Immunohistochemical studies on the class and the subclass of the anticolon antibody and the distribution of the antigen recognized by the anticolon antibody in patients with ulcerative colitis.

The immunologic mechanisms mediated by anticolon antibodies have been suggested for the injury of colonic mucosa in ulcerative colitis (UC). For the understanding of pathogenetic relevance of the anticolon antibody in UC, we examined the class and the subclass of the anticolon antibody reactive to rat colonic epithelial cells in sera from 10 patients with UC immunohistochemically by an indirect immunoperoxidase method. We also examined the distribution of the antigen recognized by the anticolon antibody by immunoelectron microscopy. The antibody reactive to the rat colonic epithelial cell was detected in 2 of the 10 patients, and the class and subclass of the antibody was mainly IgG2. The antigen recognized by the anticolon antibody was located on the apical membrane of the colonic epithelial cells and mucous substances of the goblet cells. These findings suggest that the anticolon antibody detected in this study is inadequate to cause the colonic mucosal injury by activating complements or mediating antibody-dependent cellular cytotoxicity. A potential pathogenetic role of the anticolon antibody in UC remains to be established.</p

Primary Sclerosing Cholangitis in Japanese Patients: Association with Inflammatory Bowel Disease

To characterize primary sclerosing cholangitis (PSC) in Japanese patients and its association with inflammatory bowel disease (IBD), 155 reported cases of PSC, including 6 cases of our own, were reviewed. The prevalence of IBD was less in Japanese PSC patients than in Western patients (23% versus 62-100%). Japanese PSC patients with IBD were younger (mean age, 33.1 versus 51.8 years) and were more often women (51% versus 36%) than those without IBD. Seventy-four percent of PSC patients with IBD had extensive colonic lesions, and 89% of those developed IBD simultaneously, with or prior to PSC. There were 3 cases of neutrophilic cholangitis among the PSC patients with IBD but none in those without IBD. Based on these observations, we speculate that there may be subtypes of PSC which differ pathophysiologically.</p

Immunoelectron Microscopic Localization of MHC Class 1 and 2 Antigens on Bile Duct Epithelial Cells in Patients with Primary Biliary Cirrhosis

We studied the distribution of class 1 and class 2 major histocompatibility complex (MHC) antigens on bile duct epithelial cells in liver from patients with primary biliary cirrhosis (PBC) by an immunohistochemical method using monoclonal antibodies to HLA-ABC products and HLA-D subregion products (HLA-DR, -DP, -DQ). By light microscopy, the expression of MHC class 1 antigens (HLA-ABC antigens) was enhanced in PBC compared with controls. While negligible staining of MHC class 2 antigens was detected on the bile duct in controls, de novo expression of MHC class 2 antigens, as well as the coexpression of HLA-DR, HLA-DQ, and HLA-DP antigens on the bile duct epithelial cells, was observed in PBC. By electron microscopy, HLA-ABC and HLA-DR antigens were present preferentially along the basolateral domain of the cell surface of the bile duct epithelial cells and on the membrane of the endoplasmic reticulum in the cytoplasm, suggesting that these MHC antigens are synthesized by the bile duct epithelial cells in PBC. The distribution of these MHC antigens on the basolateral surface of the bile duct epithelial cells, where they are easily accessible to immunocytes, supports the idea that MHC-restricted cytotoxic T lymphocytes are involved in the bile duct injury in PBC. </p

Mycophenolate mofetil for immune checkpoint inhibitor‐related hepatotoxicity relapsing during dose reduction of corticosteroid: A report of two cases and literature review

[Background] Immune checkpoint inhibitors (ICIs) sometimes cause immune-related liver injury, which can lead to cessation of treatment, hospitalization, and even mortality. Although high-dose corticosteroids are usually effective in treatment of ICI-related liver injury, one fifth of affected patients require additional immunosuppressive therapy. It remains uncertain how best to treat ICI-related liver injury that relapses under corticosteroid therapy after temporary remission. [Case] Here we report two cases of ICI-related liver injury successfully treated with mycophenolate mofetil (MMF). In the first case, a 74-year-old man with stage IIIA lung cancer underwent curative chemoradiotherapy. After the second infusion of durvalumab, grade 3 ICI-related liver injury (mixed pattern) developed. In the second case, a 46-year-old man with stage IVB lung cancer received pembrolizumab-containing chemotherapy. After the first cycle, grade 2 ICI-related hepatitis developed. In the both cases, liver injury improved with high-dose prednisolone but relapsed during tapering of the drug. After liver biopsy was performed to confirm the diagnosis of ICI-related liver injury, MMF (2000 mg/day) was added. MMF was effective for both patients and permitted discontinuation or reduction of prednisolone. [Conclusion] MMF appears to be an appropriate treatment option for ICI-related liver injury that respond to high-dose corticosteroids but relapse during steroid tapering

Analysis of Galactosyltransferase Activity in Rat Gastric Mucosa Using Crude Mucosal Homogenate

Mucus glycoprotein is one of the major components of gastric mucus which plays an important role in mucosal defensive mechanisms as a mucus-bicarbonate barrier. Analysis of the mucus glycoprotein synthesis is a useful tool for evaluating gastric mucosal defensive factors. UDP-galactosyltransferase (UDP-Gal-T) is one of the regulating enzymes for the synthesis of the mucus glycoprotein. In the present paper, we studied assay methods for UDP-Gal-T activity in rat gastric mucosa using radiolabeled UDP-galactose and two different kinds of acceptor proteins, namely ovomucoid and asialomucin, and analyzed effects of antisecretory agents on the UDP-Gal-T activity. We used crude supernatants of homogenized scrapings of the fundic part of rat stomach as an enzyme preparation and determined optimal conditions. In each acceptor, Mn2+ and the non-ionic detergent Triton X-100 were required for the enzyme activity. With each acceptor molecule, the type of glycosidic linkages of galactose was beta-type linkage. With asialomucin as an acceptor, UDP-Gal-T activities of rat gastric mucosa decreased after intraperitoneal administration of antisecretory agents, while change of the enzyme activity was not observed with ovomucoid as an acceptor

Non-B hepatocellular carcinoma: influence of age, sex, alcohol, family clustering, blood transfusion and chronic liver disease.

In 144 cases of hepatocellular carcinoma (HCC), 166 cases of cirrhosis without HCC and 142 cases of chronic hepatitis, we examined HBsAg, anti-HBs and anti-HBc in sera and compared the following factors between hepatitis B virus marker-negative and -positive patients: age, sex, alcohol consumption, family clustering of liver diseases, and histories of blood transfusion and post-transfusion hepatitis. Results of this study demonstrated several distinct differences in clinical backgrounds between non-B (negative for HBsAg, anti-HBs and anti-HBc) and B (positive for HBsAg) patients with HCC. Non-B patients were significantly older, had a lower frequency of familial tendencies for liver diseases, and more frequently had cancers other than HCC in their families. Some of these differences were also observed between non-B and B patients with cirrhosis and chronic hepatitis. Among patients with chronic hepatitis, the non-B patients had received blood transfusion or had post-transfusion hepatitis more frequently than the B patients. However, this difference was not apparent in patients with liver cirrhosis or HCC, suggesting that progression of non-A, non-B post-transfusion hepatitis to cirrhosis and HCC may not be as frequent as progression to chronic hepatitis.</p

Distribution of complement regulatory proteins, decay-accelerating factor, CD59/homologous restriction factor 20 and membrane cofactor protein in human colorectal adenoma and cancer.

To clarify the events related to complement-mediated immune responses in human colorectal cancers, we immunohistochemically examined the distribution of decay-accelerating factor (DAF), CD59/homologous restriction factor 20 (HRF20), membrane cofactor protein (MCP) and terminal complement complex (TCC) in human colorectal adenomas and cancers, and then compared the findings with their distribution in normal colonic mucosa. In the normal mucosa, TCC was not present on epithelial cells. Whereas DAF and CD59/HRF20 were present only occasionally on the apical surfaces of normal epithelial cells, MCP was diffusely distributed on the basolateral surfaces of most epithelial cells of the colon. These findings suggest that MCP has a primary role in the regulation of complement activation on these cells. In adenoma cells, the expression of both DAF and CD59/HRF20 was enhanced. In cancer cells, the expression of CD59/HRF20 and MCP was diminished, whereas DAF expression was markedly enhanced. Since DAF was frequently stained in the lumen of the cancer glands, it was suggested that DAF was released into the colonic lumen in patients with colorectal cancer.</p

Hepatitis B virus associated particles in the bile canaliculus.

The liver biopsy specimen from a patient with hepatitis B surface antigen was pbserved by electron microscopy. Dane particles, uncoated core particles and tubular forms were demonstrated in hepatocytes. Dane particles and tubular forms, approximately 25nm in diameter, were also found in the bile canaliculi. These findings suggest that hepatitis B virus and associated particles are released from hepatocytes into the bile duct

Electron microscopic observation of hepatitis B virus budding from hepatocytes into bile canaliculi.

In electron microscopic observation of a liver biopsy obtained from a hepatitis B surface antigen-positive patient, noncoated core particles were occasionally seen budding into the hepatocytic cisterni and many Dane particles were found in the pericanalicular vesicles of hepatocytes. Noncoated core particles were also localized in clusters within the bleb of microvilli. There were some core particles being protruded from microvilli into the lumen of bile canaliculi by budding. These findings suggest hepatitis B virus being released from the hepatocyte to the bile canaliculi by two different modes; through vesicle by reversed phagocytosis and from the microvilli by budding.</p

Immunohistochemical analysis of epithelial cell proliferation in normal-appearing rectal mucosa of patients with colorectal adenoma and cancer using an in vitro labeling method with bromodeoxyuridine.

To identify diffuse mucosal changes which may precede the development of colorectal cancer and a possible indicator for detecting high-risk populations, we immunohistochemically studied cell-cycle events in crypts of normal-appearing rectal mucosa of patients with colorectal adenoma and cancer using an in vitro labeling method with bromodeoxyuridine (BrdU). Biopsy specimens of endoscopically normal-appearing rectal mucosa were obtained during colonoscopy from 20 patients with colorectal adenocarcinoma, 20 with adenoma, and 15 without apparent colorectal diseases. The specimens were incubated with BrdU in vitro, and labeled S-phase cells were identified immunohistochemically using a monoclonal antibody to BrdU. Modification of the BrdU-labeling pattern in the normal appearing rectal mucosa, such as the presence of BrdU-labeled cells at the mucosal surface or in the upper one-fifth of the crypt column, was observed in 15 of the 20 patients with adenocarcinoma, 17 of the 20 patients with adenoma and 6 of the 15 controls. This upward shift in the frequency of proliferating cells in the crypt was significantly higher in the patients with colorectal adenoma and cancer than in the controls, and may be used to identify subjects at high risk for colorectal cancer.</p