The induction of type I interferon production in hepatitis C-infected patients

Chronic infection with hepatitis C virus (HCV) is a major global health problem. One way HCV may evade the host immune response is by inhibiting the production of type I interferon (IFN). In addition, the standard treatment for chronic HCV infection involves treatment with IFN-alpha (or its pegylated derivative), alone or in combination with ribavirin. Therefore, it is believed that an important reason that most HCV-infected individuals progress from acute to chronic infection is due to a defect in the host response. In this study, we examined the host response to HCV infection in a cohort of patients enrolled in the UTHSC Cooperative HCV Research Center by determining levels of biologically active IFN in the sera of patients. We found that 15 of 35 enrolled HCV-infected patients show serum levels of IFN (ranging from 2 to 40 IU/mL) before initiation of therapy. Uninfected individuals do not have circulating levels of IFN. Basal IFN levels do not correlate with the clinical response to therapy, nor do they reflect the age, sex, or race of patients. These results suggest that the differential response of patients most likely reflects a defect in the later stages of the host innate immune response, such as the cellular response to endogenous or exogenous IFN. In contrast, the early stage of the host immune response in vivo of many HCV-infected patients (approximately 40%) is intact as determined by IFN production.

Naturally occurring dominant resistance mutations to hepatitis C virus protease and polymerase inhibitors in treatment-naïve patients

Resistance mutations to hepatitis C virus (HCV) nonstructural protein 3 (NS3) protease inhibitors in <1% of the viral quasispecies may still allow >1000-fold viral load reductions upon treatment, consistent with their reported reduced replicative fitness in vitro. Recently, however, an R155K protease mutation was reported as the dominant quasispecies in a treatment-naïve individual, raising concerns about possible full drug resistance. To investigate the prevalence of dominant resistance mutations against specifically targeted antiviral therapy for HCV (STAT-C) in the population, we analyzed HCV genome sequences from 507 treatment-naïve patients infected with HCV genotype 1 from the United States, Germany, and Switzerland. Phylogenetic sequence analysis and viral load data were used to identify the possible spread of replication-competent, drug-resistant viral strains in the population and to infer the consequences of these mutations upon viral replication in vivo. Mutations described to confer resistance to the protease inhibitors Telaprevir, BILN2061, ITMN-191, SCH6 and Boceprevir; the NS5B polymerase inhibitor AG-021541; and to the NS4A antagonist ACH-806 were observed mostly as sporadic, unrelated cases, at frequencies between 0.3% and 2.8% in the population, including two patients with possible multidrug resistance. Collectively, however, 8.6% of the patients infected with genotype 1a and 1.4% of those infected with genotype 1b carried at least one dominant resistance mutation. Viral loads were high in the majority of these patients, suggesting that drug-resistant viral strains might achieve replication levels comparable to nonresistant viruses in vivo.

CONCLUSION

Naturally occurring dominant STAT-C resistance mutations are common in treatment-naïve patients infected with HCV genotype 1. Their influence on treatment outcome should further be characterized to evaluate possible benefits of drug resistance testing for individual tailoring of drug combinations when treatment options are limited due to previous nonresponse to peginterferon and ribavirin.

Eighteen years of experience with adult and pediatric liver transplantation at the University of Tennessee, Memphis

1. Since its inception, the liver program at UT Memphis has been striving to serve its population by stressing access, technical innovation, and by its focus on quality of life. The results for both adult and pediatric transplants over the past 18 years demonstrate that small and medium-sized programs can function efficiently and are valuable for their local communities. 2. Patient and graft survival rates exceeded 85% in the pediatric population in the first year with the 5-, 10-, and 15-year results above 75%. 3. Patient and graft survival rates in adults were 83% at one year, 68% at 5 years, and 60% at 10 years. 4. Innovative techniques in liver transplantation have had a dramatic impact on accessibility of pediatric recipients to liver transplantation and recently are becoming crucial for select populations of adults requiring expedited transplantation.

Thrombocytopenia associated with octreotide

A 42-year-old woman with a history of hepatitis C-induced cirrhosis, gastrointestinal bleeding, and alcohol abuse presented to the hospital with hematemesis and melena. Based on our previous experience, octreotide (Sandostatin) therapy was started at 50 mg/hr and continued for 5 days. Platelet count on admission (122 x 10(9)/L) dropped immediately after octreotide therapy was started; upon discontinuation, platelet count began trending up from 72 x 10(9)/L. However, octreotide was not suspected at this point as the cause of thrombocytopenia. In a subsequent admission, octreotide was again administered with a resultant prompt decrease in platelet count. To our knowledge, this is only the second case report of octreotide-induced thrombocytopenia, and the first case of this adverse effect demonstrated by inadvertent rechallenge.

Hepatitis C infection among survivors of childhood cancer

Preliminary reports have suggested that survivors of childhood cancer and aplastic anemia who are infected with the hepatitis C virus (HCV) have a low risk for progression to significant liver disease. Among our surviving patients who were transfused between 1961 and March 1992, 77 (6.6% of surviving patients tested thus far) have evidence of HCV infection, whereas 4 surviving patients who were transfused after March 1992 are HCV-infected. One patient chronically infected with HCV died of liver failure, and 2 patients died of hepatocellular carcinoma. To characterize the risk for these and other complications, 65 patients are enrolled in a longitudinal study of HCV infection, of whom 58 (89.2%) had circulating HCV RNA at the time of protocol enrollment, with genotypes 1A and 1B most commonly isolated. Most enrolled patients have few or no symptoms, carry out normal activities, and have normal liver function. To date, 35 patients have undergone liver biopsy for abnormal liver function since the diagnosis of primary malignancy; central pathology review shows 28 (80%) have chronic active hepatitis, 25 (71%) have fibrosis, and 3 (9%) have cirrhosis. These preliminary data suggest that though most survivors of childhood cancer who are infected with HCV are clinically well, some are at risk for clinically significant liver disease. Identification of other HCV-infected patients and prospective monitoring of this cohort are ongoing to determine the risk for, and to identify factors associated with the progression of, liver disease.

Heart rate variability as a predictor of autonomic dysfunction in patients awaiting liver transplantation

Chronic liver disease, both alcoholic and nonalcoholic, has been shown to be associated with autonomic neuropathy, as well as other hemodynamic and circulatory disturbances. In a longitudinal study, the presence of autonomic neuropathy and the severity of liver disease were independent risk factors for mortality. The aim of this study was to determine whether the severity of liver disease correlated with measures of heart rate variability. We studied 21 patients being evaluated for liver transplantation to determine if severity of disease correlated with heart rate variability and compared them to seven healthy controls. Heart rate variability was determined for a series of 500 consecutive R-R intervals during quiet breathing. Standard deviation, pNN50, a marker of parasympathetic function, and approximate entropy (ApEn), a recently described measure of regularity, were calculated. Four standard tests of autonomic function were also performed. pNN50 was significantly reduced in all liver disease patients compared to controls (P < 0.05). Both standard deviation and ApEn were significantly reduced in Child's class C patients suggesting a generalized dysfunction in cardiovascular homeostasis. ApEn was significantly lower in the nonsurvivors during follow-up than the survivors (P < 0.05). In conclusion, increasing severity of liver failure is associated with a reduction in total heart rate variability and regularity. Measurement of heart rate variability offers a simple, noninvasive means of assessing the cardiovascular and autonomic effects of liver disease, particularly in those awaiting liver transplantation.

A prospective, randomized, double-blind trial evaluating the efficacy of ursodeoxycholic acid in prevention of liver transplant rejection

Acute cellular rejection (ACR) after orthotopic liver transplantation occurs in 50% to 80% of patients despite the recent advances in immunosuppressive therapy. Adjuvant use of ursodeoxycholic acid (UDCA) is theoretically attractive, but studies have shown conflicting results. In this randomized, controlled study, we evaluated the efficacy of UDCA in reduction of the incidence of ACR. Thirty patients were randomized to receive either UDCA (15 mg/kg) or placebo in addition to the standard triple-drug regimen; 14 patients received UDCA, and the rest received placebo, for 3 to 6 months. The diagnosis of ACR was based on histologic criteria. Three patients withdrew from the study within 1 month of therapy, all because of capsule size. There was no difference in the total incidence of ACR between the placebo and UDCA groups, with 12 and 11 episodes within 6 months, respectively; the overall incidence of rejection was 77%. There were also no differences in the incidence of recurrent rejection, in the number of rejection episodes occurring after 5 days of therapy, or in the use of OKT3. There was no difference in 1-year survival between groups. This study shows that adjuvant therapy with UDCA in addition to standard triple-drug immunosuppressive therapy does not reduce the incidence of ACR.

Presence of autonomic neuropathy is a poor prognostic indicator in patients with advanced liver disease

Autonomic neuropathy (AN) is seen in both alcohol-induced and non-alcohol-induced liver disease, and when present is an independent predictor of mortality. We postulated that patients who were awaiting liver transplantation are likely to have a high prevalence of autonomic neuropathy with an associated increase in mortality. To test our hypothesis, we evaluated the presence of autonomic neuropathy using a battery of tests in 33 patients awaiting liver transplantation and prospectively followed them to determine their prognosis. Twenty-two of 33 (67%) patients with liver disease had evidence of autonomic neuropathy; of these, 12 (36%) had evidence of definite and 10 (31%) had early autonomic neuropathy. The prevalence of AN was similar in alcohol-induced and non-alcohol-induced liver disease. Using Child-Pugh classification, 14.3% Child A, 31.3% Child B, and 60% Child C had definite autonomic neuropathy. Six patients died during a median observation period of 10 months, and all had AN. Kaplan-Meier survival analysis showed a significantly higher mortality (P=.05) in patients with AN. On the basis of this observation, we suggest that consideration should be given for early liver transplantation in patients with advanced liver disease and autonomic neuropathy.