Toshikazu Masumoto

Dendritic cells with immature phenotype and defective function in the peripheral blood from patients with hepatocellular carcinoma

BACKGROUND/AIMS Defects and dysfunctions in antigen-presenting dendritic cells have been shown during carcinogenesis. The phenotype and function of dendritic cells have been studied in patients with hepatocellular carcinoma to explore the possibility of dendritic cell-based immune therapy in hepatocellular carcinoma. METHODS The stimulatory capacity of dendritic cells in allogenic mixed leukocytes reaction, the expression of surface makers on dendritic cells, the production of cytokines and nitric oxide by dendritic cells and the levels of maturation of dendritic cells from 17 patients with hepatocellular carcinoma, 10 patients with liver cirrhosis and 10 normal controls were compared. RESULT Dendritic cells from hepatocellular carcinoma had significantly lower capacity to stimulate allogenic T cells in allogenic mixed leukocytes reaction compared with dendritic cells from liver cirrhosis and normal controls (p<0.05). Dendritic cells from hepatocellular carcinoma expressed significantly lower levels of HLA DR and induced decreased amounts of interleukin-12 compared with dendritic cells from normal controls (p<0.05). On the other hand, dendritic cells from hepatocellular carcinoma produced significantly higher levels of nitric oxide and tumor necrosis factor-a compared with dendritic cells from liver cirrhosis and normal controls (p<0.05). The uptake of fluorescein isothiocyanate-labeled dextran revealed an immature phenotype of dendritic cells from hepatocellular carcinoma compared with dendritic cells from liver cirrhosis (p<0.05). CONCLUSION The results of this study on the function of dendritic cells in hepatocellular carcinoma, and the prevalence of immature dendritic cells in hepatocellular carcinoma in the microenvironment of high levels of inflammatory cytokines indicate a specific defect of dendritic cell maturation during hepatocarcinogenesis. These data show that induction of dendritic cell maturation might be an approach to dendritic cell-based immune therapy during hepatocellular carcinoma.

Mechanism of action of vaccine therapy in murine hepatitis B virus carriers: vaccine-induced activation of antigen presenting dendritic cells

BACKGROUND/AIMS Vaccine therapy in which vaccine containing hepatitis B surface antigen (HBsAg) is injected has shown therapeutic activity (vaccine therapy) in some human and murine chronic hepatitis B virus (HBV)-carriers. Using HBV-transgenic mice (HBV-Tg), an animal model of the HBV-carrier state, the mechanism underlying the antiviral and immune modulatory capacity of vaccine therapy was studied. METHODS Placebo-controlled, double-blind trials of vaccine therapy were conducted in HBV-Tg; some HBV-Tg responded to the therapy, whereas others were non-responders. The titers of HBV-markers, the functions of lymphocytes and antigen presenting dendritic cells were compared between vaccine responders and vaccine non-responders. RESULTS The prevaccinated titers of HBsAg, hepatitis B e-antigen (HBeAg), HBV DNA and the responses of lymphocytes to polyclonal mitogens were almost unchanged between responders and non-responders, but the levels of proliferation of HBsAg-specific lymphocytes from non-responders was significantly lower than responders (p<0.05). The capacity of dendritic cells to induce proliferation of T cells and production of antibody to HBsAg (anti-HBs) was significantly higher in responders compared with non-responders (p<0.05). Injection with HBsAg resulted in upregulation of MHC class II and CD86 antigens (p<0.05) on dendritic cells and increased production of IL-12, IL-2 and TNF-alpha in cultures (p<0.05) in vaccine responders but not in non-responders. CONCLUSIONS The activation of dendritic cells following injection with vaccine containing HBsAg is the vital factor underlying the therapeutic potentiality of vaccine therapy in HBV carriers.

Clinical characteristics of autoimmune hepatitis with histological features of acute hepatitis

The number of patients with autoimmune hepatitis with histological features of acute hepatitis (AIH-AH) has been increasing recently. Here, the clinical features of patients with AIH-AH have been compared with those of patients with AIH with histological findings of chronic hepatitis (AIH-CH) and liver cirrhosis (AIH-LC). The levels of total serum bilirubin (P<0.05) and serum transaminases (P<0.05) were significantly higher in patients with AIH-AH than in patients with AIH-CH and AIH-LC. However, the serum levels of gamma-globulin (P<0.05) and immunoglobulin G (P<0.05) were significantly lower in AIH-AH than in patients with AIH-CH and AIH-LC. The aggregate score according to the criteria of the International Autoimmune Hepatitis Group in 1999 was also significantly lower in AIH-AH patients than in patients with AIH-CH and AIH-LC (P<0.05). Eleven patients with AIH-AH were treated with corticosteroids, however, the clinical response was insignificant in three patients. In summary, it is difficult to diagnose of patients with AIH-AH using the criteria of the International AIH scoring system. We wish that this scoring system would be modified in the near future.

Placebo-controlled trial of vaccination with hepatitis B virus surface antigen in hepatitis B virus transgenic mice

BACKGROUND/AIMS Treatment of hepatitis B virus carriers by vaccine containing hepatitis B surface antigen with Pre-S protein and HBsAg/ anti-HBs complex has been reported and these studies have constituted a new and promising concept for the treatment of HBV-carriers. The present communication, a placebo-controlled trial of vaccination in HBV-transgenic mice, was designed to examine the impact of vaccination using a high dose of HBsAg for a duration of 12 months to achieve further insights about the dose, duration and effectiveness of vaccine therapy. Another aim of this study was to analyse the mechanism underlying the antiviral and immunomodulatory potentiality of vaccine therapy in HBV-transgenic mice. METHODS HBV-transgenic mice positive for HBV DNA, hepatitis B surface antigen and hepatitis B e antigen in sera received either HBV-vaccine containing HBsAg in complete Freunds adjuvant (CFA), intraperitoneally, once a month for 12 consecutive months (vaccine recipients), or only CFA, intraperitoneally once in a month for 12 consecutive months (placebo recipients). Thirty-two vaccine-recipient and 16 placebo-recipient HBV-transgenic mice were injected, checked and followed on a monthly basis for the entire duration of 12 months. RESULTS Of the 32 transgenic mice from the vaccine-recipient group, 25 became completely negative for HBsAg and 30 for HBeAg. Five mice developed anti-HBs in sera after the observation period of 12 months. Semiquantitative estimation of HBV DNA by polymerase chain reaction showed that vaccination resulted in a decrease of HBV DNA in sera. Placebo-recipient transgenic mice did not show any significant change in the titres of HBV markers after receiving 12 monthly injections of CFA. Interleukin-2 could be detected in sera from vaccine-recipient transgenic mice, but not in placebo-recipient transgenic mice. CONCLUSIONS Vaccination with a high dose of HBsAg in adjuvant over a long period had a significant antiviral as well as immunomodulatory potential in HBV-transgenic mice. This inspires optimism that vaccine alone or in combination with antiviral agents can be used successfully for the treatment of human HBV-carriers.

Interferon therapy for patients more than 60 years of age with chronic hepatitis C

Abstract Nineteen patients aged > 60 years with chronic hepatitis C (CHC) received interferon (IFN) therapy and a complete response (CR) was achieved by five of them (26%). The incidence of CH with severe fibrosis in this elderly group was significantly higher than in another 52 patients with CHC who were < 60 years of age (the younger group; P < 0.05). There was no significant difference in the hepatitis C virus (HCV) genotype distribution between the elderly group and the younger group. However, the HCV‐RNA titre was significantly higher in the elderly group than in the younger group (P < 0.05). There was no significant difference in the efficacy rate of IFN in the elderly and younger groups after standardization of the background factors. In the elderly group, the HCV‐RNA titre was significantly lower in the patients achieving CR than in those with no response (P < 0.05). These data suggest that elderly patients with a low HCV‐RNA titre can still respond well to IFN therapy.

Induction of CINC (interleukin-8) production in rat liver by non-parenchymal cells.

The production of interleukin‐8 (CINC: cytokine‐induced neutrophil chemo‐attractant) from different cell populations in the rat liver was studied and cells related to the initiation of CINC production in lipopolysaccharide (LPS)‐injected endotoxaemic rats were characterized. Sinusoidal endothelial cells (16.4 ± 10.6 ng/mL) produced significantly higher amounts of CINC in 24 h primary cultures compared with hepatocytes (0.9 ± 0.9 ng/mL; P < 0.05) and Kupffer cells (6.5 ± 5.1 ng/mL; P < 0.05). Lipopolysaccharide, tumour necrosis factor‐α (TNF‐α), and interleukin‐1α (IL‐1α) stimulated different liver cell populations to produce CINC; LPS mainly stimulated Kupffer cells, TNF‐α stimulated hepatocytes and IL‐1α stimulated all three types of cells. Intraperitoneal injection of LPS (4 mg/kg) caused CINC accumulation in non‐parenchymal cells of the rat liver within 1 h of injection, as shown by immunohistochemical staining. In contrast, CINC‐positive hepatocytes were not seen until 3 h after injection of LPS. Ethanol was not a direct inducer of CINC production by rat hepatocytes in vitro. These findings strongly suggest that non‐parenchymal liver cells, including sinusoidal endothelial cells, are the main source of CINC. Our data also suggest that during endotoxaemia, CINC production is initiated by non‐parenchymal cells and this is followed by production from hepatocytes.

Granular cell tumor occurring in the sigmoid colon treated by endoscopic mucosal resection using a transparent cap (EMR-C)

A case of granular cell tumor occurring in the sigmoid colon is reported. The patient, a 56-year-old man, visited our hospital for further evaluation of occult blood in his stool. Endoscopic examination revealed a yellowish, hemispheric submucosal tumor (SMT) with redness, about 6 mm in diameter, in the sigmoid colon. Endoscopic mucosal resection using a transparent cap (EMR-C) was performed, and histological examination revealed that the tumor consisted of a nested growth of large tumor cells with ample granular cytoplasm and small round nuclei. The tumor cells expressed S-100 protein and were stained with neuron-specific enolase (NSE) and periodic acid-Schiff, but were negative for desmin, vimentin, and cytokeratin. The resected tumor was diagnosed as a granular cell tumor. This may be the first report of a colorectal granular cell tumor successfully treated with EMR-C.

Peripheral blood T‐cell responses to pyruvate dehydrogenase complex in primary biliary cirrhosis: role of antigen‐presenting dendritic cells

Patients with primary biliary cirrhosis (PBC) are usually characterized by the presence of antibody to pyruvate dehydrogenase complex (PDC) in the sera and PDC‐specific T cells in the liver. However, most of the patients with PBC do not show peripheral blood T cells response to PDC. In this study, we re‐evaluated the peripheral blood T cell responses to PDC in PBC using antigen‐presenting dendritic cells (DCs).

Prediction of interferon-alpha-induced thyroid dysfunction in patients with chronic hepatitis C

To predict interferon‐alpha (IFN‐α)‐induced thyroid dysfunction, anti‐thyroglobulin (anti‐TgAb) and anti‐thyroid peroxidase antibodies (anti‐TPOAb) were determined by radio‐immunoassay (RIA) before IFN‐α treatment in 30 patients with chronic hepatitis C in whom the conventional haemagglutination test had failed to detect anti‐thyroid auto‐antibodies. Seven patients developed thyroid dysfunction during IFN‐α treatment (transient thyrotoxicosis in four patients, transient hypothyroidism in two, and Graves’ disease in one). Anti‐TgAb and/or anti‐TPOAb were detectable before IFN‐α treatment in six of these seven patients, while these antibodies were detected before treatment in only four of 23 patients who did not develop any thyroid dysfunction. The prevalence of these antibodies was significantly higher (P= 0.002) in the former group of patients than in the latter. In four patients with detectable anti‐TgAb before treatment but no subsequent thyroid dysfunction, the antibody disappeared during IFN‐α treatment. Haemagglutination tests for anti‐thyroid microsomal antibodies have previously been reported to be a useful predictive marker of IFN‐α‐induced thyroid dysfunction. In conclusion, sensitive detection of anti‐thyroid auto‐antibodies using RIA may also be useful for the prediction of IFN‐α‐induced thyroid dysfunction in patients with a negative haemagglutination test.

Three patients with autoimmune cholangiopathy treated with prednisolone

Abstract: We describe three patients with autoimmune cholangiopathy, i.e., anti-mitochondrial antibody-negative and anti-nuclear antibody-positive primary biliary cirrhosis, who were treated with prednisolone. Serum anti-mitochondrial antibody and anti-pyruvate dehydrogenase-E2 component antibody were determined by immunofluorescence of frozen sections and enzyme-linked immunosorbent assay, respectively. Immunoblotting using mitochondria prepared from rat liver was performed to analyze anti-mitochondrial antibody in detail. Serum from one patient reacted with a 48-kilodalton protein, but sera from the other two patients failed to react with the mitochondrial proteins. There was a marked improvement in liver function test results after prednisolone treatment. Before treatment, liver biopsy in all three patients showed histological features of primary biliary cirrhosis with hepatocellular necrosis. Repeat biopsy during treatment showed marked amelioration of hepatocellular damage in all three patients, although bile duct involvement persisted in two patients. These findings suggest that prednisolone is an effective treatment for hepatocellular damage in patients with autoimmune cholangiopathy, but has little impact on the bile duct involvement.