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Biomedical subjects

M Rizzetto

Publications and source records attributed to M Rizzetto.

At least 361 records · Page 20Linked to original sources

[Chronic HCV hepatopathy and cryoglobulinemia. The associated clinical spectrum].

BACKGROUND AND AIM: The hepatitis C infection (HCV) has numerous extrahepatic manifestations owing to the systemic nature of the infection itself. HCV infects the cells that carry a CD 81 receptor and show a marked tropism for hepatocytes, bone marrow staminal cells and circulating lymphomonocytes. One consequence of this tropism is the activation of B lymphocyte clones with the consequent production of autoantibodies and cryoglobulins. The secondary event is the formation of circulating immune complexes which, having precipitated at an intravascular level, may cause part of the extrahepatic manifestations associated with these infections. METHODS: This retrospective study evaluated the manifestations correlated and/or associated with HCV hepatitis and mixed cryoglobulinaemia. RESULTS: This analysis showed that 75% of consecutively studied patients reveal clinically important extrahepatic manifestations. CONCLUSIONS: This underlines the "broad spectrum" action played by the hepatitis C virus in the host organism.

Adult↗

Liver transplantation in viral hepatitis. New insights.

Liver transplantation is the only therapeutic option for end-stage liver disease. When disease is due to hepatitis B, C or D viruses, transplantation is aggravated by important morbidity related to the recurrence of viral infections. The risk of reinfection has led to the identification of prognostic criteria and measures for preventing or diminishing the reinfection hazard. HBV recurrences can be diminished with the use after transplantation of immunoglobulins against the HBsAg (HBIg). With this prophylaxis the risk of reinfection is proportional to the viremic load before transplantation; it is high (> 90%) in patients with elevated viremia, low in non-viremic HBsAg carriers (such as those with fulminant hepatitis or HDV coinfection), intermediate in the remaining cases. The recent availability of potent antivirals against the HBV has provided a tool to further reduce the reinfection risk. Antiviral therapy or immunoprophylaxis, however, may lead to the emergence of resistant mutants; combination therapies appear in order to prevent this event. There is at present no valid prognostic indicator to identify HCV transplants at risk of recurrent disease or prophylactic measure to prevent reinfection. Reinfection is virtually universal and the course of infection is apparently benign over the short term in the majority of cases; the disease is rapidly progressive with cholestatic features mimicking chronic rejection in 10-20% of HCV reinfected transplants. Neither the HCV genotype nor coinfection with HGV appear to influence the clinical outcome. The long-term prognosis appears at present less favourable than previously perceived; several studies indicate a progressive reduction of the survival curve due to insidious HCV cirrhosis developing over 5 to 7 years. Interferon or Ribavirin monotherapy are not effective for prevention or therapy of recurrences while their combined use yields promising results.

Hepatitis, Viral, Human↗

[Infections and cardiovascular diseases on an ischemic basis. The case of Helicobacter pylori].

Cardiac and cerebrovascular diseases are an important cause of mortality in industrialized countries. "Classical" risk factors cannot fully explain epidemiological variations of these diseases. From several years infections have been linked to ischemic vascular events and recent publications pointed to the role of Helicobacter pylori, a Gram negative bacterium, involved in the pathogenesis of gastritis and peptic ulcer. Results on the association between this bacterium and acute myocardial infarction or stroke are controversial, due to the degree of studies heterogeneity. There is the need for extensive prospectic studies to evaluate the incidence of these diseases in relation to the presence of Helicobacter pylori infection. Interventional randomized studies employing an antibiotic treatment for patients affected by ischemic vascular diseases will rapidly answer the question of wheather Helicobacter pylori has a causal role in the pathogenesis of acute myocardial infarction and ischemic stroke.

Cardiovascular Diseases↗

Hepatitis B: therapeutic perspectives.

Therapy with interferon (IFN), an immunomodulant with anti-viral activities, is efficacious only in a minority of chronic hepatitis B (CHB); it is more efficacious in the hepatitis B e antigen (HBeAg)-positive variety sustained by the wild type hepatitis B virus (HBV) than in the HBeAg-negative variety sustained by mutant forms of the virus. Several other therapeutic approaches were attempted in recent years. The most promising is therapy with synthetic nucleosides as anti-virals capable of blocking the replicative activity of the HBV. Lamivudine (LAM) is the first of this class of compounds that has entered clinical use. It is well tolerated and highly effective in inhibiting HBV and abate HBV-related inflammation both in the HBeAg positive and negative variety of CHB. In the HBeAg positive variety it induces sero-conversion to anti-HBe at a rate that linearly increases over the years, reaching 40% at the third year. In the HBeAg-negative variety maintenance of viral repression requires continuative therapy. A major drawback of continued LAM therapy is the risk of the emergence of mutants in the tyrosine-methionine-aspartate-aspartate locus of the polymerase gene. These mutants are no longer responsive to LAM and may rekindle disease; wild type HBV and related disease often return after suspension of therapy. Other anti-viral drugs, the prototype of which is adefovir, are currently under clinical investigation in CHB as monotherapy or complementary therapy to LAM.

Antiviral Agents↗

[A case of hepatocarcinoma preceded by several years by "isolated" increase in alphafetoprotein].

Hepatocarcinoma (HCC), the most frequent malignant hepatic neoplasia, is sometimes difficult to diagnose at an early stage since the symptoms may be attributed to concomitant hepatic cirrhosis. The assay of alpha-fetoprotein associated with an ultrasound examination of the hepatic parenchyma is an important screening tool for high-risk patients. Ultrasound examination is considered the most sensitive method and alpha-fetoprotein is a supplementary diagnostic tool. Elevated alpha-fetoprotein only occasionally precedes morphological anomalies and even in these cases the neoplastic aspect emerges within a short period of time. The case reported here illustrates the "astronomic" increase of alpha-fetoprotein in a high-risk patient for HCC (positive HBsAg cirrhosis) without the manifest appearance of any instrumental or histological data confirming the presence of the tumour for two years. When the tumour was identified in instrumental tests it had spread throughout the entire hepatic parenchyma in a form which could no longer be treated using any form of therapy. The case reported here emphasizes the diagnostic value of alphafetoprotein in high-risk patients for HCC, even in the prolonged absence of all other data regarding neoplastic transformation.

Carcinoma, Hepatocellular↗

Laboratory evaluation of the patient with liver disease.

Because the liver performs multiple functions, no single laboratory test or battery of tests is sufficient to provide a complete estimate of the function of the liver in every clinical situation. A broad array of biochemical tests are used to assess the many functions of the liver and to evaluate patients with suspected or established liver disease. These tests are referred to collectively as "liver function tests" (LFTs). LFTs are used to screen people for the presence of liver disease, suggest the underlying cause, estimate the severity, assess prognosis, and monitor the efficacy of therapy. Abnormal LFTs may be the first indication of sub clinical liver disease and may thereby guide further diagnostic evaluation. After the existence of hepatic dysfunction is recognized, the specific pattern of liver test abnormalities may suggest the category of the underlying liver disease, such hepatitis, biliary obstructions, or infiltrative liver disease. The value of screening healthy, asymptomatic persons for liver disease with the use of LFTs is controversial and may not be cost-effective. If screening is performed a panel of tests (e.g., AST, alkaline phosphatase, bilirubin, albumin) is preferable to using a single test because of superior sensitivity and specificity for liver disease and lower cost than the sum of individually performed tests.

Humans↗

Treatment of early chronic delta hepatitis with lymphoblastoid alpha interferon: a pilot study.

Seven carriers of the Hepatitis B surface antigen who had acquired a form of chronic hepatitis D in the recent past were treated with lymphoblastoid alpha interferon (IFN) (10 MU three times weekly for 4 months, 6 MU three times weekly for other 8 months, with a 12 month follow-up after treatment). At the beginning of the study, these patients had a chronic active hepatitis with intrahepatic hepatitis D antigen but without signs of cirrhosis. By the end of therapy, five had normal amino-transferases and no trace of HDV-RNA in the serum. In two patients the liver enzymes and viremia relapsed during follow up; biochemical and virologic remission persisted after discontinuation of therapy in the other three patients. In the early non-cirrhotic stage of chronic hepatitis D, IFN may play a more consistent therapeutic role than in the average advanced case of the disease. Cytokine should be used as soon as a diagnosis of progressive hepatitis D is reached.

Adult↗

[Eosinophilic gastroenteritis and ascites. Clinical case].

We report the case of a patient with recurrent subocclusive episodes and diarrhea (no malabsorption) associated with ascites, in the absence or liver, kidney or heart disease. The demonstration of hypereosinophilia in the peripheral blood and in the ascites fluid and the failure to identify parasitic or haematological disorders have led to a through examination of the stomach (Endoscopy, Echoendoscopy), small bowel (X-rays and Computerized Axial Tomography) and colon (colonoscopy) in a search for parietal lesions. The absence of segmental lesions and the observation of CAT images of diffuse, regular thickening of the ileum and of the mesentery, coupled with the monotonous clinical history spanning over three decades, have led to a diagnosis of eosinophilic gastroenteritis with involvement of the serosal layer. Serosal involvement is rare in eosinophilic disease of the gut; in analogy with other cases reported in the literature, steroids have improved clinical symptoms and normalized the hematological picture.

Ascites↗

Patterns of natural killer cell function activation in response to interferon in chronic HBsAG positive hepatitis: relationship with the state of viral infection and with the early clinical response.

In an effort to define immunobiological parameters identifying "responders" vs "non-responders" to IFN among hepatitis patients, 16 patients with chronic active hepatitis were screened for changes of Natural Killer cell activity (NK). 10/16 patients replicated the hepatitis B virus (HBV-DNA positive) whereas 6/16 replicated the defective B virus associated delta virus (HDV-RNA positive). Patients received 9 MU/3x/weekly/3 months of recombinant IFN alpha A. Mean NK activity of the HBV-DNA patients rose significantly from 29.9 +/- 5.3 to 45 +/- 4.7 during therapy, whereas the 6/16 HDV-RNA positive patients did not show any significant increase of NK activity. Interestingly, individual HDV-RNA positive patients exhibiting boosted NK activity also showed improvement of disease confirmed by clearance of intrahepatic delta antigen at one year. No such a correlation was found amongst the HBV-DNA positive patients. These data indicate that in spite of widespread individual variability, IFN-mediated NK boost may herald delta clearance and help in identifying "responders" and "non-responders" in IFN trials.

Adult↗

Primary biliary cirrhosis and rheumatic diseases: a clinical, immunological and immunogenetical study.

Clinical investigation of Primary Biliary Cirrhosis (PBC) patients showed an elevated frequency of rheumatic disorders, as well as their frequent appearance in asymptomatic PBC. Anticentromere region antibodies in PBC patients were pathognomonic for concomitant complete or incomplete CREST syndrome. These antibodies were only found on the HEp2 cell substrate. The constant finding of immune-complexes (IC) with IgM antibody component suggests that they play a role in the pathogenesis of PBC. No statistically significant correlation was found between the amount and classes of circulating IC, HLA class I antigens and rheumatic disorders during PBC.

Adult↗