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Biomedical subjects

M Bonacini

Publications and source records attributed to M Bonacini.

At least 19 recordsLinked to original sources
PubMed2006

Pathogenesis of hepatitis C virus infection.

The hepatitis C virus (HCV) is a single stranded RNA virus. In 60-80% of patients, it is able to escape innate and adaptive immune surveillance. Thus it establishes itself as an agent of chronic hepatitis. Cytotoxic lymphocytes then contribute to liver injury in an attempt to eradicate the virus. On the other hand, strong multispecific T-lymphocyte reaction against HCV proteins is associated with viral clearance. Both CD4+ and CD8+ lymphocyte functions are important to effect this outcome. In chronic infection, genetic and environmental factors determine the progression of inflammation and fibrosis in individual patients. Of these factors, age, gender, race and alcohol use are the most established ones. The development of hepatocellular carcinoma is mainly restricted to patients with cirrhosis.

Disease Progression↗
PubMed2004

A multicentre study of the usefulness of liver biopsy in hepatitis C.

The role of liver biopsy in the assessment of chronic hepatitis C is generally accepted yet there is no prospective data available to quantify its contribution. A previous single centre pilot study suggested that the clinician could predict the amount of fibrosis and to a lesser extent, inflammation with moderate accuracy. The 2002 National Institute of Health Hepatitis C Consensus Conference recommended further study of the role of liver biopsy. Our objective was to compare a prediction of biopsy findings by expert clinicians using usually available clinical and laboratory data to actual biopsy results in order to determine whether biopsy is required routinely. This was a prospective observational study conducted at seven university centres in which the accuracy of clinician's predictions of the degree of inflammation and fibrosis were compared with the actual liver biopsy using an adaptation of a standard histological scoring system. We studied 81 adults with previously untreated chronic hepatitis C, raised serum transaminases and positive HCV-RNA in serum. Clinicians predicted the inflammatory grade in 44 of 80 cases (55%) and the fibrosis stage in 46 of 81 cases (57%). Nine of 17 cirrhotic cases were predicted (sensitivity 53%, specificity 56%). No unexpected additional diagnoses were made on the biopsies. Thus despite knowledge of the clinical and laboratory investigations of patients with hepatitis C, clinicians are unable to accurately predict the hepatic inflammatory grade and fibrotic stage. Liver biopsy is an essential investigation to accurately evaluate the grade and stage of liver disease patients with hepatitis C.

Adult↗
PubMed2001

Effect of coexisting HIV-1 infection on the diagnosis and evaluation of hepatitis C virus.

OBJECTIVES: To evaluate the diagnostic accuracy of the test for antibodies to hepatitis C virus by enzyme-linked immunosorbent assay (anti-HCV ELISA-2) in patients with and without HIV-1 infection. DESIGN: Cohort study. METHODS: In all, 369 patients were tested and grouped by available serologic tests. HCV RNA was quantified in these 369 patients using an Amplicor HCV (and/or HIV-1) Monitor, v1.0 test. Among 110 patients who were anti-HCV negative by ELISA-2, 39 were HIV/HBV coinfected and 71 had HIV alone. One hundred twelve patients were HIV/HCV coinfected and 147 patients had HCV infection alone. RESULTS: Six of 110 (5.5%) ELISA-2 anti-HCV-negative, HIV-infected patients had circulating serum HCV RNA. Their median CD4 count was 36 cells/mm(3), which was significantly lower than that observed in the HIV/HBV group (median CD4 = 109, p <.001) or the HIV/HCV cohort (CD4 = 235; p <.0001). The positive predictive value of the ELISA-2 test for diagnosing ongoing HCV infection in HIV-infected patients was 91%, which is significantly better than that determined for the HCV group, 76% (p =.002) presumably because HCV is less likely to resolve in the HIV patients. Mean alanine aminotransferase (ALT) levels were similar in the HIV/HCV (133 IU/L) and HCV (130 IU/L) cohorts. Median HCV RNA levels were higher in the HIV/HCV group (6.53 log(10) copies/ml) compared with the patients with HCV infection (5.62 log(10) copies/ml; p <.00001). There was no significant correlation between HCV RNA levels and ALT values, CD4 counts, or HIV RNA concentrations. CONCLUSIONS: The predictive value of the anti-HCV ELISA-2 test is better in HIV-coinfected patients than in patients infected only with HCV. False negative results, usually associated with acute infection or with low CD4 counts, are uncommon. These patients may be diagnosed with the ELISA-3 assay or by reverse transcriptase polymerase chain reaction (RT-PCR). Compared with patients with only HCV infection, HIV/HCV patients display similar ALT profiles, but a higher proportion of detectable serum HCV RNA.

Adult↗
PubMed2001

Medical management of benign oesophageal disease in patients with human immunodeficiency virus infection.

Oesophageal diseases are common in human immunodeficiency virus infection, and Candida is the most frequent cause. Empiric therapy with oral antifungal therapy is cost-effective in most patients presenting with oesophageal symptoms. The "gold standard" of diagnosis, endoscopy with brushings and biopsies, is reserved for non-responders within 2 weeks. Since the use of empiric antifungal drugs, the percentage of viral and idiopathic ulcers has increased. The latter frequently recur after treatment, and have been associated with the development of oesophageal strictures. More information is needed on the role of maintenance therapy particularly for viral infections.

AIDS-Related Opportunistic Infections↗
PubMed2001

Jaundice and hepatocellular damage associated with nevirapine therapy.

OBJECTIVE: Nevirapine is a nonnucleoside reverse transcription inhibitor that is used as part of highly active antiretroviral therapeutic combinations. Nevirapine has been associated with a skin rash in 32 to 48% of patients. Recent reports indicate that hepatic toxicity also occurs. METHODS: We describe four instances of reversible hepatocellular damage associated with the use of nevirapine in patients with HIV infection. Two of the four patients were also coinfected with the hepatitis C virus. RESULTS: Evidence of malaise, skin rash, and icteric hepatitis with pruritus occurred 4-6 wk after the beginning of nevirapine therapy. No evidence of metabolic acidosis was present in any of our patients. In all cases, liver test results declined to normal or near normal levels, and pruritus disappeared 4-6 wk after discontinuation of the medication. No patient was rechallenged with the drug. CONCLUSION: Nevirapine can be associated with icteric hepatitis, which appears to be reversible after withdrawal of the drug.

Adult↗
PubMed2001

Chronic hepatitis C in ethnic minority patients evaluated in Los Angeles County.

OBJECTIVE: The aim of this study was to compare demographic, clinical, and histological features of hepatitis C in four ethnic groups seen at the Los Angeles County/University of Southern California Hepatitis Clinic. METHODS: We evaluated 256 patients with chronic hepatitis C, with 132 (52%) receiving a liver biopsy as part of their evaluation. We estimated fibrosis progression in 103 patients with known duration of disease. RESULTS: Asians (6%) were underrepresented in the hepatitis C cohort, whereas Latinos (51%) were overrepresented, as compared with the entire county population. A history of injection drug use was more frequent in whites (65%) than in African Americans (45%, p = 0.05), Latinos (47%, p = 0.01), or Asians (0%) and more frequent in Latinos (59%) than in Latinas (26%, p = 0.003). Such a gender difference was not found in African Americans or whites. Baseline laboratory values were comparable. The amount of alcohol consumed daily was higher in African Americans than in Asians (p = 0.0001) and whites (p = 0.10). African Americans (0.077 fibrosis stages/yr) and whites (0.084/yr) had significantly lower mean estimated progression of liver fibrosis than Latinos (0.215/yr) with hepatitis C virus infection (ps = 0.03 and 0.02, respectively): this was likely related to their longer estimated duration of disease. CONCLUSION: Minorities represent the majority of chronic hepatitis C cases in the Los Angeles County Hepatitis Clinic. Asians, Latinas, and African Americans are less likely to report injection drug use as a risk factor for hepatitis C virus. Latinos seem to have faster liver fibrosis progression rates than either African Americans or whites.

Adult↗
PubMed2000

Liver fibrosis progression is related to CD4 cell depletion in patients coinfected with hepatitis C virus and human immunodeficiency virus.

A total of 204 patients with liver biopsy-proven hepatitis C virus (HCV) infection, 84 with and 120 without human immunodeficiency virus (HIV) coinfection, were studied, to evaluate variables possibly associated with the stage of liver fibrosis. All patients were injection drugs users, with a mean age of 32 years and an estimated duration of HCV infection of 12 years. Twenty-four patients (11%) had many fibrous septa with (5%) or without (6%) cirrhosis, 56 (27%) had few fibrous septa, and 124 (60%) had no fibrous septa. In all patients, an association was found between CD4 cell counts <500 cells/mm(3)and the presence of many fibrous septa (odds ratio, 3.2; P=.037), independent of HIV infection and other factors. These results suggest that HIV infection-induced CD4 depletion is independently associated with the severity of liver fibrosis in chronic HCV infection.

Adult↗
PubMed2000

Pruritus in patients with chronic human immunodeficiency virus, hepatitis B and C virus infections.

AIM: The prevalence of pruritus was prospectively determined in 310 patients of whom 119 had hepatitis C virus infection, 91 hepatitis C virus and human immunodeficiency virus, 51 human immunodeficiency virus infection alone, 31 hepatitis B virus and human immunodeficiency virus coinfection and 18 were HBsAg carriers. RESULTS: Patients in the first three groups were more likely to complain of itching (22%, 28% and 25%, respectively) than HBsAg carriers (8.2%, p=0.01. Laboratory data were not different between groups, except for the human immunodeficiency virus group, whose alkaline phosphatase levels were highest, and CD4 counts were lowest (median 30 cells/mm3). Patients with hepatitis C, including those with human immunodeficiency virus, had similar hepatitis C virus RNA levels in patients with or without pruritus. There was no difference in hepatic inflammation or fibrosis between those with and those without pruritus. CONCLUSION: 20% of patients with chronic hepatitis C and 8% of hepatitis B patients complain of pruritus. Patients with pruritus have laboratory and histologic parameters comparable to those without.

Adult↗
PubMed1999

Patients co-infected with human immunodeficiency virus and hepatitis C virus demonstrate higher levels of hepatic HCV RNA.

Serum and liver hepatitis C virus (HCV) RNA levels in patients with hepatitis C have previously been quantified using different techniques. In this work, we used an automated, multicycle, polymerase chain reaction (PCR)-based technique to quantify HCV RNA in 1-2 mm of frozen liver tissue, and in serum, from 70 patients with antibodies to HCV (anti-HCV), with and without human immunodeficiency virus (HIV) co-infection. Stored liver tissue and sera collected at the time of liver biopsy were used for measurement of HCV RNA. Forty-eight HCV patients and 22 HIV/HCV co-infected patients were studied. Co-infected patients had significantly higher median serum and liver HCV RNA (6.7 log copies ml-1 serum and 2.90 log copies microg-1 liver nucleic acids) than patients with HCV alone (6.2 log copies ml-1 serum and 2.19 log copies microg-1 liver nucleic acids). There was only a weak correlation between serum and liver HCV RNA (r = 0.43). There was no correlation between liver and serum HCV RNA and host factors such as duration of disease, CD4 counts, alanine aminotransferase levels or histological score. There was no correlation with HCV genotype. Co-infected patients were more likely to harbour HCV genotype 1 (85%) when compared to patients with HCV alone (58%). An identical genotype was found in liver and serum in 89% of those tested; in 11%, a mixed genotype was present in serum. Patients with HCV genotypes 1 and non-1 had similar histological scores. Hence, an automated PCR-based technique is useful for measuring both liver and serum HCV RNA. Serum HCV genotypes closely paralleled those found in liver tissue. HIV co-infection was associated with higher serum, as well as intrahepatic, HCV RNA levels, by mechanisms not directly related to CD4 counts. The lack of correlation between liver HCV RNA and histology suggests that HCV is not directly cytopathic.

Adult↗
PubMed1999

Prevalence of enteric pathogens in HIV-related diarrhea in the midwest.

HIV disease is often associated with the condition of diarrhea, which may be accompanied by enteric infection or gastrointestinal tumor. This study prospectively investigated 27 episodes of chronic diarrhea in 24 patients with HIV infection. Upper endoscopy and sigmoidoscopy with biopsies at three sites (distal duodenum, sigmoid colon, and rectum) and viral and mycobacterial blood cultures were performed. Stool specimens were sent for standard tests. A primary infectious diagnosis was found in 10 (37%) of 27 episodes: cytomegalovirus (CMV) colitis (n = 4), 3 microsporidiosis (n = 3), cryptosporidiosis (n = 2), and colonic histoplasmosis (n = 1). Patients with CD4 counts of less than 50 cells/mm3 and with lower albumin levels were more likely to have a primary infectious diagnosis. Adenovirus was found in 7 cases but was often associated with another organism; these were not considered to be primary diagnoses. Blood cultures for viruses were not useful, and all mycobacterial cultures were negative. A flexible sigmoidoscopy with histologic examination and culture of biopsy samples were the diagnostic tools that yielded most infectious diagnoses. Follow-up showed that two thirds of patients improved with nonspecific antidiarrheal medications regardless of diagnosis. The study supports a minimalistic approach to the problem of diarrhea in patients with HIV infection. Upper and lower endoscopy lead to a precise diagnosis in a minority of cases, and the outcome was similar in patients with or without a primary infectious diagnosis.

Adult↗
PubMed1998

Prevalence of hepatitis G virus RNA in the sera of patients with HIV infection.

OBJECTIVE: The routes of transmission of the hepatitis G virus (HGV) are similar to those responsible for infection with HIV. We sought to evaluate the prevalence of HGV RNA in the sera of HIV-infected patients. METHODS: The sera of 157 HIV-infected patients were assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) using established primers for HGV. Patients were divided into group 1 (positive circulating hepatitis B surface antigen [HBsAg]), group 2 (positive anti-hepatitis C virus [HCV] antibody) and group 3 (without markers for HBV or HCV). RESULTS: The overall prevalence of HGV RNA was 22%; prevalence was higher in group 1 (49%) than in groups 2 (16%) or 3 (7%). Patients with positive HGV RNA had laboratory values similar to HGV RNA-negative patients except for higher CD4 counts. Patients with an estimated risk duration of < or = 14 years were more likely to be HGV RNA-positive than patients at risk for >15 years. HGV RNA was found as frequently in patients with a homosexual lifestyle as in injection drug users (IDU). Multivariable analysis showed that the presence of HBsAg was the strongest factor associated with the presence of HGV RNA in serum. CONCLUSIONS: Patients with HIV and HBV coinfection are significantly more likely to be HGV RNA-positive. Patients with a risk factor duration for >15 years were less likely to be HGV RNA-positive, pointing to a decrease in HGV RNA prevalence over time. This study supports the notion that homosexual lifestyle, in addition to injection drug usage and blood product transfusion, is a risk factor for HGV infection.

Adult↗
PubMed1998

Esophageal disease in patients with AIDS: diagnosis and treatment.

Patients with HIV infection often present with symptoms suggesting esophageal disease: these include odynophagia (pain with swallowing), dysphagia (difficulty in swallowing), and retrosternal chest pain. Esophageal symptoms rank second only to diarrhea in frequency of gastrointestinal complaints among patients with AIDS. Also, esophageal opportunistic infections have been associated with a poor outcome, the mean survival after diagnosis being less than 6 months in one study. Such short survival may be explained by the underlying immunosuppression, as well as a decrease in nutritional intake due to difficulty swallowing.

AIDS-Related Opportunistic Infections↗
PubMed1997

Neural networks as predictors of outcomes in alcoholic patients with severe liver disease.

We developed and evaluated neural networks as predictors of outcomes in alcoholic patients with severe liver disease using commonly available clinical and laboratory values. Hospital charts of 144 patients were reviewed. Nine variables (five laboratory, four clinical) were recorded along with in-hospital death or survival. Data were organized into separate development and validation sets. Neural network predictions of survival were compared with those of the Maddrey discriminant function and logistic regression models developed on the same data. Model performance was evaluated by comparing areas under receiver-operating characteristic (ROC) curves and the distributions of model scores. Survivors had significantly different laboratory and clinical characteristics, the most important being a higher prothrombin time, lower bilirubin, and lower incidence of encephalopathy. Neural network performance was significantly better than that of the Maddrey score (ROC areas, 81.5% vs. 73.8%; P = .04). The ROC area for neural networks was similar to that of logistic regression (ROC area 78.2%; P = .3), but the neural networks were more successful in classifying patients into low- and high-risk groups (P < .001). A neural network score with laboratory data from hospital-day 7 improved prognostic accuracy further to 84.3%. After adjusting for baseline risk, the neural network change in illness severity was still a significant predictor of mortality (P = .001). Neural networks using clinical and laboratory data showed a high prognostic accuracy for predicting mortality in alcoholic patients with severe liver disease.

Adult↗
PubMed1997

Utility of a discriminant score for diagnosing advanced fibrosis or cirrhosis in patients with chronic hepatitis C virus infection.

OBJECTIVE: The aim of the study was to assess the utility of a modified three-parameter cirrhosis discriminant score (CDS) for diagnosing advanced fibrosis or cirrhosis in patients with evidence of chronic hepatitis C. METHODS: We examined liver tissue from 79 patients. Patients with a histological fibrosis score of 0-2 made up group A, and patients with a score of 3 or 4 (advanced fibrosis or cirrhosis) group B. RESULTS: The modified CDS (possible total score 0-11) was derived from three laboratory parameters: platelets, ALT/AST ratio, and PT. The total score was significantly lower in group A (4.3 +/- 2.0) than in group B (7.9 +/- 1.4) (p < 0.0001). There was a positive correlation between the CDS and histological fibrosis score (r = 0.64,p < 0.0001). With 8 or above as the cutoff value, the CDS had a sensitivity of 46% and a specificity of 98% for the diagnosis of histological fibrosis scores of 3 or 4. CONCLUSIONS: We conclude that a three-parameter CDS is useful for identifying patients with hepatitis C and a high likelihood of cirrhosis. Patients with a CDS < or =7 still require histological examination to identify advanced fibrosis or cirrhosis.

Alanine Transaminase↗