111,832 research outputs found
Combination therapy with natural interferon-alpha and 6-methyl-prednisolone in the treatment of mixed cryoglobulinemia.
No full textIN SITU SIMULTANEOUS DETECTION OF HEPATITIS C VIRUS-RELATED ANTIGENS IN HEPATOCELLULAR CARCINOMA
No full textCIRCULATING LEVELS AND LIVER-TISSUE DISTRIBUTION OF INTERCELLULAR-ADHESION MOLECULE-1 DURING INTERFERON-BETA THERAPY OF HEPATITIS-C VIRUS-ASSOCIATED CHRONIC ACTIVE LIVER-DISEASE
No full textIntercellular adhesion molecule-1, an immunoglobulin supergene family member, is known to account for important steps in cell activation and the immune response. By a non-isotopic slot-dot immunoblotting assay, we measured circulating levels of intercellular adhesion molecule-1 in 26 patients with hepatitis C virus-associated chronic active liver disease before and after beta-interferon therapy, in 6 patients with non-A, non-B acute self-limiting hepatitis and in 13 healthy subjects. Circulating intercellular adhesion molecule-1 was found in 10 of 13 (77%) normal controls at low concentrations which were not statistically different from those measured in patients with hepatitis C virus-associated chronic active liver disease responsive to beta-interferon, whereas significantly higher levels were found in unresponsive patients. Higher serum intercellular adhesion molecule-1 levels were found in 4 of 10 (40%) beta-interferon-responsive patients compared with 13 of 16 (18%) unresponsive patients. Intercellular adhesion molecule-1 levels persisted after discontinuation of beta-interferon treatment and did not correlate with hepatocytolysis (as indicated by alanine aminotransferase serum activity) either in chronic active liver disease or acute hepatitis. However, a good correlation was found between intercellular adhesion molecule-1 and its expression on liver cells, thus emphasizing that induced circulating levels may reflect the state of activation at the sites of the inflammatory process. These data strongly support the view that intercellular adhesion molecule-1 plays an important role in liver cell damage in hepatitis C virus-associated acute and chronic liver disease, and that its circulating levels may be a good prognostic parameter of responsiveness to beta-interferon therapy
In situ simultaneous detection of hepatitis C virus RNA and hepatitis C virus-related antigens in hepatocellular carcinoma
No full textBACKGROUND:
The overwhelming evidence that chronic infection with the hepatitis C virus (HCV) is an important cause of hepatocellular carcinoma (HCC) is based on epidemiologic, case-control, and cohort studies as well as laboratory investigations. To address better the pathogenesis of HCV infection at the single-cell level, the authors developed a specific reproducible method for the simultaneous detection of HCV specific sequences and antigens in liver tissue, using a combination of nonradioactive in situ hybridization and immunohistochemistry.
METHODS:
After immunohistochemical staining of the liver sections for E2/NS-1, C22-3, C33c, C100-3, and NS-5 antigens with immunogold-silver technique, in situ hybridization was performed on the same sections using digoxigenin-labeled HCV 5' NonCoding specific probes. The hybridization signal was detected by an antidigoxigenin, Fab fragment-alkaline phosphatase conjugate. This simultaneous detection permitted the subcellular localization of HCV RNA and antigens with excellent preservation of tissue morphology and absence of background staining. In addition, the types and percentages of cells harboring HCV in tissue could be determined.
RESULTS:
The in situ detection of HCV showed positive signals in both cancerous and noncancerous areas of liver tissue in six of six HCV-infected patients with HCC and in none of four controls, including three HCV negative HCC patients and one patient with epithelioid hemangioendothelioma. Two classes of infected cells were distinguished throughout the liver: (1) cells containing large amounts of negative-stranded HCV RNA, which were probably undergoing active viral replication; and (2) cells displaying positive-stranded HCV RNA only, with unpredictable levels of viral replication. Both types expressed core, envelope, and NS-3, -4, and -5 proteins. HCV RNA and antigens were exclusively cytoplasmic. Detection of viral proteins was highly predictive of the presence of large amounts of HCV RNA in the same cell. Fewer HCV positive cells were consistently demonstrated in the cancerous area.
CONCLUSIONS:
These findings support the contention that HCV infects hepatocytes and replicates in them, even after their malignant transformation
Immunohistochemical detection of hepatitis C virus-related proteins in liver tissue
No full textOBJECTIVE:
Hepatitis C virus (HCV)-associated antigens (Ags) are hard to detect and poorly defined in liver tissue, and are of uncertain interpretation. The failure of immunohistochemistry in HCV infection may be due to the affinity of specific antisera, the levels of Ags in infected tissues, the labile and unstable expression of antigenic determinants, and the use of fixatives that may alter or destroy viral epitopes. Strategies to optimize all stages of tissue specimen processing have therefore been devised in the liver biopsies of patients with acute and chronic hepatitis, and those with hepatocellular carcinoma (HCC).
METHODS:
HCV-Ags were detected with a two-stage indirect immunostaining procedure on unfixed cryostat liver sections from 7 acute and 23 chronic HCV-infected patients, and from 4 patients with HCV-associated HCC. A mixture of monoclonal antibodies directed to structural and non-structural HCV-related proteins were used as the primary reagents.
RESULTS:
HCV-Ags in 50-70% of the hepatocytes were found in all seven acute hepatitis patients compared with < or = 20% hepatocytes (P < 0.05) in 10 out of 23 patients (43.5%) with chronic hepatitis. Immunoreactive signals appeared as diffuse or coarse granular deposits in the cytoplasm only. The nuclei were unstainable. No clear membranous pattern was found, although fine granular, submembranous accumulation in distinct areas of the cytoplasm was observed. In acute hepatitis, HCV-Ag positive hepatocytes were distributed in the lobules in direct relation to the areas of necrosis and inflammatory cell accumulation, whereas in chronic hepatitis the immunoreactive cells were not clearly related to the necrotic foci. HCV-Ag immunodeposits were demonstrated in all patients with HCC. The immunoreactive signal in neoplastic cells was primarily located in the cytoplasm and rarely in the nuclei. As compared with the non-neoplastic zones, neoplasia demonstrated a significantly higher specific signal.
CONCLUSIONS:
Immunohistology is a powerful tool for the identification of HCV-related proteins in liver tissue. Sensitivity was significantly enhanced by the use of fresh-frozen tissues, which presumably preserve their HCV antigen structure, and by a mixture of monoclonal antibodies directed against HCV-related proteins, possibly on account of the separate access of each probe to different target proteins. The demonstration of HCV infection in hepatocyte cytoplasm indicates that this is the primary site of HCV replication, while its presence in malignant cells suggests that the virus could be substantially involved in the pathogenesis of HCC
LOCALIZATION OF HEPATITIS-C VIRUS-ANTIGENS IN LIVER AND SKIN TISSUES OF CHRONIC HEPATITIS-C VIRUS - INFECTED PATIENTS WITH MIXED CRYOGLOBULINEMIA
No full textSkin and/or liver biopsy specimens were obtained from the following patients: 15 anti-hepatitis C virus (HCV), HCV RNA-positive patients and 3 anti-HCV, HCV RNA-negative patients with type II mixed cryoglobulinemia (MC); 7 anti-HCV, HCV RNA-positive patients with chronic active liver disease (CALD); 5 anti-HCV, HCV RNA-negative patients with noncryoglobulinemic vasculitis; and 7 anti-HCV, HCV RNA-negative patients with lichen ruber planus. A pool of murine monoclonal antibodies (MAbs) developed against c22-3, c33c, and c100-3 proteins was used to detect HCV-related antigens (Ags) by indirect immunohistochemistry. Acid electroelution (AEE) of tissue sections was performed to enhance the sensitivity of the immunohistochemical method. In anti-HCV-positive MC patients, specific HCV-related Ags were detected in the small vessels of the skin and in the cytoplasm of hepatocytes. Prior AEE of biopsy sections allowed detection of HCV Ags in 6 of 15 (40%) skin biopsy and in 9 of 14 (64.3%) liver biopsy specimens. HCV immunoreactive deposits in the skin displayed two immunohistochemical patterns: (1) coarse intraluminal material associated with dermal inflammatory infiltrates and intravascular deposition of eosinophilic hyaline material; and (2) reactivity confined to the vessel wall in the context of an apparently normal tissue. Immunoglobulin (Ig) G and IgM deposition in the skin showed immunohistochemical features comparable with those found for HCV Ag deposits
Espansione clonale dei linfociti B intraepatici ottenuti da portatori cronici del virus C dell'epatite (HCV) con e senza crioglobulinemia mista
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