Optical Biopsies Using Probe-Based Confocal Laser Endomicroscopy for Autoimmune Pulmonary Alveolar Proteinosis.

INTRODUCTION: Increasing numbers of cases of mild asymptomatic pulmonary alveolar proteinosis (PAP) are being reported with the recent increase in chest computed tomography (CT). Bronchoscopic diagnosis of mild PAP is challenging because of the patchy distribution of lesions, which makes it difficult to obtain sufficient biopsy samples. Additionally, the pathological findings of mild PAP, particularly those that differ from severe PAP, have not been fully elucidated. This study aimed to clarify the pathological findings of mild PAP and the usefulness of optical biopsy using probe-based confocal laser endomicroscopy (pCLE). METHODS: We performed bronchoscopic optical biopsy using pCLE and tissue biopsy in 5 consecutive patients with PAP (three with mild PAP and two with severe PAP). We compared the pCLE images of mild PAP with those of severe PAP by integrating clinical findings, tissue pathology, and chest CT images. RESULTS: pCLE images of PAP showed giant cells with strong fluorescence, amorphous substances, and thin alveolar walls. Images of affected lesions in mild PAP were equivalent to those obtained in arbitrary lung lesions in severe cases. All 3 patients with mild PAP spontaneously improved or remained stable after ≥3 years of follow-up. Serum autoantibodies to granulocyte-macrophage colony-stimulating factor were detected in all 5 cases. CONCLUSION: Optical biopsy using pCLE can yield specific diagnostic findings, even in patients with mild PAP. pCLE images of affected areas in mild and severe PAP showed similar findings, indicating that the dysfunction level of pathogenic alveolar macrophages in affected areas is similar between both disease intensities.

Predictive risk factors for pneumothorax after transbronchial biopsy using endobronchial ultrasonography with a guide sheath.

BACKGROUND: Pneumothorax is one complication of transbronchial biopsy (TBB) using endobronchial ultrasonography with a guide sheath (EBUS-GS-TBB). We sought to clarify the risk factors for pneumothorax after EBUS-GS-TBB under fluoroscopic guidance. METHODS: We retrospectively reviewed data from 916 patients who underwent EBUS-GS-TBB at Fujita Health University Hospital. We evaluated the following risk factors for pneumothorax after EBUS-GS-TBB: patient characteristics (sex, age, and pulmonary comorbidities); lesion data (location, size, existence of ground-glass opacities [GGOs], pleural involvement, computed tomography [CT] bronchus sign, visibility on fluoroscopy, and EBUS findings); final diagnosis; years of bronchoscopist experience; and guide sheath size. Univariate and multivariate logistic regression analyses were performed. RESULTS: Among the 916 patients, 30 (3.28%) presented with pneumothorax. With a univariate analysis, factors that independently predisposed to pneumothorax included lesions containing GGOs, lesions in sagittal lung segments on fluoroscopy, lesions that were not visible on fluoroscopy, and infectious lesions. A univariate analysis also showed that lesions in the right upper lobe or left upper division, as well as malignant lesions, were less likely to lead to pneumothorax. Age, underlying pulmonary disease, CT bronchus sign, EBUS findings, bronchoscopist experience, and guide sheath size did not influence the incidence of pneumothorax. A multivariate analysis revealed that only lesions containing GGOs (odds ratio [OR] 6.47; 95% confidence interval [CI] 2.13-19.6, P = 0.001) and lesions in lung segments with a sagittal orientation on fluoroscopy (OR 2.47; 95% CI 1.09-5.58, P = 0.029) were significant risk factors for EBUS-GS-TBB-related pneumothorax. CONCLUSIONS: EBUS-GS-TBB of lesions containing GGOs or lesions located in sagittal lung segments on fluoroscopy correlate with a higher pneumothorax risk.

Progression of autoimmune hepatitis is mediated by IL-18-producing dendritic cells and hepatic CXCL9 expression in mice.

UNLABELLED: Clinical manifestations of autoimmune hepatitis (AIH) range from mild chronic to acute, sometimes fulminant hepatitis. However, it is unknown how the progression to fatal hepatitis occurs. We developed a mouse model of fatal AIH by inducing a concurrent loss of forkhead box P3(+) regulatory T cells and programmed cell death-1 (PD-1)-mediated signaling. In this model, dysregulated follicular helper T cells in the spleen are responsible for the induction, and the C-C chemokine receptor 6/C-C chemokine ligand 20 axis is crucial for the migration of these T cells into the liver. Using this fatal AIH model, we aimed to clarify key molecules triggering fatal AIH progression. During progression, T-bet together with interferon (IFN)-γ and C-X-C chemokine receptor (CXCR)3 were highly expressed in the inflamed liver, suggesting helper T (Th)1-type inflammation. T cells that dominantly expanded in the spleen and the inflamed liver were CXCR3-expressing CD8(+) T cells; depletion of these CD8(+) T cells suppressed AIH progression. Expression of one CXCR3 ligand, chemokine (C-X-C motif) ligand (CXCL)9, was elevated in the liver. CXCL9-expressing macrophages/Kupffer cells were colocalized with infiltrating T cells, and in vivo administration of anti-CXCL9 suppressed AIH progression. In addition, serum levels of interleukin (IL)-18, but not IL-1ß, were elevated during progression, and dendritic cells in the spleen and liver highly produced IL-18. In vivo administration of anti-IL-18R suppressed the increase of splenic CXCR3(+) T cells and the progression to fatal AIH. Moreover, tumor necrosis factor alpha, but not IFN-γ, was involved in up-regulating CXCL9 in the liver and for increased serum levels of IL-18. CONCLUSION: These data suggest that, in our mouse model, fatal progression of AIH is mediated by IL-18-dependent differentiation of T cells into Th1 cells and effector T cells, respectively, and that CXCR3-CXCL9 axis-dependent migration of those T cells is crucial for fatal progression.

Splenectomy prolongs the effects of corticosteroids in mouse models of autoimmune hepatitis.

BACKGROUND & AIMS: Most patients with autoimmune hepatitis (AIH) initially respond to treatment with corticosteroids but often experience a relapse after treatment is withdrawn. BALB/c mice with disruption of programmed cell death 1 (PD-1(-/-) mice) that undergo thymectomy 3 days after birth develop a deregulated immune system, have reduced numbers of Foxp3(+) regulatory T cells, and develop fulminant hepatic failure that resembles acute-onset AIH in humans. We examined whether splenectomy overcomes corticosteroid insufficiency and reduces the severity of AIH in these mice. We also developed a mouse model of chronic AIH to investigate the effects of splenectomy. METHODS: After thymectomy, BALB/c PD-1(-/-) mice were treated with dexamethasone before or after induction of AIH; splenectomy was performed in mice that had and had not been treated with dexamethasone. Neonatal C57BL/6 PD-1(-/-) mice underwent thymectomy to create a model of chronic AIH. RESULTS: Injection of dexamethasone before or after induction of AIH prevented development of fatal AIH in BALB/c PD-1(-/-) mice. However, injection of dexamethasone after induction of AIH did not suppress splenic production of follicular helper T cells, and discontinuation of dexamethasone led to a relapse of AIH. Splenectomy (even without administration of dexamethasone) prevented AIH. Neonatal C57BL/6 PD-1(-/-) mice that underwent thymectomy developed chronic hepatitis with fibrosis and hypergammaglobulinemia and produced antinuclear antibodies; AIH was found to be induced in the spleen. Splenectomy reduced liver inflammation in these mice and in BALB/c PD-1(-/-) mice with AIH. CONCLUSIONS: AIH can be induced in mice via disruption of PD-1 and thymectomy; these cause the same disruptions in immune regulation in BALB/c and C57BL/6 mice but produce different phenotypes. Splenectomy overcomes corticosteroid insufficiency in mice and prolongs the effects of dexamethasone.

Increased susceptibility to autoimmune gastritis in thymic stromal lymphopoietin receptor-deficient mice.

Thymic stromal lymphopoietin (TSLP), mainly produced by epithelial cells, activates a variety of cell types, including dendritic cells, mast cells, T cells, and B cells. It is involved in the pathogenesis of allergic inflammation in the lung, skin, and gastrointestinal tract. In addition, TSLP promotes Th2-type intestinal immunity against helminth infection and regulates Th1-type inflammation in a mouse model of colitis, suggesting that it plays crucial roles in intestinal immune homeostasis. Although autoimmune gastritis (AIG), mediated by inflammatory Th1 responses, develops in the gastric mucosa, it is not clear whether TSLP is involved in regulating these responses in AIG. The aim of this study was to examine the roles of TSLP in the development of AIG. Because BALB/c mice thymectomized 3 d after birth (NTx mice) develop AIG, we used this model to test the role of TSLP in the development of AIG. We found that in AIG-bearing mice, TSLP was expressed in the inflamed stomach and that the serum anti-parietal cell Ab levels in neonatal thymectomized TSLPR-deficient mice (NTx-TSLPR(-/-) mice) were significantly elevated over those in NTx-TSLPR(+/+) mice. In addition, NTx-TSLPR(-/-) mice exhibited an earlier onset of AIG than that observed in NTx-TSLPR(+/+) mice. The rapid development of AIG in NTx-TSLPR(-/-) mice resulted in more aggressive CD4(+) T cell infiltration and more severe loss of parietal and chief cells in the progression phase of AIG, accompanied by enhanced production of IL-12/23p40 and IFN-γ. Taken together, these data suggested that TSLP negatively regulates the development of AIG.

It might be a dead end: immune checkpoint inhibitor therapy in EGFR-mutated NSCLC.

Despite innovative advances in molecular targeted therapy, treatment strategies using immune checkpoint inhibitors (ICIs) for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) have not progressed significantly. Accumulating evidence suggests that ICI chemotherapy is inadequate in this population. Biomarkers of ICI therapy, such as programmed cell death ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs), are not biomarkers in patients with EGFR mutations, and the specificity of the tumor microenvironment has been suggested as the reason for this. Combination therapy with PD-L1 and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors is a concern because of its severe toxicity and limited efficacy. However, early-stage NSCLC may differ from advanced-stage NSCLC. In this review, we comprehensively review the current evidence and summarize the potential of ICI therapy in patients with EGFR mutations after acquiring resistance to treatment with EGFR-tyrosine kinase inhibitors (TKIs) with no T790M mutation or whose disease has progressed on osimertinib.

TNF-α is essential in the induction of fatal autoimmune hepatitis in mice through upregulation of hepatic CCL20 expression.

It is unclear what roles TNF-α has in the development of autoimmune hepatitis (AIH) and whether AIH is responsive to anti-TNF-α. We recently developed a mouse model of fatal AIH that develops in PD-1-deficient mice thymectomized three days after birth, finding that CCR6-CCL20 axis-dependent migration of dysregulated splenic T cells is crucial to induce AIH. In this study, we show the indispensable role of TNF-α in the development of AIH. Administering anti-TNF-α prevented the induction, but treatment by anti-TNF-α after the induction did not suppress progression. Administering anti-TNF-α did not prevent splenic T-cell activation, but did suppress hepatic CCL20 expression. In contrast, administering anti-CCL20 suppressed AIH but not elevated serum TNF-α levels. TNF-α stimulation enhanced CCL20 expression in hepatocytes. These findings suggest that TNF-α is essential in the induction of AIH through upregulation of hepatic CCL20 expression, which allows migration of dysregulated splenic T cells.

Interleukin-21 and tumor necrosis factor-α are critical for the development of autoimmune gastritis in mice.

BACKGROUND AND AIM: Autoimmune gastritis (AIG), an organ-specific autoimmune disease, is accompanied by achlorhydria, pernicious anemia, gastric carcinoid tumors, and gastric cancer. Patients with AIG initially respond to corticosteroids but have a great potential to relapse after treatment is withdrawn. This study examines the roles of cytokines in order to identify potential therapeutic options for AIG patients. METHODS: Using a mouse model of AIG, we monitored disease progression and administered antibodies in vivo to block cytokines. RESULTS: We developed a mouse model of AIG with early onset and rapid progression in which neonatal thymectomy (NTx) was performed on programmed cell death 1-deficient (PD-1(-/-) ) mice on the BALB/c background. Using NTx-PD-1(-/-) mice, we found that in AIG lesions, interferon-γ, and tumor necrosis factor (TNF)-α together with interleukin-21 (IL-21) were highly expressed in the inflamed gastric mucosa. In addition, as with the injection of dexamethasone, in vivo administration of either anti-TNF-α or anti-IL-21 suppressed the development of AIG in NTx-PD-1(-/-) mice. CONCLUSIONS: These data reveal the essential role of IL-21 in the development of AIG and suggest that in addition to corticosteroids, anti-TNF-α as well as anti-IL-21 have the potential to induce the remission of AIG, offering additional therapeutic options for AIG patients.

Beta-1,4-galactosyltransferase-3 deficiency suppresses the growth of immunogenic tumors in mice.

Background: Beta-1,4-galactosyltransferase-3 (B4GALT3) belongs to the family of beta-1,4-galactosyltransferases (B4GALTs) and is responsible for the transfer of UDP-galactose to terminal N-acetylglucosamine. B4GALT3 is differentially expressed in tumors and adjacent normal tissues, and is correlated with clinical prognosis in several cancers, including neuroblastoma, cervical cancer, and bladder cancer. However, the exact role of B4GALT3 in the tumor immune microenvironment (TIME) remains unclear. Here, we aimed to elucidate the function of B4GALT3 in the TIME. Methods: To study the functions of B4GALT3 in cancer immunity, either weakly or strongly immunogenic tumor cells were subcutaneously transplanted into wild-type (WT) and B4galt3 knockout (KO) mice. Bone marrow transplantation and CD8+ T cell depletion experiments were conducted to elucidate the role of immune cells in suppressing tumor growth in B4galt3 KO mice. The cell types and gene expression in the tumor region and infiltrating CD8+ T cells were analyzed using flow cytometry and RNA sequencing. N-glycosylated proteins from WT and B4galt3 KO mice were compared using the liquid chromatography tandem mass spectrometry (LC-MS/MS)-based glycoproteomic approach. Results: B4galt3 KO mice exhibited suppressed growth of strongly immunogenic tumors with a notable increase in CD8+ T cell infiltration within tumors. Notably, B4galt3 deficiency led to changes in N-glycan modification of several proteins, including integrin alpha L (ITGAL), involved in T cell activity and proliferation. In vitro experiments suggested that B4galt3 KO CD8+ T cells were more susceptible to activation and displayed increased downstream phosphorylation of FAK linked to ITGAL. Conclusion: Our study demonstrates that B4galt3 deficiency can potentially boost anti-tumor immune responses, largely through enhancing the influx of CD8+ T cells. B4GALT3 might be suppressing cancer immunity by synthesizing the glycan structure of molecules on the CD8+ T cell surface, as evidenced by the changes in the glycan structure of ITGAL in immune cells. Importantly, B4galt3 KO mice showed no adverse effects on growth, development, or reproduction, underscoring the potential of B4GALT3 as a promising and safe therapeutic target for cancer treatment.

Availability of Home sleep apnea test equipment LS-140 on a comparison with Polysomnography.

OBJECTIVE: The prevalence of obstructive sleep apnea (OSA) in Japan is 9% among males and 3% among females. Up to 2.5 million patients are estimated to suffer from the disease, but limited number of facilities are capable of carrying out polysomnography (PSG), leaving more than 80% of these individuals are undiagnosed. In recent years, the development of new portable sleep monitoring (PMs) devices has been remarkable. We evaluate the correlation between the results of the LS-140 PMs device (Fukuda Denshi Tech Co. Ltd.), released in 2017, and those of PSG. METHODS: We obtained contemporaneous data from the same patients by equipping 58 patients with PMs (LS-140) devices while they underwent PSG. Our primary outcome was Case 2 of the intraclass correlation coefficient (ICC), i.e., the ICC (2.1). And we used a Bland-Altman analysis to compare the apnea-hypopnea index (AHI) given by PSG and the respiratory event index (REI) given by LS-140 and examined the sensitivity and specificity of the REI relative to the AHI in the diagnosis of OSA. We also carried out the same comparison but in terms of the presence or absence of periodic limb movements (PLMs). RESULTS: The ICC (2.1) between The REI and the AHI was 0.944, a rather high value (p<0.0001). The mean difference between AHI and REI values was -3.6 (p<0.0001), indicating a negative fixed bias. Sensitivity may decrease in groups with PLMs. CONCLUSION: The REI and the AHI are highly correlated, giving LS-140 sufficient diagnostic sensitivity and specificity to screen for OSA.

Dual roles of CagA protein in Helicobacterpylori-induced chronic gastritis in mice.

Cytotoxin-associated gene A (CagA) acts directly on gastric epithelial cells. However, the roles of CagA in host adaptive immunity against Helicobacter pylori (H. pylori) infection are not fully understood. In this study, to investigate the roles of CagA in the development of H. pylori-induced chronic gastritis, we used an adoptive-transfer model in which spleen cells from C57BL/6 mice with or without H. pylori infection were transferred into RAG2(-/-) mice, with gastric colonization of either CagA(+) H. pylori or CagA(-) H. pylori. Colonization of CagA(+) H. pylori but not CagA(-) H. pylori in the host gastric mucosa induced severe chronic gastritis in RAG2(-/-) mice transferred with spleen cells from H. pylori-uninfected mice. In addition, when CagA(+) H. pylori-primed spleen cells were transferred into RAG2(-/-) mice, CD4(+) T cell infiltration in the host gastric mucosa were observed only in RAG2(-/-) mice infected with CagA(+) H. pylori but not CagA(-) H. pylori, suggesting that colonization of CagA(+) H. pylori in the host gastric mucosa is essential for the migration of H. pylori-primed CD4(+) T cells. On the other hand, transfer of CagA(-) H. pylori-primed spleen cells into CagA(+) H. pylori-infected RAG2(-/-) mice induced more severe chronic gastritis with less Foxp3(+) regulatory T-cell infiltration as compared to transfer of CagA(+) H. pylori-primed spleen cells. In conclusion, CagA in the stomach plays an important role in the migration of H. pylori-primed CD4(+) T cells in the gastric mucosa, whereas CagA-dependent T-cell priming induces regulatory T-cell differentiation, suggesting dual roles for CagA in the pathophysiology of H. pylori-induced chronic gastritis.

Budd-Chiari syndrome caused by latent hepatic metastasis from a thymoma.

A 34-year-old woman visited our hospital because she had had abdominal bloating for 2 months. She had been diagnosed with invasive thymoma (WHO pathological type B2), for which she had undergone chemotherapy and total thymectomy 10 years previously. Six years previously, pleural dissemination was diagnosed and she had undergone right extra-pleural pneumonectomy. On presentation to our hospital, abdominal computed tomography and ultrasound scans revealed abundant ascites and a huge liver lesion, likely a metastasis from her thymoma, obstructing the inferior vena cava. The serum-ascites albumin gradient was high at 1.4 g/dL, which indicated portal hypertension. We diagnosed Budd-Chiari syndrome caused by liver metastasis from a previous thymoma. Steroid therapy resulted in shrinkage of her liver tumor and a marked decrease in her ascites. Although rare, Budd-Chiari syndrome caused by liver metastasis from a thymoma is a possible serious complication of advanced invasive thymoma.

Successful management of hyperammonemia with hemodialysis on day 2 during 5-fluorouracil treatment in a patient with gastric cancer: a case report with 5-fluorouracil metabolite analyses.

PURPOSE: Hyperammonemia is an important adverse event associated with 5-fluorouracil (5FU) from 5FU metabolite accumulation. We present a case of an advanced gastric cancer patient with chronic renal failure, who was treated with 5FU/leucovorin (LV) infusion chemotherapy (2-h infusion of LV and 5FU bolus followed by 46-h 5FU continuous infusion on day 1; repeated every 2 weeks) and developed hyperammonemia, with the aim of exploring an appropriate hemodialysis (HD) schedule to resolve its symptoms. METHODS: The blood concentrations of 5FU and its metabolites, α-fluoro-ß-alanine (FBAL), and monofluoroacetate (FA) of a patient who had hyperammonemia from seven courses of palliative 5FU/LV therapy for gastric cancer were measured by liquid chromatography-mass spectrometry. RESULTS: On the third day of the first cycle, the patient presented with symptomatic hyperammonemia relieved by emergency HD. Thereafter, the 5FU dose was reduced; however, in cycles 2-4, the patient developed symptomatic hyperammonemia and underwent HD on day 3 for hyperammonemia management. In cycles 5-7, the timing of scheduled HD administration was changed from day 3 to day 2, preventing symptomatic hyperammonemia. The maximum ammonia and 5FU metabolite levels were significantly lower in cycles 5-7 than in cycles 2-4 (NH3 75 ± 38 vs 303 ± 119 µg/dL, FBAL 13.7 ± 2.5 vs 19.7 ± 2.0 µg/mL, FA 204.0 ± 91.6 vs 395.9 ± 12.6 ng/mL, mean ± standard deviation, all p < 0.05). After seven cycles, partial response was confirmed. CONCLUSION: HD on day 2 instead of 3 may prevent hyperammonemia in 5FU/LV therapy.

Identification of diacetonamine from soybean curd residue as a sporulation-inducing factor toward Bacillus spp.

Under bioassay-guided investigation, a sporulation-inducing factor (SIF) toward Bacillus spp. was searched for in methanol (MeOH) extracts of soybean curd residues, and diacetonamine (1) was identified as the active compound. SIF was first isolated as a monoacetylated derivative (2, 4.1 mg from 655 g soybean curd residues), and its chemical structure was elucidated by field desorption mass spectrometry, electron ionization mass spectrometry, and nuclear magnetic resonance (NMR) analyses. After 48-h incubation, 40 µM diacetonamine hydrochloride (1b) exhibited sporulation-inducing activity with 35% sporulation frequency toward a Bacillus amyloliquefaciens wild-type strain (AHU 2170), whereas 40 µM diacetone acrylamide (3) showed 99% sporulation induction, which was much higher than that of 1b. Although Bacillus megaterium NBRC 15308 was sporulated by the treatment with 400 µM 1b with 36 and 70% sporulation frequency after 72- and 96-h incubation respectively, 3 at the same concentration showed only 2% sporulation after 72-h incubation. Hence, diacetonamine (1) was characterized as a genuine SIF from soybean curd residues, but it was uncertain whether 1 is a natural product or an artifact. Spores of B. amyloliquefaciens induced by 1b survived after treatment with heating at 95 °C for 10 min, also suggesting that 1 is genuine SIF in soybean curd residue. As sporulation induction is likely linked to activation of antibiotic production in some spore-forming Firmicutes bacteria, compound 1 would be a possible chemical tool to develop an effective fermentation technology in Bacillus species.

A simple and rapid determination of biapenem in plasma by high-performance liquid chromatography.

A simple, rapid and precise HPLC method using ultrafiltration to remove plasma protein was developed to determine biapenem concentrations in human plasma. Plasma was separated by centrifugation at 4 degrees C from blood collected in heparinized vacuum tubes, and biapenem was stabilized by immediate mixing the plasma with 1M 3-morpholinopropanesulfonic acid (MOPS) buffer (pH 7.0) (1:1). Biapenem was detected by ultraviolet absorbance at 300nm with no interfering plasma peak. The calibration curve of biapenem in human plasma was linear from 0.04 to 50microg/mL. The limit of detection was 0.01microg/mL, which was more than 40-fold lower than that of conventional plasma protein precipitation using ammonium sulfate. The assay has been clinically applied to pharmacokinetic studies in patients.

IFN-γ is reciprocally involved in the concurrent development of organ-specific autoimmunity in the liver and stomach.

Interferon (IFN)-γ acts as a critical proinflammatory mediator in autoimmune processes, whereas it exerts regulatory functions to limit tissue damage associated with inflammation. However, a detailed understanding of the complex roles of IFN-γ in the development of organ-specific autoimmunity is still lacking. Recently, we found that programmed cell death 1-deficient mice thymectomized 3 days after birth (NTx-PD-1(-/-) mice) concurrently developed autoimmune hepatitis (AIH) and autoimmune gastritis (AIG). In this study, we investigated the roles of IFN-γ in the development of AIH and AIG in this mouse model. In NTx-PD-1(-/-) mice, serum levels of IFN-γ were markedly elevated. Neutralization of IFN-γ prevented the development of AIG. However, the same treatment exacerbated hepatic T-cell infiltration in AIH. Because of the loss of anti-proliferative effects by IFN-γ, neutralization of IFN-γ increased T-cell proliferation in the spleen and liver, resulting in exacerbated T-cell infiltration in the liver. On the other hand, in the development of AIG, CD4+ T-cell migration into the gastric mucosa is essential for induction. CCL20 expression was up-regulated in the gastric mucosa, and anti-CCL20 suppressed CD4+ T-cell infiltration into the gastric mucosa. Importantly, anti-IFN-γ suppressed CCL20 expression and infiltration of CD4+ T cells in the gastric mucosa, whereas in vivo injection of recombinant IFN-γ up-regulated CCL20 expression in the stomach, suggesting that IFN-γ is critically involved in CD4+ T-cell accumulation in AIG by up-regulating local CCL20 expression. In conclusion, IFN-γ is involved differently in the development of AIH and of AIG. IFN-γ negatively regulates T-cell proliferation in fatal AIH, whereas it initiates development of AIG. These findings imply that increased production of IFN-γ induced by an organ-specific autoimmunity may trigger the concurrent development of another organ-specific autoimmune disease.