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Biomedical subjects

G Realdi

Publications and source records attributed to G Realdi.

At least 91 records · Page 5Linked to original sources
PubMed1986

Liver cirrhosis associated with chronic hepatitis B virus infection in childhood.

We evaluated the prevalence and the clinical features of liver cirrhosis associated with chronic hepatitis B virus (HBV) infection in a prospective study of 292 consecutive children who were chronic HBsAg carriers with increased aminotransferase activity. Liver histologic changes at presentation were consistent with cirrhosis in 10 (3.4%) patients (100% boys, mean age 4.0 +/- 3.3 years). In none of the remaining children, including 166 with histologic evidence of chronic active hepatitis, did the condition progress to cirrhosis during an observation period of 1 to 10 years. This lack of progression suggests that cirrhosis is an early complication of chronic HBV disease in some patients. A higher prevalence of delta infection and increased incidence of blood transfusions were observed in patients with cirrhosis, supporting the hypothesis that superinfection with delta or non-A, non-B agents may play a synergistic role. Eight of 10 patients had histologic features of disease activity at presentation, although only two had symptoms. During follow-up, persistence of disease activity was observed only in the three delta antigen-positive patients. None of the patients with inactive cirrhosis have developed signs of liver failure or portal hypertension.

Child↗
PubMed1986

Antibody to the hepatitis B virus receptor for polymerized albumin in acute infection and in hepatitis B vaccine recipients.

A receptor for polymerized human serum albumin is encoded by the pre-S region of the hepatitis B virus genome and may mediate attachment of the virion to hepatocytes. To investigate antibody response to the virus receptor we studied sera and their IgG fractions for inhibitory activity on hemagglutination of polyalbumin-coated red cells by virus particles containing the pre-S polypeptide. By this method antibody to the receptor was detected in serum in a goat immunized with pre-S containing particles, with no relation to levels of antibody to hepatitis B surface antigen, and in the sera of 33% and 83%, respectively, of acute hepatitis B patients studied during the early phase of illness and during convalescence. In contrast, antibody to the receptor was not detected in serum in any of the 47 subjects immunized with a commercial, plasma-derived, hepatitis B vaccine. These results demonstrate that natural acute infection with hepatitis B virus leads to production of antibody to the virus receptor for polyalbumin, while such antibody response is absent after immunization with currently licensed hepatitis B vaccines.

Animals↗
PubMed1986

Changes in serum hepatitis B virus (HBV) DNA positivity in chronic HBV infection: results of a long-term follow-up study of 138 patients.

In an assessment of the clinical relevance of serum hepatitis B virus (HBV) DNA testing in chronic HBV infection, changes in the presence of this marker were investigated by spot hybridization in 138 hepatitis B surface antigen (HBsAg)-positive patients with chronic liver disease who were followed up for one to eight years. Forty-one patients were treated with steroids, often with evidence of potentiation of viral replication, whereas 92 patients remained untreated and had no evidence of sigma agent infection during follow-up. Data analysis in these patients allowed us to determine the significance of testing for hepatitis B e antigen and for HBV DNA in the natural history of the infection. The findings indicate that sequential testing for serum HBV DNA may be of great importance in HBsAg chronic carriers with liver disease for adequate evaluation of HBV replication and for the contribution of HBV DNA to the clinical assessment of chronic hepatitis.

DNA, Viral↗
PubMed1986

Serum hepatitis B virus DNA in acute hepatitis type B.

Sera obtained within 7 days after clinical onset of acute hepatitis type B were positive for hepatitis B virus (HBV) DNA by spot hybridization only in 4 out of 45 patients who subsequently recovered, but in 10 out of 10 patients who instead developed chronic infection. These results indicate that in uncomplicated acute hepatitis B, virus replication is limited to an early phase of infection, often preceding the onset of clinical symptoms, and suggest that serum HBV-DNA may represent an early and predictive marker of chronicity.

Acute Disease↗
PubMed1986

In-vitro cell-mediated cytotoxicity for autologous liver cells in chronic non-A, non-B hepatitis.

To investigate the possible mechanisms of liver cell injury in chronic non-A, non-B (NANB) hepatitis, peripheral blood lymphocytes (PBL) from 16 patients with chronic NANB hepatitis were incubated with autologous hepatocytes in a microcytotoxicity assay. Significant cytotoxicity was demonstrated in 11 patients. T-enriched lymphocytes exhibited significantly greater cytotoxicity than non-T enriched cells. No significant inhibition of cytotoxicity was observed following preincubation of the liver cells with either monoclonal or polyclonal anti-HBc, or monoclonal anti-HBs, or addition of either purified HBsAg or recombinant HBcAg to the culture, indicating that there was no detectable cross-reactivity in this system between hepatitis B virus (HBV) and NANB-associated antigen(s). Preincubation of the patients' hepatocytes with polyclonal IgG purified from a serum of a patient who recovered from an acute NANB hepatitis, did not significantly alter cytotoxicity. Liver cell surface-bound IgG was detected by immunofluorescence in only two of the patients, a finding consistent with existing evidence of poor antibody responses to both liver membrane and NANB-associated antigens. Control experiments using PBL from allogeneic normal donors exhibited normal cytotoxicity for the patients' hepatocytes supporting the hypothesis that antibody-dependent cell-mediated cytotoxicity (ADCC) is unlikely to play a significant role in this clinical setting.

Adolescent↗
PubMed1986

Natural killer activity in patients with acute viral hepatitis.

Using the natural killer (NK) sensitive K562 cell line, enhanced NK cell cytotoxicity was demonstrable early in the course of acute hepatitis B while normal values were obtained in patients studied during convalescence. No evidence of enhanced NK activity was instead obtained in the course of acute non-A, non-B hepatitis. Serum levels of alpha-interferon, as determined by radioimmunoassay (RIA), were significantly increased in patients with acute hepatitis B showing enhanced NK cell activity but not in those with acute non-A, non-B hepatitis and normal NK cell activity. These results suggest that natural cytotoxicity may play a role early in the course of acute hepatitis type B, before antigen-specific T lymphocytes become fully operative.

Acute Disease↗
PubMed1985

Hepatitis B virus markers in children with acute leukemia: the effect of chemotherapy.

Hepatitis B virus markers were tested in the serum of 49 children with acute leukemia on clinical presentation and during subsequent chemotherapy. Hepatitis B surface antigenemia was observed in only six patients (12%), none of whom progressed to chronic infection. Chemotherapy had a marked suppressive effect on the production of antibodies to hepatitis B virus antigens and overt infection occurred in two children after suppression of protective immunity. Evidence of liver damage was frequently observed and was largely independent of serologic data. These results indicate that active immunization with hepatitis B vaccine may not find a clear place in this clinical setting.

Acute Disease↗
PubMed1985

Hepatitis B core antigen (HBcAg) in serum of patients with chronic hepatitis B detected by a modified radioimmunoassay.

Serum hepatitis B core antigen (HBcAg) was investigated in 85 patients with chronic hepatitis B virus (HBV) infection using a modified radioimmunoassay technique, based on high molarity treatment of samples to avoid masking of the antigen by the excess homologous antibody. Eighty-eight percent of HBeAg-positive cases and 19% of anti-HBe-positive cases were HBcAg positive in serum, with a positive correlation with the presence of HBcAg in the liver. Although the sensitivity of the method for the presence of complete virions was not absolute, as shown by the comparison with serum HBV-DNA testing, this technique may be helpful for assessing virus synthesis in patients with HBV infection.

Carrier State↗
PubMed1985

Relationship between HBcAg in serum and liver and HBV replication in patients with HBsAg-positive chronic liver disease.

The expression of hepatitis B core antigen (HBcAg) in serum and in hepatocytes was evaluated in relation to HBV replication. Fifty chronic HBsAg carriers with histological evidence of liver disease were studied, including 24 HBeAg-positive patients, 2 HBeAg/anti-HBe-negative patients, and 24 anti-HBe-positive cases, two of them with evidence of delta agent infection. Serum HBV-DNA was evaluated in all patients and related to HBcAg examined at the same time in frozen liver biopsies by immunofluorescence and to HBcAg detected in the corresponding serum by a recently developed radioimmunoassay. HBV-DNA was present in serum in 20 (83%) HBeAg-positive patients, all positive for serum HBeAg, whereas liver core antigen was detected in 14 (73%) of 19 cases. Among HBeAg-negative patients, 50% showed the presence of circulating DNA viral sequences, and HBcAg was identified in five of 26 (19%) cases in serum and in six of 24 (25%) in the liver respectively. In 15 patients, liver fragments permitted examination in parallel by immunofluorescence for HBcAg and molecular hybridization for viral DNA in liver cells. A DNA pattern characteristic of viral replication was found in cases with evidence of active virion production, independently from HBeAg and anti-HBe, and in these patients HBcAg was present both in serum and in hepatocytes. In two cases with free HBV-DNA, without evidence of replicative activity, core antigen was not detected in the liver, but in one patient HBcAg was found in the serum. A similar finding was also noted in another patient, in whom the hybridization pattern was consistent with integration of viral genome into high-molecular-weight cellular DNA. Whether serum HBcAg detected in these patients without HBV-DNA in serum reflects the presence of defective viral particles or of core antigen released as a viral protein remains to be determined.

Chronic Disease↗
PubMed1985

Different mechanisms responsible for in vitro cell-mediated cytotoxicity to autologous hepatocytes in children with autoimmune and HBsAg-positive chronic liver disease.

To investigate mechanisms of hepatocyte injury, lymphocytes from 41 children with chronic liver disease were incubated with autologous liver cells in a microcytotoxicity assay. Cytotoxicity was significantly increased in 18 of 25 patients with chronic hepatitis B virus (HBV) infection, in five of nine with "autoimmune" chronic active hepatitis (CAH), and in only one of seven with histologically inactive liver disorders. There was a good correlation between cytotoxicity and biochemical and histologic markers of disease activity in children with autoimmune CAH, whereas in HBsAg-positive disease a positive correlation was found only with serum alanine aminotransferase (SGPT). Children with autoimmune CAH receiving steroid treatment had normal cytotoxicity, whereas increased values were found in two of three HBsAg-positive patients receiving prednisolone. Fractionation studies revealed that non-T cells were cytotoxic in both autoimmune and HBcAg-positive chronic liver disease. T cell cytotoxicity was exclusively found in children with chronic HBV infection, particularly with HBc antigenemia. Blocking experiments showed that T-lymphocytes from HBsAg-positive children reacted with HBV core antigen on the hepatocyte surface. Non-T cells were directed against hepatocyte membrane antigens in both HBsAg-positive and HbsAg-negative children. These results suggest that different immune mechanisms of liver damage are involved in autoimmune and HBsAg-positive chronic liver disease.

Adolescent↗
PubMed1985

Liver-specific autoantibodies in chronic hepatitis B virus infection.

Anti-liver-specific protein (LSP) antibody and liver membrane autoantibody (LMA) have been evaluated in 88 patients with hepatitis B virus (HBV)-induced chronic liver disease by means of radioimmunoprecipitation and immunofluorescence. Among our patients, 38 presented circulating HBe antigen while 43 had HBe antibody and seven were negative for both. Anti-LSP was mainly found in HBeAg positive chronic active hepatitis (CAH), anti-HBe in positive CAH and in anti-HBe positive chronic persistent hepatitis (CPH). Similar prevalences of LMA (range 13-33%) were detected in the various groups studied. Taking into account the histological diagnosis of disease activity (periportal inflammation and piecemeal necrosis) no significant differences were found between active and inactive patients. Taking into account the HBeAg/anti-HBe status, no significant differences were found between the patients positive for 'e' antigen or 'e' antibody. Humoral autoimmune reactions may also play a role in HBV-induced chronic (active) liver disease irrespective of HBeAg/anti-HBe status and hence of the viral replication activity of the patients.

Autoantibodies↗
PubMed1985

Prognostic value of hepatitis B core antigen (HBcAg) expression in the liver of children with chronic hepatitis type B.

During a prospective follow-up study of 65 children with chronic hepatitis B, the HBcAg expression pattern in the liver was investigated, by immunofluorescence, in relation to biochemical and histological features and to the evolution of the disease. HBcAg was detected in 50 (77%) cases, with a diffuse pattern of distribution (more than 60% positive nuclei) in 20 cases, and with a focal pattern (less than 40% positive nuclei) in 30 cases. The diffuse pattern significantly prevailed in younger children, while the focal pattern was more frequent in children beyond 10 years of age. Transaminase levels were higher and histological features of activity were more frequent in patients with the focal pattern than in those with a diffuse pattern. Twenty-five hepatitis B e antigen (HBeAg) positive children, all initially HBcAg positive, were followed prospectively for 24 months. Seroconversion to anti-HBe, with subsequent normalization of transaminases, occurred in 72% of cases with a focal pattern, but only in 21% of those with a diffuse HBcAg pattern. In four patients transition from the diffuse to the focal pattern was observed during follow-up. These results suggest that, in children with chronic hepatitis B, the diffuse HBcAg pattern in the liver might reflect an earlier phase of infection. In HBeAg positive cases the focal HBcAg pattern may represent a prognostic marker of short-term favourable evolution of the disease.

Child↗
PubMed1985

Hepatitis B virus replication in acute glomerulonephritis with chronic active hepatitis.

A 3 year old boy who had chronic active hepatitis type B with features of ongoing liver damage and active virus replication, developed acute membranous glomerulonephritis two years after the clinical onset of liver disease, when both hepatitis B e antigen and antibody were detectable in serum. After withdrawal of short term steroid treatment and resolution of hepatitis B virus replication, both glomerulonephritis and chronic hepatitis went into remission. Some months later hepatitis B surface antigen was no longer found in serum.

Acute Disease↗