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.

FOXO3/TGF-ß signal-dependent ciliogenesis and cell functions during differentiation of temperature-sensitive mouse cochlear precursor hair cells.

The transcription factor FOXO3 is necessary to preserve cochlear hair cells. Growth factors, including TGF-ß, closely contribute to cochlear hair cell regeneration. In the present study, to investigate the roles of FOXO3 in the ciliogenesis and cell functions of cochlear hair cells, UB/OC-2 temperature-sensitive mouse cochlear precursor hair cells were treated with TGF-ß receptor type 1 inhibitor EW-7197 or EGF receptor inhibitor AG-1478 after transfection with or without siRNA-FOXO3a. GeneChip analysis revealed that treatment with EW-7197 increased Foxo3 genes and decreased genes of Smads. During cell differentiation, treatment with EW-7197 or AG-1478 induced an increase in length of cilia-like structures that were positive for acetylated tubulin and inhibited cell migration. Treatment with EW-7197 also increased cell metabolism measured as mitochondrial basal respiration (oxygen consumption rate). The effects of EW-7197 were stronger than those of AG-1478. Knockdown of FOXO3 prevented the growth of cilia-like structures induced by EW-7197 or AG-1478 and induced cell migration under treatment with EW-7197. No change of the epithelial cell polarity molecule PAR3 was observed with any treatment. Treatment with the antimicrobial agent amikacin prevented the growth of cilia-like structures induced by EW-7197 and induced apoptosis. Pretreatment with the glucocorticoid dexamethasone inhibited the apoptosis induced by amikacin. This in vitro model of mouse cochlear hair cells suggests that FOXO3/TGF-ß signaling plays a crucial role in ciliogenesis and cell functions during differentiation of cochlear hair cells. This model is useful for analysis of the mechanisms of hearing loss and to find therapeutic agents to prevent it.

Effects of HMGB1 on Tricellular Tight Junctions via TGF-ß Signaling in Human Nasal Epithelial Cells.

The airway epithelium of the human nasal mucosa acts as a physical barrier that protects against inhaled substances and pathogens via bicellular and tricellular tight junctions (bTJs and tTJs) including claudins, angulin-1/LSR and tricellulin. High mobility group box-1 (HMGB1) increased by TGF-ß1 is involved in the induction of nasal inflammation and injury in patients with allergic rhinitis, chronic rhinosinusitis, and eosinophilic chronic rhinosinusitis. However, the detailed mechanisms by which this occurs remain unknown. In the present study, to investigate how HMGB1 affects the barrier of normal human nasal epithelial cells, 2D and 2.5D Matrigel culture of primary cultured human nasal epithelial cells were pretreated with TGF-ß type I receptor kinase inhibitor EW-7197 before treatment with HMGB1. Knockdown of angulin-1/LSR downregulated the epithelial barrier. Treatment with EW-7197 decreased angulin-1/LSR and concentrated the expression at tTJs from bTJs and increased the epithelial barrier. Treatment with a binder to angulin-1/LSR angubindin-1 decreased angulin-1/LSR and the epithelial barrier. Treatment with HMGB1 decreased angulin-1/LSR and the epithelial barrier. In 2.5D Matrigel culture, treatment with HMGB1 induced permeability of FITC-dextran (FD-4) into the lumen. Pretreatment with EW-7197 prevented the effects of HMGB1. HMGB1 disrupted the angulin-1/LSR-dependent epithelial permeability barriers of HNECs via TGF-ß signaling in HNECs.

Cytotoxic Tph-like cells are involved in persistent tissue damage in IgG4-related disease.

OBJECTIVES: The aim of this study was to determine pathological features of T peripheral helper (Tph)-like (PD-1+CXCR5-CD4+ T) cells in IgG4-related disease (IgG4-RD). METHODS: Tph-like cells in the blood and submandibular glands (SMGs) from IgG4-RD patients were analyzed by flow cytometry. Correlations between level of a Tph-like cell subset and clinical parameters of IgG4-RD were investigated. The cytotoxic capacity of Tph-like cells was also examined. Expression profiles of a molecule related to a Tph-like cell subset in IgG4-RD SMGs were assessed by immunohistochemistry. RESULTS: Tph-like cells from IgG4-RD patients highly expressed a fractalkine receptor, CX3CR1. Percentages of circulating CX3CR1+ Tph-like cells were significantly correlated with clinical parameters including IgG4-RD Responder Index, number of involved organs, and serum level of soluble IL-2 receptor. CX3CR1+ Tph-like cells abundantly possessed cytotoxic T lymphocyte-related molecules such as granzyme A, perforin, and G protein-coupled receptor 56. Functional assays revealed their cytotoxic potential against vascular endothelial cells and ductal epithelial cells. Immunohistochemistry showed that fractalkine was markedly expressed in vascular endothelial cells and ductal epithelial cells in IgG4-RD SMGs. CONCLUSION: CX3CR1+ Tph-like cells are thought to contribute to persistent tissue injury in IgG4-RD and are a potential clinical marker and/or therapeutic target for inhibiting progression of IgG4-RD.

Upregulation of adipocyte enhancer-binding protein 1 in endothelial cells promotes tumor angiogenesis in colorectal cancer.

Tumor angiogenesis is an important therapeutic target in colorectal cancer (CRC). We aimed to identify novel genes associated with angiogenesis in CRC. Using RNA sequencing analysis in normal and tumor endothelial cells (TECs) isolated from primary CRC tissues, we detected frequent upregulation of adipocyte enhancer-binding protein 1 (AEBP1) in TECs. Immunohistochemical analysis revealed that AEBP1 is upregulated in TECs and stromal cells in CRC tissues. Quantitative RT-PCR analysis showed that there is little or no AEBP1 expression in CRC cell lines, but that AEBP1 is well expressed in vascular endothelial cells. Levels of AEBP1 expression in Human umbilical vein endothelial cells (HUVECs) were upregulated by tumor conditioned medium derived from CRC cells or by direct coculture with CRC cells. Knockdown of AEBP1 suppressed proliferation, migration, and in vitro tube formation by HUVECs. In xenograft experiments, AEBP1 knockdown suppressed tumorigenesis and microvessel formation. Depletion of AEBP1 in HUVECs downregulated a series of genes associated with angiogenesis or endothelial function, including aquaporin 1 (AQP1) and periostin (POSTN), suggesting that AEBP1 might promote angiogenesis through regulation of those genes. These results suggest that upregulation of AEBP1 contributes to tumor angiogenesis in CRC, which makes AEBP1 a potentially useful therapeutic target.

Cutting Edge: A Critical Role of Lesional T Follicular Helper Cells in the Pathogenesis of IgG4-Related Disease.

IgG4-related disease (IgG4-RD) is a newly recognized systemic chronic fibroinflammatory disease. However, the pathogenesis of IgG4-RD remains unknown. To determine the pathophysiologic features of IgG4-RD, we examined T follicular helper (Tfh) cells in lesions and blood from patients with IgG4-RD. Patients with IgG4-related dacryoadenitis and sialadenitis (IgG4-DS) showed increased infiltration of Tfh cells highly expressing programmed death 1 and ICOS in submandibular glands. Tfh cells from IgG4-DS submandibular glands had higher expression of B cell lymphoma 6 and a greater capacity to help B cells produce IgG4 than did tonsillar Tfh cells. We also found that the percentage of programmed death 1hi circulating Tfh cells in IgG4-DS patients was higher than that in healthy volunteers and was well correlated with clinical parameters. Our findings indicate that anomalous Tfh cells in tissue lesions of IgG4-RD have features distinct from those in lymphoid counterparts or blood and potentially regulate local IgG4 production in IgG4-RD.

Guanylate binding protein-1-mediated epithelial barrier in human salivary gland duct epithelium.

Guanylate-binding protein-1 (GBP-1) is an interferon-inducible large GTPase involved in the epithelial barrier at tight junctions. To investigate the role of GBP-1 in the epithelial barrier, primary human salivary gland duct epithelial cells were treated with the the proinflammatory cytokines IFNγ, IL-1ß, TNFα and the growth factor TGF-ß. Treatment with IFNγ, IL-1ß, or TNFα markedly enhanced GBP-1 and the epithelial barrier function, and induced not only CLDN-7 but also the tricellular tight junction molecule lipolysis-stimulated lipoprotein receptor (LSR). Knockdown of GBP-1 by its siRNA induced endocytosis of tight junction molecules, and prevented the increases of CLDN-7 and LSR with the upregulation of the epithelial barrier function induced by treatment with IFNγ or TNFα. Treatment with a PKCα inhibitor induced expression of GBP-1, CLDN-7 and LSR and enhanced the epithelial barrier function. In almost intact salivary gland ducts from patients with IgG4-related disease (IgG4-RD) indicated significant infiltration of IgG-positive plasma cells, expression of GBP-1, CLDN-7 and LSR was increased. These findings indicated that GBP-1 might play a crucial role in barrier function of normal human salivary gland duct epithelium and perform a preventive role in the duct epithelium of IgG4-RD disease.

Immunoreactivity patterns of tight junction proteins are useful for differential diagnosis of human salivary gland tumors.

The expression pattern of tight junction proteins (TJPs) varies among organs and tumor types. In this study, we examined the immunoreactivity of claudin (CLDN)-1, -4, and -7, and JAM-A in salivary gland tumors (SGTs) by histological types and cell types to estimate their usefulness as differential diagnostic markers. Immunoreactivity of CLDN1 was higher in ductal epithelium cells of SGTs than in non-tumor tissues. Conversely, immunoreactivity of CLDN1 was significantly decreased in basal/myoepithelium cells of SGTs compared with that in non-tumor tissues. There was no significant difference between the immunoreactivity of CLDN1 in benign tumors and that in malignant tumors. Immunoreactivity of CLDN4, CLDN7, and JAM-A in ductal epithelium cells was higher in many SGTs than in non-tumor tissues. There was a difference depending on the histological type of SGT in immunoreactivity of CLDN4, CLDN7, and JAM-A in basaloid/myoepithelial cells. It was possible to classify SGTs by a hierarchical clustering using immunoreactivity of TJPs. The results suggest that an immunohistochemical marker panel including these TJPs may be useful for differential diagnosis of SGTs and that CLDN1 is associated with tumorigenesis of SGTs.

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.

Evaluation of consistency in quantification of gene copy number by real-time reverse transcription quantitative polymerase chain reaction and virus titer by plaque-forming assay for human respiratory syncytial virus.

The plaque-forming assay is the standard technique for determining viral titer, and a critical measurement for investigating viral replication. However, this assay is highly dependent on experimental technique and conditions. In the case of human respiratory syncytial virus (RSV) in particular, it can be difficult to objectively confirm the accuracy of plaque-forming assay because the plaques made by RSV are often small and unclear. In recent studies, RT-qPCR methods have emerged as a supportive procedure for assessment of viral titer, yielding highly sensitive and reproducible results. In this report, we compare the viral replication, as determined by plaque-forming assay, and the copy numbers of RSV genes NS1, NS2, N, and F, as determined by RT-qPCR. Two real-time PCR systems, SYBR Green and TaqMan probe, gave highly similar results for measurement of copy numbers of RSV N genes of virus subgroups A. We determined the RSV gene copy numbers in the culture cell supernatant and cell lysate measured at various multiplicities of infection. We found that copy number of the RSV N gene in the culture supernatant and cell lysate was highly correlated with plaque-forming units. In conclusion, RT-qPCR measurement of RSV gene copy number was highly dependent on viral titer, and the detailed comparison between each gene copy number and virus titer should be useful and supportive in confirming RSV plaque-forming assay and virus dynamics. The technique may also be used to estimate the amount of RSV present in clinical specimens.

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.

Stage classification of IgG4-related dacryoadenitis and sialadenitis by the serum cytokine environment.

OBJECTIVES: Patients with immunoglobulin-G4 related disease (IgG4-RD) diagnosed according to the comprehensive diagnostic criteria (CDC) show varied therapeutic responses and prognoses. We assumed that there are clinical stages in IgG4-RD and have verified it using serum cytokine levels in the groups classified by lesion distribution. METHODS: Definite IgG4-related dacryoadenitis and sialadenitis (IgG4-DS) cases were divided according to the CDC for IgG4-RD into 11 cases with focal type and 30 cases with systemic type. The levels of serum interleukin (IL)-4, IL-5, IL-6, IL-10, IL-13, IL-15, IL-21, interferon (IFN)-α, IFN-γ, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-ß1, and monocyte chemotactic protein (MCP)-1 were measured in healthy controls, allergic patients, probable IgG4-RD cases, and focal and systemic type cases. The cytokine environment was analyzed in each group. The 52 definite IgG4-RD cases were next classified into four groups with cluster analysis in terms of therapeutic responses and prognosis. The relationships between each cytokine level and therapeutic responses were also analyzed. RESULTS: Both serum IL-5 and IFN-α concentrations were very low in healthy controls, but they increased in the allergic cases, probable cases, and focal and systemic type cases. The level of serum IL-5 was significantly higher in definite cases than in healthy controls. The serum IL-5 level was also significantly increased in the groups with a poor prognosis than in the good prognosis group. CONCLUSION: These results suggest that there are clinical stages in IgG4-RD, and serum IL-5 play roles in the pathogenesis of IgG4-RD.

Bob1 limits cellular frequency of T-follicular helper cells.

T follicular helper (Tfh) cells are involved in specific humoral immunity at initial and recall phases. The fact that the transcription repressors B-cell lymphoma-6 and Blimp-1 determine lineages of Tfh cells and other types of effector CD4(+) T cells, respectively, suggests that there are unique mechanisms to establish Tfh-cell identity. In this study, we found that Tfh cells preferentially express the transcriptional coactivator Bob1. Bob1 of Tfh cells was dispensable for the expression of B-cell lymphoma-6 and the functional property of the cells for B cell help. However, upon initial immunization of foreign antigens, the percentages of Tfh cells in Bob1(-/-) mice were much higher than those in wild-type (WT) mice. In addition, expansion of Tfh cells within Bob1(-/-) CD4(+) T cells transferred into WT mice revealed that the high frequency of Tfh cells was caused by a T-cell-intrinsic mechanism. These findings were further supported by the results of in vitro studies demonstrating that Bob1(-/-) Tfh cells had greater proliferative activity in response to stimuli by CD3/CD28 monoclonal antibody and were also refractory to CD3-induced cell death in comparison to WT Tfh cells. These results suggest that Tfh cells harbor a Bob1-related mechanism to restrict numerical frequency against stimulation of TCRs.

Mitochondrial proteins NIP-SNAP-1 and -2 are a target for the immunomodulatory activity of clarithromycin, which involves NF-κB-mediated cytokine production.

Macrolide antibiotics have immunomodulatory activities, including suppression of cytokine production, cell adhesion molecule expression, and mucin production. These immunomodulatory activities improve the symptoms of respiratory diseases associated with chronic inflammation. However, the underlying molecular mechanism(s) is not well understood yet. To address this, we prepared clarithromycin (CAM)-conjugated Sepharose and examined bound cellular proteins by proteome analysis. We identified mitochondrial proteins 4-nitrophenylphosphatase domain and non-neuronal synaptosomal associated protein 25-like protein homolog (NIP-SNAP)-1 and -2 and very long-chain acyl-CoA dehydrogenase (VLCAD) as CAM-binding proteins. Production of proinflammatory cytokines (IL-8 and IL-6) induced by lipopolysaccharides (LPSs) and Pam3-CSK4 in human epithelial cell lines BEAS-2B and T24 were suppressed by knockdown of NIP-SNAP-1 or -2, and partly by knockdown of VLCAD. Also, knockdown of NIP-SNAP-1 or -2 in various cell lines suppressed LPS-induced expression of IL-8 and IL-6 mRNA and NF-κB activity. Thus, CAM suppresses NF-κB-mediated proinflammatory cytokine production by interacting with mitochondrial proteins, NIP-SNAP-1 and -2.

NIP-SNAP-1 and -2 mitochondrial proteins are maintained by heat shock protein 60.

NIP-SNAP-1 and -2 are ubiquitous proteins thought to be associated with maintenance of mitochondrial function, neuronal transmission, and autophagy. However, their physiological functions remain largely unknown. To elucidate their functional importance, we screened for proteins that interact with NIP-SNAP-1 and -2, resulting in identification of HSP60 and P62/SQSTM1 as binding proteins. NIP-SNAP-1 and -2 localized in the mitochondrial inner membrane space, whereas HSP60 localized in the matrix. Native gel electrophoresis and filter trap assays revealed that human HSP60 prevented aggregation of newly synthesized NIP-SNAP-2 in an in vitro translation system. Moreover, expression levels of NIP-SNAP-1 and -2 in cells were decreased by knockdown of HSP60, but not HSP10. These findings indicate that HSP60 promotes folding and maintains the stability of NIP-SNAP-1 and -2.

Clarithromycin prevents human respiratory syncytial virus-induced airway epithelial responses by modulating activation of interferon regulatory factor-3.

Macrolide antibiotics exert immunomodulatory activity by reducing pro-inflammatory cytokine production by airway epithelial cells, fibroblasts, vascular endothelial cells, and immune cells. However, the underlying mechanism of action remains unclear. Here, we examined the effect of clarithromycin (CAM) on pro-inflammatory cytokine production, including interferons (IFNs), by primary human nasal epithelial cells and lung epithelial cell lines (A549 and BEAS-2B cells) after stimulation by Toll-like receptor (TLR) and RIG-I-like receptor (RLR) agonists and after infection by human respiratory syncytial virus (RSV). CAM treatment led to a significant reduction in poly I:C- and RSV-mediated IL-8, CCL5, IFN-ß and -λ production. Furthermore, IFN-ß promoter activity (activated by poly I:C and RSV infection) was significantly reduced after treatment with CAM. CAM also inhibited IRF-3 dimerization and subsequent translocation to the nucleus. We conclude that CAM acts a crucial modulator of the innate immune response, particularly IFN production, by modulating IRF-3 dimerization and subsequent translocation to the nucleus of airway epithelial cells. This newly identified immunomodulatory action of CAM will facilitate the discovery of new macrolides with an anti-inflammatory role.

Alteration of circulating type 2 follicular helper T cells and regulatory B cells underlies the comorbid association of allergic rhinitis with bronchial asthma.

Allergic rhinitis (AR), the most common allergic disorder of the airway, is often accompanied by bronchial asthma. However, little is known about the mechanism by which AR advances to AR comorbid with bronchial asthma (AR+Asthma). To determine the pathophysiologic features of AR and AR+Asthma, we examined subsets of follicular helper T (Tfh) cells and regulatory B (Breg) cells in peripheral blood from AR and AR+Asthma patients. The results showed polarization of Tfh2 cells within Tfh cell subsets in both AR and AR+Asthma cases. Interestingly, the %Breg cells in total B cells were decreased in AR cases and, more extensively, in AR+Asthma cases. Moreover, we found significant correlations of fractional exhaled nitric oxide and blood eosinophil levels with the index %Tfh2 cells per %Breg cells. Our findings indicate that relative decrease in Breg cells under the condition of Tfh2 cell skewing is a putative exaggerating factor of AR to bronchial asthma.

Irsogladine maleate regulates gap junctional intercellular communication-dependent epithelial barrier in human nasal epithelial cells.

The airway epithelium of the human nasal mucosa acts as the first physical barrier that protects against inhaled substances and pathogens. Irsogladine maleate (IM) is an enhancer of gastric mucosal protective factors via upregulation of gap junctional intercellular communication (GJIC). GJIC is thought to participate in the formation of functional tight junctions. However, the effects of IM on GJIC and the epithelial barrier in human nasal epithelial cells (HNECs) remain unknown. To investigate the effects of IM on GJIC and the tight junctional barrier in HNECs, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were treated with IM and the GJIC inhibitors oleamide and 18ß-GA. Some cells were pretreated with IM before treatment with TLR3 ligand poly(I:C) to examine whether IM prevented the changes via TLR3-mediated signal pathways. In hTERT-HNECs, GJIC blockers reduced the expression of tight junction molecules claudin-1, -4, -7, occludin, tricellulin, and JAM-A. IM induced GJIC activity and enhanced the expression of claudin-1, -4, and JAM-A at the protein and mRNA levels with an increase of barrier function. GJIC blockers prevented the increase of the tight junction proteins induced by IM. Furthermore, IM prevented the reduction of JAM-A but not induction of IL-8 and TNF-α induced by poly(I:C). In conclusion, IM can maintain the GJIC-dependent tight junctional barrier via regulation of GJIC in upper airway nasal epithelium. Therefore, it is possible that IM may be useful as a nasal spray to prevent the disruption of the epithelial barrier by viral infections and exposure to allergens in human nasal mucosa.

Identification of relapse predictors in IgG4-related disease using multivariate analysis of clinical data at the first visit and initial treatment.

OBJECTIVES: Inducting clinical remission by glucocorticoid treatment is relatively easy in IgG4-related disease (IgG4-RD), but relapse also occurs easily with tapering of the steroid dose. The present study tried to analyse the cases to extract predictors of relapse present at the diagnosis of IgG4-RD. METHODS: Subjects comprised 79 patients with IgG4-related dacryoadenitis and sialadenitis, known as Mikulicz's disease, who were diagnosed between April 1997 and October 2013 and followed-up for >2 years from the initial induction treatment. They were applied to Cox proportional hazard modelling, based on the outcome of interval to relapse. We performed multivariate analysis for the clinical factors of these cases and identified predictors of relapse. RESULTS: Identified factors were male sex and younger onset in cases without organ involvement at diagnosis and low levels of serum IgG4 in cases with organ dysfunction at diagnosis. Complication with autoimmune pancreatitis and low steroid dose at initial treatment also tended to be associated with recurrence. CONCLUSION: Follow-up is important in cases with recognized risk factors for relapse, including male sex and younger onset in cases without organ damage.