, respectively. HDAC inhibition also suppressed the migration and invasiveness of primary cultured HNSCC cells. Collectively, the results of the present study indicate that HDAC inhibitors suppress the proliferation, migration and invasiveness of HNSCC by downregulating the p63­mediated tight junction molecules JAM­A and claudin­1, and inducing p63 or p21­mediated growth arrest.

Role of RANK-L as a potential inducer of ILC2-mediated type 2 inflammation in chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 inflammation with accumulation of activated group 2 innate lymphoid cells (ILC2s) and elevation of thymic stromal lymphopoietin (TSLP). A member of the TNF superfamily (TNFSF), TNFSF15, is known to induce the production of type 2 cytokines in ILC2s. Although ILC2s have been implicated in CRSwNP, the presence and role of TNFSFs in ILC2-mediated type 2 inflammation in CRSwNP has not been elucidated. Here, we investigate the involvement of TNFSFs in ILC2-mediated type 2 inflammation in CRSwNP. We found that receptor activator of NF-κB (RANK) ligand (RANK-L (TNFSF11)) was significantly elevated in nasal polyps (NPs), and that the receptor of RANK-L, RANK, was expressed on ILC2s in human peripheral blood and NPs. An agonistic antibody against RANK induced production of type 2 cytokines in human ILC2s, and TSLP significantly enhanced this reaction. The membrane-bound RANK-L was detected mainly on CD45 + immune cells, including TH2 cells in NPs. The co-culture of NP-derived ILC2s and TH2 cells significantly enhanced production of type 2 cytokines, and anti-RANK-L monoclonal antibody suppressed this enhancement. In conclusion, RANK-L, together with TSLP, may play an inductive role in the ILC2-mediated type 2 inflammation in CRSwNP.

Interleukin 5-producing ST2+ memory Th2 cells in IgG4-related dacryoadenitis and sialadenitis.

Objectives: Immunoglobulin (Ig) G4-related disease (IgG4-RD) is often complicated by allergic disorders. This study was conducted to investigate the mechanism of type 2 helper T-inflammation (Th2-inflammation) in IgG4-related dacryoadenitis and sialadenitis (IgG4-DS). Methods: We separated and analyzed the proportion of growth stimulation expressed gene 2 (ST2)+ memory Th2 cells among the peripheral blood mononuclear cells by flow cytometry in cases with IgG4-DS and healthy individuals. Finally, we identified the role of ST2+ memory Th2 cells in the involved tissues. Results: The proportion of circulating ST2+ memory Th2 cells was much higher in the patients with IgG4-DS than in the healthy controls. Abundant infiltration of ST2+ memory Th2 cells was detected in the involved salivary glands and lymph nodes, and these cells produced interleukin-5. Conclusion: We demonstrated that there is an increase of interleukin-5 producing ST2+ memory Th2 cells in the involved tissues in IgG4-DS. This subset of cells is considered to be an important player in inducing the inflammatory Th2 environment characteristic of IgG4-DS.

A serious case of primary Raynaud's phenomenon in an infant.

We present a case of severe Raynaud phenomenon (RP) in an infant. The current strategy of RP treatment is incomplete; excluding secondary Raynaud phenomenon is vital as well. This case aims to help those with similar symptoms in the future by gathering data on cases.

Can a pulse oxygen saturation of 95% to 96% help predict further vital sign destabilization in school-aged children?: A retrospective observational study.

To determine whether a peripheral capillary oxygen saturation (SpO2) of 95% to 96% should be considered "nonurgent" in school-aged children, as suggested by the Canadian Emergency Department Triage and Acuity Scale.School-aged children (6-12 years old) with a normal body temperature (36.5-37.4°C) who visited our department between September, 2014 and August, 2015 (n = 4556) were divided into 4 groups based on SpO2: group A: 99% to 100%; group B: 97% to 98%; group C: 95% to 96%; and group D: ≤94%. The heart rate (HR), respiratory rate (RR), and hospitalization rate were compared among the groups, and also between children with SpO2 95% to 96% and matched controls with SpO2 ≥97% (n = 280 each).Among 4556 eligible patients, groups A, B, C, and D comprised 2700 patients (59.3%), 1534 patients (33.6%), 280 patients (6.2%), and 42 patients (0.9%), respectively. The median (interquartile range [IQR]) RR significantly increased with decreasing SpO2 (23 [20-25], 24 [20-26], 24 [23-30], and 30 [24-40] breaths/min in groups A-D, respectively; P < .001). Similarly, the median (IQR) HR significantly increased with decreasing SpO2 (93 [83-104], 98 [87-110], 107 [93-119], and 121 [109-137] bpm, groups A-D, respectively; P < .001). Group D had the highest annual hospital admission rate (18 cases/42 patients, 42.9%). Further, the HR and RR differed significantly between the cases (107 [93-119] bpm; 24 [23-30] breaths/min) and controls (96 [86-106] bpm; 24 [20-28] breaths/min, respectively) (P < .001 and P = .02, respectively).An SpO2 of 95% to 96% among school-aged children should not be considered "nonurgent," but rather a significant clinical situation that requires early review of HR and RR. Prompt interventions among this group of children will help prevent further destabilization of vital signs, which will, in turn, contribute to decreased healthcare costs.

Predicting therapeutic response in IgG4-related disease based on cluster analysis.

To bring the clinical practice of immunoglobulin (Ig)G4-related disease (IgG4-RD) close to personalized medicine, we classified the patient groups and clarified the therapeutic responses of each group. A total of 147 patients enrolled in our registry were classified into four groups by cluster analysis with the software. The therapeutic responses and prognosis of each group were examined. The cluster analysis classified the subjects into four groups: Cluster 1, patients who presented with prominent hypergammaglobulinemia, elevated levels of serum IgG4, and hypocomplementemia; Cluster 2, patients who presented with eosinophilia, elevated concentrations of serum IgG, IgG4, and IgE, and in whom CRP tended to be positive; Cluster 3, patients with younger onset and serum levels of IgG, IgG4, and IgE and peripheral eosinophil counts lower than the other clusters; and Cluster 4, patients with elder onset and low peripheral eosinophil counts. The amounts of glucocorticoid for maintenance treatment were from 5 to 7 mg/d in all groups, but the amounts were significantly greater in Cluster 1 (patients with hypergammaglobulinemia, elevated levels of serum IgG4, and hypocomplementemia) than in Cluster 4 (elder onset patients, relatively low concentrations of peripheral eosinophils). With regard to the use of immunosuppressants and the relapse rate, there were high frequencies in Cluster 1 and Cluster 3 (younger onset patients who presented with mild elevations of serum IgG and IgG4). On the other hand, Cluster 4 showed a low rate of relapse and often could discontinue steroids. The present results suggest that personalized medicine could be provided in IgG4-RD by classifying patients based on their clinical features.

Downregulation of lipolysis-stimulated lipoprotein receptor promotes cell invasion via claudin-1-mediated matrix metalloproteinases in human endometrial cancer.

Lipolysis-stimulated lipoprotein receptor (LSR) is a novel molecule present at tricellular contacts which recruits tricellulin (TRIC), a molecular component of tricellular tight junctions (tTJs). LSR and TRIC are colocalized with the bicellular tight junction (bTJ) protein claudin (CLDN)-1-based tight junction strands at tricellular corners. Knockdown of LSR in normal epithelial cells affects tTJ formation and the epithelial barrier function. In cancer cells knockdown of LSR has been demonstrated to increase cell invasion. However, the detailed mechanisms of how the downregulation of LSR enhances cell invasion in cancer remain unclear. In the present study, knockdown of LSR by small interfering RNA (siRNA) in Sawano human endometrial adenocarcinoma cells induced cell invasion. In LSR-knockdown Sawano cells, upregulation of CLDN-1 protein, which contributes to the cell invasion via matrix metalloproteinases (MMPs), was observed compared with the control group by western blotting and immunostaining. Knockdown of LSR significantly induced Sp1 transcription factor activity in the CLDN-1 promoter region. In LSR-knockdown Sawano cells, DNA microarray analysis demonstrated that MMP-1, MMP-2 and MMP-10 mRNA levels were increased, and the protein levels of membrane-type 1-MMP, MMP-2, MMP-9 and MMP-10 were shown to be increased on western blots. Knockdown of CLDN-1 with siRNA prevented the upregulation of cell invasion induced by the knockdown of LSR in Sawano cells. On the invasive front of human endometrial carcinoma tissue samples, a decrease in LSR and increase in CLDN-1 protein levels were observed using immunohistochemical methods. In conclusion, the results indicate that the downregulation of LSR promotes cell invasion of human endometrial cancer via CLDN-1 mediation of MMPs. This mechanism is important for studying the association of tTJs with the cellular invasion of cancer.

Regulation of claudin-4 via p63 in human epithelial cells.

P63 is a regulator of cell-cell junction complexes in the epidermis. Claudin-4 is regulated via various factors in normal epithelial cells and diseases. We found that claudin-4 was directly regulated via p63 (TAp63 and ΔNp63) in human keratinocytes and nasal epithelial cells. In the epidermis of atopic dermatitis (AD), which contains ΔNp63-deficient keratinocytes, high expression of claudin-4 was observed. In primary keratinocytes, downregulation of ΔNp63 by treatment with short interfering RNA (siRNA)-p63 induced claudin-4 expression. In nasal epithelial cells in the context of rhinitis or nasal polyps, upregulation of TAp63 and downregulation of claudin-4 were observed. In primary nasal epithelial cells transfected with the human telomerase reverse transcriptase gene, knockdown of p63 by siRNAs induced claudin-4 expression. Taken together, these findings indicate that p63 is a negative regulator of claudin-4 expression. Understanding the regulation of claudin-4 via p63 in human epithelial cells may be important for developing therapies for allergies and drug delivery systems.

The role of transcriptional factor p63 in regulation of epithelial barrier and ciliogenesis of human nasal epithelial cells.

Disruption of nasal epithelial tight junctions (TJs) and ciliary dysfunction are found in patients with chronic rhinosinusitis (CRS) and nasal polyps (NPs), along with an increase of p63-positive basal cells and histone deacetylase (HDAC) activity. To investigate these mechanisms, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were transfected with siRNAs of TAp63 and ΔNp63, treated with the NF-kB inhibitor curucumin and inhibitors of HDACs, and infected with respiratory syncytial virus (RSV). In TERT-HNECs, knockdown of p63 by siRNAs of TAp63 and ΔNp63, induced claudin-1 and -4 with Sp1 activity and enhanced barrier and fence functions. The knockdown of p63 enhanced the number of microvilli with the presence of cilia-like structures. Treatment with curcumin and inhibitors of HDACs, or infection with RSV prevented expression of p63 with an increase of claudin-4 and the number of microvilli. The knockdown or downregulation of p63 inhibited phospho-p38MAPK, and the p38MAPK inhibitor downregulated p63 and upregulated the barrier function. Thus, epithelial barrier and ciliogenesis of nasal epithelium are regulated in a p63-negative manner in normal and upper airway diseases. Understanding of the regulation of p63/p38 MAPK/NF-κB may be important in the therapy for airway allergy and its drug delivery system.

Loss of sorting nexin 5 stabilizes internalized growth factor receptors to promote thyroid cancer progression.

Thyroid carcinoma is the most common endocrine malignancy and its prevalence has recently been increasing worldwide. We previously reported that the level of sorting nexin 5 (Snx5), an endosomal translocator, is preferentially decreased during the progression of well-differentiated thyroid carcinoma into poorly differentiated carcinoma. To address the functional role of Snx5 in the development and progression of thyroid carcinoma, we established Snx5-deficient (Snx5-/- ) mice. In comparison to wild-type (Snx5+/+ ) mice, Snx5-/- mice showed enlarged thyroid glands that consisted of thyrocytes with large irregular-shaped vacuoles. Snx5-/- thyrocytes exhibited a higher growth potential and higher sensitivity to thyroid-stimulating hormone (TSH). A high content of early endosomes enriched with TSH receptors was found in Snx5-/- thyrocytes, suggesting that loss of Snx5 caused retention of the TSH receptor (TSHR) in response to TSH. Similar data were found for internalized EGF in primary thyrocytes. The increased TSH sensitivities in Snx5-/- thyrocytes were also confirmed by results showing that Snx5-/- mice steadily developed thyroid tumors with high metastatic potential under high TSH. Furthermore, a thyroid cancer model using carcinogen and an anti-thyroidal agent revealed that Snx5-/- mice developed metastasizing thyroid tumors with activation of MAP kinase and AKT pathways, which are postulated to be major pathways of malignant progression of human thyroid carcinoma. Our results suggest that thyrocytes require Snx5 to lessen tumorigenic signaling driven by TSH, which is a major risk factor for thyroid carcinoma. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.