The use of hepatitis B core antibody-positive donor livers does not appear to have a deleterious effect on graft survival in liver transplantation for hepatitis C.

INTRODUCTION: The use of hepatitis B core antibody-positive donor livers (HBcAb(+)) has steadily increased. According to a recent multivariate analysis of United Network for Organ Sharing (UNOS) data, there was no significant increase in the risk of using these donors. The increased risk among the hepatitis C virus (HCV)-positive subgroup noted in a univariate model disappeared upon multivariate analysis. However, deeper scrutiny may show that HCV-positive recipients may be at increased risk with HBcAb(+) donor livers, as they require simultaneous treatment with two antiviral regimens there may be deleterious interactions between the two viruses. Thus, the issue of HBcAb(+) donors for HCV-positive recipients merits more detailed analysis. METHODS: Using UNOS registry data of all liver transplantations performed during the Model for End-Stage Liver Disease era from February 2002 through November 2007, we analyzed graft survival using Kaplan-Meier and Cox regression analyses. RESULTS: Of the 12,543 HCV-positive recipients, 2,543 received HBcAb(-) livers and 853 received HBcAb(+) livers. While Kaplan-Meier analysis showed significantly lower graft survival among HCV-negative recipients of HBcAb(+) livers (P = .0001), there was no significant effect on graft survival among the HCV-positive population (P = .2). To detect an early effect in HCV-positive recipients, we examined 1-year graft survival, observing no significant difference (P = .3). To exclude a possible late effect, we examined graft survival in the HCV-positive population conditional upon surviving at least 1 year after transplantation; no significant difference was observed (P = .6). The elimination of potentially confounding codiagnoses, such as hepatitis B virus, alcoholism, acute graft failure, and hepatocellular cancer did not alter the findings. On univariate analysis, the lack of a significant effect persisted among the HCV population. However, the significant effect observed in the univariate model for the HCV-negative population became insignificant when combined with other risk factors in the multivariate model. CONCLUSION: The use of HBcAb(+) livers in recipients with HCV did not appear to have a significant impact on graft survival.

Clinical trial: interferon alpha-2b continuous long-term therapy vs. repeated 24-week cycles for re-treating chronic hepatitis C.

BACKGROUND: Treatment options are limited for patients with hepatitis C virus who do not experience sustained viral eradication with pegylated interferon and ribavirin therapy. AIM: To compare, in an open-label, randomized study, long-term continuous interferon alpha-2b treatment with repeated 24-week courses in patients with chronic hepatitis C virus that relapsed after prior interferon monotherapy. METHODS: A total of 499 patients received 24 weeks of interferon alpha-2b, 3 MIU administered 3 TIW. Responders (normal alanine aminotransferase and negative hepatitis C virus -RNA, n = 244) were then randomized to continuous interferon therapy (1, 2 or 3 MIU TIW depending on response) or cyclical therapy (3 MIU TIW for 24 weeks per relapse). Mean Knodell inflammation (I + II + III) and necrosis (IV) scores at baseline vs. year 2 were compared. RESULTS: Patients receiving continuous low-dose therapy vs. cycled therapy had larger reductions in inflammation (-3.9 vs. -3.1) and fibrosis (-0.49 vs. -0.24). Among both groups, the mean change was -3.4 for inflammation and -0.36 for fibrosis. Overall, 73% (95% CI: 67-79) of patients experienced reduced inflammation and 28% (95% CI: 22-34) had reduced fibrosis. CONCLUSIONS: Our results suggest hepatitis C virus patients experiencing viral suppression during long-term maintenance therapy with interferon demonstrate histological improvement. Further prospective trials testing this hypothesis are in progress.

Hepatitis C in clinical practice.

Hepatitis C virus infection is now one of the most important causes of chronic liver disease. Primary care physicians play an important role in the diagnosis and initial work-up of patients infected with this virus. Understanding which patients may be at risk is the first step. By understanding the correct use of hepatitis C virus diagnostic testing and the risk and benefits of antiviral therapy, providers will be better equipped to screen and counsel their patients.

Chronic hepatitis C. Implications for health-related quality of life.

Hepatitis C viral infection with its sequelae is a significant healthcare problem. Hepatitis C infects nearly 4 million Americans with almost half of these unaware of their infection. Many of those individuals infected with hepatitis C develop chronic hepatitis C and in 15% of these patients, the infection will progress to cirrhosis within 20 years. Several cross-sectional and longitudinal studies have demonstrated the negative impact of chronic hepatitis C on health-related quality of life. This review describes what is currently known about the impact of chronic hepatitis C on health-related quality of life during pharmacologic treatment and after liver transplantation. It is important to note that few studies have prospectively followed patients over time with respect to quality of life or examined other factors including symptoms, markers of disease progression, or host immune function. Studies suggest that patients with chronic hepatitis C, even without major disease-related complications, perceive themselves to be unwell and have significant changes in their physical and mental well being. Such results have important implications for nursing care and management. Intervention studies focused on self-care management with an emphasis on symptom reduction are warranted.

Prospective characterization of full-length hepatitis C virus NS5A quasispecies during induction and combination antiviral therapy.

The hepatitis C virus (HCV) nonstructural 5A (NS5A) protein has been controversially implicated in the inherent resistance of HCV to interferon (IFN) antiviral therapy in clinical studies. In this study, the relationship between NS5A mutations and selection pressures before and during antiviral therapy and virologic response to therapy were investigated. Full-length NS5A clones were sequenced from 20 HCV genotype 1-infected patients in a prospective, randomized clinical trial of IFN induction (daily) therapy and IFN plus ribavirin combination therapy. Pretreatment NS5A nucleotide and amino acid phylogenies did not correlate with clinical IFN responses and domains involved in NS5A functions in vitro were all well conserved before and during treatment. A consensus IFN sensitivity-determining region (ISDR(237-276)) sequence associated with IFN resistance was not found, although the presence of Ala(245) within the ISDR was associated with nonresponse to treatment in genotype 1a-infected patients (P<0.01). There were more mutations in the 26 amino acids downstream of the ISDR required for PKR binding in pretreatment isolates from responders versus nonresponders in both HCV-1a- and HCV-1b-infected patients (P<0.05). In HCV-1a patients, more amino acid changes were observed in isolates from IFN-sensitive patients (P<0.001), and the mutations appeared to be concentrated in two variable regions in the C terminus of NS5A, that corresponded to the previously described V3 region and a new variable region, 310 to 330. Selection of pretreatment minor V3 quasispecies was observed within the first 2 to 6 weeks of therapy in responders but not nonresponders, whereas the ISDR and PKR binding domains did not change in either patient response group. These data suggest that host-mediated selective pressures act primarily on the C terminus of NS5A and that NS5A can perturb or evade the IFN-induced antiviral response using sequences outside of the putative ISDR. Mechanistic studies are needed to address the role of the C terminus of NS5A in HCV replication and antiviral resistance.

Diagnostic testing for hepatitis C.

Diagnostic tests for hepatitis C virus have improved dramatically over the past decade. Highly accurate tests are now available for screening patients for possible hepatitis C infections and confirming the presence of active viral infection. HCV RNA levels and genotype are very useful in assessing the likelihood of response to antiviral therapy and in guiding the optimum duration of treatment. Absence of detectable HCV RNA using PCR methodology has become the gold standard of successful treatment of patients with chronic hepatitis C. The various tests for hepatitis C are expensive and have their limitations. However, selective use of these assays has greatly improved the care of patients with chronic hepatitis C.

The protein kinase-interacting domain in the hepatitis C virus envelope glycoprotein-2 gene is highly conserved in genotype 1-infected patients treated with interferon.

The hepatitis C virus (HCV) envelope glycoprotein-2 inhibits the interferon (IFN)-induced, double-stranded RNA-activated protein kinase (PKR) via the PKR eukaryotic initiation factor-2alpha phosphorylation homology domain (PePHD). The present study examined the genetic variability of the PePHD in patients receiving IFN therapy. The PePHD from 12 HCV genotype 1 (HCV-1)-infected patients receiving daily IFN therapy was amplified by reverse-transcriptase polymerase chain reaction and analyzed by direct and clonal sequencing. The PePHD was highly conserved in 38 HCV GenBank isolates. There was no difference in pretreatment PePHD sequences isolated from IFN responders versus nonresponders. The major PePHD quasi-species variant did not change after 6 weeks of daily IFN therapy, and in 1 patient the major quasi-species variant did not change during 9 months of observation. Sequencing of 25 pretreatment PePHD clones from 3 patients confirmed that there was extremely low sequence variability surrounding the PePHD. The PePHD is highly conserved in HCV-1-infected IFN responders and nonresponders and does not appear to evolve in response to IFN therapy.

Pretreatment symptoms and dosing regimen predict side-effects of interferon therapy for hepatitis C.

We analysed data from a multicentre interferon (IFN) treatment trial to evaluate symptoms in patients with chronic hepatitis C and to identify factors that might predict development of debilitating IFN side-effects. Two hundred and twenty-two patients (120 US, 102 French) received 3 or 5 million units (MU) of IFN-alpha three times weekly (t.i.w.) for 3 months. Those who had detectable hepatitis C virus (HCV) RNA, as detected by the branched DNA signal amplification (bDNA) assay, at 3 months were intensified to daily therapy, while patients who were bDNA negative continued t.i.w. dosing for the subsequent 3 months of treatment. Symptoms were assessed at baseline, and adverse effects were evaluated at 6 months of therapy. Prior to treatment, the most common symptom that interfered with daily functioning was fatigue, occurring in 25% of patients. The frequency of debilitating fatigue, myalgia, arthralgia, headache, the presence of dry eyes and dry mouth, and use of antidepressant medication increased significantly from baseline to 6 months of IFN therapy (all P < 0.01). In multivariate analysis, the development of a debilitating side-effect at 6 months of treatment was associated with the presence of that symptom prior to therapy in all cases. Symptoms and adverse effects varied by gender and country. Compared with patients maintained on t.i.w. dosing, those who were dose intensified to daily IFN reported more debilitating fatigue, malaise, myalgia, arthralgia, fever, nausea, and headache, and the presence of dry mouth (all P < 0.05). In conclusion, patient characteristics, including pretreatment symptoms, gender and nationality, as well as daily IFN dosing are associated with the development of debilitating adverse effects on IFN therapy.

Pharmacokinetics of diclofenac sodium in chronic active hepatitis and alcoholic cirrhosis.

The objective of this study was to assess the pharmacokinetics of diclofenac sodium and its five metabolites following administration of a 150 mg oral dose to healthy subjects and patients with either chronic active hepatitis of varying morphology or alcoholic cirrhosis. Six healthy subjects, 6 chronic active hepatitis patients, and 6 alcoholic cirrhosis patients were enrolled in this prospective, open-label, parallel study. Blood samples were drawn at 0, 0.25, 0.5, 0.75, 1, 2, 4, 6, 8, 12, 24, 48, 72, 144, 312, and 480 hours, and urine samples were collected for 144 hours after administration of a single oral dose of diclofenac sodium. The mean area under the serum concentration-time curve extrapolated to infinity, oral clearance, half-life, maximal concentration, and time to peak concentration for diclofenac and its metabolites were determined and compared using analysis of variance. Cirrhotics had a mean +/- SD diclofenac AUC value (19,114 +/- 6806 ng.h/ml) significantly different (p < 0.02) from hepatitis patients (6071 +/- 1867 ng.h/ml) and healthy subjects (7008 +/- 2006 ng.h/ml), whereas healthy subjects and hepatitis patients had similar values. Comparable results were found for 4'-hydroxydiclofenac. The AUC values for 3'-hydroxydiclofenac and 3'-hydroxy-4'methoxydiclofeanc were significantly different when healthy subjects were compared to cirrhotics. However, hepatitis subjects were not significantly different from either group. The results indicate that hepatitis does not alter the pharmacokinetics of diclofenac. Alcoholic cirrhosis increased the mean diclofenac AUC approximately three times compared to normal subjects, indicating that one-third of the usual dose in cirrhotics would produce equivalent AUC values in normal subjects and subjects with alcoholic cirrhosis. However, since pharmacodynamic measurements were not made and no increase in untoward or side effects was noted in the alcoholic cirrhosis patients after a single dose, maintenance doses should be titrated to patients response.

Hyperbilirubinemia and cholestatic liver injury in hepatitis C-infected liver transplant recipients.

OBJECTIVE: A cholestatic pattern of liver injury has been observed in liver transplant recipients with rapidly progressive hepatitis C. We assessed the frequency and causes of cholestasis in hepatitis C-infected liver transplant patients, and evaluated the clinical and pathological course of those with cholestatic hepatitis C. METHODS: Sixty-nine sequential liver transplant recipients who had detectable hepatitis C viremia were studied retrospectively. Records and diagnostic tests were examined from patients who developed hyperbilirubinemia. RESULTS: Hyperbilirubinemia occurred in 33 of 69 (48%) hepatitis C-infected liver transplant patients. A thorough evaluation including review of clinical and laboratory data, ultrasound with Doppler, cholangiogram, and liver biopsy identified causes of hyperbilirubinemia other than hepatitis C in 26 of 33 patients. Seven patients developed cholestatic hepatitis C characterized by histological features of recurrent hepatitis C and cholestatic liver injury with ballooning of centrilobular hepatocytes, bile ductular proliferation, and canalicular cholestasis, in the absence of other causes of cholestasis. Five progressed rapidly to bridging fibrosis and two died of complications related to liver failure. Four patients with cholestatic hepatitis C showed extended survival after the onset of hyperbilirubinemia. CONCLUSIONS: 1) Hepatitis C is a relatively infrequent cause of cholestasis in liver transplant recipients. 2) The diagnosis of cholestatic hepatitis C requires a multimodality approach to exclude other causes of cholestasis. 3) Cholestatic hepatitis C ranges in severity and is not always associated with rapid development of graft failure, although significant histological abnormalities are frequent.

Maternal hemodynamics and pregnancy outcome in women with prior orthotopic liver transplantation.

The aim of this study is to evaluate the hemodynamics and pregnancy outcome of women with prior orthotopic liver transplantation. Hemodynamic measurements by Doppler technique were performed on pregnant subjects with prior orthotopic liver transplantation. Maternal characteristics, renal function, pregnancy complications, delivery indications, delivery mode, and neonatal outcomes were evaluated. Six pregnancies occurred in 5 women after orthotopic liver transplantation at the University of Washington Medical Center (Seattle, WA) between 1991 and 1999. Four of the 6 pregnancies were complicated by chronic hypertension, fetal growth restriction, and preterm delivery. Two pregnancies had worsening hypertension characterized by vasoconstriction in the second trimester despite antihypertensive therapy. These 2 subjects were administered cyclosporine for maintenance immunosuppression and had greater mean arterial pressures preconception and in the first trimester than the other subjects. One of these pregnancies resulted in fetal demise at 25 weeks' gestation. The other subject was delivered at 28 weeks' gestation for nonreassuring fetal status and superimposed preeclampsia. All pregnancies were complicated by renal insufficiency; however, the 2 subjects with poor obstetric outcome had preconception serum creatinine levels greater than 1.5 mg/dL and creatinine clearances less than 40 mL/min. Pregnancies complicated by second-trimester vasoconstriction and moderate renal insufficiency are at risk for preeclamspia, fetal growth restriction, and fetal demise. Good obstetric outcome can occur in women with mild renal insufficiency and well-controlled chronic hypertension. Improved hypertensive control preconception may decrease the risk for preeclampsia and poor obstetric outcome.

In situ distribution of hepatitis C virus replicative-intermediate RNA in hepatic tissue and its correlation with liver disease.

Liver failure from chronic hepatitis C is the leading indication for liver transplantation in the United States. However, the pathogenesis of liver injury resulting from chronic hepatitis C virus (HCV) infection is not well understood. To examine the relationship between HCV replication in liver tissue and hepatocellular injury, a strand-specific in situ hybridization procedure was developed. The sensitivity and specificity of digoxigenin-labeled riboprobes were optimized by analyzing Northern blots and cell lines expressing HCV RNAs. For the current study, both genomic (sense) and replicative-intermediate (antisense) HCV RNAs were detected and quantified in 8 of 8 liver tissue specimens from infected patients versus 0 of 11 liver tissue specimens from noninfected controls. The distribution pattern for HCV replicative-intermediate RNA in liver was different from that for HCV genomic RNA. HCV genomic RNA was variably distributed throughout infected livers and was located primarily in the cytoplasm of hepatocytes, with some signal in fibroblasts and/or macrophages in the surrounding fibroconnective tissue. However, HCV replicative-intermediate RNA showed a more focal pattern of distribution and was exclusively localized in the cytoplasm of hepatocytes. There was no significant relationship between the distribution pattern for HCV genomic RNA and any indices of hepatocellular injury. However, a highly significant correlation was observed between the percentage of cells staining positive for replicative-intermediate RNA and the degree of hepatic inflammatory activity (P, < 0.0001). Furthermore, the ratio of cells staining positive for HCV replicative-intermediate versus genomic RNA correlated with the histological severity of liver injury (P, 0. 0065), supporting the hypothesis that active replication of HCV in liver tissue may be a significant determinant of hepatocellular injury.

Liver transplantation. American Association for the Study of Liver Diseases.

Liver transplantation has revolutionized the care of patients with end-stage liver disease. Liver transplantation is indicated for acute or chronic liver failure from any cause. Because there are no randomized controlled trials of liver transplantation versus no therapy, the efficacy of this surgery is best assessed by carefully comparing postoperative survival with the known natural history of the disease in question. The best examples of this are in primary biliary cirrhosis and primary sclerosing cholangitis, for which well-validated disease-specific models of natural history are available. There are currently relatively few absolute contraindications to liver transplantation. These include severe cardiopulmonary disease, uncontrolled systemic infection, extrahepatic malignancy, severe psychiatric or neurological disorders, and absence of a viable splanchnic venous inflow system. One of the most frequently encountered contraindications to transplantation is ongoing destructive behavior caused by drug and alcohol addiction. The timing of the surgery can have a profound impact on the mortality and morbidity of patients undergoing liver transplantation. Because of the long waiting lists for donor organs, the need to project far in advance when transplantation might be required has proven to be one of the greatest challenges to those treating patients with end-stage liver disease. Three important questions must be addressed in a patient being considered for liver transplantation: (1) when should the patient be referred for possible transplantation? (2) when should the patient be listed for transplantation? and (3) when is the patient too sick to have a reasonable chance of surviving the perioperative period?

The effect of ursodeoxycholic acid on the florid duct lesion of primary biliary cirrhosis.

The frequency with which florid duct lesions are seen in needle-biopsy specimens of the liver was assessed in patients with primary biliary cirrhosis (PBC) enrolled in a 2-year randomized, double-blind, placebo-controlled trial of ursodeoxycholic acid (UDCA) versus placebo. Paired biopsy specimens obtained at entry and after 2 years on medication were reviewed blindly and mostly simultaneously by a panel of 5 hepatopathologists who, earlier, had characterized the florid duct lesion, which has been well described in the pathology literature. Florid duct lesions at entry were identified in approximately 36%. Patients with earlier disease showed florid duct lesions much more frequently than those with more advanced disease. The prevalence of florid duct lesions in 60 patients receiving placebo medication fell from 38.3% to 21.7%, P =. 025, over the period of 2 years. The prevalence of florid duct lesions also decreased in the 55 patients receiving UDCA, from 32.7% to 18.2%, P =.046. The prevalences of these lesions in the placebo and UDCA patients at entry and at 2 years were not significantly different from each other. The findings suggest that UDCA does not prevent ongoing bile duct destruction in patients with PBC. Instead, they support the impression that UDCA exerts its beneficial effects by protecting against the consequences of bile duct destruction.

Biliary bile acids in primary biliary cirrhosis: effect of ursodeoxycholic acid.

Bile acid composition in fasting duodenal bile was assessed at entry and at 2 years in patients with primary biliary cirrhosis (PBC) enrolled in a randomized, double-blind, placebo-controlled trial of ursodeoxycholic acid (UDCA) (10-12 mg/kg/d) taken as a single bedtime dose. Specimens were analyzed by a high-pressure liquid chromatography method that had been validated against gas chromatography. Percent composition in bile (mean +/- SD) for 98 patients at entry for cholic (CA), chenodeoxycholic (CDCA), deoxycholic (DCA), lithocholic (LCA), and ursodeoxycholic (UDCA) acids, respectively, were 57.4 +/- 18.6, 31.5 +/- 15.5, 8.0 +/- 9.3, 0.3 +/- 1.0, and 0.6 +/- 0.9. Values for CA were increased, whereas those for CDCA, DCA, LCA, and UDCA were decreased when compared with values in normal persons. Bile acid composition of the major bile acids did not change after 2 years on placebo medication. By contrast, in patients receiving UDCA for 2 years, bile became enriched with UDCA on average to 40.1%, and significant decreases were noted for CA (to 32.2%) and CDCA (to 19.5%). No change in percent composition was observed for DCA and LCA. Percent composition at entry and changes in composition after 2 years on UDCA were similar in patients with varying severity of PBC. In patients whose bile was not enriched in UDCA (entry and placebo-treated specimens), CA, CDCA, DCA, and the small amount of UDCA found in some of these specimens were conjugated to a greater extent with glycine (52%-64%) than with taurine (36%-48%). Treatment with UDCA caused the proportion of all endogenous bile acids conjugated with glycine to increase to 69% to 78%, while the proportion conjugated with taurine (22%-31%) fell (P <.05). Administered UDCA was also conjugated predominantly with glycine (87%).

Cholestasis and alcoholic liver disease.

Histologic cholestasis and clinical jaundice may be seen in all stages of alcoholic liver disease. In rare cases, isolated cholestasis without significant steatosis, hepatitis, or cirrhosis is identified in an alcoholic patient. The mechanisms of ethanol-induced cholestasis are not well studied but may involve compression of intrahepatic biliary radicals or interference with basolateral uptake and intracellular transport of bile acids. In the evaluation of the jaundiced alcoholic patient, clinical, biochemical, and radiologic data are usually sufficient to distinguish alcohol-induced liver disease from extrahepatic biliary obstruction. In cases where the diagnosis is not readily apparent, more invasive studies such as liver biopsy or ERCP may be necessary. The risk of these invasive studies is directly related to the degree of underlying hepatic dysfunction.

Hepatitis C and renal failure.

Chronic hepatitis C virus (HCV) infection is common among patients with chronic renal failure. This chronic viral infection can result in significant morbidity and mortality. Liver failure from chronic hepatitis C is one of the leading causes of death among long-term survivors of renal transplantation. HCV infection also can be a cause of glomerulonephritis and nephrotic syndrome. Recognition of these conditions is important to optimize the management of these patients.

Donor-recipient sharing of HLA class II alleles predicts earlier recurrence and accelerated progression of hepatitis C following liver transplantation.

Both direct viral cytopathic effects and host immune responses appear to be important in the pathogenesis of hepatitis C virus (HCV) infection. Liver transplantation provides a means to explore the role of the immune system in the development of HCV-related liver damage through comparing the natural history of HCV in patients with different degrees of donor-recipient human leukocyte antigen (HLA) matching. We evaluated 36 patients with recurrent hepatitis C viremia following liver transplantation to determine whether hepatocellular injury or progression to bridging fibrosis occur more rapidly when donor and recipients share HLA alleles. HLA typing for the HLA-A and HLA-B loci was performed by serological techniques and PCR-based oligotyping was used to type alleles of the DRB1, DRB3, DQA1, and DQB1 loci. A median of eight liver biopsies, obtained during a median follow-up of 36 months, were reviewed per patient. Donor-recipient sharing of alleles of HLA-DQB1 or DRB1 was associated with more rapid development of recurrent hepatitis by univariate analysis (chi2=5.7, P=0.02 and chi2=5.54, P=0.02 respectively). However, only sharing of HLA-DRB1 alleles was identified as an independent predictor of reduced time to recurrent histologic injury by multivariate analysis (chi2 =5.74, P=0.02). Furthermore, sharing of HLA-DRB3 and histologic evidence of rejection were associated with more rapid progression to bridging fibrosis both by univariate methods (chi2=4.12, P=0.04 and chi2=4.66, P=0.03 respectively), and by multivariate analysis (chi2=13.01, P=0.001). These findings suggest that HLA class II-restricted immune responses may contribute to the pathogenesis of HCV-related liver injury in liver transplant recipients.

Multigene tracking of hepatitis C virus quasispecies after liver transplantation: correlation of genetic diversification in the envelope region with asymptomatic or mild disease patterns.

To investigate the role of hepatitis C virus (HCV) quasispecies mutation in the pathogenesis of HCV infection, we analyzed changes in the genetic diversity of HCV genomes in 22 patients before and after liver transplantation by using heteroduplex mobility assay (HMA) technology. All patients were infected with HCV genotype 1 and developed high-titer posttransplant viremia. Each patient was classified according to the severity of posttransplant hepatitis, as assessed by standard biochemical and histological criteria. HCV quasispecies were characterized by HMA analysis of eight separate subgenomic regions of HCV, which collectively comprise 44% of the entire genome. The glycoprotein genes E1 and E2, as well as the nonstructural protein genes NS2 and NS3, had the greatest genetic divergence after liver transplantation (the change in the heteroduplex mobility ratio [HMR] ranged from 2.5 to 7.0%). In contrast, genes encoding the core, NS4, and NS5b proteins had the least amount of genetic divergence after liver transplantation (range, 0.3 to 1.2%). The E1/E2 region showed the greatest change in genetic diversity after liver transplantation, and the change in HMRs was 2.5- to 3.3-fold greater in patients with asymptomatic or moderate disease than in those with severe disease. The E1-5' region of HCV quasispecies isolated from patients in the asymptomatic group had a significantly greater degree of diversification after liver transplantation than the same regions of HCV quasispecies isolated from patients in the severe disease group (P = 0.05). While changes in the genetic diversity of some nonstructural genes were also greater in asymptomatic patients or in patients with mild disease than in patients with severe disease, the results were not significant. Data from this cohort demonstrate that greater rates of HCV quasispecies diversification are associated with mild or moderate liver disease activity in this immunosuppressed population.