Hereditary hemochromatosis: time for targeted screening

The discovery of the HFE gene in 1996 heralded a decade of major advances in the understanding of the mechanisms that control iron absorption and body iron stores. A genetic definition of the common form of hereditary hemochromatosis became possible, and testing for the common causative HFE mutations is now widely available in clinical laboratories. Several population screening studies have confirmed that disease penetrance in HFE-related hereditary hemochromatosis is lower than previously believed, making universal population-based screening for this disorder unattractive. However, hereditary hemochromatosis may still cause morbidity and mortality because of iron overload. Early detection and use of appropriate therapy can prevent these manifestations and can only be achieved by targeted case finding. In this article, the authors draw attention again to hereditary hemochromatosis as a cause of preventable organ dysfunction and propose targeted case finding for Caucasian men of Northern European ancestry.     

Serum alpha-fetoprotein levels in patients with advanced hepatitis C: results from the HALT-C Trial

BACKGROUND/AIMS: Alpha-fetoprotein (AFP) has been useful in the diagnosis of hepatocellular carcinoma (HCC) but lacks specificity. We assessed serum AFP among patients with chronic hepatitis C and advanced fibrosis to establish predictors of AFP elevations and changes with antiviral therapy. METHODS: Serum AFP was measured at baseline and on therapy in patients in the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C). AFP levels were correlated with patient demographic and clinical features. RESULTS: Baseline AFP was > or = 20 ng/mL in 191 of 1145 patients (16.6%). Mean AFP values were significantly higher in patients with cirrhosis than in those with bridging fibrosis (22.5 vs. 11.4 ng/mL, P < 0.0001). Factors independently associated with raised serum AFP in patients with cirrhosis were female gender, black race, decreased platelet count, increased serum AST/ALT ratio, serum ferritin, and Mallory bodies in liver biopsies. Serum AFP levels decreased significantly during therapy with pegylated interferon alpha-2a and ribavirin. HCC was identified in six subjects, only three of whom had AFP > 20 ng/mL. CONCLUSIONS: Among patients with advanced chronic hepatitis C, serum AFP values are frequently elevated, even in the absence of HCC. Factors associated with raised AFP include severity of liver disease, female gender and black race. Serum AFP levels decline during antiviral therapy.     

Comparative analysis of portal hepatic infiltrating leucocytes in acute drug‐induced liver injury,idiopathic autoimmune and viral hepatitis

Drug‐induced liver injury (DILI) is often caused by innate and adaptive host immune responses. Characterization of inflammatory infiltrates in the liver may improve understanding of the underlying pathogenesis of DILI. This study aimed to enumerate and characterize leucocytes infiltrating liver tissue from subjects with acute DILI (n = 32) versus non‐DILI causes of acute liver injury (n = 25). Immunostains for CD11b/CD4 (Kupffer and T helper cells), CD3/CD20 (T and B cells) and CD8/CD56 [T cytotoxic and natural killer (NK) cells] were evaluated in biopsies from subjects with acute DILI, either immunoallergic (IAD) or autoimmune (AID) and idiopathic autoimmune (AIH) and viral hepatitis (VH) and correlated with clinical and pathological features. All biopsies showed numerous CD8⁺ T cells and macrophages. DILI cases had significantly fewer B lymphocytes than AIH and VH and significantly fewer NK cells than VH. Prominent plasma cells were unusual in IAD (three of 10 cases), but were associated strongly with AIH (eight of nine) and also observed in most with AID (six of nine). They were also found in five of 10 cases with VH. Liver biopsies from subjects with DILI were characterized by low counts of mature B cells and NK cells in portal triads in contrast to VH. NK cells were found only in cases of VH, whereas AIH and VH both showed higher counts of B cells than DILI. Plasma cells were associated most strongly with AIH and less so with AID, but were uncommon in IAD.     

Predicting cirrhosis in patients with hepatitis C based on standard laboratory tests: results of the HALT-C cohort

Knowledge of the presence of cirrhosis is important for the management of patients with chronic hepatitis C (CHC). Most models for predicting cirrhosis were derived from small numbers of patients and included subjective variables or laboratory tests that are not readily available. The aim of this study was to develop a predictive model of cirrhosis in patients with CHC based on standard laboratory tests. Data from 1,141 CHC patients including 429 with cirrhosis were analyzed. All biopsies were read by a panel of pathologists (blinded to clinical features), and fibrosis stage was determined by consensus. The cohort was divided into a training set (n = 783) and a validation set (n = 358). Variables that were significantly different between patients with and without cirrhosis in univariate analysis were entered into logistic regression models, and the performance of each model was compared. The area under the receiver-operating characteristic curve of the final model comprising platelet count, AST/ALT ratio, and INR in the training and validation sets was 0.78 and 0.81, respectively. A cutoff of less than 0.2 to exclude cirrhosis would misclassify only 7.8% of patients with cirrhosis, while a cutoff of greater than 0.5 to confirm cirrhosis would misclassify 14.8% of patients without cirrhosis. The model performed equally well in fragmented and nonfragmented biopsies and in biopsies of varying lengths. Use of this model might obviate the requirement for a liver biopsy in 50% of patients with CHC. In conclusion, a model based on standard laboratory test results can be used to predict histological cirrhosis with a high degree of accuracy in 50% of patients with CHC.     

Hepatitis C, porphyria cutanea tarda and liver iron: an update

Porphyria cutanea tarda (PCT) is the most common form of porphyria across the world. Unlike other forms of porphyria, which are inborn errors of metabolism, PCT is usually an acquired liver disease caused by exogenous factors, chief among which are excess alcohol intake, iron overload, chronic hepatitis C, oestrogen therapy and cigarette smoking. The pathogenesis of PCT is complex and varied, but hereditary or acquired factors that lead to hepatic iron loading and increased oxidative stress are of central importance. Iron loading is usually only mild or moderate in degree [less than that associated with full-blown haemochromatosis (HFE)] and is usually acquired and/or mutations in HFE. Among acquired factors are excessive alcohol intake and chronic hepatitis C infection, which, like mutations in HFE, decrease hepcidin production by hepatocytes. The decrease in hepcidin leads to increased iron absorption from the gut. In the liver, iron loading and increased oxidative stress leads to the formation of non-porphyrin inhibitor(s) of uroporphyrinogen decarboxylase and to oxidation of porphyrinogens to porphyrins. The treatment of choice of active PCT is iron reduction by phlebotomy and maintenance of a mildly iron-reduced state without anaemia. Low-dose antimalarials (cinchona alkaloids) are also useful as additional therapy or as alternative therapy for active PCT in those without haemochromatosis or chronic hepatitis C. In this review, we provide an update of PCT with special emphasis upon the important role often played by the hepatitis C virus.     

Increased heme oxygenase activity in splanchnic organs from portal hypertensive rats: role in modulating mesenteric vascular reactivity

BACKGROUND/AIMS: We have recently demonstrated that heme oxygenase-1 is upregulated in splanchnic organs of portal hypertensive rats. In the present study, we assessed whether heme oxygenase enzymatic activity is increased in splanchnic organs of portal hypertensive rats, and the relative contribution of heme oxygenase and nitric oxide synthase to the vascular hyporeactivity in portal hypertension. METHODS: Heme oxygenase activity was measured in splanchnic organs of portal hypertensive and sham-operated rats. The effects of heme oxygenase and nitric oxide synthase inhibition on pressure responses to potassium chloride and methoxamine were assessed in perfused mesenteric vascular beds of portal hypertensive and sham-operated rats. RESULTS: Heme oxygenase activity was increased in the mesentery, intestine, liver, and spleen of portal hypertensive rats. The hyporeactivity to potassium chloride in portal hypertensive rats was overcome after simultaneous inhibition of both heme oxygenase and nitric oxide synthase, but only partially attenuated after nitric oxide synthase inhibition alone. The hyporeactivity to methoxamine was completely reversed after nitric oxide synthase blockade. CONCLUSIONS: These results demonstrate that heme oxygenase activity is increased in splanchnic organs of portal hypertensive rats. They also suggest that heme oxygenase contributes to the hyporeactivity to potassium chloride, but not to methoxamine, in portal hypertensive rats.     

Intravenous Interferon Administered During Liver Transplantation Is Not Effective in Preventing Hepatitis C Reinfection

Background

Post-transplant hepatitis C is a major challenge after liver transplantation (LT). Antiviral therapy is associated with lower efficacy in the post-transplant setting.

Aims

The purpose of this study was to determine the safety and effect of intravenous interferon (IFN) during the anhepatic phase of LT on hepatitis C viral load.

Methods

Fifteen consecutive subjects undergoing liver transplant for hepatitis C cirrhosis were enrolled in the study, ten of which received study drug and five subjects served as controls. Cases received weight-based ribavirin and subcutaneous IFN at time of incision followed by intravenous IFN at the start of the anhepatic phase. Adverse events and viral levels were recorded. Repeated measures ANOVA was employed to test for differences over time, between the groups, and time by group interaction.

Results

All subjects had genotype 1 virus. Hepatitis C viral load was lower at week 4 in cases compared to controls (769,004 ± 924,082 IU/ml and 2,329,896 ± 3,731,749 IU/ml, respectively), but did not reach statistical significance (p = 0.50). Three subjects developed adverse events related to IFN including pulmonary edema, rejection, and neutropenia.

Conclusions

Intravenous IFN administered during the anhepatic phase of liver transplant did not prevent graft reinfection and was associated with manageable adverse events. This regimen could be further studied if direct acting antiviral agents alone are insufficient for treating post-transplant hepatitis C.