[Improvement of tissue fibrosis in TAFRO syndrome by prednisolone monotherapy].

We report the case of a 48-year-old man who presented with fatigue and weight loss. A local physician observed elevated alkaline phosphatase levels, anemia, thrombocytopenia, and renal dysfunction. Fever also appeared, and the patient was admitted to our hospital. Computed tomography revealed hepatosplenomegaly, pleural and ascitic fluid, and left axillary lymphadenopathy. Bone marrow biopsy indicated hyperplasia with increased megakaryocytes and reticulin fibrosis. Axillary lymph node biopsy showed Castleman's disease-like features. Liver biopsy revealed proliferation of reticulin fibrosis. Therefore, TAFRO syndrome was diagnosed and treatment with 1 mg/kg prednisolone was started. Anemia and thrombocytopenia improved, and after 24 weeks of treatment, serum hyaluronic acid and type IV collagen decreased to the normal range. Bone marrow biopsy after 18 weeks of treatment showed decreased reticular fibers. In TAFRO syndrome, improvement of liver and bone marrow fibrosis can be expected with adequate intervention, and serum hyaluronic acid and type IV collagen are useful for evaluating fibrosis.

[A Case of Immune-Related Adverse Events Affecting the Lungs, Skin, and Pituitary Gland during Pembrolizumab Treatment].

The patient was a 69-year-old man diagnosed with stage ⅣB lung adenocarcinoma with 95% programmed death- ligand 1 expression, and pembrolizumab monotherapy was initiated. The patient exhibited fatigue from the 12th course(36 weeks after treatment initiation) of treatment. Chest computed tomography revealed scattered ground-glass opacities in the upper lobes of both lungs, and he was subsequently diagnosed with interstitial pneumonia. Fatigue persisted even after a drug holiday from pembrolizumab, and the patient was diagnosed with hypopituitarism based on the results of endocrinological examinations. Rashes appeared on both legs 40 weeks after treatment initiation, which led to the patient being diagnosed with a drug-induced skin disorder. All the adverse events resolved upon treatment with hydrocortisone. Immune- related adverse events due to pembrolizumab may occur in multiple organs simultaneously.

Immunopathological Analysis of a Mouse Model of Arthritis-Associated Scleritis and Implications for Molecular Targeted Therapy for Severe Scleritis.

Scleritis involves inflammation of the sclera, which constitutes 75% of the wall of the eye. This pathology is often seen as an ocular lesion associated with systemic inflammatory diseases. Severe types of scleritis such as posterior scleritis require urgent immunosuppressive treatments, including molecularly targeted therapies to avoid permanent visual impairment. Which molecules should be selected as targets has remained unclear. To clarify the pathogenesis of scleritis and propose appropriate target molecules for therapy, we have established novel animal model of scleritis by modifying the Collagen-II Induced Arthritis (CIA) model. Immunization twice with collagen II emulsified with complete Freund's adjuvant (CFA) caused arthritis and scleritis. The clinical appearance resembled human diffuse scleritis. Histopathological analysis suggested that macrophages, plasma cells, deposition of immune complexes, and growth of blood and lymphatic vessels are involved in the pathogenesis of CIA-associated scleritis. In addition, we analysed the background diseases of posterior scleritis and responses to molecularly targeted therapies as a case series study. We inferred from both the animal model and case series study that targets should not be T cells, but factors inhibiting macrophage activity such as tumor necrosis factor (TNF) and interleukin (IL)-6, and molecules suppressing antibody-producing cells such as CD20 on B cells should be targeted by molecularly targeted therapies.

Immune Checkpoints Contribute Corneal Immune Privilege: Implications for Dry Eye Associated with Checkpoint Inhibitors.

The eye is provided with immune protection against pathogens in a manner that greatly reduces the threat of inflammation-induced vision loss. Immune-mediated inflammation and allograft rejection are greatly reduced in the eye, a phenomenon called 'immune privilege'. Corneal tissue has inherent immune privilege properties with underlying three mechanisms: (1) anatomical, cellular, and molecular barriers in the cornea; (2) an immunosuppressive microenvironment; and (3) tolerance related to regulatory T cells and anterior chamber-associated immune deviation. This review describes the molecular mechanisms of the immunosuppressive microenvironment and regulatory T cells in the cornea that have been elucidated from animal models of ocular inflammation, especially those involving corneal transplantation, it also provides an update on immune checkpoint molecules in corneal and systemic immune regulation, and its relevance for dry eye associated with checkpoint inhibitor therapy.

Immune Cells on the Corneal Endothelium of an Allogeneic Corneal Transplantation Rabbit Model.

Purpose: Corneal endothelial cell density undergoes a progressive decrease for many years after transplantation, eventually threatening patients with late endothelial failure. The purpose of this study was to investigate the possibility of an immunologic response in successfully grafted corneal endothelium. Methods: The corneal endothelium of patients who had undergone corneal transplantation was evaluated by specular microscopy. Rabbit models were subjected to penetrating keratoplasty (PK) with either syngeneic or allogeneic corneal transplants and Descemet's stripping endothelial keratoplasty (DSEK) with allogeneic corneal transplants. The presence of immune cells and expression of proinflammatory cytokines were determined by immunostaining. The corneal endothelium and immune cells were also evaluated by scanning electron microscopy. Results: Scanning slit contact specular microscopy of patients with no features of graft rejection revealed cell-like white dots on the grafted corneal endothelium. The corneal endothelium of the allogeneic PK and DSEK rabbit models displayed the presence of immune cells, including CD4+ T-helper cells, CD8+ cytotoxic T cells, CD20+ B lymphocytes, CD68+ macrophages, and neutrophils, but these immune cells were rarely observed in the syngeneic PK model. These immune cells also produced proinflammatory cytokines. Notably, some of the corneal endothelial cells situated near these immune cells exhibited features of apoptosis. Conclusions: T lymphocytes, B lymphocytes, macrophages, and neutrophils are present on the grafted corneal endothelium in both PK and DSEK allogeneic rabbit models. The potential involvement of immune cells as an underlying pathophysiology for late endothelial failure deserves further examination.

[A case of pancreatic mixed acinar-endocrine carcinoma suggested by preoperative ultrasound-guided fine needle aspiration].

A 73-year-old man visited our hospital for consultation regarding a pancreatic tumor. Abdominal computed tomography, magnetic resonance imaging, and endoscopic ultrasound scan (EUS) revealed tumor 2 cm in diameter located in the pancreatic tail. EUS-guided fine needle aspiration (EUS-FNA) suggested pancreatic mixed acinar-endocrine carcinoma, and he underwent distal pancreatectomy. Few reports exist where preoperative EUS-FNA suggested pancreatic mixed acinar-endocrine carcinoma; thus, we report this case.

GITR ligand-mediated local expansion of regulatory T cells and immune privilege of corneal allografts.

PURPOSE: The pathway between the glucocorticoid-induced tumor necrosis factor receptor family-related protein (GITR) and GITR ligand (GITRL) has been shown to control the function of regulatory T cells (Treg). The present study was conducted to investigate the role of this pathway and Treg in establishing immune privilege status for corneal allografts. METHODS: Corneas of C57BL/6 mice were orthotopically transplanted into the eyes of BALB/c mice, and graft survival was assessed. A separate set of BALB/c mice received an anterior chamber injection of C57BL/6 splenocytes, and induction of allo-specific anterior chamber-associated immune deviation was assessed. Recipients were intraperitoneally administrated anti-GITRL, anti-CD25 monoclonal antibodies (mAb), or control immunoglobulin (IgG). Expressions of GITRL, GITR, and Foxp3 in the allografts were assessed. In vitro, cornea pretreated with anti-GITRL mAb or control IgG was incubated with T cells, and destruction of corneal endothelial cells and the population of Foxp3(+)CD25(+)CD4(+) T cells were assessed. RESULTS: GITRL was expressed constitutively in the cornea and iris-ciliary body. GITRL-expressing allografts were infiltrated with Foxp3+GITR+CD25+CD4(+) T cells. Blockade of GITRL did not affect allo-specific ACAID but led to infiltration of Foxp3(-)CD4(+) T cells and allograft rejection. Depletion of CD25+CD4(+) Treg also accelerated allograft rejection. Destruction of corneal endothelial cells by T cells was significantly enhanced in GITRL-blocked cornea compared with control cornea. Foxp3+CD25+CD4(+) T cells were increased after incubation with GITRL-expressing cornea, but not with GITRL-blocked cornea. CONCLUSIONS: Presence of Foxp3+CD25+CD4(+) Treg in the allograft is necessary for allograft survival. GITRL-dependent expansion of Treg within the cornea is one mechanism underlying immune privilege in corneal allografts.

Role of metallothionein in Helicobacter pylori-positive gastric mucosa with or without early gastric cancer and the effect on its expression after eradication therapy.

BACKGROUND AND AIM: Metallothionein (MT) has a proven relationship with various kinds of cancer and reduces tissue damage. Helicobacter pylori (H. pylori) infection is associated with the alteration of gastric epithelial cell cycle events, a condition implicated in the initiation and development of gastric cancer. This study investigates the role of MT in H. pylori-induced gastritis with or without early gastric cancer (ECG) and evaluates the effect on MT expression after eradication therapy. METHODS: Gastric biopsy samples were immunohistochemically examined for MT expression in 36 H. pylori-negative patients without ECG and 98 positive patients with or without ECG. Real time polymerase chain reaction was performed in 14 antral biopsy samples with or without H. pylori. The severity of gastritis was also evaluated according to the updated Sydney System. In 31 successfully eradicated patients, the above assessment was repeated for two consecutive years. RESULTS: MT expression was higher in H. pylori-negative patients than in positive patients (P < 0.01). Moreover, in the corpus it was higher in H. pylori-positive patients without ECG compared to those with ECG (P < 0.05). The MT labeling index had a negative correlation with the severity of gastritis (P < 0.01). A positive correlation was shown between the MT labeling index and apoptosis: proliferation ratio (r = 0.41, P < 0.01). The MT labeling index in H. pylori-positive patients was gradually recovered after eradication (P < 0.05). CONCLUSION: The decrease of MT expression cannot prevent tissue damage in H. pylori-positive gastric mucosa and leads to more severe gastritis. This phenomenon may be attributed to gastric carcinogenesis. H. pylori eradication increases MT expression and may reduce the risk of ECG.

Retinal transplantation.

Degenerative diseases of the retina afflict millions of Americans, and very few effective treatments are available at present. Transplantation of solid tissue or stem cell grafts represents a promising, albeit challenging, approach to replace photoreceptor cells lost due to injury or disease. However, there remain a number of formidable obstacles to be overcome before these techniques can be applied in a clinical setting. Foremost of these challenges is immunological acceptance and survival of the graft. We will refer to studies performed in collaboration with J. Wayne Streilein over the past decade that address this issue. The immune-privileged status of the subretinal space, as well as the inherent immune privilege of retinal pigment epithelium, neuronal retina and neural stem cells will be described. The goal of these studies is to gain a better understanding of the immunological properties of both the donor tissues and recipient graft site in retinal transplantation. This information will allow for the development of strategies to improve graft outcome and lead to successful repair of the diseased eye.

B7-H1-induced apoptosis as a mechanism of immune privilege of corneal allografts.

The programmed death-1 (PD-1) costimulatory pathway has been demonstrated to play a role in the regulation of immune responses and peripheral tolerance. We investigated the role of this pathway in establishing an immune privilege status of corneal allografts in mice. B7-H1, but not B7-DC or PD-1, was expressed constitutively in the eye, i.e., cornea, iris-ciliary body, and retina. After corneal allografting, PD-1(+)CD4(+) T cells infiltrated and adhered with B7-H1(+) corneal endothelium. Blockade of PD-1 or B7-H1, but not B7-DC, led to accelerated corneal allograft rejection. In B7-H1-expressing corneal allografts, apoptosis of the infiltrating PD-1(+)CD4(+) or CD8(+) T cells was observed, after which there was allograft acceptance. In contrast, B7-H1 blockade suppressed apoptosis of infiltrating PD-1(+) T cells, which led to allograft rejection. In vitro, destruction of corneal endothelial cells by alloreactive T cells was enhanced when the cornea was pretreated with anti-B7-H1 Ab. This is the first demonstration that the constitutive expression of B7-H1 plays a critical role in corneal allograft survival. B7-H1 expressed on corneal endothelial cells maintains long-term acceptance of the corneal allografts by inducing apoptosis of effector T cells within the cornea.

Immunological characteristics of amniotic epithelium.

We review recent experimental evidence of the immunosuppressive and immunogenic potential of amniotic epithelial cells. Since cryopreserved amniotic membrane (AM) has been used in clinical applications, much research has focused on the beneficial effects of amniotic stromal matrix rather than on the function of viable amniotic cells. However, viable human amniotic epithelial cells (HAECs) have been shown to elicit beneficial effects on secretion of anti-inflammatory factors. Topical application of culture supernatant from HAECs leads to profound suppression of suture-induced neovascularization in cornea and fewer major histocompatibility complex (MHC) class II antigen-presenting cells (APCs) in inflamed cornea after thermal cautery. Furthermore, expression of interleukin (IL)-1beta mRNA was suppressed in cauterized cornea. These results suggest that HAECs are a source of soluble anti-inflammatory factors that suppress corneal inflammation. However, viable amniotic epithelial cells display antigenicity and immunogenicity as allografts. Fresh allogeneic amniotic epithelium (AE) expresses MHC class I antigens and sensitizes recipients when placed in the eye, although long-term memory of allo-specific delayed hypersensitivity (DH) was not acquired. Allogeneic AE was clearly vulnerable to acute immune rejection in specifically sensitized recipients and recipients of repeated AE transplantation. We therefore suggest that immunogenicity of AE should not be ignored, and use of AM from different donor placentas should be emphasized when repeated AM transplantation is required in patients clinically.

Phacoemulsification associated corneal damage evaluated by corneal volume.

PURPOSE: To determine the usefulness of the Pentacam corneal volume assay in the assessment of corneal endothelial damage caused by phacoemulsification and aspiration (PEA). DESIGN: Prospective, comparative, observational case series. METHODS: PEA was performed in 85 eyes by three surgeons under different conditions. Central cell density (CD) was determined using a specular microscope before and one month after surgery. Pentacam was used before and one day, one week, and one month after surgery to determine 3- and 10-mm corneal volumes. RESULTS: For all surgeons, no significant differences in the 3-mm corneal volumes were noted between the before and one-month after surgery values. However, 10-mm corneal volumes at one month were significantly higher than preoperative levels. No correlation was noted between the increasing rate of the 10-mm corneal volume and decreasing rate of CD. CONCLUSIONS: Pentacam-determined corneal volumes may be useful in assessing PEA-caused corneal damage.

Topical application of culture supernatant from human amniotic epithelial cells suppresses inflammatory reactions in cornea.

Human amniotic epithelial cells (HAEC) may be a source of soluble anti-inflammatory factors. The purpose of this study is to determine the effect of topically applied HAEC culture supernatant on corneal inflammatory reactions. HAEC were obtained from a placenta and cultured for 48 hr, and the supernatant was collected. The conditioned medium from HAEC contained small amounts of human interleukin-1 receptor antagonist (IL-1ra). Intrastromal sutures were placed in the cornea of BALB/c mice to induce corneal neovascularisation. Superficial cauterisation was applied to induce recruitment or activation of antigen presenting cells (APCs) in the cornea without neovascularisation. HAEC conditioned medium, placebo, or recombinant human IL-1ra was topically applied three times daily for 2 weeks. Suture-induced corneal neovascularisation was evaluated microscopically for 8 weeks. The cauterised corneas were harvested at 2 weeks, and the MHC class II(+) APCs were quantified by immunofluorescent staining and confocal microscopy. Inflammatory cytokine gene expression in the cauterised corneas was analyzed by a multiprobe ribonuclease protection assay. Conditioned medium from HAEC led to a profound suppression of corneal neovascularisation and fewer MHC class II(+) APCs in the epithelium. In contrast, human IL-1ra was only slightly effective in suppressing corneal inflammatory reactions. mRNA expression of murine IL-1ra and IL-1beta in the cauterised corneas was markedly suppressed after application of the conditioned medium. These results suggest that HAEC are a source of soluble anti-inflammatory factors and that conditioned medium from HAEC contains factors other than IL-1ra that suppress corneal inflammation.

Neural progenitor cells lack immunogenicity and resist destruction as allografts.

Multipotent, self-renewing stem and progenitor cells isolated from the mammalian central nervous system (CNS) have been shown to survive as allografts following transplantation to sites throughout the neuraxis. However, studies of this type shed little light upon the immunologic properties of the cells themselves, primarily because little is learned about the intrinsic immunogenic properties of a cell when it is grafted into an immune-privileged site. We have therefore investigated the immunogenic and antigenic properties of CNS progenitor cells by grafting them into a conventional (i.e., non-immune-privileged) site, namely, beneath the kidney capsule. Our results indicate that allogeneic CNS progenitor cells survive at least 4 weeks in a conventional site, during which time they neither sensitize their hosts nor express detectable levels of major histocompatibility complex (MHC) class I or II. These in vivo data are in accord with flow cytometric results showing that CNS progenitor cells do not express MHC class I or class II, either at baseline or upon differentiation in 10% serum. Exposure to interferon gamma, however, reversibly upregulates expression of these key transplantation antigens. Together, these results reveal CNS progenitor cells to possess inherent immune privilege. Since CNS progenitor cell allografts were rejected beneath the kidney capsule following specific sensitization of the host, CNS progenitor cells were able to display alloantigens, albeit not in an immunogenic form.