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Biomedical subjects

F Bonino

Publications and source records attributed to F Bonino.

At least 19 recordsLinked to original sources
PubMed2003

Increasing serum levels of IgM anti-HCV are diagnostic of recurrent hepatitis C in liver transplant patients with ALT flares.

Recurrent hepatitis and acute rejection share common features which make difficult for diagnosis in liver transplant hepatitis C virus (HCV) positive patients. We studied the usefulness of quantitative monitoring of HCV RNA and immunoglobulin (Ig)M anti-HCV in the differential diagnosis between recurrent hepatitis and acute rejection in 98 consecutive anti-HCV positive liver transplant patients. Aminotransferase levels, serum HCV RNA and IgM anti-HCV were measured at the time of transplantation and monthly thereafter. A liver biopsy (LB) was obtained when serum aminotransferase levels increased to twice or more than normal. During a mean follow-up of 16 months 86 aminotransferase flares were observed. Histology was compatible with recurrent hepatitis C in 44 cases and with acute rejection in 28, doubtful in 14. The fluctuations of HCV RNA serum levels were not significantly different in the three groups. Serum IgM anti-HCV levels increased (from negative to positive or with value variations > or = 0.18) in 36 of 44 cases with recurrent hepatitis C at the time of alanine aminotransferase (ALT) flare. IgM anti-HCV remained unchanged in all rejection cases (P < 0.001), but increased in 10 of 11 histologically doubtful cases that were diagnosed as hepatitis at the second LB. Increasing serum levels of IgM anti-HCV at the time of ALT flares are significantly associated with recurrent hepatitis C in liver transplant patients. The quantitative monitoring of IgM anti-HCV appears to be an additional diagnostic tool for distinguishing recurrent hepatitis C from acute graft rejection with a 100% specificity; 100% positive predictive value and 88.9% diagnostic accuracy.

Adult↗
PubMed2001

Hepatitis C virus infection: early diagnosis and identification of response to antiviral therapy.

Early diagnosis of hepatitis C infection and early identification of virologic response to antiviral therapy represent major hallmarks of the quality of a case. They contribute to reducing the risk of hepatitis C infection from blood product and improve disease management in patients treated with antivirals. Some of the current issues and perspectives involved in detection and quantification of viral load during the incubation phase of infection and monitoring the early phase of antiviral therapy are discussed.

Antiviral Agents↗
PubMed2001

RT-PCR method to quantify vascular endothelial growth factor expression.

The vascular endothelial growth factor (VEGF) is implicated in the progression of cancers. Its expression is well correlated with tumor growth and metastases. The availability of a rapid and sensitive method to detect the amounts of VEGF mRNA in biological samples of limited size, very small biopsies, or samples containing relatively few cells could provide an interesting prognostic tool for clinicians. We have developed an RT-PCR method that allows us to detect the VEGF mRNA from as little as 3 micrograms total mRNA. We have also shown that this protocol can be generalized to all cell lines tested. This method constitutes a very potent tool for the analysis of VEGF mRNA expression in different contexts.

Adenocarcinoma↗
PubMed2000

Foreword

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Journal Article↗
PubMed2000

Tailoring interferon dose and monitoring viral load in hepatitis C virus genotype 1b infected patients: a pilot study.

BACKGROUND AND AIMS: Complete [biochemical and virological) primary response remains the first goal of any antiviral therapy and its early assessment could be particularly useful in the management of the high viral load, genotype 1b infected patients, who have the worst chance of response. We evaluated whether tailoring interferon dose according to pre-treatment viral load and early monitoring of quantitative HCV-RNA could either improve or predict the results of recombinant alpha-2a interferon treatment in these patients. PATIENTS: Fifty-three consecutive genotype 1b HCV-infected patients, stratified in two groups by viral load (cut off 6 MEq/ml), received randomly 6 or 9 MU of recombinant alpha-2a interferon thrice weekly for 6 months, followed by 6 MU for another 6 months. METHODS: HCV-RNA was measured [b-DNA] assay) two months apart prior to therapy, at baseline, after 2 weeks of therapy and monthly thereafter. RESULTS: In the high viraemic group, complete primary response was observed in 80% of patients treated with high dose recombinant alpha 2a interferon and only in 14.3% of low dose treated patients [p<0.03]. In low viraemic patients, complete primary response was 53. 8% in low dose patients and 80% (8 out of 10) in the high dose group. Sustained response was 60% in high viraemic patients treated with high dose and absent in those treated with low dose [p<0.05]. One log viral load decrease at 2 or 4 weeks showed 0.87 and 0.80 positive predictive values, 0.95 and 1.0 negative predictive values with 96% and 100% sensitivities and 83% and 70% specificities. CONCLUSIONS: 6 MU recombinant alpha-2a interferon thrice weekly schedules were completely ineffective in the large majority (85.7%) of patients with viral load above 6 million HCV-RNA copies/ml and the treatment failure could be predicted by lack of one log viral load decrease after 2-4 weeks of treatment.

Adult↗
PubMed1999

Defective thymocyte maturation in p44 MAP kinase (Erk 1) knockout mice.

The p42 and p44 mitogen-activated protein kinases (MAPKs), also called Erk2 and Erk1, respectively, have been implicated in proliferation as well as in differentiation programs. The specific role of the p44 MAPK isoform in the whole animal was evaluated by generation of p44 MAPK-deficient mice by homologous recombination in embryonic stem cells. The p44 MAPK-/- mice were viable, fertile, and of normal size. Thus, p44 MAPK is apparently dispensable and p42 MAPK (Erk2) may compensate for its loss. However, in p44 MAPK-/- mice, thymocyte maturation beyond the CD4+CD8+ stage was reduced by half, with a similar diminution in the thymocyte subpopulation expressing high levels of T cell receptor (CD3high). In p44 MAPK-/- thymocytes, proliferation in response to activation with a monoclonal antibody to the T cell receptor in the presence of phorbol myristate acetate was severely reduced even though activation of p42 MAPK was more sustained in these cells. The p44 MAPK apparently has a specific role in thymocyte development.

Animals↗
PubMed1999

High prevalence of G1 and G2 TT-virus infection in subjects with high and low blood exposure risk: identification of G4 isolates in Italy.

BACKGROUND/AIMS: A non-enveloped single-stranded DNA virus (TTV) was detected in Japanese patients with fulminant hepatitis (47%) and chronic liver disease of unknown etiology (46%) more frequently than in blood donors (12%). Subsequent studies, however, questioned the association of TTV with liver disease. We further investigated the role of this novel virus in liver diseases. METHODS: We tested 106 patients and 102 blood donors for TTV by polymerase chain reaction using conserved region primers. RESULTS: TTV DNA was found in 19 of 102 volunteer blood donors (18.6%) and in 27 of 106 patients with liver disease (25.5%): 10 of 28 chronic hepatitis B (35.7%), 9 of 28 chronic hepatitis C (32.1%) and 8 of 50 (16%) cryptogenic liver disease patients. Previous interferon treatment was not associated with a significantly lower prevalence of TTV infection. TTV prevalence was higher in patients with blood exposure (42.8%, 6/14) than in patients without risk factors (21.4%, 18/84). Four of five patients (80%) with HBV familial infection and without blood exposure were also TTV positive. Partial nucleotide sequences from 3 Italian isolates diverged more than 30% from the 2 prototype genotypes G1 and G2 and were 88% homologous to the recently described genotype G4. CONCLUSIONS: G1 and G2 TTV are common in Italy and in the USA in liver disease patients and in blood donors. The prevalence is high in patients with blood exposure but also in subjects without risk factors; other routes of transmission should therefore be considered.

Adolescent↗
PubMed1999

Treatment of patients with chronic hepatitis C and cirrhosis.

The most cost effective strategy for antiviral therapy of chronic hepatitis C is the earliest identification and treatment of patients at risk of developing life-threatening complications such as hepatocellular carcinoma. Liver fibrosis represents the best predictor of unfavourable outcome. However, some patients with liver fibrosis already have a histological diagnosis of cirrhosis and there is a debate about whether alpha interferon is still effective in lowering the risk of disease progression in such patients. We identified some of the reasons that may explain seemingly contradictory results of studies addressing this issue. A major cause appears the beginning of follow-up at different starting points during the course of clinically compensated cirrhosis. Some investigators recruited patients because of anti-HCV positivity and elevated transaminases and found cirrhosis only at histology, whereas others recruited patients because cirrhosis had been diagnosed. Ultrasonographic signs of portal hypertension appear to be a useful tool to distinguish the two phases of the disease. Another important cause of reduced response rate to antiviral therapy is the presence of cofactors of liver disease and hepatocellular carcinoma such as present or past HBV infection. Early phase cirrhotics without cofactors appear to benefit most from therapy with a significant lower risk for hepatocellular carcinoma than untreated controls. The therapeutic decision in these patients could be the same as in patients with chronic hepatitis C without cirrhosis. In contrast, the efficacy of interferon remains questionable in HCV patients who already have ultrasonographic signs of portal hypertension and/or past or present HBV coinfection. Prospective, randomized clinical trials should be performed after stratification of these patients for stage and cofactors of liver disease.

Antiviral Agents↗
PubMed1999

Prediction of relapse or sustained response in biochemical responders by serum hepatitis C virus RNA monitoring during interferon therapy.

Normalization of serum aminotransferase levels is achieved in approximately 50% of chronic hepatitis C patients treated with interferon (IFN); however, in about one-half of these patients the hepatitis relapses after therapy. In this study we investigated the efficacy of serum hepatitis C virus (HCV) RNA monitoring during IFN therapy to predict the outcome of a biochemical end-of-treatment (ETR) response. Eighty patients with chronic hepatitis C received leucocyte (natural) IFN-alpha (13 patients) or recombinant IFN-alpha2a (67 patients). Antiviral therapy was given for 12 months to 43 (53.7%) responders and this group was analysed further. During follow-up, 15 relapsed and 28 showed a sustained response (median follow-up 50 months, range 39-67 months). Viraemia was monitored at baseline, and at months 1, 3, 6, 9 and 12 of treatment, by nested polymerase chain reaction (PCR) (sensitivity 10-100 copies ml-1). A combination of positive nested PCR and HCV RNA values at the 3rd and 6th months of treatment was 100% predictive of relapse (sensitivity, 66.6%; specificity, 100%). A combination of negative nested PCR and HCV RNA values at the 1st and 3rd months of treatment was 100% predictive of sustained response (sensitivity, 39.3%; specificity, 100%). In conclusion, serum HCV RNA monitoring is an appropriate and reliable tool for predicting early outcome of the biochemical ETR response after IFN discontinuation. This could be useful in the modulation of therapeutic management of chronic hepatitis C.

Adult↗
PubMed1999

Long term response to therapy of chronic anti-HBe-positive hepatitis B is poor independent of type and schedule of interferon.

OBJECTIVE: The response rate to alpha interferon (IFN) of chronic anti-HBe-positive hepatitis B is variable. We studied whether type, dose, and schedule of IFN, and type and frequency of posttreatment monitoring, influence the response rate. METHODS: Seventy-two consecutive anti-HBe-positive chronic hepatitis B patients (59 male and 13 female, median age 41 yr) stratified by sex and histology were randomly allocated to three treatment arms. Twenty-seven patients (A) received 10 million units alpha-N1 IFN i.m. t.w. for 24 wk (total dose: 720 million units); 21 (B) received 9 million units alpha-2a IFN i.m. t.w. for 4 wk, followed by 18 million units for 12 wk and 9 million units for 8 wk (972 million units); 24 (C) received 2 alpha-2a IFN courses (9 million units i.m. t.w. for 16 and 12 wk separated by a 6-month interval [756 million units]). Primary response was defined by normal ALT and serum HBV-DNA levels below 10 pg/ml at the end of therapy and sustained response by normal ALT (tested monthly), undetectable HBV-DNA and IgM anti-HBc (<7 I.U. Paul Ehrlich Institute) (tested every 3 months) during the posttreatment follow-up. RESULTS: At the end of treatment, 12, 8, and 13 patients from groups A, B, and C, respectively, were responders. At the 18-month follow-up, two patients in group A and only one in groups B and C maintained the response. Overall, after 34 months (median posttreatment follow-up), three patients were long term responders, whereas three showed a sustained remission after relapse. CONCLUSIONS: The rate of long term response to interferon of anti-HBe-positive chronic hepatitis B is poor, independent of IFN type, dose, or schedule; the more stringent the monitoring, the higher the relapse rate.

Adult↗
PubMed1999

Hepatitis B virus mutants.

During hepatitis B virus (HBV) infection, selection and takeover of mutant viruses are frequent events driven by both humoral and cellular host-immune response and antiviral therapy. Therefore, dynamic studies of the variations of viral mutants over time within the overall viral population in relation with the host-virus interactions are extremely important to better understand the biological and pathogenic role of each mutant. With these premises, we review the more frequent mutations detected in each of the 4 open reading frames of HBV. A detailed analysis of the pathobiologic implications of pre-C region mutations which suppress the expression of the hepatitis B 'e' antigen, will be presented, as these mutations induce a specific change in virus biology and the variations of the ratio between wild-type and mutant correlate with significant events in host-virus interactions.

Carrier State↗
PubMed1998

Generation of an MHC class II-restricted T cell epitope by extracellular processing of hepatitis delta antigen.

Hepatitis delta virus is a human pathogen that is responsible for a severe form of hepatitis affecting hepatitis B envelope Ag carriers. We have previously identified a series of hepatitis delta Ag (HDAg) epitopes that are recognized by CD4+ T cell clones isolated from infected subjects. Herein, we show that the presentation of soluble HDAg to CD4+ T cell clones that are specific for the HDAg(106-121) epitope was exceptionally unaffected by the inhibition of the APC-processing machinery when APCs were fixed with glutaraldehyde before Ag pulsing or treated with chloroquine or brefeldin A. Interestingly, 5 h of pulsing was strictly required for the efficient presentation of the HDAg(106-21) epitope by fixed APCs, suggesting that some form of extracellular processing had occurred. Indeed, fixed APCs were able to present HDAg after only 1 h of pulsing when HDAg was preincubated with serum for 5 h. More important, presentation was completely abrogated when Ag was previously incubated in medium containing serum in the presence of a potent inhibitor of trypsin activity such as the secretory leukoprotease inhibitor. These results show that HDAg may undergo extracellular processing and suggest that the generation of immunogenic epitopes directly by serum proteases could play a role in the immune response against hepatitis delta virus during infection.

Amino Acid Sequence↗