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Biomedical subjects

M Rizzetto

Publications and source records attributed to M Rizzetto.

At least 19 recordsLinked to original sources
PubMed1992

Orthotopic liver transplantation for chronic viral hepatitis: an overview.

The aim of this review is to discuss the problem of orthotopic liver transplantation in patients suffering from chronic viral liver disease due to hepatitis B, C and D viruses. The decision to operate these patients is often controversial, as the risk of a recurrence of viral infection is very high and reinfection may be severe enough to require a second or even multiple grafts. However, the quality of life and the survival rate improve after transplantation in chronic viral hepatitis patients.

Chronic Disease↗
PubMed1992

Detection of hepatitis delta virus RNA by a nonradioactive in situ hybridization procedure.

A digoxigenin-tailed, synthetic oligodeoxynucleotide was used to detect genomic hepatitis delta virus (HDV) RNA in formalin-fixed, paraffin-embedded liver sections by a nonisotopic in situ hybridization (NISH) procedure. Twenty-three liver samples from chronically HDV-infected patients were studied. Eight liver specimens from humans and chimpanzees without markers of active HDV infection served as negative controls. In three samples, the NISH findings were compared with characteristic nuclear features and with the distribution of the HDV encoded antigen, HDAg, as detected by direct immunofluorescence. All samples from HDV-infected patients were positive for HDV RNA by NISH. The viral genome was exclusively observed within the hepatocytic nuclei. No enzymatic reaction was detected after hybridization with the negative controls. "Sanded" nuclei, a cytopathologic change associated with HDV infection, were HDV RNA-positive, but only a small percentage of infected cells showed that feature. Hepatocytes containing the HDV RNA were sometimes binucleated or exhibited giant nuclei. When HDAg and HDV RNA were sequentially detected within the same sections, the localization of the viral antigen almost completely overlapped with the expression of the HDV transcripts, and vice versa. In conclusion, detection of intrahepatic HDV RNA by NISH is a rapid, sensitive, and specific technique that is easily applicable to routine histopathology and allows correlation of HDV with the morphology of hepatocyte nuclei.

Antigens, Viral↗
PubMed1992

Hepatitis B x antigen and polymerase antibodies in the serum of hepatitis B carriers with or without hepatitis delta virus infection. Effects of interferon treatment.

Previous work has shown that the hepatitis B x antigen (HBxAg) and antibodies directed against the polymerase of hepatitis B virus (anti-pol) are early markers of hepatitis B virus (HBV) replication in natural infections. The present study was carried out to test the hypothesis that the appearance of one or both of these markers signaled reactivation in chronic carriers with liver disease who were treated with alpha-interferon (IFN). The results show that HBV DNA decreased among the patients who responded to therapy, and that among these responders, neither HBxAg nor anti-pol became detectable in serum for 12 months after treatment, in contrast to controls. Hence, the loss of HBxAg and anti-pol correlate with decreased levels of HBV DNA in response to IFN therapy. However, different patterns of HBxAg and anti-pol were observed among alpha-IFN-treated HBV carrier patients who were also chronically infected with the hepatitis delta virus (HDV). The treatment of such patients often resulted in the loss of HDV RNA from serum and delta antigen from liver. Most of these patients had increased levels of HBV DNA in serum. HBxAg and/or anti-pol also became detectable in patients who lost markers of HDV, implying that the suppression of HDV by IFN is accompanied by the appearance of early markers of HBV reactivation in some of the treated patients.

Adult↗
PubMed1991

Hepatitis delta virus (HDV) infections. Epidemiological and clinical heterogeneity.

Heterogeneity is a feature of all aspects of HDV infection and biology. Epidemiological studies indicate wide variations in the global distribution of the virus, often with different and bizarre rates of prevalence within apparently homogeneous populations. The medical expression of the infection is likewise manifold, ranging from the asymptomatic carrier of HDV to terminal cirrhosis. The clinical variability is matched at the biological level by extensive molecular heterogeneities, as expected with a small RNA virus such as the HDV.

Hepatitis D↗
PubMed1991

Hepatitis C virus-related chronic liver disease with autoantibodies to liver-kidney microsomes (LKM). Clinical characterization from idiopathic LKM-positive disorders.

This study was carried out on 33 patients who were sero-positive for liver-kidney microsomal antibodies (LKM) in order to examine clinical features and the presence of underlying hepatitis C virus infection. Twenty-four sera were positive for antibodies against HCV (anti-HCV) as detected by enzyme immunoassay and confirmed by recombinant immunoblot assay. These patients had chronic liver disease and the majority of those treated with interferon responded favourably. Three of the nine anti-HCV-negative patients had idiopathic chronic hepatitis and two responded favourably to steroids. Two patients were diagnosed as having toxic hepatitis and the other four had various extrahepatic disorders without evidence of liver involvement. The immunoblotting analysis showed reactivity with a 50 kDa microsomal protein which presumably corresponded to cytochrome P-450 db1 both in anti-HCV-positive and -negative sera. In addition a few anti-HCV-positive sera also reacted with a 35 kDa microsomal antigen. Autoimmune markers different from LKM were absent in both groups. The high prevalence of antibodies to the hepatitis C virus among LKM-positive sera confirms that this infection plays a role in forms of chronic hepatitis that had previously been labelled autoimmune. In patients with LKM the presence of anti-HCV may help to forecast a therapeutic response to interferon, while its absence may forecast response to steroid therapy.

Adolescent↗
PubMed1991

[Intrahepatic cholestasis in hyperthyroidism].

Three cases of cholestatic liver disease related to hyperthyroidism are reported. Features indicative of a role of the endocrine disease in the pathogenesis of the cholestatic syndrome were the appearance of liver damage in temporal relation with the clinical onset of thyroid hyperfunction and its disappearance with the amelioration of the hyperthyroidism; the absence of congestive heart failure and of infectious, toxic or obstructive agents of liver damage; the pathological and biochemical findings of intrahepatic cholestasis. Hyperthyroidism can be rarely complicated by a severe cholestatic syndrome that may dominate the clinical presentation and course.

Biopsy↗
PubMed1991

Hepatitis B virus replication modulates pathogenesis of hepatitis D virus in chronic hepatitis D.

Hepatitis D virus and hepatitis B virus nucleic acids were detected by Northern and Southern blot hybridization in the sera and livers of 85 chronic carriers of HBsAg and anti-hepatitis D followed up for a mean of 10 yr. We identified three subsets of patients: 13 with hepatitis D virus and hepatitis B virus viremia, 53 with serum hepatitis D virus RNA, but without hepatitis B virus DNA and 19 negative for both nucleic acids. Genomic and subgenomic forms of hepatitis D virus RNA were detected only in patients with hepatitis D virus and hepatitis B virus viremia. Histological findings and disease activity at admission were comparable in the three groups of patients, but the outcome was significantly worse in patients with active replication of both viruses; two of them died of terminal liver failure and hepatocellular carcinoma developed in two; the remaining patients had an uneventful course. These results suggest that active hepatitis B virus replication represents an important previously unrecognized determinant of severe liver damage in patients with chronic hepatitis D virus infection. Since hepatitis B virus provides the means for hepatitis D virus secretion and release from infected cells, active hepatitis B virus multiplication favoring the spread of hepatitis D virus from cell to cell may increase the pathogenetic potential of the defective agent.

Adolescent↗