PubMed Health⌕ Search

Biomedical subjects

P Colombatto

Publications and source records attributed to P Colombatto.

At least 19 recordsLinked to original sources
PubMed2005

Validation and comparison of different PCR-based methods for detection of hepatitis B virus precore region mutants.

Hepatitis virus variants detection is useful in clinical practice; however, methods that are used for their identification may influence the results significantly. Three PCR-based assays for quantitation of G1896A precore HBV mutants: two allele specific PCRs, single tube (single-AS-PCR) with enzymatic restriction or separate tubes (twin-AS-PCR) and one oligohybridization assay (OA) with three probes were developed and standardized. Wild type and mutant plasmids and 10 sera were used as reference. All methods had sensitivity limits of 10(4)copies/ml and their specificity encompassed 3 logs (10(4)-10(7)copies/ml) with dynamic ranges of logs for OA, twin-AS-PCR and single-AS-PCR, respectively. Single-AS-PCR and OA detected minor viral populations when their relative prevalence was at least 10% of the overall viral population whereas their detection by twin-AS-PCR ranged from 0.1 to 10% for samples with 10(7) and 10(5)copies/ml viral loads, respectively. Twin-AS-PCR was the most sensitive to detect the minor viral population, whereas single-AS-PCR and OA were more accurate to quantify the relative proportions of the two viral populations independently of the overall viral load. In conclusion, an accurate characterization of HBV precore heterogeneity should be warranted by a careful choice of the most appropriate assay according to the aim of the study.

DNA, Viral↗
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↗
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

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

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↗
PubMed1998

Natural beta interferon in acute type-C hepatitis patients: a randomized controlled trial.

AIM OF THE STUDY: A multicentre randomized controlled trial to assess whether a short course of beta-interferon could reduce the rate of chronic evolution of acute hepatitis C, in line with recent observations, was started in Northern Italy in 1991. METHODS: Forty acute hepatitis C patients were randomized to receive natural beta interferon 3,000,000 international units intramuscularly three times a week for 4 weeks or symptomatic drugs, and were followed up for a median period of 22.5 months. RESULTS: The chronicity rate was 75% (15/20 patients) in the interferon-treated group, and 80% (16/20) in the untreated group. No difference in the duration of the acute phase of hepatitis was observed. Hepatitis C virus ribonucleic acid was determined in 21 cases and was positive in 19 cases at baseline and in 15/17 chronic and 1/4 non chronic cases at the end of follow-up. Side effects of therapy (flu-like syndrome in 40% of cases) were mild and short-lasting. No aminotransferase flare-ups were observed during treatment. CONCLUSIONS: Beta interferon at the suggested regimen is well tolerated but does not seem to significantly influence the natural course of acute hepatitis C.

Acute Disease↗
PubMed1997

Quantitative detection of hepatitis C virus RNA in the serum of patients with chronic hepatitis C treated with interferon: a pilot study.

BACKGROUND: It is not known whether the measurement of serum hepatitis C virus (HCV) RNA by reverse transcription polymerase chain reaction (RT-PCR) could improve the management of patients with chronic hepatitis C being treated with interferon. OBJECTIVES: We analysed, in a pilot study, the relations between the variations of HCV-RNA and alanine aminotransferase (ALT) serum levels in 18 anti-HCV positive patients treated with interferon. STUDY DESIGN: Serum HCV-RNA was measured, using a non competitive coamplification assay (Amplicor HCV Monitor), before (at 3, 2 and 1 months and baseline), during (first, third and sixth month) and after treatment for at least 8 months (range 8-17 months). HCV-RNA levels fluctuations were correlated with those of ALT and treatment outcome. According to the ALT pattern, four patients were non responders, seven partial responders, four relapsers and two long term responders. RESULTS: The median and mean baseline HCV-RNA levels were significantly different in patients infected by HCV type 1, 2 and 3, being 248,449, 235,506; 4170, 17,866 and 22,315, 79,273 molecules per ml, respectively (P < 0.0001). We did not find any significant difference between median and mean baseline viremia of responders and non responders. After 1 month of treatment viremia was below the sensitivity levels of the assay in 77.7% (14/18) of the patients who normalized ALT, at least temporarily. On the contrary, HCV-RNA remained detectable in non responders. CONCLUSIONS: Our data suggest that HCV-RNA detection using Amplicor Monitor at the first month of treatment can be useful to identify non responders, avoiding three additional months of treatment as would be required by ALT monitoring alone. During the post-treatment follow-up, persistence of undetectable HCV-RNA and normal ALT levels helps to identify long term responders from patients with the risk of relapse in spite of biochemical remission.

Adolescent↗
PubMed1997

The prevalence of hepatitis C virus types in patients of the same geographic area, according to the source of infection and liver disease.

BACKGROUND: The duration and stage of hepatitis C might be associated with the source of infection and hepatitis C virus (HCV) types. OBJECTIVE: We studied the relationship among the different HCV types, source, duration, and stage of infection in 100 patients from the Apulia, southern Italy, selected from consecutive clinical records. They were 20 parenterally infected haemophiliacs with 10-20 years of disease history, but without cirrhosis; 20 patients (matched for sex, age and disease) and without known risk factor for parenteral infections; 60 patients with community acquired infection (ten with CAH and ten with cirrhosis with less than 20 years disease history; 20 with cirrhosis and hepatocellular carcinoma (HCC) and more than 20 years of liver disease and 20 matched cases with cirrhosis without HCC). RESULTS: Type 1 and 2 HCVs had comparable prevalence in patients with long lasting and recent HCV infection, 56 and 64%, 26 and 30% respectively. HCV type 3 was found in 6.5-12% of the patients with recent HCV infection, but it was not detected in those with infection longer than 20 years. Type 1 b HCV was more frequently found in HCC patients (68% of cases) than in the other forms of liver disease. The opposite was observed for HCV types (2 and 3). CONCLUSIONS: The prevalence of the different HCV types appears associated with the source and duration of the infection. The interesting association between HCV type 1 b and HCC prompts further studies in larger series of patients.

Adolescent↗
PubMed1997

An atypical verrucous carcinoma of the tongue arising in a patient with oral lichen planus associated with hepatitis C virus infection.

Recently, a clinical relationship between oral lichen planus (OLP) and hepatitis C virus (HCV) infection has been suggested, but the role of this virus on the course of OLP is unknown. We report an unusual lingual localisation of verrucous carcinoma arising in a patient with histologically confirmed OLP and HCV infection diagnosed with second generation enzyme-linked immunosorbent assay and recombinant immunoblot assay. Serum HCV-RNA detected using nested reverse transcriptase polymerase chain reaction (RT-PCR) confirm HCV replication. No classical risk factors associated with verrucous carcinoma were present.

Aged↗
PubMed1997

IgM antibody against measles virus in patients with inflammatory bowel disease: a marker of virus-related disease?

OBJECTIVE: Viral infections of the mesenteric microvascular endothelium have been hypothesized as pathogenetic factors in inflammatory bowel diseases. The aim of this study was to determine whether immunoglobulin M (IgM) antibody against measles virus is associated with disease. PATIENTS AND METHODS: The IgM antibody was detected by indirect antibody test in 36 patients with evidence of Crohn's disease (23 males and 13 females, median age 40 years, range 20-66), 22 patients with ulcerative colitis (14 males and 8 females, median age 42 years; range 19-65), 59 patients with a chronic active hepatitis (35 males and 24 females, median age 56 years, range 38-77) and 30 blood donors (20 males and 10 females, median age 45 years, range 29-62). RESULTS: Twenty-eight of 36 patients (78%) with Crohn's disease and 13 of 22 patients (59%) with ulcerative colitis tested positive as compared to only 3 of 89 (3.3%) controls (P < or = 0.001). CONCLUSION: The detection of IgM anti-measles virus in the majority of patients with Crohn's disease and in about half of ulcerative colitis patients as compared to a very low prevalence in patients with other chronic inflammatory disease is consistent with the hypothesis that the measles virus has pathogenetic implications in inflammatory bowel diseases.

Adult↗
PubMed1997

A new hepatitis C virus-like flavivirus in patients with cryptogenic liver disease associated with elevated GGT and alkaline phosphatase serum levels.

The intriguing co-infection of two flaviviruses (GBV-A and GBV-B) in tamarins and the recent discovery of another flavivirus (GBV-C/HGV) in humans raises the question of the relations between hepatitis C virus (HCV) and GBV-C/HGV. To address this issue the sera of 285 patients with liver disease (102 patients with cryptogenic and 183 with known forms of chronic liver disease) and 19 patients without liver disease were tested for HGV-RNA. GBV-C/HGV-RNA was detected by RT-PCR using primers encompassing 5'NC and NS5 regions and hybridization with specific biotinilated and radiolabelled probes. GBV-C/HGV RNA was found in 11 of 20 (55%) acute hepatitis C patients, in 13 of 117 (11.1%) patients with chronic hepatitis C, in 11 of 27 patients with a liver transplant (40.7%), one of 19 (5.3%) patients with chronic HBV infection, 15 out of 102 (14.7%) patients with cryptogenic liver disease and two out of 19 patients with inflammatory bowel disease. In cryptogenic patients, elevated serum gammaglutamyl transpeptidase (GGT, higher than twice the normal values) and alkaline phosphatase (ALP, above normal values) levels were significantly associated with GBV-C/HGV-RNA infection (P < 0.001). In conclusion GBV-C/HGV appears to be transmitted in humans by blood exposure and to be associated with liver disease in HCV co-infected patients and in a minority of patients with cryptogenic disease. The virus is only occasionally pathogenic for the liver and when liver damage is present; the association with the combined elevation of GGT and APH serum levels might represent a specific feature of the liver tropism of the agent.

Adolescent↗
PubMed1997

Impact of interferon-alpha therapy on the development of hepatocellular carcinoma in patients with liver cirrhosis: results of an international survey.

Clinico-epidemiological data show that the most severe forms of hepatitis C virus (HCV) associated liver disease occur in patients with multifactorial liver damage. We found that the prevalence of hepatitis B virus (HBV) markers in anti-HCV positive patients with cirrhosis complicated by hepatocellular carcinoma (HCC) is higher than in cirrhotics with comparable age and disease history, but without HCC. HBV can persist in integrated forms in HBsAg negative, anti-HBc positive individuals and we may speculate that in such patients concurrent liver pathogens, as HCV, could cause HCC more easily than in patients without previous exposure to HBV. Analysing the relations between age at HCC diagnosis and the different risk factors in consecutive HCC patients we found that patients with single hepatitis virus infections (HBsAg and/or anti-HCV positive) were of an older median age than patients with multiple hepatitis virus infections. We also studied patients with compensated cirrhosis and hepatitis virus infections. untreated or treated with interferon-alpha. The independent effect of treatment was analysed by matching groups with regard to all the other significant HCC risk factors. The overall relative HCC risk was three times higher (risk ratio 3.1) in untreated vs treated anti-HCV positive patients and more than six times higher (risk ratio 6.2) in untreated vs treated anti-HCV positive/anti-HBc negative patients. The difference between treated and untreated patients was not statistically significant in hepatitis B surface antigen carriers and in anti-HCV positive/anti-HBc positive patients. The evidence that HBV coinfection may worsen the course of liver cirrhosis in patients with chronic hepatitis C is intriguing, but it has important practical consequences. It warrants the identification of high risk patients with chronic hepatitis C who need to be treated as early as possible and patients who can still benefit from interferon-alpha therapy once cirrhosis has already been diagnosed.

Carcinoma, Hepatocellular↗
PubMed1997

Clinical relevance of anti-interferon antibodies in the serum of chronic hepatitis C patients treated with interferon-alpha.

The development of anti-interferon (anti-IFN) antibodies in the serum of patients undergoing antiviral therapy has been postulated as one possible cause of interpatient variability in response to therapy. We analyzed the relationship between the appearance of anti-IFN antibodies and the loss of response to interferon-alpha (IFN-alpha), as characterized by a breakthrough of serum aminotransferase after a period of complete biochemical remission. The analysis involved clinical trials where neutralizing anti-IFN antibodies were detected by standardized and comparable methods. The results show that a time relationship between breakthrough and anti-IFN antibodies is observed in only a few cases and is independent of the type of IFN-alpha preparation used. Thus, causes of IFN resistance other than anti-IFN antibodies must also be implicated in most breakthrough cases. Another potential is the selection of drug-resistant viral strains. Current ration behavior following the appearance of breakthrough (from whatever cause) in clinical practice advocates changing treatment to a different type of IFN-alpha. The detection of anti-IFN enzyme-linked immunosorbent assay (ELISA) antibodies or IFN neutralizing antibodies does not appear to provide any additional information for decision making.

Alanine Transaminase↗
PubMed1997

Platelet and white blood cell counts during therapy with different types of alpha interferon in patients with chronic viral hepatitis. Investigators of the Alpha Interferon Study Group of Piemonte, Italy.

BACKGROUND: Platelet and white blood cell counts decrease in chronic viral hepatitis patients treated with alpha interferon. AIM: To analyse whether delta negative variations in platelets and white blood cells are influenced by type, dose and duration of alpha interferon treatment, we studied 340 consecutive patients (mean treatment 8 months, range 4-18 months). PATIENTS AND METHODS: A total of 204 (60%) patients were treated with recombinant alpha interferons (30% alpha-2a and 30% alpha-2b), 64 (19%) with N3.leukocytic and 72 (21%) N1.lymphoblastoid natural interferons. Median age and male/female ratios were comparable in the 3 groups (41, 41 and 43 years and 2.3, 2.6 and 2.5, respectively). The lowest platelets and white blood cells counts were observed between the 2nd and the 4th month of therapy in all patients. Age, sex, aetiology and duration of interferon therapy did nor influence the platelets and white blood cells reduction rates. The decrease was lower for patients treated with N3.leukocytic interferon than for the other interferons. A significant difference was observed between interferon doses when the groups treated with 3 or 9-10 MIU were compared. However, dose or cirrhosis-related bias are ruled out by similar proportions of cirrhosis and patients treated with 3 MIU in the 3 groups of patients treated with different types of interferon. CONCLUSIONS: The type of interferon appears to represent a major cause of the different haemopoietic toxicity. The lowest toxicity of N3.leukocytic interferon may have clinical implications for the choice of interferon in patients with low baseline platelets and white blood cells counts. These findings prompt prospective studies on larger series of patients.

Adult↗