Early primary biliary cholangitis is characterised by brain abnormalities on cerebral magnetic resonance imaging.

BACKGROUND: Brain change can occur in primary biliary cholangitis (PBC), potentially as a result of cholestatic and/or inflammatory processes. This change is linked to systemic symptoms of fatigue and cognitive impairment. AIM: To identify whether brain change occurs early in PBC. If the change develops early and is progressive, it may explain the difficulty in treating these symptoms. METHODS: Early disease brain change was explored in 13 patients with newly diagnosed biopsy-proven precirrhotic PBC using magnetisation transfer, diffusion-weighted imaging and 1 H magnetic resonance spectroscopy. Results were compared to 17 healthy volunteers. RESULTS: Cerebral magnetisation transfer ratios were reduced in early PBC, compared to healthy volunteers, in the thalamus, putamen and head of caudate with no greater reduction in patients with greater symptom severity. Mean apparent diffusion coefficients were increased in the thalamus only. No 1 H magnetic resonance spectroscopy abnormalities were seen. Serum manganese levels were elevated in all PBC patients, but no relationship was seen with imaging or symptom parameters. There were no correlations between neuroimaging data, laboratory data, symptom severity scores or age. CONCLUSIONS: This is the first study to be performed in this precirrhotic patient population, and we have highlighted that neuroimaging changes are present at a much earlier stage than previously demonstrated. The neuroimaging abnormalities suggest that the brain changes seen in PBC occur early in the pathological process, even before significant liver damage has occurred. If such changes are linked to symptom pathogenesis, this could have important implications for the timing of second-line-therapy use.

Cerebral microglial activation in patients with hepatitis C: in vivo evidence of neuroinflammation.

Patients with chronic hepatitis C infection may exhibit neuropsychological symptoms and cognitive impairment. Post-mortem studies of hepatitis C virus HCV quasispecies and replicative intermediates indicate that the brain might act as a separate compartment for viral replication and microglia may be the locus for infection and subsequent neuroinflammatory activity. We sought to use two independent in vivo imaging techniques to determine evidence of neuroinflammation in patients with histologically mild chronic hepatitis C. Using positron emission tomography (PET) with a ligand for microglial/brain macrophage activation, (11)C-(R)-PK11195 (PK11195) and cerebral proton magnetic resonance spectroscopy, we determined whether there was evidence of neuroinflammation in a pilot study of 11 patients with biopsy-proven mild chronic hepatitis C, compared to healthy volunteers. Patients were characterized by cognitive testing and the fatigue impact scale to assess for CNS impairment. PK11195 binding potential was significantly increased in the caudate nucleus of patients, compared to normal controls (P = 0.03). The caudate and thalamic binding potential were more significantly increased in six patients with genotype 1 infection (P = 0.007) and positively correlated with viraemia (r = 0.77, P = 0.005). Basal ganglia myo-inositol/creatine and choline/creatine ratios were also significantly elevated in patients with chronic hepatitis C compared to normal controls (P = 0.0004 and P = 0.01, respectively). Using PET, we demonstrated evidence of microglial activation, which positively correlated with HCV viraemia and altered cerebral metabolism in the brains of patients with mild hepatitis C. This provides further in vivo evidence for a neurotropic role for HCV.

A comparison of 31P magnetic resonance spectroscopy and microbubble-enhanced ultrasound for characterizing hepatitis c-related liver disease.

We compared in vivo hepatic (31) P magnetic resonance spectroscopy ((31) P MRS) and hepatic vein transit times (HVTT) using contrast-enhanced ultrasound with a microbubble agent to assess the severity of hepatitis C virus (HCV)-related liver disease. Forty-six patients with biopsy-proven HCV-related liver disease and nine healthy volunteers had (31) P MRS and HVTT performed on the same day. (31) P MR spectra were obtained at 1.5 T. Peak areas were calculated for metabolites, including phosphomonoesters (PME) and phosphodiesters (PDE). Patients also had the microbubble ultrasound contrast agent, Levovist (2 g), injected into an antecubital vein, and time-intensity Doppler ultrasound signals of the right and middle hepatic veins were measured. The HVTT was calculated as the time from injection to a sustained rise in Doppler signal 10% greater than baseline. The shortest times were used for analysis. Based on Ishak histological scoring, there were 15 patients with mild hepatitis, 20 with moderate/severe hepatitis and 11 with cirrhosis. With increasing severity of disease, the PME/PDE ratio was steadily elevated, while the HVTT showed a monotonic decrease. Both imaging modalities could separate patients with cirrhosis from the mild and moderate/severe hepatitis groups. No statistical difference was observed in the accuracy of each test to denote mild, moderate/severe hepatitis and cirrhosis (Fisher's exact test P =1.00). (31) P MRS and HVTT show much promise as noninvasive imaging tests for assessing the severity of chronic liver disease. Both are equally effective and highly sensitive in detecting cirrhosis.

Hepatic vein transit times of a microbubble agent in assessing response to antiviral treatment in patients with chronic hepatitis C.

Microbubble measurement of hepatic vein transit times (HVTT) may have the potential to assess severity of hepatitis C virus (HCV)-related liver disease, where there is a shorter HVTT with more severe disease. We investigated the utility of this test as a marker of response to antiviral treatment. Thirty-seven patients with biopsy-proven HCV-related disease undergoing antiviral treatment were studied. All had baseline scans and then repeat scans 6 months after the end of treatment. HVTT using Levovist were obtained from the right and middle hepatic veins, and the shorter time was used for analysis. The aspartate aminotransferase to platelet ratio index (APRI) scores were calculated retrospectively. There were seven patients with mild hepatitis, 23 with moderate/severe hepatitis and seven with cirrhosis. The mean baseline HVTT in responders ± SE increased from 27.3 ± 2.29 s to 33.5 ± 2.8 s posttreatment (P = 0.01). In the 10 nonresponders, the HVTT remained the same; 43.3 ± 9 s baseline compared to 44 ± 7.8 s posttreatment (P = 0.84). This trend was also seen with the APRI score where in responders, the mean score decreased from 1.1 ± 0.2 to 0.74 ± 1 (P = 0.03) and in nonresponders, the score remained unchanged; 0.88 ± 0.2 compared to 0.84 ± 0.2 (P = 0.31). HVTT measurement lengthened, while APRI scores decreased in patients who responded to antiviral treatment while both remained the same, shortened (HVTT) or increased (APRI), respectively, in patients who were nonresponders. These results are encouraging and indicate that these tests could be potentially used as markers of response to treatment and could obviate the need for serial biopsies in antiviral future treatment studies.

Optimal combinations of ultrasound-based and serum markers of disease severity in patients with chronic hepatitis C.

Combinations of noninvasive markers may improve discrimination of chronic liver disease severity. The aims of this study were to compare four validated serum and ultrasound-based markers of hepatic disease severity head-to-head with liver biopsy and to assess optimal combinations with consideration of cost. A total of 67 patients with biopsy-proven chronic hepatitis C underwent all four techniques on the same visit [aspartate aminotransferase (AST) to platelet ratio index (APRI); Enhanced Liver Fibrosis (ELF) panel; transient elastography (TE) and ultrasound microbubble hepatic transit times (HTT)]. Markers were combined according to increasing financial cost and ordinal regression used to determine contributions. APRI, ELF, TE and HTT predicted cirrhosis with diagnostic accuracy of 86%, 91%, 90% and 83% respectively. ELF and TE were the most reliable tests with an intra-class correlation of 0.94 each. Either ELF or TE significantly enhanced the prediction of fibrosis stage when combined with APRI, but when combined together, did not improve the model further. Addition of third or fourth markers did not significantly improve prediction of fibrosis. Combination of APRI with either ELF or TE effectively predicts fibrosis stage, but combinations of three or more tests lead to redundancy of information and increased cost.

Epidemiology, risk factors, and pathogenesis of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a fatal cancer of the biliary epithelium, arising either within the liver (intrahepatic, ICC) or in the extrahepatic bile ducts (extrahepatic ECC). Globally, CCA is the second most common primary hepatic malignancy. Several recent epidemiological studies have shown that the incidence and mortality rates of ICC are increasing. This review of the literature on the international epidemiological rates of CCA, both intra- and extrahepatic, explores possible explanations for the trends found. The possible role of epidemiological artifact in the findings is discussed and the known risk factors for CCA are summarized. These include primary sclerosing cholangitis, liver fluke infestation, congenital fibropolycystic liver, bile duct adenomas, and biliary papillomatosis, hepatolithiasis, chemical carcinogens such as nitrosamines, Thorotrast, chronic viral hepatitis, cirrhosis, chronic non-alcoholic liver disease and obesity. Potential pathways involved in the molecular pathogenesis of CCA are also summarized.

Transient elastography for the assessment of chronic liver disease: ready for the clinic?

Transient elastography is a recently developed non-invasive technique for the assessment of hepatic fibrosis. The technique has been subject to rigorous evaluation in a number of studies in patients with chronic liver disease of varying aetiology. Transient elastography has been compared with histological assessment of percutaneous liver biopsy, with high sensitivity and specificity for the diagnosis of cirrhosis, and has also been used to assess pre-cirrhotic disease. However, the cut-off values between different histological stages vary substantially in different studies, patient groups and aetiology of liver disease. More recent studies have examined the possible place of transient elastography in clinical practice, including risk stratification for the development of complications of cirrhosis. This review describes the technique of transient elastography and discusses the interpretation of recent studies, emphasizing its applicability in the clinical setting.

In vivo imaging of cerebral "peripheral benzodiazepine binding sites" in patients with hepatic encephalopathy.

BACKGROUND AND AIMS: One proposed mechanism whereby hepatic encephalopathy (HE) leads to loss of brain function is dysregulated synthesis of neurosteroids. Mitochondrial synthesis of neurosteroids is regulated by "peripheral benzodiazepine binding sites" (PBBS). Expressed in the brain by activated glial cells, PBBS can be measured in vivo by the specific ligand [11C](R)-PK11195 and positron emission tomography (PET). Recently, it has been suggested that PBBS expressing glial cells may play a role in the general inflammatory responses seen in HE. Therefore, we measured PBBS in vivo in the brains of patients with minimal HE using [11C](R)-PK11195 PET. METHODS: Five patients with minimal HE and biopsy proven cirrhosis of differing aetiology were assessed with a neuropsychometric battery. Regional expression of PBBS in the brain was detected by [11C](R)-PK11195 PET. RESULTS: All patients showed brain regions with increased [11C](R)-PK11195 binding. Significant increases in glial [11C](R)-PK11195 binding were found bilaterally in the pallidum, right putamen, and right dorsolateral prefrontal region. The patient with the most severe cognitive impairment had the highest increases in regional [11C](R)-PK11195 binding. CONCLUSION: HE is associated with increased cerebral binding of [11C](R)-PK11195 in vivo, reflecting increased expression of PBBS by glial cells. This supports earlier experimental evidence in rodent models of liver failure, suggesting that an altered glial cell state, as evidenced by the increase in cerebral PBBS, might be causally related to impaired brain functioning in HE.

ATP8B1 mutations in British cases with intrahepatic cholestasis of pregnancy.

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) affects approximately 0.7% of pregnancies in the UK and is associated with prematurity, fetal distress, and intrauterine death. Homozygous mutations in the ATP8B1 gene cause cholestasis with a normal serum gamma-glutamyl transpeptidase (gamma-GT), and have been reported in two forms of cholestasis: progressive familial intrahepatic cholestasis type 1 (PFIC1) and benign recurrent intrahepatic cholestasis (BRIC). AIMS: To establish whether mutations in ATP8B1 are associated with ICP in British cases PATIENTS: Sixteen well phenotyped women with ICP without raised gamma-GT were selected for sequence analysis. Subsequently, 182 patients and 120 controls were examined for the presence of the variants detected. METHODS: All coding exons were sequenced in 16 cases. Eight ICP cases, including two women carrying a mutation, were investigated using in vivo hepatic (31)P magnetic resonance spectroscopy (MRS) RESULTS: Two heterozygous ATP8B1 transitions (208G>A and 2599C>T) that resulted in amino acid substitutions were identified; 208G>A was identified in three cases. MRS revealed an increased phosphodiester signal (Mann-Whitney U test, p = 0.03) and a decreased phosphomonoester/phosphodiester ratio (p = 0.04) in ICP cases compared with controls. CONCLUSIONS: We were able to demonstrate ATP8B1 mutations in ICP. MRS studies suggest that susceptibility to ICP is associated with a relative rise in biliary phospholipid. These data also suggest that MRS may be used for non-invasive assessment of the liver and biliary constituents in cholestasis.

Hepatic triglyceride content and its relation to body adiposity: a magnetic resonance imaging and proton magnetic resonance spectroscopy study.

BACKGROUND: Hepatic steatosis is associated with obesity and type II diabetes. Proton magnetic resonance spectroscopy (1H MRS) is a non-invasive method for measurement of tissue fat content, including intrahepatocellular lipids (IHCL) and intramyocellular lipids (IMCL). PATIENTS AND METHODS: We used 1H MRS and whole body magnetic resonance imaging (MRI) to assess the relationship between IHCL accumulation, total body adipose tissue (AT) content/distribution, and IMCL content in 11 subjects with biopsy proven hepatic steatosis and 23 normal volunteers. RESULTS: IHCL signals were detectable in all subjects but were significantly greater in hepatic steatosis (geometric mean (GM) 11.5 (interquartile range (IQR) 7.0-39.0)) than in normal volunteers (GM 2.7 (IQR 0.7-9.3); p=0.02). In the study group as a whole, IHCL levels were significantly greater in overweight compared with lean subjects (body mass index (BMI) >25 kg/m2 (n=23): GM 7.7 (IQR 4.0-28.6) v BMI <25 kg/m2 (n=11): GM 1.3 (IQR 0.3-3.6; p=0.004)). There was a significant association between IHCL content and indices of overall obesity (expressed as a percentage of body weight) for total body fat (p=0.001), total subcutaneous AT (p=0.007), and central obesity (subcutaneous abdominal AT (p=0.001) and intra-abdominal AT (p=0.001)), after allowing for sex and age. No correlation between IHCL content and IMCL was observed. A significant correlation was observed between serum alanine aminotransferase and liver fat content (r=0.57, p=0.006). CONCLUSIONS: Our results suggest that hepatic steatosis appears to be closely related to body adiposity, especially central obesity. MRS may be a useful method for monitoring IHCL in future interventional studies.

Hepatic vein transit times using a microbubble agent can predict disease severity non-invasively in patients with hepatitis C.

BACKGROUND AND AIMS: A reliable non-invasive assessment of the severity of diffuse liver disease is much needed. We investigated the utility of hepatic vein transit times (HVTT) for grading and staging diffuse liver disease in a cohort of patients with hepatitis C virus (HCV) infection using an ultrasound microbubble contrast agent as a tracer. MATERIALS AND METHODS: Eighty five untreated patients with biopsy proven HCV induced liver disease were studied prospectively. All were HCV RNA positive on polymerase chain reaction testing. Based on their histological fibrosis (F) and necroinflammatory (NI) scores, untreated patients were divided into mild hepatitis (F < or =2/6, NI < or =3/18), moderate/severe hepatitis (3 < or =F <6 or NI > or =4), and cirrhosis (F=6/6) groups. In addition, 20 age matched healthy volunteers were studied. After an overnight fast, a bolus of contrast agent (Levovist) was injected into an antecubital vein and spectral Doppler signals were recorded from both the right and middle hepatic veins for analysis. HVTTs were calculated as the time from injection to a sustained rise in Doppler signal >10% above baseline. The Doppler signals from the carotid artery were also measured in 60 patients and carotid delay times (CDT) calculated as the difference between carotid and hepatic vein arrival times. The earliest HVTT in each patient was used for analysis. RESULTS: Mean (SEM) HVTT for the control, mild hepatitis, moderate/severe hepatitis, and cirrhosis groups showed a monotonic decrease of 38.1 (2.8), 38.8 (2.4), 26.0 (2.4), and 15.8 (0.8) seconds, respectively. Mean (SEM) CDT for the control, mild hepatitis, moderate/severe hepatitis, and cirrhosis patients again showed progressive shortening of 30.3 (2.6), 25.9 (2.6), 14.8 (2.1), and 5.6 (1.2) seconds, respectively. There were significant differences between the groups for HVTT (ANOVA, p<0.001) and CDT (ANOVA, p<0.001). There was 100% sensitivity and 80% specificity for diagnosing cirrhosis and 95% sensitivity and 86% specificity for differentiating mild hepatitis from more severe liver disease. CONCLUSION: We have shown, for the first time, that HVTT using an ultrasound microbubble contrast agent can assess HCV related liver disease with clear differentiation between mild hepatitis and cirrhosis. There were significant differences between these two groups and the moderate/severe hepatitis group. CDT offers no additional benefit or greater differentiation than HVTT and can be omitted, thus simplifying this technique. HVTT may complement liver biopsy and may also be a useful alternative for assessment of liver disease in patients who have contraindications to biopsy.

MR-guided laser thermal ablation of primary and secondary liver tumours.

AIM: To test the hypothesis that magnetic resonance (MR)-guided hepatic tumour ablation is (i) safe and feasible, (ii) is associated with favourable patient survival, and (iii) decreases viable tumour. MATERIALS AND METHODS: One hundred and twenty-five MR-guided laser thermal ablations (LTA) were performed on 35 patients with hepatocellular carcinoma (HCC, n=19), hepatic metastases (n=11, mainly colorectal) and carcinoid liver tumours (n=5). RESULTS: Mean overall survival was 14.8 months (HCCs 14.6 months, metastases 15.2 months). Near real-time T1-weighted colourized thermal maps correlated moderately with follow-up gadolinium-enhanced MR imaging in predicting ablated tumour area (Pearson correlation coefficient=0.5). There was a significant difference in percentage enhancing pre- and post-LTA (Wilcoxon signed ranks test=0.0001). An average of 50.7% of tumour was ablated by each treatment. In patients with multiple liver tumours ablated tumours grew significantly less than untreated tumours (108%compared with 196% growth, follow-up period 5.8 months, WSRTp=0.07). CONCLUSION: MR- guided LTA of primary and secondary liver tumours is safe, feasible, and significantly decreased amount of enhancing or viable tumour. MR-guided LTA produces a better survival in patients with HCC than would be expected in untreated patients, and has a mean survival in patients with metastases at least equal to the longest median survival in untreated patients.

DNA adducts, detected by 32P postlabelling, in human cholangiocarcinoma.

BACKGROUND: Reported mortality from intrahepatic cholangiocarcinoma (CCa) has risen steeply in the UK and other industrialised countries over the past 30 years, the cause of which has not been explained. DNA adduct formation is promutagenic and demonstrates exposure to a DNA damaging agent. It is a key step in chemically induced carcinogenesis. We hypothesise that the increase in CCa mortality is caused by a rise in a genotoxic environmental agent(s), causing cholangiocyte DNA damage. AIMS: To investigate and compare tumour and tumour adjacent CCa tissue, and non-cancer control bile duct tissue, for DNA adducts as a biomarker of genotoxin exposure. METHODS: DNA from 32 intrahepatic CCa patients (and in 28 cases DNA from adjacent non-tumour tissue) and from biliary ducts of seven non-cancer patients were investigated for the presence of DNA adducts using the nuclease P1 method of (32)P postlabelling. DNA adduct levels (number of adducts/10(8) nucleotides) were quantified. RESULTS: There was no significant difference in relative adduct labellings (RALs) between tumour adjacent DNA (median 8.6, range 1.2-51.6) and CCa DNA (7.2, 1.8-48.4). However, RALs were significantly higher in DNA from cancer patients (tumour adjacent and CCa DNA) compared with non-cancer patient DNA (2.9, 0.6-11.5; p=0.032, two tailed Mann-Whitney U test). Different adduct patterns were also seen in CCa compared with non-cancer patients. CONCLUSION: Quantitative and qualitative differences in adducts between cancer and non-cancer patients support the hypothesis that genotoxins may play a role in the development of intrahepatic CCa.

Hepatocellular adenoma: diagnostic difficulties and novel imaging techniques.

We report the case of a 30-year-old eastern European female who presented with right upper quadrant pain. Clinical examination was unremarkable and liver function tests were normal. CT identified a 5 cm lesion in segment V of the liver, which was of homogeneous low density with no calcification or significant enhancement. MRI showed the lesion to be hypointense to liver on T(1) weighted sequences and isointense on T(2) weighted sequences. Rapid arterial enhancement with gadolinium-DTPA faded without leaving a definite central scar. Ultrasound showed the lesion to be echogenic with minimal vascularity. Administration of a liver-specific microbubble contrast agent showed low uptake relative to the surrounding liver. Phosphorus-31 MR spectroscopy, localized to the lesion itself, revealed a markedly increased phosphomonoester resonance with a decreased phosphodiester resonance, compatible with increased cell turnover. Biopsy confirmed the lesion to be a hepatocellular adenoma. The diagnosis of a hepatic adenoma is difficult with tissue diagnosis the gold standard, but it may be suggested by a combination of imaging modalities. We have described two new imaging techniques not previously described in characterization of hepatic adenomata, namely ultrasound with contrast agent and MR spectroscopy.

Ablative therapy for liver tumours.

Established ablative therapies for the treatment of primary and secondary liver tumours, including percutaneous ethanol injection, cryotherapy, and radiofrequency ablation, are discussed. Newer techniques such as magnetic resonance imaging guided laser interstitial thermal therapy of liver tumours has produced a median survival rate of 40.8 months after treatment. The merits of this newly emerging technique are discussed, together with future developments, such as focused ultrasound therapy, which holds the promise of non-invasive thermoablation treatment on an outpatient basis.