Christopher Liddle

Hepatocellular proliferation and development of hepatocellular carcinoma: A case-control study in chronic hepatitis C

Patients with hepatitis C have an increased risk of developing hepatocellular carcinoma (HCC). This is related to the stage of chronic liver disease, as characterized histologically by hepatic fibrosis and architectural distortion, but it is unclear whether histological markers can define the risk of developing HCC. We conducted a case-control immunohistochemical study of Ki-67, a marker for hepatocellular proliferation, in livers of 18 patients who had developed HCC more than 2 years after the biopsy specimen had been taken. Using conditional logistic regression analysis, the results were compared with 18 selected controls, who were age-matched patients with hepatitis C of similar histological stage who had not developed HCC. We also examined livers for cellular dysplasia, p53 mutations, and bcl-2 overexpression, and assessed whether the results could be correlated with demographic and disease-related variables, such as gender, region of birth, alcohol consumption, severity of liver disease, HCV genotype, and markers of hepatitis B virus (HBV) infection. Livers from patients who developed HCC were more often positive for Ki-67 (13 of 18 [72%] v 9 of 18 [50%]; P = .06) and tended to have higher mean Ki-67 scores (6 +/- 7.5 v 3 +/- 4.4; P = .10) compared with control cases. In the HCC-predisposed group, three livers showed large cell dysplasia, two were positive for p53 mutations, and two for bcl-2 overexpression. In contrast, in the non-HCC group, only one case had dysplasia, and none were positive for immunostaining for p53 or bcl-2 mutations. With the exception of one case, all livers with large cell dysplasia or p53 mutations and bcl-2 overexpression were also positive for Ki-67. Twelve (55%) of the 22 Ki-67-positive cases were anti-HBc-positive in the serum, in contrast to 2 of 14 (14%) patients in the Ki-67-negative group (P = .01). Patients with evidence of past infection with HBV were more often Ki-67 positive than those who had no evidence of past infection (85% [11 of 13] v 45% [10 of 22]; P = .02). There were no other associations between demographic or disease-related variables and Ki-67 expression. Increased hepatocellular proliferative activity, as assessed by Ki-67 expression, may be one factor indicative of an increased risk of developing HCC among patients with chronic hepatitis C. Furthermore, past infection with HBV appears to be an important correlate of increased hepatocellular proliferation in hepatitis C.

How much does alcohol contribute to the variability of hepatic fibrosis in chronic hepatitis C

In order to determine the contribution of alcohol intake to the severity of hepatic fibrosis in patients with chronic hepatitis C, we studied associations between various levels of alcohol intake, other demographic variables and semiquantitative liver histology in 434 cases of chronic hepatitis C. Clinical, demographic and disease‐related data were entered into a relational database. Liver histology was scored according to Scheuer. The average daily alcohol intake for the year preceding liver biopsy (recent exposure) and for earlier periods (past exposure) was categorized into five levels of intake. One‐third of patients gave a history of alcohol intake that had exceeded 40g/day for at least 5 years. By univariate analysis, age, but not recent or past alcohol intake or other baseline variables, was associated with portal score (r=0.14, P= 0.004), fibrosis score (r= 0.46, P < 0.001), total Scheuer score (r= 0.35, P < 0.001), However, by multivariate analysis, age (P < 0.001), past (but not present) alcohol intake (P < 0.001) and birth in Egypt (P= 0.006) were independently associated with fibrosis score. Age, past alcohol and birth place in Egypt contributed 27% to total variance of the hepatic fibrosis score, while age alone accounted for 23%. Age also independently predicted portal activity (P=0.02) and total Scheuer score (P < 0.001), whereas past alcohol intake correlated with total Scheuer score (P= 0.002) but not with other histological indices. A separate multivariate analysis was performed on a more homogeneous subgroup of 196 patients who acquired hepatitis C by injection drug use. In this subgroup, age (P < 0.05) and past alcohol (P < 0.05) were independently associated with fibrosis score. In both the overall and subgroup analyses, there was a threshold level of past alcohol intake (>80g/day) beyond which the risk of fibrosis increased significantly. It is concluded that toxic levels of alcohol exposure for at least 5 years accentuate hepatic fibrosis in hepatitis C but the influence of alcohol appears to be minor compared with age and other variables and is exerted only at toxic levels of intake.

Effects of hepatitis G virus coinfection on severity of hepatitis C: Relationship to risk factors and response to interferon treatment

The aims of the present study were to identify characteristics that are more often associated with hepatitis G virus (HGV) coinfection in Australian patients infected with the hepatitis C virus (HCV) and to investigate the effects of HGV on the histological and functional severity of chronic hepatitis C. Serum samples from 209 patients with chronic hepatitis C were tested for HGV‐RNA using single‐round reverse transcriptase—polymerase chain reaction to primers directed at the NS5 region of the HGV genome. Hepatitis G virus RNA was detected in 40 cases (19%). Hepatitis G virus‐coinfected patients tended to be younger and parenteral risks could be identified in all but six. Although country of birth did not differ significantly between the coinfected and HCV‐alone groups, HGV‐positive patients appeared to be less likely to have originated from Asia. On logistic regression analysis, HCV genotype 3a was found in a significantly higher proportion of patients with HGV coinfection than other genotypes (P<0.01). Liver histology and response to interferon were similar in the HGV‐coinfected and HCV‐alone groups and liver‐related complications appeared to occur less frequently in patients with both HGV and HCV. On univariate analysis, antipyrine clearance was found to be higher in the coinfected group (P<0.05), implying better preservation of hepatic metabolic function, but this difference was lost when adjusted for HCV genotype. In conclusions coinfection with HGV was more commonly associated with HCV genotype 3a, a genotype associated with injection drug use in younger patients. However, the presence of HGV coinfection did not adversely affect liver disease or the response to interferon treatment in patients with chronic hepatitis C.

Increased serum levels of dipeptidyl peptidase IV (CD26) in rats undergoing liver regeneration

Abstract Dipeptidyl Peptidase IV (DPP IV; CD26) is a cell surface ectopeptidase that has been shown to alter the binding of hepatocytes to the extracellular matrix (ECM), play a role in lymphocyte proliferation and alter the biological activity of several proteins. During hepatic regeneration, there is obvious alteration in the interaction between hepatocytes and the ECM during a rapid phase of hepatic growth. In addition, there is an upregulation of many hepatic and non-hepatic molecules. Our aim was to determine whether the expression of DPP IV in liver regeneration is consistent with a role in either binding of hepatocytes to ECM or modification of growth factors. To achieve this we have measured serum DPP IV levels and compared the expression of DPP IV at the protein and mRNA levels in regenerating and sham-operated liver and kidney tissue. This study reports elevated serum DPP IV levels during hepatic regeneration. Serum DPP IV enzyme activity and antigen levels were increased up to 10-fold at 48 h after partial hepatectomy. This followed the same time course as the increase in hepatic DNA replication. There was no significant increase in the serum levels of another bile canalicular enzyme, leucine aminopeptidase. Analysis of hepatic and renal tissue during regeneration showed no detectable increases in DPP IV enzyme or mRNA. The lack of a detectable increase in enzyme and mRNA levels in the kidney or liver suggests other sources for serum DPP IV or increased release of soluble DPP IV from the liver. The increase in serum may be part of a response to control the biological activity of molecules that appear in the blood during the regenerative process.

Culture and transfection of mammalian primary hepatocytes and hepatocyte‐derived cell lines

Mammalian hepatocytes and hepatocyte-derived cell lines provide a convenient model for the study of hepatic parenchymal cell function while minimizing the multiplicity of variables inherent in the in vivo situation (Table 1). However, such models do have their limitations and require optimization for specific tasks. Our own interest in cytochrome P450 (P450) regulation provides an excellent paradigm for the use of cell culture models. This is because P450 expression represents a highly specialized function of the hepatocyte which, up until recently, has been difficult to achieve in vitro. The aim of this review is to provide practical advice regarding hepatocyte culture, rather than an exhaustive review of the subject.

A Placebo Controlled Trial of Clonidine in the Outpatient Management of Heroin Withdrawal

We report the outcome of thirty-one patients, entered in a double blind controlled trial of clonidine in the outpatient management of heroin withdrawal. All study patients were monitored on a daily basis and their treatment regime was modified to control symptoms experienced during withdrawal. Symptoms and signs were recorded daily. Clonidine was no more effective than placebo in achieving a successful withdrawal although symptoms were less severe in those patients who received the active drug. The study design engendered anxiety in all patients and this may have decreased the efficacy of the treatment regime. Further studies of clonidine in the management of heroin withdrawal in a variety of settings are warranted.