Paul V. Desmond

Serum hepatitis B surface antigen and hepatitis B e antigen titers: disease phase influences correlation with viral load and intrahepatic hepatitis B virus markers.

Although threshold levels for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) titers have recently been proposed to guide therapy for chronic hepatitis B (CHB), their relationship to circulating hepatitis B virus (HBV) DNA and intrahepatic HBV replicative intermediates, and the significance of emerging viral variants, remains unclear. We therefore tested the hypothesis that HBsAg and HBeAg titers may vary independently of viral replication in vivo. In all, 149 treatment‐naïve CHB patients were recruited (HBeAg‐positive, n = 71; HBeAg‐negative, n = 78). Quantification of HBeAg and HBsAg was performed by enzyme immunoassay. Virological characterization included serum HBV DNA load, HBV genotype, basal core promoter (BCP)/precore (PC) sequence, and, in a subset (n = 44), measurement of intrahepatic covalently closed circular DNA (cccDNA) and total HBV DNA, as well as quantitative immunohistochemical (IHC) staining for HBsAg. In HBeAg‐positive CHB, HBsAg was positively correlated with serum HBV DNA and intrahepatic cccDNA and total HBV DNA (r = 0.69, 0.71, 0.76, P < 0.01). HBeAg correlated with serum HBV DNA (r = 0.60, P < 0.0001), although emerging BCP/PC variants reduced HBeAg titer independent of viral replication. In HBeAg‐negative CHB, HBsAg correlated poorly with serum HBV DNA (r = 0.28, P = 0.01) and did not correlate with intrahepatic cccDNA nor total HBV DNA. Quantitative IHC for hepatocyte HBsAg confirmed a relationship with viral replication only in HBeAg‐positive patients. Conclusion: The correlation between quantitative HBsAg titer and serum and intrahepatic markers of HBV replication differs between patients with HBeAg‐positive and HBeAg‐negative CHB. HBeAg titers may fall independent of viral replication as HBeAg‐defective variants emerge prior to HBeAg seroconversion. These findings provide new insights into viral pathogenesis and have practical implications for the use of quantitative serology as a clinical biomarker. (HEPATOLOGY 2010)

Hepatitis B surface antigen levels during the natural history of chronic hepatitis B: A perspective on Asia

BACKGROUND & AIMS Data from clinical trials suggest a potential role for on-treatment monitoring of serum HBsAg titres during interferon-alpha (pegIFN) therapy in predicting virological responses. However, baseline HBsAg titres during the natural history of chronic hepatitis B (CHB) have not been well-characterized. We aimed to define the serum HBsAg titres during the different phases of CHB in a cohort of Asian patients infected with either genotype B or C HBV. METHODS Two-hundred and twenty patients were classified into immune-tolerant (IT), immune-clearance (IC), non/low-replicative (LR) or hepatitis B e antigen negative hepatitis (ENH) phases. Serum HBsAg was quantified using the ARCHITECT platform (Abbott Laboratories, Chicago, USA). Correlation of HBsAg titre with HBV DNA and serum ALT within each phase of infection was performed. RESULTS Median HBsAg titres were different between each phase of CHB (p=0.001): IT (4.53 log(10)IU/ml), IC (4.03 log(10)IU/ml), LR (2.86 log(10)IU/ml), and ENH (3.35 log(10)IU/ml). HBsAg titres were highest in the IT phase, and lowest in the LR phase. In general, median HBsAg titres were similar between genotypes B and C HBV. Serum HBsAg titres only correlated with HBV viral load in the IC phase. No correlation between the serum HBsAg level and ALT was observed. CONCLUSIONS This study demonstrated significant differences in median baseline serum HBsAg titres across the different phases of CHB. These results provide further insight into the HBV viral life cycle in the setting of the various phases of CHB. Baseline HBsAg quantification may help refine future treatment algorithms for both immune-modulator therapy and oral nucleos(t)ide analogue therapy.

Regulation of Toll‐like receptor‐2 expression in chronic hepatitis B by the precore protein

Toll‐like receptors (TLRs) play a key role in the innate immune response. The aim of this study was to examine the expression of TLR2 and TLR4 in chronic hepatitis B (CHB). The TLR2 and TLR4 expression on hepatocytes and Kupffer cells from fresh liver biopsies was measured from 21 patients with untreated hepatitis B e antigen (HBeAg)‐positive and HBeAg‐negative CHB. Parallel studies were also undertaken on monocytes from their peripheral blood. Expression of TLR2 on hepatocytes, Kupffer cells, and peripheral monocytes was significantly reduced in patients with HBeAg‐positive CHB in comparison with HBeAg‐negative CHB and controls, whereas it was significantly increased in HBeAg‐negative CHB compared with controls. The level of TLR4 expression did not differ significantly between the groups. These results were confirmed in vitro using hepatic cell lines transduced with recombinant HBV baculovirus expressing wild‐type HBV (HBeAg‐positive), precore stop codon (G1896A) mutant HBV (HBeAg‐negative). The functional relevance of these findings was established by the demonstration of significantly reduced cytokine production (TNF‐α) and phospho‐p38 kinase expression in the presence of the HBeAg. In the absence of HBeAg, HBV replication was associated with up‐regulation of the TLR2 pathway leading to increased TNF‐α production. Conclusion: This study demonstrates a potentially important interaction between HBeAg, HBV, and the innate immune response. (HEPATOLOGY 2007;45:102–110.)

Effects of aging and liver disease on disposition of lorazepam

The disposition of lorazepam after intravenous administration (2 mg) was investigated in patients with alcoholic cirrhosis and acute viral hepatitis, and compared to that in normal subjects ranging in age from 15 to 73 yr. No statistically significant age‐dependent relationships in the drugs pharmacokinetic parameters were observed. Cirrhosis was associated with a doubling of the mean elimination half‐life (21.7 ± 7.6 to 41.2 ± 24.5 hr). This was due to a similar increase in the volume of distribution of lorazepam, caused by a reduction in the extent of the drugs plasma binding (88.6 ± 2.5 from 93.2 ± 1.8). No changes in systemic plasma clearance of either the unbound (about 11 ml/min/kg) or bound plus unbound (about 0.75 ml/min/kg) lorazepam, or urinary recovery of conjugated drug (about 50%) were detected. In contrast, there were no significant changes in the kinetics of lorazepam in the patients with acute viral hepatitis. Comparison of lorazepams systemic plasma clearance in the liver disease patients in whom studies with antipyrine and chlordiazepoxide had also been performed indicated impairment in their values but this was not the case for lorazepam. It is concluded that the degree of impairment, if any, in the metabolism of lorazepam in patients with liver disease is considerably less than that of certain other drugs including related benzodiazepines. Aging also does not lead to alterations either in distribution or metabolism as have been observed with other benzodiazepines. It is speculated that these observations may reflect characteristics of the drugs associated with their metabolic fate, i.e., glucuronidation or oxidative biotransformation.

The Mediterranean diet improves hepatic steatosis and insulin sensitivity in individuals with non-alcoholic fatty liver disease

BACKGROUND & AIMS Non-alcoholic fatty liver disease (NAFLD) affects up to 30% of the population and signifies increased risk of liver fibrosis and cirrhosis, type 2 diabetes, and cardiovascular disease. Therapies are limited. Weight loss is of benefit but is difficult to maintain. We aimed at examining the effect of the Mediterranean diet (MD), a diet high in monounsaturated fatty acids, on steatosis and insulin sensitivity, using gold standard techniques. METHODS Twelve non-diabetic subjects (6 Females/6 Males) with biopsy-proven NAFLD were recruited for a randomised, cross-over 6-week dietary intervention study. All subjects undertook both the MD and a control diet, a low fat-high carbohydrate diet (LF/HCD), in random order with a 6-week wash-out period in- between. Insulin sensitivity was determined with a 3-h hyperinsulinemic-euglycemic clamp study and hepatic steatosis was assessed with localized magnetic resonance (1)H spectroscopy ((1)H-MRS). RESULTS At baseline, subjects were abdominally obese with elevated fasting concentrations of glucose, insulin, triglycerides, ALT, and GGT. Insulin sensitivity at baseline was low (M=2.7 ± 1.0 mg/kg/min(-1)). Mean weight loss was not different between the two diets (p=0.22). There was a significant relative reduction in hepatic steatosis after the MD compared with the LF/HCD: 39 ± 4% versus 7 ± 3%, as measured by (1)H-MRS (p=0.012). Insulin sensitivity improved with the MD, whereas after the LF/HCD there was no change (p=0.03 between diets). CONCLUSIONS Even without weight loss, MD reduces liver steatosis and improves insulin sensitivity in an insulin-resistant population with NAFLD, compared to current dietary advice. This diet should be further investigated in subjects with NAFLD.

Crohn's disease management after intestinal resection: a randomised trial.

BACKGROUND Most patients with Crohns disease need an intestinal resection, but a majority will subsequently experience disease recurrence and require further surgery. This study aimed to identify the optimal strategy to prevent postoperative disease recurrence. METHODS In this randomised trial, consecutive patients from 17 centres in Australia and New Zealand undergoing intestinal resection of all macroscopic Crohns disease, with an endoscopically accessible anastomosis, received 3 months of metronidazole therapy. Patients at high risk of recurrence also received a thiopurine, or adalimumab if they were intolerant to thiopurines. Patients were randomly assigned to parallel groups: colonoscopy at 6 months (active care) or no colonoscopy (standard care). We used computer-generated block randomisation to allocate patients in each centre to active or standard care in a 2:1 ratio. For endoscopic recurrence (Rutgeerts score ≥i2) at 6 months, patients stepped-up to thiopurine, fortnightly adalimumab with thiopurine, or weekly adalimumab. The primary endpoint was endoscopic recurrence at 18 months. Patients and treating physicians were aware of the patients study group and treatment, but central reading of the endoscopic findings was undertaken blind to the study group and treatment. Analysis included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT00989560. FINDINGS Between Oct 13, 2009, and Sept 28, 2011, 174 (83% high risk across both active and standard care groups) patients were enrolled and received at least one dose of study drug. Of 122 patients in the active care group, 47 (39%) stepped-up treatment. At 18 months, endoscopic recurrence occurred in 60 (49%) patients in the active care group and 35 (67%) patients in the standard care group (p=0.03). Complete mucosal normality was maintained in 27 (22%) of 122 patients in the active care group versus four (8%) in the standard care group (p=0.03). In the active care arm, of those with 6 months recurrence who stepped up treatment, 18 (38%) of 47 patients were in remission 12 months later; conversely, of those in remission at 6 months who did not change therapy recurrence occurred in 31 (41%) of 75 patients 12 months later. Smoking (odds ratio [OR] 2.4, 95% CI 1.2-4.8, p=0.02) and the presence of two or more clinical risk factors including smoking (OR 2.8, 95% CI 1.01-7.7, p=0.05) increased the risk of endoscopic recurrence. The incidence and type of adverse and severe adverse events did not differ significantly between patients in the active care and standard care groups (100 [82%] of 122 vs 45 [87%] of 52; p=0.51) and (33 [27%] of 122 vs 18 [35%] of 52; p=0.36), respectively. INTERPRETATION Treatment according to clinical risk of recurrence, with early colonoscopy and treatment step-up for recurrence, is better than conventional drug therapy alone for prevention of postoperative Crohns disease recurrence. Selective immune suppression, adjusted for early recurrence, rather than routine use, leads to disease control in most patients. Clinical risk factors predict recurrence, but patients at low risk also need monitoring. Early remission does not preclude the need for ongoing monitoring. FUNDING AbbVie, Gutsy Group, Gandel Philanthropy, Angior Foundation, Crohns Colitis Australia, and the National Health and Medical Research Council.

Tenofovir disoproxil fumarate rescue therapy following failure of both lamivudine and adefovir dipivoxil in chronic hepatitis B

Objective To determine the efficacy of tenofovir disoproxil fumarate (TDF) in adults with chronic hepatitis B virus (HBV) infection who had previously failed lamivudine (LAM) and had significant viral replication (HBV DNA >105 copies/ml if HBeAg positive, >104 copies/ml if HBeAg negative) despite at least 24 weeks of treatment with adefovir dipivoxil (ADV). Design A prospective open-label study of TDF 300 mg daily. Patients receiving combination ADV/LAM prior to baseline were switched to TDF/LAM. Setting Multiple tertiary referral centres. Methods Sixty patients were enrolled. The median age was 48.5 years (range 21–80), 46 (77%) were male and 40 (67%) were HBeAg positive. Thirty-eight patients (63%) were switched from ADV to TDF, the remainder from ADV/LAM to TDF/LAM. At baseline, substitutions conferring resistance to LAM or ADV were present in 20 patients (33%) and 17 patients (28%), respectively. The median baseline viral load was 5.33 log10 IU/ml (range 2.81–8.04). Patients initially treated with TDF monotherapy with persistent viral replication at or after 24 weeks were switched to TDF/LAM. The main outcome measures were change in HBV viral load from baseline and percentage of patients achieving an undetectable viral load (<15 IU/ml). Results Results are reported at 96 weeks of treatment. One patient discontinued TDF at 10 days due to rash. The time-weighted change in viral load from baseline to week 12 was −2.19 log10 IU/ml overall. The median change in HBV DNA from baseline to weeks 12, 24, 48 and 96 was −2.86, −3.23, −3.75 and −4.03 log10 IU/ml, respectively. At 48 and 96 weeks, 27/59 (46%) and 38/59 (64%) patients achieved a HBV DNA <15 IU/ml. The response was independent of baseline LAM therapy or mutations conferring ADV resistance. Conclusions In heavily pretreated patients with a high rate of genotypic resistance, TDF retains significant activity against HBV although this appears diminished in comparison with studies of naïve patients.

Cimetidine impairs elimination of chlordiazepoxide (librium) in man

We have studied chlordiazepoxide (Librium) disposition and elimination in eight normal subjects before and after 1 week of cimetidine therapy, 300 mg orally four times a day. Cimetidine strikingly impaired the clearance of chlordiazepoxide from plasma, and this was, at least in part, due to decreased demethylation of the drug to N-desmethylchlordiazepoxide. Since the volume of distribution of chlordiazepoxide was not altered by cimetidine, the elimination half-life of chlordiazepoxide was also significantly prolonged by cimetidine therapy.

Normal Metabolism of Morphine in a Cirrhosis

Morphine disposition and elimination was studied in 6 healthy male subject s and 6 male patients with cirrhosis, to assess the role of differences, if any, on the reported intolerance of morphine in cirrhosis. In addition the elimination of indocyanine green was studied in the same subjects on a separate occasion. The elimination half-life of indocyanine green was increased and its plasma clearance was markedly reduced in patients with cirrhosis as compared with controls (p less than 0.05). In contrast the disposition and elimination of morphine were unaffected by moderate to severe cirrhosis. Furthermore, while marked sedation was observed in normal subjects, the cirrhotics demonstrated mild sedation with no clinical evidence of hepatic coma. The normal elimination of morphine in cirrhosis is in contrast to the decreased elimination of high clearance drugs metabolized by oxidation, such as lidocaine and meperidine. Morphine is also normally a high clearance drug that is detoxified by conjugation with glucuronic acid. Since intra- or extrahepatic shunting, or both, in cirrhosis do not significantly impair morphine clearance, we postulate that significant extrahepatic morphine conjugation may occur in both normal subjects and in patients with cirrhosis. Furthermore, the reported morphine intolerance to the central effects of morphine cannot be explained by impaired drug elimination and increased availability of morphine to cerebral receptors.

Capsule endoscopy vs. push enteroscopy and enteroclysis in suspected small-bowel Crohn's disease

BACKGROUND The diagnosis of small-bowel Crohns disease sometimes is difficult and may be missed by conventional imaging studies. Capsule endoscopy might identify small-bowel disease undetected by other investigations. METHODS Patients with or without known Crohns disease who were suspected to have small-bowel Crohns disease were prospectively evaluated with push enteroscopy, enteroclysis, and capsule endoscopy. Each examiner was blinded to results of other investigations. Referring doctors were required to complete questionnaires before and after the investigations. RESULTS Twenty-two patients were known to have Crohns disease (Group 1), and 21 were suspected to have small-bowel Crohns disease (Group 2). In Group 1, capsule endoscopy detected more erosions than the other two investigations (p < 0.001). In Group 2, a new diagnosis of Crohns disease was made in two patients, but there was no significant difference in yield compared with the other two investigations. Referring physicians rated the usefulness of capsule endoscopy as 4.4 on a scale of 5. Capsule endoscopy changed management for 30 patients (70%). CONCLUSIONS Capsule endoscopy has a higher yield than push enteroscopy and enteroclysis in patients with known Crohns disease when small-bowel mucosal disease is suspected, and this leads to a change in management in the majority of these patients.