Search

Sjögren's syndrome is a chronic autoimmune disorder whose pathogenesis is poorly understood and that lacks effective therapies. Detailed quantitative and spatial analyses of tissues affected by Sjögren's syndrome were undertaken, including the quantitation of the frequency of selected cell-cell interactions in the disease milieu. Quantitative analyses of CD4

How T follicular (Tfh) cells contribute to many different B-cell class-switching events during T-cell-dependent immune responses has been unclear. Diseases with polarized isotype switching offer a unique opportunity for the exploration of Tfh subsets. Secondary and tertiary lymphoid organs in patients with elevated tissue expression levels of IgE (Kimura disease, KD) and those of IgGWe sought to identify disease-specific Tfh cell subsets in secondary and tertiary lymphoid organs expressing IL-10 or IL-13 and thus identify different cellular drivers of class switching in 2 distinct types of fibrotic disorders: allergic fibrosis (driven by type 2 immune cells) and inflammatory fibrosis (driven by cytotoxic T lymphocytes).Single-cell RNA sequencing, in situ sequencing, and multicolor immunofluorescence analysis were used to investigate B cells, Tfh cells, and infiltrating type 2 cells in lesion tissues from patients with KD or IgGInfiltrating Tfh cells in tertiary lymphoid organs from IgGOur analysis revealed a novel subset of IL-10

IgG4-related disease (IgG4-RD) is a fibro-inflammatory condition that can affect multiple organs. We previously demonstrated that TLR7-transgenic C57BL/6 mice showed elevated serum IgG1 levels and inflammation with fibrosis in the salivary glands (SGs), lungs, and pancreas. Moreover, we observed extensive Toll-like receptor 7 (TLR-7)-positive CD163+ M2 macrophage infiltration in SGs from IgG4-RD patients. We undertook this study to examine the fibrotic mechanism via the TLR-7 pathway.Gene expression in SGs from human TLR7-transgenic mice and IgG4-RD patients was analyzed using DNA microarrays. We extracted the common up-regulated TLR-7-related genes in SGs from TLR7-transgenic mice and IgG4-RD patients. Finally, we investigated the interaction between CD163+ M2 macrophages and fibroblasts before and after stimulation with the TLR-7 agonist loxoribine.In TLR7-transgenic mice and IgG4-RD patients, IRAK3 and IRAK4 were significantly overexpressed. Real-time polymerase chain reaction validated the up-regulation of only IRAK4 in IgG4-RD patients compared with the other groups (P 0.05). Interleukin-1 receptor-associated kinase 4 (IRAK4) was strongly detected in and around germinal centers in SGs from patients with IgG4-related dacryoadenitis and sialadenitis alone. Double immunofluorescence staining showed that IRAK4-positive cells were mainly colocalized with CD163+ M2 macrophages in SGs (P 0.05). After stimulation with loxoribine, CD163+ M2 macrophages exhibited significantly enhanced expression of IRAK4 and NF-κB and increased supernatant concentrations of fibrotic cytokines. Finally, we confirmed that the number of fibroblasts was increased by culture with the supernatant of CD163+ M2 macrophages following stimulation with loxoribine (P 0.05).CD163+ M2 macrophages promote fibrosis in IgG4-RD by increasing the production of fibrotic cytokines via TLR-7/IRAK4/NF-κB signaling.

Immunoglobulin G4 (IgG4)-related dacryoadenitis and sialoadenitis (IgG4-DS) are part of a multiorgan fibroinflammatory condition of unknown etiology termed IgG4-related disease (IgG4-RD), which has been recognized as a single diagnostic entity for less than 15 years. Histopathologic examination is critical for diagnosis of IgG4-RD. CD4+ T and B cells, including IgG4-expressing plasma cells, constitute the major inflammatory cell populations in IgG4-RD and are thought to cause organ damage and tissue fibrosis. Patients with IgG4-RD who have active, untreated disease exhibit significant increase of IgG4-secreting plasmablasts in the blood. Considerable insight into the immunologic mechanisms of IgG4-RD has been achieved in the last decade using novel molecular biology approaches, including next-generation and single-cell RNA sequencing. Exploring the interactions between CD4+ T cells and B lineage cells is critical for understanding the pathophysiology of IgG4-RD. Establishment of pathogenic T cell clones and identification of antigens specific to these clones constitutes the first steps in determining the pathogenesis of the disease. Herein, the clinical features and mechanistic insights regarding pathogenesis of IgG4-RD were reviewed.

OBJECTIVE IgG4-related disease (IgG4-RD) is a unique inflammatory disorder in which Th2 cytokines promote IgG4 production. In addition, recent studies have implicated the Toll-like receptor (TLR) pathway. This study was undertaken to examine the expression of TLRs in salivary glands (SGs) from patients with IgG4-RD. METHODS SGs from 15 patients with IgG4-RD, 15 patients with Sjogren's syndrome (SS), 10 patients with chronic sialadenitis, and 10 healthy controls were examined histologically. TLR family gene expression (TLR-1 through TLR-10) was analyzed by DNA microarray in the submandibular glands (SMGs). Up-regulation of TLRs was confirmed in SGs from patients with IgG4-RD. Finally, the phenotype of human TLR-7 (huTLR-7)-transgenic C57BL/6 mice was assessed before and after stimulation with TLR agonist. RESULTS In patients with IgG4-RD, TLR-4, TLR-7, TLR-8, and TLR-9 were overexpressed. Polymerase chain reaction validated the up-regulation of TLR-7 in IgG4-RD compared with the other groups. Immunohistochemical analysis confirmed strong infiltration of TLR-7-positive cells in the SGs of patients with IgG4-RD. Double immunohistochemical staining showed that TLR-7 expression colocalized with CD163+ M2 macrophages. After in vitro stimulation with a TLR-7 agonist, CD163+ M2 macrophages produced higher levels of interleukin-33 (IL-33), which is a Th2-activating cytokine. In huTLR-7-transgenic mice, the focus and fibrosis scores in SMGs, pancreas, and lungs were significantly higher than those in wild-type mice (P < 0.05). Moreover, the concentration of serum IgG, IgG1, and IL-33 in huTLR-7-transgenic mice was distinctly increased upon stimulation with a TLR-7 agonist (P < 0.05). CONCLUSION TLR-7-expressing M2 macrophages may promote the activation of Th2 immune responses via IL-33 secretion in IgG4-RD.

Osteoid osteoma is a benign bone-forming tumor and characterized by its limited growth potential, not exceeding 2 cm. The radiological hallmark of this tumor is a nidus, which is a small round area of relative radiolucency. Osteoid osteoma can involve any bone but is most commonly found in long bones and is extremely rare in the head and neck region. This disease characteristically presents with dull pain, worse at night, and sometimes relieved with NSAIDs. A 24-year-old Japanese woman presented with spontaneous pain and tenderness on the lingual side of her mandibular second molar on the right side. The patient reported that her pain had gradually increased, becoming more continuous and severe and no longer responding to NSAIDs. An initial panoramic radiograph revealed an oval, internally non-uniform, somewhat obscure boundaries in the right mandible. Computed tomography (CT) scan revealed a sclerotic lesion with a delineated central calcified nidus surrounded by a radiolucent band. The interior of the nidus was a non-uniform, irregularly shaped area of high absorption. The nidus was removed with intralesional curettage under general anesthesia. The histopathology of the specimen consisted of actively proliferating osteoblasts mixed with an interlacing network of immature bone and osteoid trabeculae. Immunohistochemistry revealed that hardly detected osteoblasts or fibrous stromal cells with intense nuclear immunoreactivity for p16 and/or murine double minute 2 (mdm2). We thus distinguished the tumor from Low-grade central osteosarcoma (LGCO) with immunohistochemical findings. The histopathological diagnosis was thus osteoid osteoma.

Clear cell squamous cell carcinoma (CCSCC), where cells show abundant clear cytoplasm, -is a variant of squamous cell carcinoma (SCC) and a rare entity in the oral cavity. The characteristics of CCSCC, especially in immunohistochemical features, remain unclear. We characterized a case of CCSCC arising from the oral mucosal epithelium of tongue, where the clear cell lesion accounted for a predominant portion of the tumor. This CCSCC, which was partially surrounded by conventional SCC, exhibited cellular atypia immunohistopathologically and histopathologically with a high Ki-67 index, increased number of mitotic figures and enlarged nuclei. Intravascular invasion of the carcinoma cells was also observed. Furthermore, the CCSCC recurred and metastasized to the cervical lymph nodes and both lungs three months after resection. Immunohistochemical analyses demonstrated decreased expression of p40 (an isoform of SCC marker p63), ADP-ribosylation factor (ARF)-like 4c (ARL4C), yes-associated protein (YAP) and 5-methylcytosine (5mC) in the CCSCC lesion compared with the surrounding SCC lesion, where the expression of ARL4C was upregulated compared with non-tumor region and YAP showed nuclear translocation. In addition, siRNA loss-of-function experiments revealed that p63 expression was required for ARL4C expression and DNA methylation was induced by p63 and YAP/transcriptional co-activator with PDZ-binding motif (TAZ) signaling in oral SCC cell lines. These results suggest that CCSCC, in which several markers of SCC-associated intracellular signaling pathways are downregulated, together with evidence of altered epigenetic regulation, is characterized as an undifferentiated SCC variant.

Objectives IgG4-related disease (IgG4-RD) is a systemic fibro-inflammatory disorder characterized by a dysregulated resolution of inflammation and wound healing response that might develop after an apoptotic insult induced by cytotoxic T lymphocytes (CTLs). Mer receptor tyrosine kinase (MerTK) and its ligand, protein S (ProS1), have a pivotal role in the resolution of inflammation, being implicated in the clearance of apoptotic cells, quenching of the immune response and development of tissue fibrosis. In the present work we aimed to investigate a possible involvement of the MerTK signalling pathway in the pathogenesis of IgG4-RD and development of tissue fibrosis. Methods MerTK and ProS1 expression patterns in IgG4-RD lesions were evaluated by immunohistochemistry and immunofluorescence studies. Circulating MerTK+ monocytes, soluble Mer and MerTK ligands were measured in the peripheral blood of IgG4-RD patients and healthy controls by flow cytometry and ELISA, respectively. Results MerTK was highly expressed by macrophages infiltrating IgG4-RD lesions. MerTK+ macrophages were more abundant in IgG4-RD than in Sjögren’s syndrome and interacted with apoptotic cells and ProS1-expressing T and B lymphocytes. Moreover, they expressed the pro-fibrotic cytokine TGF-β and their numbers declined following rituximab-induced disease remission. Circulating MerTK+ monocytes, soluble Mer and MerTK ligands were not increased in the peripheral blood of patients with IgG4-RD. Conclusions The MerTK–ProS1 axis is activated in IgG4-RD lesions, possibly leading to persistent stimulation of processes involved in the resolution of inflammation and tissue fibrosis.

Background: IgG(4)-related disease (IgG(4)-RD) is an immune-mediated fibrotic disorder that has been linked to CD4(+) cytotoxic T lymphocytes (CD4(+)CTLs). The effector phenotype of CD4(+)CTLs and the relevance of both CD8(+) cytotoxic T lymphocytes (CD8(+)CTLs) and apoptotic cell death remain undefined in IgG(4)-RD.Objective: We sought to define CD4(+)CTL heterogeneity, characterize the CD8(+)CTL response in the blood and in lesions, and determine whether enhanced apoptosis may contribute to the pathogenesis of IgG(4)-RD.Methods: Blood analyses were undertaken using flow cytometry, cell sorting, transcriptomic analyses at the population and single-cell levels, and next-generation sequencing for the TCR repertoire. Tissues were interrogated using multicolor immunofluorescence. Results were correlated with clinical data.Results: We establish that among circulating CD4(+)CTLs in IgG(4)-RD, CD27(lo)CD28(lo)CD57(hi) cells are the dominant effector subset, exhibit marked clonal expansion, and differentially express genes relevant to cytotoxicity, activation, and enhanced metabolism. We also observed prominent infiltration of granzyme A-expressing CD8(+)CTLs in disease tissues and clonal expansion in the blood of effector/memory CD8(+) T cells with an activated and cytotoxic phenotype. Tissue studies revealed an abundance of cells undergoing apoptotic cell death disproportionately involving nonimmune, nonendothelial cells of mesenchymal origin. Apoptotic cells showed significant upregulation of HLA-DR.Conclusions: CD4(+)CTLs and CD8(+)CTLs may induce apoptotic cell death in tissues of patients with IgG(4)-RD with preferential targeting of nonendothelial, nonimmune cells of mesenchymal origin.

Background IgG4-related disease (IgG4-RD) is a fibroinflammatory condition involving loss of B-cell tolerance and production of autoantibodies. However, the relevant targets and role of these aberrant humoral immune responses are not defined. Objective Our aim was to identify novel autoantibodies and autoantigen targets that promote pathogenic responses in IgG4-RD. Methods We sequenced plasmablast antibody repertoires in patients with IgG4-RD. Representative mAbs were expressed and their specificities characterized by using cytokine microarrays. The role of anti–IL-1 receptor antagonist (IL-1RA) autoantibodies was investigated by using in vitro assays. Results We identified strong reactivity against human IL-1RA by using a clonally expanded plasmablast-derived mAb from a patient with IgG4-RD. Plasma from patients with IgG4-RD exhibited elevated levels of reactivity against IL-1RA compared with plasma from the controls and neutralized IL-1RA activity, resulting in inflammatory and fibrotic mediator production in vitro. IL-1RA was detected in lesional tissues from patients with IgG4-RD. Patients with anti–IL-1RA autoantibodies of the IgG4 subclass had greater numbers of organs affected than did those without anti–IL-1RA autoantibodies. Peptide analyses identified IL-1RA epitopes targeted by anti–IL-1RA antibodies at sites near the IL-1RA/IL-1R interface. Serum from patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) also had elevated levels of anti–IL-1RA autoantibodies compared with those of the controls. Conclusion A subset of patients with IgG4-RD have anti–IL-1RA autoantibodies, which promote proinflammatory and profibrotic meditator production via IL-1RA neutralization. These findings support a novel immunologic mechanism underlying the pathogenesis of IgG4-RD. Anti–IL-1RA autoantibodies are also present in a subset of patients with SLE and RA, suggesting a potential common pathway in multiple autoimmune diseases.

Systemic sclerosis (SSc) is an autoimmune fibrotic disease whose pathogenesis is poorly understood and lacks effective therapies. We undertook quantitative analyses of T cell infiltrates in the skin of 35 untreated patients with early diffuse SSc and here show that CD4(+) cytotoxic T cells and CD8(+) T cells contribute prominently to these infiltrates. We also observed an accumulation of apoptotic cells in SSc tissues, suggesting that recurring cell death may contribute to tissue damage and remodeling in this fibrotic disease. HLA-DR-expressing endothelial cells were frequent targets of apoptosis in SSc, consistent with the prominent vasculopathy seen in patients with this disease. A circulating effector population of cytotoxic CD4(+) T cells, which exhibited signatures of enhanced metabolic activity, was clonally expanded in patients with systemic sclerosis. These data suggest that cytotoxic T cells may induce the apoptotic death of endothelial and other cells in systemic sclerosis. Cell loss driven by immune cells may be followed by overly exuberant tissue repair processes that lead to fibrosis and tissue dysfunction.

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a chronic, systemic, inflammatory condition of unknown etiology. Histopathologic examination is the key to diagnosis of IgG4-RD. The histopathologic features of IgG4-RD are lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis. As for fewer than 15 years, IgG4-RD has been recognized as a unified diagnostic entity. CD4+ T and B cells, which likely cause organ damage and disabling tissue fibrosis, constitute the major inflammatory cell population in patients with IgG4-RD. Affected patients with active, untreated disease have a marked expansion of IgG4-secreting plasmablasts in the blood. Important mechanistic insights regarding the pathogenesis of IgG4-RD have been gradually disclosed in recent years. Exploring the role of interactions between these CD4+ T and B cells in patients with IgG4-RD is a highly promising field of investigation. In this review, we focus on CD4+ T cell subsets and the T-cell clones that are involved in the pathogenesis of IgG4-RD.

IgG4-related disease (IgG4-RD) is a systemic, multi-organ disorder with heterogeneous clinical features but distinctive presentations.1, 2 The classic onset of this disease is subacute, taking the form of tumor-like lesions that develop gradually. These lesions are generally identified either on physical examination (e.g., salivary gland enlargement) or imaging (e.g., a renal, lung, or pancreatic mass), frequently at a time when the patient feels well. In the first years following recognition of IgG4-RD, the diagnosis was often made by pathologists in the complete absence of clinical suspicion for the disease. More recently, because of growing familiarity with typical IgG4-RD presentations and the use of blood IgG4 testing, presumptive diagnoses are often rendered by clinicians before the performance of diagnostic tests. Biopsy confirmation of the diagnosis remains important in most cases. IgG4-RD is not a new disease. Cases of the disease are well documented in medical history going back at least to the late 1800s3 , but the individual organ manifestations were considered to be distinct disease entities for more than a century, each confined to single organs and given eponymic designations: e.g., Riedel’s thyroiditis (circa 1883), Kuttner’s tumor (dacryoadenitis involving the submandibular gland, circa 1896), and Ormond’s disease (circa 1960).4, 5, 6 In 2001, Hamano, Kawa, and colleagues demonstrated that an elevated serum IgG4 level was useful in distinguishing “sclerosing pancreatitis,” now termed type 1 (IgG4-related) autoimmune pancreatitis, from other diseases of the pancreatic and biliary tract.7 In 2003, Kamisawa and Nakajima recognized similar pathology findings in extra-pancreatic organs of patients with sclerosing pancreatitis.8 They described a disease typified by elevated serum IgG4 levels, responsiveness to glucocorticoids, multi-organ involvement, and a fibroinflammatory infiltrate. The name “IgG4-related autoimmune disease” was given to this disorder initially because of the abundance of IgG4-expressing plasma cells within affected tissues, thereby unifying seemingly disparate conditions. The involvement of bile ducts, major salivary glands, lymph nodes, and retroperitoneal tissue was also described in this original case series. Since that time, IgG4-RD has been reported to affect virtually every organ in the body. The lacrimal gland, lung, and kidney are other common sites of disease involvement [Figure 1, A–B].2 The aorta, pachymeninges, and bile ducts comprise exceptions to the tumefactive clinical presentation, presumably because of their tubular structures and/or thin walls.9, 10, 11 Open in a separate window Open in a separate window Figure 1 (A) Head and neck illustration highlighting involvement of the lacrimal and major salivary glands. Lacrimal and salivary gland enlargement is most often bilateral in distribution. (B) Abdomen illustration highlighting typical organ involvement including the pancreas, bile ducts, kidneys, and retroperitoneal tissue. Radiographically, the retroperitoneal fibrosis often extends inferiorly to encase the iliac vessels. Not depicted here, the aorta and lung are other common sites of disease involvement.

BACKGROUND: IgG4-related disease (IgG4-RD) is an immune-mediated fibrotic disorder that has been linked to CD4+ cytotoxic T lymphocytes (CD4+CTLs). The effector phenotype of CD4+CTLs, the relevance of both CD8+ cytotoxic T lymphocytes (CD8+CTLs) and of apoptotic cell death remain undefined in IgG4-RD. OBJECTIVE: The goals of this study were to define CD4+CTL heterogeneity, characterize the CD8+CTL response in the blood and in lesions, and determine whether enhanced apoptosis may contribute to the pathogenesis of IgG4-RD. METHODS: Blood analyses were undertaken using flow cytometry, cell sorting, transcriptomic analyses at the population and single cell levels and next generation sequencing for the TCR repertoire. Tissues were interrogated using multi-color immunofluorescence. Results were correlated with clinical data. RESULTS: We establish that among circulating CD4+CTLs in IgG4-RD, CD27loCD28loCD57hi cells are the dominant effector subset, exhibit marked clonal-expansion and differentially express genes relevant to cytotoxicity, activation and enhanced metabolism. We also observed prominent infiltration of granzyme A-expressing CD8+CTLs in disease tissues and clonal-expansion in the blood of effector/memory CD8+ T cells with an activated and cytotoxic phenotype. Tissue studies revealed an abundance of cells undergoing apoptotic cell death disproportionately involving non-immune, non-endothelial cells of mesenchymal origin. Apoptotic cells showed significant upregulation of HLA-DR. CONCLUSION: CD4+CTLs and CD8+CTLs may induce apoptotic cell death in tissues of patients with IgG4-RD with preferential targeting of non-endothelial, non-immune cells of mesenchymal origin. CLINICAL IMPLICATION: T cell mediated apoptosis in disease lesions may contribute to the induction of fibrosis in IgG4-RD. Effector CD4+CTLs and CD8+CTLs correlate with disease severity in IgG4-RD.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a prominent stromal reaction that has been variably implicated in both tumor growth and tumor suppression. B-lymphocytes have been recently implicated in PDAC progression but their contribution to the characteristic stromal desmoplasia has never been assessed before. In the present work, we aimed to verify whether B-lymphocytes contribute to stromal cell activation in PDAC. CD19+ B-lymphocytes purified from peripheral blood of patients with PDAC were cultivated in the presence of human pancreatic fibroblasts and cancer-associated fibroblasts. Released pro-fibrotic soluble factors and collagen production were assessed by ELISA and Luminex assays. Quantitative RT-PCR was used to assess fibroblast activation in the presence of B cells. The expression of selected pro-fibrotic and inflammatory molecules was confirmed on PDAC tissue sections by multi-color immunofluorescence studies. We herein demonstrate that B-cells from PDAC patients (i) produce the pro-fibrotic molecule PDGF-B and stimulate collagen production by fibroblasts; (ii) express enzymes implicated in extracellular matrix remodeling including LOXL2; and (iii) produce the chemotactic factors CCL-4, CCL-5, and CCL-11. In addition we demonstrate that circulating plasmablasts are expanded in the peripheral blood of patients with PDAC, stimulate collagen production by fibroblasts, and infiltrate pancreatic lesions. Our results indicate that PDAC is characterized by perturbations of the B-cell compartment with expansion of B-lymphocyte subsets that directly contribute to the stromal reaction observed at disease site. These findings provide an additional rationale for modulating B-cell activity in patients with pancreatic cancer.

Tumor-associated macrophages (TAMs) promote tumor progression and inhibit anti-tumor immune response by producing various mediators and preferentially express CD163, CD204, and CD206. However, the role of these TAM subsets in oral squamous cell carcinoma (OSCC) remains unclear. Here we investigated the expression and function of TAM subsets in OSCC, especially in cancer cell proliferation. Biopsy sample from 44 patients with OSCC were examined for the expression of TAM markers and EGF by immunohistochemistry. EGF production of TAM subsets isolated from OSCC patients was assessed by flow cytometry. We also examined the effect of conditioned medium from TAM subsets on the proliferation of OSCC cells. CD163+ cells were detected diffusely all over the tumor and connective tissue area, while CD204+ and CD206+ cells were mainly detected in/around the tumors. Flow cytometric analysis found that CD206+ TAMs strongly produced EGF compared with CD163+ and CD204+ TAMs. Cell proliferation and invasion of OSCC cells cultured with conditioned medium of CD206+ TAMs were strongly enhanced and inhibited by anti-EGFR. The number of CD206+ TAMs positively correlated with worse clinical prognosis. Our results revealed differences in localization and EGF production among these TAM subsets. CD206+ TAMs might play a critical role in the proliferation of OSCC via EGF production.

Background Plate fixation is one of the standard surgical treatments for distal femoral fractures. There are few reports on the relationship between the screw position and bone union when fixing by the bridging plate (relative stability) method. Methods This retrospective study included 71 distal femoral fractures of 70 patients who were treated with the locking compression plate for distal femur (DePuy Synthes Co., Ltd, New Brunswick, CA, USA). The following measurements were evaluated and analyzed: (1) bone union rate, (2) bridge span length (distance between screws across the fracture), (3) plate span ratio (plate length/bone fracture length), (4) number of empty holes (number of screw holes not inserted around the fracture), and (5) medial fracture distance (bone fracture distance on the medial side of the distal femur). Patient demographics (age), comorbidities (smoking, diabetes, chronic steroid use, dialysis), and injury characteristics (AO type, open fracture, infection) were obtained for all participants. Univariate analysis was performed on them. Results Of 71 fractures, 26 fractures were simple fractures, 45 fractures were comminuted fractures, and 7 fractures resulted in non-union. Non-union rate was significantly higher in comminuted fractures with bone medial fracture distance exceeding 5 mm. Non-union was founded in simple fractures with bone medial fracture distance exceeding 2 mm, but not significant (p = 0.06). In cases with simple fractures, one non-union case had one empty hole and one non-union case had four empty holes, whereas in cases with comminuted fractures, five non-union cases had two more empty holes. Conclusions We concluded that bone fragment distance between fracture fragments is more important than bridge span length of the fracture site and the number of empty holes. Smoking and medial fracture distance are prognostic risk factors of nonunion in distal femoral fractures treated with LCP as bridging plate.

Study DesignProspective study.PurposeDuring fluoroscopically guided spinal procedure, the hands of spinal surgeons are placed close to the field of radiation and may be exposed to ionizing radiation. This study directly measured the radiation exposure to the hand of a spinal interventionalist during fluoroscopically guided procedures.Overview of LiteratureFluoroscopically guided spinal procedures have been reported to be a cause for concern due to the radiation exposure to which their operators are exposed.MethodsThis prospective study evaluated the radiation exposure of the hand of one spinal interventionalist during 52 consecutive fluoroscopic spinal procedures over a 3-month period. The interventionalist wore three real-time dosimeters secured to the right forearm, under the lead apron over the chest, and outside the lead apron over the chest. Additionally, one radiophotoluminescence glass dosimeter was placed under the lead apron over the left chest and one ring radiophotoluminescence glass dosimeter was worn on the right thumb. The duration of exposure and radiation dose were measured for each procedure.ResultsThe average radiation exposure dose per procedure was 14.9 µSv, 125.6 µSv, and 200.1 µSv, inside the lead apron over the chest, outside the lead apron over the chest, and on the right forearm, respectively. Over the 3-month period, the protected radiophotoluminescence glass dosimeter over the left chest recorded less than the minimum reportable dose, whereas the radiophotoluminescence glass ring dosimeter recorded 368 mSv for the thumb.ConclusionsOur findings indicated that the cumulative radiation dose measured at the dominant hand may exceed the annual dose limit specified by the International Commission on Radiological Protection. Spinal interventionalists should take special care to limit the duration of fluoroscopy and radiation exposure.

Background IgG 4 -related disease (IgG 4 -RD) is a systemic condition of unknown cause characterized by highly fibrotic lesions with dense lymphoplasmacytic infiltrates. CD4 + T cells constitute the major inflammatory cell population in IgG 4 -RD lesions. Objective We used an unbiased approach to characterize CD4 + T-cell subsets in patients with IgG 4 -RD based on their clonal expansion and ability to infiltrate affected tissue sites. Methods We used flow cytometry to identify CD4 + effector/memory T cells in a cohort of 101 patients with IgG 4 -RD. These expanded cells were characterized by means of gene expression analysis and flow cytometry. Next-generation sequencing of the T-cell receptor β chain gene was performed on CD4 + SLAMF7 + cytotoxic T lymphocytes (CTLs) and CD4 + GATA3 + T H 2 cells in a subset of patients to identify their clonality. Tissue infiltration by specific T cells was examined by using quantitative multicolor imaging. Results CD4 + effector/memory T cells with a cytolytic phenotype were expanded in patients with IgG 4 -RD. Next-generation sequencing revealed prominent clonal expansions of these CD4 + CTLs but not CD4 + GATA3 + memory T H 2 cells in patients with IgG 4 -RD. The dominant T cells infiltrating a range of inflamed IgG 4 -RD tissue sites were clonally expanded CD4 + CTLs that expressed SLAMF7, granzyme A, IL-1β, and TGF-β1. Clinical remission induced by rituximab-mediated B-cell depletion was associated with a reduction in numbers of disease-associated CD4 + CTLs. Conclusions IgG 4 -RD is prominently linked to clonally expanded IL-1β– and TGF-β1–secreting CD4 + CTLs in both peripheral blood and inflammatory tissue lesions. These active, terminally differentiated, cytokine-secreting effector CD4 + T cells are now linked to a human disease characterized by chronic inflammation and fibrosis.

ObjectivesIgG4-related disease (IgG4-RD) is a chronic, systemic, inflammatory condition of unknown aetiology. We have recently described clonally expanded circulating CD4+ cytotoxic T lymphocytes (CTLs) in IgG4-RD that infiltrate affected tissues where they secrete interleukin (IL)-1β and transforming growth factor -β1 (TGF-β1). In this study, we sought to examine the role of CD4+ CTLs in the pathogenesis of IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS) and to determine whether these cells secrete interferon-gamma (IFN-γ) at lesional sites.MethodsSalivary glands of 25 patients with IgG4-DS, 22 patients with Sjögren's syndrome (SS), 12 patients with chronic sialoadenitis (CS) and 12 healthy controls were analysed in this study. Gene expression analysis was performed on submandibular glands (SMGs) from five patients with IgG4-DS, three with CS and three healthy controls. Infiltrating CD4+ CTLs were examined by quantitative multicolour imaging in tissue samples from 20 patients with IgG4-DS, 22 patients with SS, 9 patients with CS and 9 healthy controls.ResultsIn IgG4-DS tissues, nine genes associated with CD4+ CTLs were overexpressed. The expression of granzyme A (GZMA) mRNA was significantly higher in samples from patients with IgG4-RD compared with corresponding tissues from SS and healthy controls. Quantitative imaging showed that infiltrating CD4+ GZMA+ CTLs were more abundant in patients with IgG4-DS than in the other groups. The ratio of CD4+GZMA+ CTLs in SMGs from patients with IgG4-DS correlated with serum IgG4 concentrations and the number of affected organs. A large fraction of CD4+GZMA+ CTLs in SMGs from patients with IgG4-DS secreted IFN-γ.ConclusionsThe pathogenesis of IgG4-DS is associated with tissue infiltration by CD4+GZMA+ CTLs that secrete IFN-γ.

For the definitive diagnosis of IgG4-related disease (IgG4-RD), biopsies of local lesions are recommended so as to exclude other diseases, including lymphoma and cancer. However, performing biopsies of underlying organs is technically difficult. In this study, we examined the diagnostic utility of labial salivary gland (LSG) biopsy as a less invasive procedure.Sixty-six patients with suspected IgG4-RD by clinical findings or high serum IgG4 underwent LSG biopsy. We examined the relationship between the number of IgG4-positive plasma cells in LSG and clinical findings.The final diagnosis was 45 patients with IgG4-RD, 12 with Sjögren's syndrome, four with suspected Sjögren's syndrome, three with malignant lymphoma, one with systemic lupus erythematosus, and one with Warthin's tumor. The sensitivity, specificity, and accuracy of LSG biopsy were 55.6%, 100.0%, and 70.0%, respectively. Forty-five IgG4-RD patients were divided into two groups: 1) 25 with lesions of salivary glands (IgG4-RD S+) and 2) 20 without these lesions (IgG4-RD S-). Seventeen of 25 (68.0%) IgG4-RD S + and 8 of 20 (40.0%) IgG4-RD S - patients were positive for LSG biopsy. In the IgG4-RD S - patients, the mean number of affected organs and serum IgG4 in the positive cases for LSG biopsy were significantly higher than in the negative cases.A solo LSG biopsy is insufficient for the diagnosis of IgG4-RD because of its low sensitivity. However, LSG biopsy combined with clinical findings, including serum IgG4 and number of affected organs, may contribute towards a diagnosis of IgG4-RD patients with affected underlying organs.

Background:IgG4-Related Disease (IgG4-RD) is characterized by fibrotic lesions, serum IgG4 elevation, and prompt response to glucocorticoids. B and T lymphocytes are considered the initiators of tissue inflammation in IgG4-RD, but the prominent stromal reaction observed at disease sites suggest that a dysregulation of processes involved in the resolution of inflammation could be pathologically relevant as well. Mer receptor tyrosine kinase (MerTK) and its ligands protein S (Pros1) have a pivotal role in the resolution of inflammation through the activation of a well-characterized signaling pathway that ultimately dampens the immune response and promotes the recovery of tissue function. MerTK and the processes involved in the resolution of inflammation have never been addressed in IgG4-RD.Objectives:To investigate MerTK involvement in the pathogenesis of IgG4-RD by evaluating (a) the expression of MerTK and of its endogenous ligands in IgG4-RD tissues; (b) the presence of circulating precursors of MerTK+ cells infiltrating IgG4-RD lesions in the peripheral blood of IgG4-RD patients; (c) the effects of immunosuppressive therapies on MerTK expression in IgG4-RD tissues.Methods:Three distinct cohorts of IgG4-RD patients were included in this study. 8 active patients were used for immunohistochemistry studies for MerTK expression. 16 IgG4-RD and 14 Sjögren syndrome patients, together with 6 control tonsils, were used for multicolor immunofluorescence studies and TissueQuest software quantification of the expression of MerTK, CD68, CD163, Pros1, Gas6, CD4, SLAMF7, CD19, IgG4, cleaved caspase-3. 10 untreated IgG4-RD patients were used to evaluate MerTK expression in circulating monocytes subsets and fibrocytes by flow cytometry.Results:MerTK was highly expressed in IgG4-RD affected organs. MerTK+ cells accounted on average for 16% (range 5-35%) of all cells in the tissue, and the majority of them expressed CD68,reflecting a monocyte-macrophage origin. 33.5 % (interquartile range (IQR) 26-41%) of MerTK+ cells co-expressed CD68 and CD163, while 30.5% (IQR 19-41.5%) expressed CD68 but not CD163. CD68+MerTK+ cells displayed two main morphological appearances, compatible with those of macrophages and of myofibroblasts. In addition, MerTK+ cell number was significantly increased in salivary glands from IgG4-RD patients compared to Sjögren syndrome (p < 0.0001). Circulating precursors of CD68+MerTK+ cells infiltrating IgG4-RD lesions were identified by flow cytometery in the peripheral blood of patients with active IgG4-RD as MerTK+ populations of intermediate monocytes, nonclassical monocytes and collagen expressing fibrocytes. MerTK ligand Pros1 was exposed on 52% (IQR 42-57%) of infiltrating B lymphocytes, 74% (IQR 54-89%) of infiltrating T lymphocytes, and, likely, on apoptotic cells that were detected in IgG4-RD tissues. CD68+MerTK+ cells were found in physical contact with Pros1+ cells in IgG4-RD lesions and their number decreased by 56% after successful treatment with rituximab.Conclusion:MerTK is abundant in IgG4-RD affected organs and is preferentially expressed on CD68+ macrophages and myofibroblasts that infiltrate IgG4-RD lesions. MerTK+ cells might interact with apoptotic cells and Pros1 expressing T and B lymphocytes in IgG4-RD tissues, leading to the persistent activation of processes involved in the resolution of inflammation and promoting the development of tissue fibrosis.Disclosure of Interests:None declared

Objectives: In this study, we investigated the diagnostic utility of submandibular gland (SMG) sonography and labial salivary gland (LSG) biopsy as a less invasive procedure for diagnosing ...

Background IgG4-related disease (IgG4-RD) is a fibroinflammatory condition marked by rapid clinical improvement after selective depletion of B lymphocytes with rituximab. This feature suggests that B cells might participate in fibrogenesis and wound healing. Objective In the present work we aimed to demonstrate that B lymphocytes contribute directly to tissue fibrosis in patients with IgG4-RD. Methods Total circulating CD19+ B lymphocytes, naive B cells, memory B cells, or plasmablasts from patients with IgG4-RD were cultivated with human fibroblasts. Profibrotic soluble factors and collagen production in cocultures were assessed by using ELISAs and Luminex assays. RNA sequencing and quantitative RT-PCR were used to assess fibroblast activation in the presence of B cells, as well as induction of profibrotic pathways in B-cell subsets. Relevant profibrotic and inflammatory molecules were confirmed in vitro by using functional experiments and on IgG4-RD tissue sections by using multicolor immunofluorescence studies. Results B cells from patients with IgG4-RD (1) produced the profibrotic molecule platelet-derived growth factor B and stimulated collagen production by fibroblasts; (2) expressed enzymes implicated in extracellular matrix remodeling, such as lysyl oxidase homolog 2; (3) produced the chemotactic factors CCL4, CCL5, and CCL11; and (4) induced production of these same chemokines by activated fibroblasts. Plasmablasts expressed sets of genes implicated in fibroblast activation and proliferation and therefore represent cells with intrinsic profibrotic properties. Conclusion We have demonstrated that B cells contribute directly to tissue fibrosis in patients with IgG4-RD. These unanticipated profibrotic properties of B lymphocytes, particularly plasmablasts, might be relevant for fibrogenesis in patients with other fibroinflammatory disorders and for wound-healing processes in physiologic conditions.

Immunoglobulin G4-related disease (IgG4-RD), recognized only recently as a single diagnostic entity, is a chronic inflammatory condition of unknown etiology. The diagnosis of IgG4-RD relies heavily on histopathological analysis and the correlation of histology findings with clinical, serological, and radiological data. CD4+ T and B cells, including IgG4-expressing plasmablasts, constitute the major inflammatory cell populations in IgG4-RD and are believed to cause organ damage and tissue fibrosis. Patients with IgG4-RD, who have active, untreated disease, exhibit marked expansion of IgG4-secreting plasmablasts in the blood. Important mechanistic insights correlated with the pathogenesis of IgG4-RD have been disclosed in recent years through the application of novel molecular biology approaches, including next-generation and single-cell RNA sequencing. Exploration of the interactions between these CD4+ T cells and cells of the B lymphocyte lineage is critical to understanding the pathophysiology of IgG4-RD. The establishment of pathogenic T cell clones and the identification of antigens specific to these clones constitute the first steps in determining the pathogenesis of this disease. This review focuses on clinical features and mechanistic insights regarding IgG4-related dacryoadenitis and sialoadenitis, from a perspective suitable for oral and maxillofacial surgeons.

Distinct TFH subsets that influence specific class-switching events are assumed to exist, but the accumulation of isotype-specific TFH subsets in secondary and tertiary lymphoid organs has not been hitherto demonstrated. IL-4 expressing TFH cells are surprisingly sparse in human secondary lymphoid organs. In sharp contrast, in IgG4-related disease (IgG4-RD), a disorder characterized by polarized Ig class switching, most TFH cells in tertiary and secondary lymphoid organs make IL-4. Human IL-4+ TFH cells do not express GATA-3 but express nuclear BATF, and the transcriptomes of IL-4 secreting TFH cells differ both from PD1hi TFH cells that do not secrete IL-4 and IL4-secreting non-TFH cells. Unlike IgG4-RD, IL-4+ TFH cells are rarely found in tertiary lymphoid organs in Sjögren’s syndrome, a disorder in which IgG4 is not elevated. The proportion of CD4+IL-4+BATF+ T cells as well as of CD4+IL-4+CXCR5+ T cells in IgG4-RD tissues correlates tightly with tissue IgG4 plasma cell numbers and plasma IgG4 levels in patients but not with the total plasma levels of other isotypes. These data describe a disease-related TFH sub-population in human tertiary and secondary lymphoid organs that is linked to IgG4 class switching.

The purpose of this study was to assess the effect of timing (Early (E) group vs Delayed (D) group) of internal fixation for distal radius fractures on forearm and wrist function in patients who underwent the surgery. The subjects were one hundred six patients who had extra-articular fractures of the dorsally displaced distal radius and were treated with a volar locking plate. The subjects were divided into two groups: E group (Operation on the day of injury or the next day, n = 76 ; and the D group (Operation at 7 days after injury or later, n = 30). Follow-up examinations conducted at 4, 12, and 48 weeks after surgery included measurements of wrist and forearm ranges of motion (ROM), measurement of grip strength (GS), Disability of the Arm, Shoulder and Hand score (DASH), and complications, retrospectively. The patients in both groups improved significantly with respect to ROM, GS, and DASH. At 4 weeks, the patients in the E group had better forearm motion, At 4 and 12 weeks, those who had undergone early surgery had significantly better wrist motion, GS and DASH. At 48 weeks, there were no differences between the groups in ROM, GS, or DASH. Patients with dorsally displaced extra-articular fractures of the distal radius can expect to have better short-term outcomes with early treatment, open reduction and internal fixation using a volar locking plates.

Purpose The purpose of this study was to clarify the usefulness of noninvasive examination items such as sialometry and Visual Analog Scale (VAS) in distinguishing Sjogren's syndrome (SS) in dry mouth patients from neurogenic/neuropsychiatric disorders and drugs (DND). Patients and methods The study cohort comprised 50 patients with SS and 28 patients with DND. The gum test and Saxon test for stimulated salivary flow rate (SSFR), the spitting test for unstimulated salivary flow rate (USFR) and VAS were performed in all the patients with dry mouth. Results In SS patients, the SSFR (mean: gum test, 6.34 mL/10 min; Saxon test, 1.19 g/2 min) and USFR (0.61 mL/15 min) were decreased. In DND patients, the SSFR (gum test, 16.35 mL/10 min; Saxon test, 3.58 g/2 min) was within the normal range, but the USFR (0.90 mL/15 min) was decreased. In VAS, SS patients scored significantly higher in the items of “water-drinking at meals”, “difficulty in swallowing”, and “taste abnormality”, while significantly lower in the item of “oral pain”. Conclusion These results suggest that the SSFR, USFR and VAS could be useful in distinguishing DND from SS.

IgG4-related disease (IgG4-RD) is a chronic inflammatory disease characterized by tumescent lesions with characteristic storiform fibrosis, obliterative phlebitis and a marked lymphoplasmacytic infiltrate that includes a large number of IgG4 positive plasma cells. It's widely accepted that rituximab-mediated B cell depletion therapy is effective for this disease. Important mechanistic insights correlated with the pathogenesis of IgG4-RD have been gradually disclosed from studies of patients treated by B cell depletion. 1) IgG4-RD patients have the large clonal expansion of activated plasmablasts and CD4+CTLs, so this disease might be antigen-driven. 2) CD4+CTLs are the dominant population in affected tissues, on the other hands direct examination of TH1 and TH2 cells in tissues reveal that these subsets are sparse. 3) CD4+CTLs into affected lesions secret cytotoxic, inflammatory, and pro-fibrotic cytokines, indicating reactivation by antigen in tissue sites. 4) The decline in CD4+CTLs number by B cell depletion is associated with clinical remission of IgG4-RD patients. 5) CD4+CXCR5+TFH cells that express IL-4 are located outside germinal centers and specialized TFH cells that expanded dramatically in conditions with polarized class switching to IgG4. These results suggested that the disease pathogenesis might be based on orchestrating of activated plasmablasts, CD4+CTLs, and TFH cells.

IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS) is characterized by serum IgG4 elevation and the infiltration of IgG4-positive plasma cells in glandular tissues. For definitive diagnosis of IgG4-DS, biopsies of local lesions are recommended to exclude Sjögren's syndrome (SS), malignant tumours, and similar disorders. In this study, we examined the diagnostic utility of submandibular gland (SMG) and labial salivary gland (LSG) biopsies in IgG4-DS. Fourteen patients presenting with swelling of the SMG (eight females and six males) underwent both SMG and LSG biopsies. The sensitivity, specificity, and accuracy of SMG biopsies were all 100.0%. In contrast, those of LSG biopsies were 69.2%, 100.0%, and 71.4%, respectively. Thirty-three out of 61 LSG biopsies (54.1%) from all 14 patients were positive for the diagnostic criteria of IgG4-DS (IgG4-positive/IgG-positive plasma cells >0.4). None of the patients experienced complications such as facial nerve palsy, sialocele, or hyposalivation. The IgG4/IgG ratio showed no significant correlation between the LSG and SMG. The final diagnosis was IgG4-DS in 13 patients and marginal zone B-cell lymphoma (MZL) in one. These results suggest that incisional biopsy of the SMG is useful and appropriate for the definitive diagnosis of IgG4-DS, while diagnosis by LSG biopsy alone requires more caution.

IgG4-related disease (IgG4-RD) is a systemic disease characterized by the elevation of serum IgG4 and infiltration of IgG4-positive plasma cells in multiple target organs, including the pancreas, kidney, biliary tract and salivary glands. In contrast, Mikulicz's disease (MD) has been considered a subtype of Sjögren's syndrome (SS) based on histopathological similarities. However, it is now recognized that MD is an IgG4-RD distinguishable from SS and called as IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS). Regarding immunological aspects, it is generally accepted that CD4+ T helper (Th) cells play a crucial role in the pathogenesis of SS. Since it is well known that IgG4 is induced by Th2 cytokines such as interleukin (IL)-4 and IL-13, IgG4-DS is speculated to be a unique inflammatory disorder characterized by Th2 immune reactions. However, the involvement of Th cells in the pathogenesis of IgG4-DS remains to be clarified. Exploring the role of Th cell subsets in IgG4-DS is a highly promising field of investigation. In this review, we focus on the selective localization and respective functions of Th cell subsets and discuss the differences between SS and IgG4-DS to clarify the pathogenic mechanisms of these diseases.