Biomedical subjects

Ramsey C Cheung

Publications and source records attributed to Ramsey C Cheung.

15 recordsLinked to original sources

PubMed2007

Clinical implications of hepatic steatosis in patients with chronic hepatitis C: a multicenter study of U.S. veterans.

Studies have indicated a high prevalence of hepatic steatosis in patients with chronic hepatitis C (CHC). To address the impact of steatosis on the clinical course of CHC and treatment response requires large multicenter studies. The present study analyzed hepatitis C virus (HCV)-infected veterans enrolled in a U.S. Veteran Administration multicenter study of the epidemiology and response to interferon alpha-2b and ribavirin treatment. Of the 357 patients, 97.1% were males, with a mean age of 48.7+/-6.4 years, and 184 (51.5%) had hepatic steatosis. The mean body mass index (BMI) was 29.3+/-5.2 kg/m(2), including 37.1% who were obese (BMI, > or =30 kg/m(2)). Stage III-IV fibrosis was present in 111 of 334 (33.3%) of the patients. After adjusting for age, race, and history of alcohol use in the past 12 months, only stage III-IV fibrosis was independently and significantly associated with hepatic steatosis (P=0.03). There was a trend of association between obesity and steatosis independent of the other factors. Only HCV genotype was independently associated with a sustained virological response (SVR) to interferon alpha-2b and ribavirin treatment after adjusting for age, alcohol use, steatosis, BMI, stage III-IV fibrosis, serum AFP, and HCV load. In conclusion, analyses of our multicenter trial data demonstrated that the prevalence of hepatic steatosis is 51.5% in HCV-infected U.S. veterans. We found that steatosis is independently associated with stage III-IV fibrosis. However, only HCV genotype, and not steatosis, obesity, or stage III-IV fibrosis, was associated with SVR to interferon alpha-2b and ribavirin treatment.

Adult↗

PubMed2006

Incidence of statin hepatotoxicity in patients with hepatitis C.

BACKGROUND AND AIMS: Statins are considered contraindicated in patients with chronic liver disease. Our objective was to determine the risk of developing hepatotoxicity from statin therapy in hyperlipidemic patients with hepatitis C. METHODS: Changes in liver biochemistry values within 12 months compared with baseline were determined in 3 cohorts matched for age, sex, and body mass index: (I) 166 anti-hepatitis C virus (HCV)-positive hyperlipidemic veterans who were initiated on statin therapy; (II) 332 anti-HCV-positive veterans who had not received statin therapy; and (III) 332 anti-HCV-negative hyperlipidemic veterans who were initiated on statin therapy. An increase in liver biochemistry values was defined as mild-moderate or severe as proposed in a previous study on statin hepatotoxicity in a non-hepatitis C population. RESULTS: In patients with hepatitis C, statin therapy (cohort I) was associated with a higher incidence of mild-moderate liver biochemistry value increases compared with those not on statin therapy (cohort II) (22.9% vs 13.3%, respectively, P = .009), but a lower incidence of severe increases (1.2% vs 6.6%, respectively, P = .015). Among patients started on statin therapy (cohorts I and III), the incidence of mild-moderate liver biochemistry value increases (22.9% vs 16.3%, respectively, P = .094), severe increases (1.2% vs 1%, respectively, P = .874), or discontinuation of statin therapy as a result of hepatotoxicity (21.6% vs 9.2%, respectively, P = .147) were similar in hepatitis C-positive and hepatitis C-negative patients. CONCLUSIONS: Statin therapy was not associated with a higher risk of severe hepatotoxicity in patients with chronic hepatitis C and appeared safe.

Alanine Transaminase↗

PubMed2006

Effectiveness of a screening program for hepatitis C.

We sought to determine the outcomes of a screening program for hepatitis C virus (HCV) infection. Of 536 veterans initially screened between July 2000 and June 2001 for risk factors and then tested positive for antibody for HCV, only 260 (48.5%) kept their initial appointments for further evaluation; 51 were not viremic and only 19 (9.1%) were treatment eligible. Of the 276 who did not keep their initial appointments, 92 were subsequently evaluated over the next 2 years and 23 (25%) were treatment eligible, along with another 15 from the first group. Thus, with appropriate intervention and long-term follow-up, there were 57 treatment candidates. In conclusion, most veterans who tested positive either failed to keep their appointment or were ineligible for treatment when first evaluated. Over the following 2 years, some were lost to follow-up, many continued to have contraindication(s) to antiviral therapy, and relatively few were treatment candidates.

Adult↗

PubMed2006

Identification of two gene variants associated with risk of advanced fibrosis in patients with chronic hepatitis C.

BACKGROUND & AIMS: Previously identified clinical risk factors such as sex, alcohol consumption, and age at infection do not accurately predict which patients with chronic hepatitis C (CHC) will develop advanced fibrosis (bridging fibrosis and cirrhosis). The aim of this study was to identify genetic polymorphisms that can predict the risk of advanced fibrosis in patients with CHC. METHODS: A total of 916 subjects with CHC was enrolled from 2 centers. A gene-centric disease association study of 24,832 putative functional, single nucleotide polymorphisms (SNPs) was performed. Of the 1609 SNPs that were significantly associated (P </= .05) with advanced fibrosis in the discovery cohort (University of California San Francisco [UCSF], N = 433), the first batch of 100 SNPs were selected for validation in the replication cohort (Virginia Commonwealth University [VCU], N = 483). RESULTS: A missense SNP in the DEAD box polypeptide 5 (DDX5) gene was significantly associated with an increased risk of advanced fibrosis in both the UCSF and the VCU cohorts (OR, 1.8 and 2.2, respectively). Two diplotype groups, carrying the haplotypes composed of the DDX5 SNP and 2 neighboring POLG2 SNPs were also significantly associated with an increased risk of advanced fibrosis and had comparable or better risk estimates. In addition, a missense SNP in the carnitine palmitoyltransferase 1A (CPT1A) gene was associated with a decreased risk of advanced fibrosis in both the UCSF and the VCU cohorts (OR, 0.3 and 0.6, respectively). CONCLUSIONS: Subjects with CHC carrying DDX5 minor allele or DDX5-POLG2 haplotypes are at an increased risk of developing advanced fibrosis, whereas those carrying the CPT1A minor allele are at a decreased risk.

Adolescent↗

PubMed2006

Hepatitis B vaccines.

Immunization is the most effective way to prevent transmission of HBV and, hence, the development of acute or chronic hepatitis B. The national strategy to eliminate transmission of the virus in the United States includes vaccination of all newborn infants, children, adolescents, and high-risk adults. Postexposure prophylaxis is also advocated, depending on the vaccination and anti-HBs status of the exposed person. Seroprotection after vaccination, defined as anti-HBs > or = 10 mIU/mL, is achieved in over 95% of all vaccinees. The hepatitis B vaccines are very well tolerated with usually minimal adverse effects. Predictors of non-response include increasing age, male gender, obesity, tobacco smoking, and immunocompromising chronic dis-ease. For those who remain nonresponders after the second series of vaccination, adjuvants such as GM-CSF may be considered, but their results are variable.

Journal Article↗

PubMed2006

The impact of chronic hepatitis C and comorbid psychiatric illnesses on health-related quality of life.

GOALS: To determine the relative impact of chronic hepatitis C (CHC) and comorbid psychiatric illness on the health-related quality of life (HRQoL). BACKGROUND: Psychiatric conditions are more common among patients with CHC but their relative influence on HRQoL is not well understood. STUDY: We identified 864 veterans who had previously completed a veteran-specific HRQoL questionnaire (SF-36V) as part of the 1999 VA Large Health Survey with known HCV antibody (anti-HCV) status before the survey. For 201 anti-HCV(+) and 663 anti-HCV(-) patients, we compared the HRQoL status and the prevalence of 6 major psychiatric diagnoses. We conducted multiple regression analyses to measure the effect of anti-HCV status and psychiatric comorbidity. RESULTS: Compared with the anti-HCV(-) group, anti-HCV(+) veterans were more likely to have alcohol dependence (P<0.001), depression (P=0.01), or posttraumatic stress disorder (PTSD) (P<0.004). The anti-HCV(+) group also reported lower HRQoL on 4 of the 8 SF-36V subscales (P<0.01) and the mental component summary scale (P<0.001). Even after adjusting for demographic variables and comorbid psychiatric illness, anti-HCV(+) patients reported a significantly lower mental component summary score (P<0.01) than did anti-HCV(-) patients. Multiple regression analysis found that depression and PTSD predicted lower HRQoL scores for all 8 HRQoL subscales (P<0.01) and both the physical (P<0.001) and mental component (P<0.03) summary scales independent of anti-HCV status. CONCLUSIONS: The HRQoL is significantly impaired in veterans with CHC, particularly the mental health components of HRQoL. In contrast, comorbid depression and PTSD are associated with both lower physical and mental components of HRQol, independent of CHC.

California↗

PubMed2005

High mortality rate in patients with advanced liver disease independent of exposure to general anesthesia.

STUDY OBJECTIVE: To evaluate the survival of patients with advanced liver disease to determine if known exposure to general anesthesia within a 5-year period has a measurable effect on mortality. DESIGN: Retrospective survival analysis of male veterans with advanced liver disease. SETTING: Tertiary referral VA Medical Center and university-affiliated teaching hospital. MEASUREMENTS: One hundred twenty-seven patients with a history of alcoholic cirrhosis and documented hepatitis C infection and stable platelet counts were identified and then divided into 3 groups. The 5-year survival rates in all 3 groups were compared using Kaplan-Meier survival curves. MAIN RESULTS: Ninety patients had marked thrombocytopenia (<100000/mm3). Their survival rates with and without known exposure to general anesthesia were compared with those of control subjects with alcoholic cirrhosis and hepatitis C infection but with platelet counts greater than 100000/mm3. The 5-year survival rate of 57% in the group that received general anesthesia was comparable to the 58% rate observed in the group without this exposure. Both groups' rates were statistically lower than the 5-year survival rate of 77% in the group with advanced liver disease but without thrombocytopenia. CONCLUSION: Comparably high mortality rates were observed in patients with advanced liver disease with or without exposure to general anesthesia. Higher survival rates were noted in patients with advanced liver disease who were not thrombocytopenic.

Adult↗

PubMed2005

Chronic hepatitis C in Latinos: natural history, treatment eligibility, acceptance, and outcomes.

OBJECTIVES: The natural history of chronic hepatitis C and treatment response are different between blacks and Caucasians, but little comparable data is available about Latinos. METHODS: A cross-sectional secondary analysis to investigate differences between 421 anti-HCV-positive, treatment-naïve, HCV-viremic Latinos and 2,510 Caucasians in 24 VA medical centers enrolled in a prospective study. RESULTS: Latinos were infected at a younger age and were less likely to have blood contact during combat, surgery, and needle stick injury, but were more frequently HIV coinfected (20.4%vs 3.9%, p < 0.0001) and prior HAV infection (39.9%vs 26.4%, p= 0.0001). Latinos were more likely to be treatment candidates, but less likely to actually initiate treatment. Liver histology (123 Latinos, 743 Caucasians) showed no difference in fibrosis or fibrosis rate, but steatosis (54.7%vs 43.2%, p= 0.038) was more common in Latinos. Eighty-eight Latinos and 481 Caucasians were subsequently treated with interferon-ribavirin: body mass index (BMI), duration of infection, baseline tests, liver histology and genotype distribution were similar. Compared with Caucasians, Latinos discontinued treatment prematurely more often (39.8%vs 28.9%, p= 0.043) and tended to have lower sustained virological response (SVR) rates (14.8%vs 22.5%, p= 0.10). Multivariate analysis found Latino race and history of recent alcohol use to be associated with early treatment discontinuation, whereas genotype and viral load but not ethnicity to be associated with SVR. CONCLUSIONS: Latinos were infected younger, more frequently HIV coinfected, more likely to meet criteria for antiviral therapy yet less likely to initiate treatment and had a trend toward lower SVR rates than Caucasians, but not in severity of liver disease. Latino ethnicity was associated with early discontinuation but not as an independent predictor of SVR.

Adult↗

PubMed2005

A randomized, double-blind, placebo-controlled dose-escalation trial of merimepodib (VX-497) and interferon-alpha in previously untreated patients with chronic hepatitis C.

Inhibition of inosine monophosphate dehydrogenase (IMPDH) is one of several proposed mechanisms of action for ribavirin (RBV), a critical component of the current treatment for chronic hepatitis C (CHC). This study was a double-blind, placebo-controlled dose-escalation study of a novel, selective, orally active small molecule inhibitor of IMPDH, merimepodib (VX-497 or MMPD) in combination with standard interferon-alpha (IFN-alpha). Fifty-four treatment-naive patients with genotype-1 CHC were randomized to receive IFN-alpha 3 MIU subcutaneously three times a week, alone or in combination with 100 mg or 300 mg (every 8 h) of MMPD for 4 weeks. At the end of 4 weeks, all patients were offered 48 weeks of treatment with IFN-alpha/RBV. The objectives of the study were to evaluate the tolerability of the IFN-alpha/MMPD combination and to evaluate whether MMPD had an on-treatment effect on HCV-RNA, similar to RBV when added to IFN-alpha. The drug combination was generally well tolerated; one patient at the higher dose discontinued because of elevated alanine aminotransferase levels. No pharmacokinetic interactions were evident between the two drugs. Analysis of covariance that adjusted for a baseline imbalance in HCV-RNA in the intent-to-treat population did not show any significant differences between the treatment groups, or between MMPD plus IFN-alpha compared with IFN-alpha alone. However, the per-protocol primary efficacy analysis based on treatment-compliant patients demonstrated a greater reduction in mean HCV-RNA in the combination of 100 mg MMPD plus IFN-alpha compared with IFN-alpha alone (-1.78 log vs -0.86 log, P=0.037). In conclusion, the addition of a selective IMPDH inhibitor to IFN-alpha was well tolerated. In a low-dose range, the addition of MMPD may have the potential to add to the antiviral efficacy of IFN-alpha. Larger, longer duration trials incorporating pegylated IFN would be required to determine whether this combination, alone or with RBV, would increase either early or sustained virological response rates.

Administration, Oral↗

PubMed2004

Genetic variability of hepatitis C virus non-structural protein 3 and virus-specific CD8+ response in patients with chronic hepatitis C.

Hepatitis C virus (HCV) variation in specific T-cell epitopes may represent a mechanism of viral persistence in chronic infection. We examined the HCV non-structural protein 3 (NS3), including the immunologically relevant epitopes HCV NS3-2 KLVALGINAV (human leukocyte antigen [HLA]-A2-restricted) and HCV NS3-1391 LIFCHSKKK (HLA-A3-restricted), in 22 HLA-A2+ patients with chronic infection. Significant amino acid variation was found in HCV NS3-2 epitope sequences when compared to the HCV-1 prototype virus. Six of the nine different HCV NS3-2 peptide variants were identified in patients with HCV NS3-2-specific CD8+ cells, detected with an HLA-A2 tetramer made with the HCV-1 prototype peptide. Phylogenetic analysis, including HCV reference sequences other than HCV-1, suggested however that most of the variations in the HCV NS3-2 epitope could be related to genetic heterogeneity between HCV reference subtypes. Variation was less common when comparing HCV NS3-2 epitope sequences from the clinical isolates to the most-closely related HCV reference subtype in each case. Some subtype-independent variations were found in epitopic residues probably important for T-cell receptor interaction. In contrast, no significant variation was found in HLA primary anchor sites, flanking regions, or in the contiguous HLA A3-restricted CD8+ T-cell epitope. Ongoing variation was not evident in two selected patients with follow-up. In conclusion, (i) the HCV NS3-2 epitope is not conserved between different HCV strains/subtypes, and (ii) an HLA-A2 tetramer loaded with the HCV-1 prototype NS3-2 peptide may still detect NS3-specific CD8+ cells in some patients with variant viruses. These data may be useful to improve T-cell assays using HCV NS3 peptides, taking into account the genetic diversity of this virus.

Adult↗

PubMed2004

Hepatitis B vaccines.

Immunization is the most effective way to prevent transmission of HBV and, hence, the development of acute or chronic hepatitis B. The national strategy to eliminate transmission of the virus in the United States includes vaccination of all newborn infants, children, adolescents, and high-risk adults. Postexposure prophylaxis is also advocated, depending on the vaccination and anti-HBs status of the exposed person. Seroprotection after vaccination, defined as anti-HBs > or = 10 mIU/mL, is achieved in over 95% of all vaccinees. The hepatitis B vaccines are very well tolerated with usually minimal adverse effects. Predictors of non-response include increasing age, male gender, obesity, tobacco smoking, and immunocompromising chronic disease. For those who remain nonresponders after the second series of vaccination, adjuvants such as GM-CSF may be considered, but their results are variable.

Adolescent↗

PubMed2004

The use of class-I HLA tetramers for the detection of hepatitis C virus NS3-specific CD8(+) T cells in patients with chronic infection.

BACKGROUND/AIMS: New methods to detect virus-specific T-cell responses have recently been developed. Several human leukocyte antigen (HLA)-peptide tetramers for the detection of hepatitis C virus (HCV)-specific CD8(+) T cells are under evaluation. METHODS: Evaluation of one HLA class I-tetramer (HCVNS3-2) for the detection of HCV NS3-specific CD8(+) T cells in a series of 38 HLA-A2(+) chronically infected patients. RESULTS: Almost half (42%) of the patients had detectable NS3-specific CD8(+) T cells. The frequencies of such cells ranged from 0.01% to 0.22% of total CD8(+) T cells. No significant differences in clinical features or mean viral load were detected between patients with or without tetramer + CD8(+) T cells. CONCLUSIONS: The tetramer HCVNS3-2 may be very useful for the study of the HCV-specific CD8(+) immune response. Combination of this reagent with other tetramers based on other HCV peptides may help in the understanding of the immune response to the virus. However, a panel of tetramers based on several parts of the HCV polyprotein may be a mandatory requirement to explore the whole breadth of the CD8(+) T-cell response against HCV and to detect that response in the majority of patients with chronic infection.

Adult↗

PubMed2003

The impact of hepatitis C status on postoperative outcome.

UNLABELLED: The impact of the hepatitis C virus (HCV) infection on the postoperative complication rate is unknown. We identified a population of surgical patients (n = 2457) for whom the HCV antibody (anti-HCV) had been measured and compared after surgical complications and mortality between those who were positive (17.9%) versus negative. The complication rates were 10% in the anti-HCV positive and 13% in the negative group (P = 0.125), whereas the mortality rates were 0.7% and 2.5%, respectively (P = 0.017). The anti-HCV positive patients were younger, had lower ASA physical status, and underwent shorter procedures. In the univariate analysis, emergent surgery and high ASA physical status but not anti-HCV positivity were associated with a more frequent complication. In the multivariate analysis, the urgency of surgery, age, ASA physical status, length of surgery, and preoperative hematocrit (but not platelet count) were associated with complications. Anti-HCV positivity was associated with an odds ratio for having a complication of 1.08 (95% confidence interval, 0.90-1.30), which was not statistically significant (P = 0.405). In conclusion, we were unable to show HCV antibody status to be an independent risk factor for postoperative complications when other co-factors were considered. IMPLICATIONS: In this large study at a Veterans Administration medical center, the urgency of surgery, age, ASA physical status, length of surgery, and preoperative hematocrit were all independently associated with postoperative complications. However, hepatitis C infection was not an independent risk factor for postoperative complications.

Hepatitis C↗

PubMed2002

Viral hepatitis and other infectious diseases in a homeless population.

GOALS: To determine the prevalence of four common infectious diseases-hepatitis B, hepatitis C, human immunodeficiency virus (HIV), and tuberculosis-as well as co-infection rates and risk factors in a homeless population. BACKGROUND: The prevalence of infectious diseases, especially viral hepatitis, among the homeless population is largely unknown. STUDY: This study consists of a retrospective analysis of the history and laboratory data collected from all homeless veterans admitted to a Veterans Administration (VA) domiciliary from May 1995 to March 2000. RESULTS: Of the homeless veterans admitted to a VA domiciliary program, 597 of 829 were screened for markers of all four infectious diseases. The overall prevalence of anti-hepatitis C virus (HCV) antibody, and positive result for purified protein derivative (PPD), anti-HIV antibody, and hepatitis B surface antigen (HbsAg) were 41.7%, 20.6%, 1.84% and 1.17%, respectively. At least one of the four markers was positive in 52.6% and more than one in 12%. Co-infection with HCV occurred commonly in veterans who were positive for anti-HIV (72.7%) and HBsAg (57.1%). Four self-reported major risk factors (intravenous drug use, alcohol abuse, previous imprisonment, and prior stay in a shelter) were evaluated. Multivariate analysis indicates that intravenous drug use and anti-HBs reactivity are independent risk factors for HCV infection, HCV infection for anti-hepatitis B surface antibody reactivity, and older age for PPD positivity. CONCLUSIONS: Chronic hepatitis C and co-infections are common among the homeless population. Patients infected with HIV and hepatitis B virus frequently are co-infected with HCV. Infections frequently are associated with certain identifiable risk factors.

Adult↗

PubMed2002

Depression, anxiety, post-traumatic stress, and alcohol-related problems among veterans with chronic hepatitis C.

OBJECTIVE: The aim of this study was to determine the incidence of psychiatric comorbidities among veterans with chronic hepatitis C. METHODS: Depression, anxiety sensitivity, post-traumatic stress symptoms, and alcohol use were assessed using standardized questionnaires in 120 consecutive veterans with chronic hepatitis C referred to the Liver Clinic. RESULTS: Using well-established scoring criteria of the questionnaires, clinically significant levels of depression (44.2%), anxiety (38.1%), post-traumatic stress disorder (20.8%), and alcohol-related problems (26.7%) were observed. The majority of patients had a clinically significant score for at least one questionnaire, whereas 37.2% had significant scores in two or more questionnaires. Positive correlations were found between post-traumatic symptoms and depressive symptoms, anxiety sensitivity, and alcohol use problems. Depressive symptoms were also correlated with anxiety. Responses to the questionnaires, in general, correlated poorly with psychiatric histories documented in the medical record. Overall, 79 (65.8%) patients had one or more possible contraindications to antiviral therapy: coexisting unstable psychiatric disorders and/or recent substance use was found in 73.4% of these patients. CONCLUSIONS: Psychiatric comorbidities were very common among veterans with chronic hepatitis C and correlated poorly with diagnoses documented in the medical record. We recommend a multidisciplinary approach that includes psychological assessment using standardized questionnaires in the evaluation of these patients for antiviral therapy.

Adult↗