Predictive value of metabolomic biomarkers for cardiovascular disease risk: a systematic review and meta-analysis.

Background: Metabolomic analysis aids in the identification of novel biomarkers by revealing the metabolic dysregulations underlying cardiovascular disease (CVD) aetiology. The aim of this study was to evaluate which metabolic biomarkers could add value for the prognosis of CVD events using meta-analysis.Methods: The PRISMA guideline was followed for the systematic review. For the meta-analysis, biomarkers were included if they were tested in multivariate prediction models for fatal CVD outcomes. We grouped the metabolites in biological classes for subgroup analysis. We evaluated the prediction performance of models which reported discrimination and/or reclassification statistics.Results: For the systematic review, there were 22 studies which met the inclusion/exclusion criteria. For the meta-analysis, there were 41 metabolites grouped into 8 classes from 19 studies (45,420 subjects, 5954 events). A total of 39 of the 41 metabolites were significant with a combined effect size of 1.14 (1.07-1.20). For the predictive performance assessment, there were 21 studies, 54,337 subjects, 6415 events. The average change in c-statistic after adding the biomarkers to a clinical model was 0.0417 (SE 0.008).Conclusions: This study provides evidence that metabolomic biomarkers, mainly lipid species, have the potential to provide additional prognostic value. Current data are promising, although approaches and results are heterogeneous.

Cellular mechanisms of metabolic syndrome-related atrial decompensation in a rat model of HFpEF.

Heart failure (HF) with preserved ejection fraction (HFpEF) is present in about 50% of HF patients. Atrial remodeling is common in HFpEF and associated with increased mortality. We postulate that atrial remodeling is associated with atrial dysfunction in vivo related to alterations in cardiomyocyte Calcium (Ca) signaling and remodeling. We examined atrial function in vivo and Ca transients (CaT) (Fluo4-AM, field stim) in atrial cardiomyocytes of ZSF-1 rats without (Ln; lean hypertensive) and with metabolic syndrome (Ob; obese, hypertensive, diabetic) and HFpEF. RESULTS: At 21weeks Ln showed an increased left ventricular (LV) mass and left ventricular end-diastolic pressure (LVEDP), but unchanged left atrial (LA) size and preserved atrial ejection fraction vs. wild-type (WT). CaT amplitude in atrial cardiomyocytes was increased in Ln (2.9±0.2 vs. 2.3±0.2F/F0 in WT; n=22 cells/group; p<0.05). Studying subcellular Ca release in more detail, we found that local central cytosolic CaT amplitude was increased, while subsarcolemmal CaT amplitudes remained unchanged. Moreover, Sarcoplasmic reticulum (SR) Ca content (caffeine) was preserved while Ca spark frequency and tetracaine-dependent SR Ca leak were significantly increased in Ln. Ob mice developed a HFpEF phenotype in vivo, LA area was significantly increased and atrial in vivo function was impaired, despite increased atrial CaT amplitudes in vitro (2.8±0.2; p<0.05 vs. WT). Ob cells showed alterations of the tubular network possibly contributing to the observed phenotype. CaT kinetics as well as SR Ca in Ob were not significantly different from WT, but SR Ca leak remained increased. Angiotensin II (Ang II) reduced in vitro cytosolic CaT amplitudes and let to active nuclear Ca release in Ob but not in Ln or WT. SUMMARY: In hypertensive ZSF-1 rats, a possibly compensatory increase of cytosolic CaT amplitude and increased SR Ca leak precede atrial remodeling and HFpEF. Atrial remodeling in ZSF-1 HFpEF is associated with an altered tubular network in-vitro and atrial contractile dysfunction in vivo, indicating insufficient compensation. Atrial cardiomyocyte dysfunction in vitro is induced by the addition of angiotensin II.

Relevance of MicroRNA200 Family and MicroRNA205 for Epithelial to Mesenchymal Transition and Clinical Outcome in Biliary Tract Cancer Patients.

Extensive stromal interaction is one reason for the dismal outcome of biliary tract cancer (BTC) patients. Epithelial to mesenchymal transition (EMT) is involved in tumor invasion and metastasis and is partly regulated by microRNAs (miRs). This study explores the expression of anti-EMT miR200 family (miR141, -200a/b/c, -429) and miR205 as well as the EMT-related proteins E-cadherin and vimentin in a panel of BTC cell lines and clinical specimens by quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry, respectively. MicroRNA expression was correlated to (i) the expression patterns of E-cadherin and vimentin; (ii) clinicopathological characteristics; and (iii) survival data. MicroRNA-200 family and miR205 were expressed in all BTC cells and clinical specimens. E-cadherin and vimentin showed a mutually exclusive expression pattern in both, in vitro and in vivo. Expression of miR200 family members positively correlated with E-cadherin and negatively with vimentin expression in BTC cells and specimens. High expression of miR200 family members (but not miR205) and E-cadherin was associated with longer survival, while low miR200 family and high vimentin expression was a predictor of unfavorable survival. Overall, the current study demonstrates the relevance of the miR200 family in EMT of BTC tumors and suggests these miRs as predictors for positive outcome.

Oral ponesimod in relapsing-remitting multiple sclerosis: a randomised phase II trial.

OBJECTIVE: This double-blind, placebo-controlled, dose-finding phase IIb study evaluated the efficacy and safety of ponesimod, an oral selective S1P1 receptor modulator, for the treatment of patients with relapsing-remitting multiple sclerosis (RRMS). METHODS: 464 patients were randomised to receive once-daily oral ponesimod 10, 20 or 40 mg, or placebo for 24 weeks. The primary endpoint was the cumulative number of new T1 gadolinium-enhanced (T1 Gd+) lesions per patient recorded every 4 weeks from weeks 12 to 24 after study drug initiation. Secondary endpoints were the annualised confirmed relapse rate (ARR) and time to first confirmed relapse. Safety and tolerability were also evaluated. RESULTS: The mean cumulative number of new T1 Gd+ lesions at weeks 12-24 was significantly lower in the ponesimod 10 mg (3.5; rate ratio (RR) 0.57; p=0.0318), 20 mg (1.1; RR 0.17; p<0.0001) and 40 mg (1.4; RR 0.23; p<0.0001) groups compared with placebo (6.2). The mean ARR was lower with 40 mg ponesimod versus placebo, with a maximum reduction of 52% (0.25 vs 0.53; p=0.0363). The time to first confirmed relapse was increased with ponesimod compared with placebo. The proportion of patients with ≥ 1 treatment-emergent adverse events (AEs) was similar across ponesimod groups and the placebo group. Frequently reported AEs with higher incidence in the three ponesimod groups compared with placebo were anxiety, dizziness, dyspnoea, increased alanine aminotransferase, influenza, insomnia and peripheral oedema. CONCLUSIONS: Once-daily treatment with ponesimod 10, 20 or 40 mg significantly reduced the number of new T1 Gd+ lesions and showed a beneficial effect on clinical endpoints. Ponesimod was generally well tolerated, and further investigation of ponesimod for the treatment of RRMS is under consideration. TRIAL REGISTRATION NUMBER: NCT01006265.

Activated hedgehog pathway is a potential target for pharmacological intervention in biliary tract cancer.

Hedgehog (Hh) signalling contributes to carcinogenesis and represents a valid druggable target in human cancers, possibly also in biliary tract cancer (BTC). We analysed the expression of Hh components in BTC using eight heterogeneously differentiated cell lines, xenograft tumours and a human tissue microarray. The dose-, time- and cell line-dependent effects of two Hh inhibitors (cyclopamine and Gant-61) were analysed in vitro for survival, apoptosis, cell cycle distribution and possible synergism with conventional chemotherapeutic agents. In human BTC samples, the sonic Hh ligand and the Gli1 transcription factor showed increased expression in tumours compared to normal adjacent tissue and were significantly associated with high tumour grade and positive lymph node status. In BTC cell lines, we could confirm the Hh component expression at varying extent within the employed cell lines in vitro and in vivo indicating non-canonical signalling. Both Hh inhibitors showed dose-dependent cytotoxicity above 5 µM with a stronger effect for Gant-61 inducing apoptosis whereas cyclopamine rather inhibited proliferation. Cytotoxicity was associated with low cytokeratin expression and higher mesenchymal marker expression such as vimentin. Additionally, drug combinations of Gant-61 with conventional chemotherapy (cisplatin) exerted synergistic effects. In conclusion, Hh pathway is significantly activated in human BTC tissue compared to normal adjacent tissue. The current data demonstrate for the first time an effective anticancer activity of especially Gant-61 in BTC and suggest second generation Hh pathway inhibitors as a potential novel treatment strategy in BTC.

MicroRNAs associated with the efficacy of photodynamic therapy in biliary tract cancer cell lines.

Photodynamic therapy (PDT) is a palliative treatment option for unresectable hilar biliary tract cancer (BTC) showing a considerable benefit for survival and quality of life with few side effects. Currently, factors determining the cellular response of BTC cells towards PDT are unknown. Due to their multifaceted nature, microRNAs (miRs) are a promising analyte to investigate the cellular mechanisms following PDT. For two photosensitizers, Photofrin® and Foscan®, the phototoxicity was investigated in eight BTC cell lines. Each cell line (untreated) was profiled for expression of n=754 miRs using TaqMan® Array Human MicroRNA Cards. Statistical analysis and bioinformatic tools were used to identify miRs associated with PDT efficiency and their putative targets, respectively. Twenty miRs correlated significantly with either high or low PDT efficiency. PDT was particularly effective in cells with high levels of clustered miRs 25-93*-106b and (in case of miR-106b) a phenotype characterized by high expression of the mesenchymal marker vimentin and high proliferation (cyclinD1 and Ki67 expression). Insensitivity towards PDT was associated with high miR-200 family expression and (for miR-cluster 200a/b-429) expression of differentiation markers Ck19 and Ck8/18. Predicted and validated downstream targets indicate plausible involvement of miRs 20a*, 25, 93*, 130a, 141, 200a, 200c and 203 in response mechanisms to PDT, suggesting that targeting these miRs could improve susceptibility to PDT in insensitive cell lines. Taken together, the miRNome pattern may provide a novel tool for predicting the efficiency of PDT and-following appropriate functional verification-may subsequently allow for optimization of the PDT protocol.

Randomised trial of clazosentan, an endothelin receptor antagonist, in patients with aneurysmal subarachnoid hemorrhage undergoing surgical clipping (CONSCIOUS-2).

We report here results of a randomized, double-blind, placebo-controlled study ( http://www.ClinicalTrials.gov , NCT00558311) that investigated the effect of clazosentan (5 mg/h, n = 768) or placebo (n = 389) administered for up to 14 days in patients with aneurysmal subarachnoid hemorrhage (SAH) repaired by surgical clipping. The primary endpoint was a composite of all-cause mortality, new cerebral infarction or delayed ischemic neurological deficit due to vasospasm, and rescue therapy for vasospasm. The main secondary endpoint was the Glasgow Outcome Scale Extended (GOSE), which was dichotomized. Twenty-one percent of clazosentan- compared to 25% of placebo-treated patients met the primary endpoint (relative risk reduction [RRR] [95% CI]: 17% [-4% to 33%]; p = 0.10). Poor outcome (GOSE score ≤ 4) occurred in 29% of clazosentan- and 25% of placebo-treated patients (RRR: -18% [-45% to 4%]; p = 0.10). In prespecified subgroups, mortality/vasospasm-related morbidity was reduced in clazosentan-treated patients by 33% (8-51%) in poor WFNS (World Federation of Neurological Surgeons) grade (≥III) and 25% (5-41%) in patients with diffuse, thick SAH. Lung complications, anemia and hypotension occurred more frequently with clazosentan. Mortality (week 12) was 6% in both groups. The results showed that clazosentan nonsignificantly decreased mortality/vasospasm-related morbidity and nonsignificantly increased poor functional outcome in patients with aneurysmal SAH undergoing surgical clipping.

Supervised exercise training in patients with advanced heart failure and left ventricular assist device: A multicentre randomized controlled trial (Ex-VAD trial).

AIMS: Small studies and observations suggested that exercise training may improve peak oxygen consumption (peakVO2 ) in patients with advanced heart failure and left ventricular assist device (LVAD). We investigated whether in this patient group a supervised exercise training can improve exercise capacity. METHODS AND RESULTS: In this multicentre, prospective, randomized, controlled trial, patients with stable heart failure and LVAD were randomly assigned (2:1) to 12 weeks of supervised exercise training or usual care, with 12 weeks of follow-up. The primary endpoint was the change in peakVO2 after 12 weeks (51 patients provided a power of 90% with an expected group difference in peakVO2 of 3 ml/kg/min). Secondary endpoints included changes in submaximal exercise capacity and quality of life. Among 64 patients enrolled (97% male, mean age 56 years), 54 were included in the analysis. Mean difference in the change of peakVO2 after 12 weeks was 0.826 ml/min/kg (95% confidence interval [CI] -0.37, 2.03; p = 0.183). There was a positive effect of exercise training on 6-min walk distance with a mean increase in the intervention group by 43.4 m (95% CI 16.9, 69.9; p = 0.0024), and on the Kansas City Cardiomyopathy Questionnaire physical domain score (mean 14.3, 95% CI 3.7, 24.9; p = 0.0124), both after 12 weeks. The overall adherence was high (71%), and there were no differences in adverse events between groups. CONCLUSION: In patients with advanced heart failure and LVAD, 12 weeks of exercise training did not improve peakVO2 but demonstrated positive effects on submaximal exercise capacity and physical quality of life.

Randomized trial of clazosentan in patients with aneurysmal subarachnoid hemorrhage undergoing endovascular coiling.

BACKGROUND AND PURPOSE: Clazosentan, an endothelin receptor antagonist, has been shown to reduce vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). CONSCIOUS-3 assessed whether clazosentan reduced vasospasm-related morbidity and all-cause mortality postaSAH secured by endovascular coiling. METHODS: This double-blind, placebo-controlled, phase III trial randomized patients with aSAH secured by endovascular coiling to ≤ 14 days intravenous clazosentan (5 or 15 mg/h) or placebo. The primary composite end point (all-cause mortality; vasospasm-related new cerebral infarcts or delayed ischemic neurological deficits; rescue therapy for vasospasm) was evaluated 6 weeks postaSAH. The main secondary end point was dichotomized extended Glasgow Outcome Scale (week 12). RESULTS: CONSCIOUS-3 was halted prematurely following completion of CONSCIOUS-2; 577/1500 of planned patients (38%) were enrolled and 571 were treated (placebo, n=189; clazosentan 5 mg/h, n=194; clazosentan 15 mg/h, n=188). The primary end point occurred in 50/189 of placebo-treated patients (27%), compared with 47/194 patients (24%) treated with clazosentan 5 mg/h (odds ratio [OR], 0.786; 95% CI, 0.479-1.289; P=0.340), and 28/188 patients (15%) treated with clazosentan 15 mg/h (OR, 0.474; 95% CI, 0.275-0.818; P=0.007). Poor outcome (extended Glasgow Outcome Scale score ≤ 4) occurred in 24% of patients with placebo, 25% of patients with clazosentan 5 mg/h (OR, 0.918; 95% CI, 0.546-1.544; P=0.748), and 28% of patients with clazosentan 15 mg/h (OR, 1.337; 95% CI, 0.802-2.227; P=0.266). Pulmonary complications, anemia, and hypotension were more common in patients who received clazosentan than in those who received placebo. At week 12, mortality was 6%, 4%, and 6% with placebo, clazosentan 5 mg/h, and clazosentan 15 mg/h, respectively. CONCLUSIONS: Clazosentan 15 mg/h significantly reduced postaSAH vasospasm-related morbidity/all-cause mortality; however, neither dose improved outcome (extended Glasgow Outcome Scale).

Incremental prognostic value of a novel metabolite-based biomarker score in congestive heart failure patients.

AIMS: The Cardiac Lipid Panel (CLP) is a newly discovered panel of metabolite-based biomarkers that has shown to improve the diagnostic value of N terminal pro B type natriuretic peptide (NT-proBNP). However, little is known about its usefulness in predicting outcomes. In this study, we developed a risk score for 4-year cardiovascular death in elderly chronic heart failure (CHF) patients using the CLP. METHODS AND RESULTS: From the Cardiac Insufficiency Bisoprolol Study in Elderly trial, we included 280 patients with CHF aged >65 years. A targeted metabolomic analysis of the CLP biomarkers was performed on baseline serum samples. Cox regression was used to determine the association of the biomarkers with the outcome after accounting for established risk factors. A risk score ranging from 0 to 4 was calculated by counting the number of biomarkers above the cut-offs, using Youden index. During the mean (standard deviation) follow-up period of 50 (8) months, 35 (18%) subjects met the primary endpoint of cardiovascular death. The area under the receiver operating curve for the model based on clinical variables was 0.84, the second model with NT-proBNP was 0.86, and the final model with the CLP was 0.90. The categorical net reclassification index was 0.25 using three risk categories: 0-60% (low), 60-85% (intermediate), and >85% (high). The continuous net reclassification index was 0.772, and the integrated discrimination index was 0.104. CONCLUSIONS: In patients with CHF, incorporating a panel of three metabolite-based biomarkers into a risk score improved the prognostic utility of NT-proBNP by predicting long-term cardiovascular death more precisely. This novel approach holds promise to improve clinical risk assessment in CHF patients.

Biomarker-based phenotyping of myocardial fibrosis identifies patients with heart failure with preserved ejection fraction resistant to the beneficial effects of spironolactone: results from the Aldo-DHF trial.

BACKGROUND: Myocardial fibrosis is characterized by excessive cross-linking and deposition of collagen type I and is involved in left ventricular stiffening and left ventricular diastolic dysfunction (LVDD). We investigated whether the effect of spironolactone on LVDD in patients with heart failure with preserved ejection fraction (HFpEF) depends on its effects on collagen cross-linking and/or deposition. METHODS AND RESULTS: We investigated 381 HFpEF patients from the multicentre, randomized, placebo-controlled Aldo-DHF trial with measures of the E:e' ratio. The ratio of serum carboxy-terminal telopeptide of collagen type I to serum matrix metalloproteinase-1 (CITP:MMP-1, an inverse index of myocardial collagen cross-linking) and serum carboxy-terminal propeptide of procollagen type I (PICP, a direct index of myocardial collagen deposition) were determined at baseline and after 1-year treatment with spironolactone 25 mg once daily or placebo. Patients were classified by CITP:MMP-1 and PICP tertiles at baseline. While CITP:MMP-1 tertiles at baseline interacted (P < 0.05) with spironolactone effect on E:e', PICP tertiles did not. In fact, while spironolactone treatment did not modify E:e' in patients with lower CITP:MMP-1 levels, this ratio was significantly reduced in the remaining spironolactone-treated patients. In addition, PICP was unchanged in patients with lower CITP:MMP-1 levels but was reduced in the remaining spironolactone-treated patients. CONCLUSIONS: A biochemical phenotype of high collagen cross-linking identifies HFpEF patients resistant to the beneficial effects of spironolactone on LVDD. It is suggested that excessive collagen cross-linking, which stabilizes collagen type I fibres, diminishes the ability of spironolactone to reduce collagen deposition in these patients.

Comprehensive analysis of alterations in the miRNome in response to photodynamic treatment.

Photodynamic therapy (PDT) is a local tumour treatment accepted for a number of indications. PDT operates via the cellular stress response through the production of reactive oxygen species and subsequent cellular damage, resulting in cell death. Although PDT-induced signalling and cytotoxicity mechanisms have been investigated, the effect of PDT on microRNA (miRNA) expression is largely unknown. Therefore, we conducted a comprehensive microarray-based analysis of the miRNome of human epidermoid carcinoma cells (A431) following in vitro photodynamic treatment using polyvinylpyrrolidone hypericin (PVPH) as a photosensitiser and nearly homogeneous apoptosis-inducing conditions. Using microarray analysis we found eight miRNAs to be significantly differentially expressed 5h post treatment compared with the baseline levels and three miRNAs with more than 2-fold differential expression that could be detected in 1 or 2 biological replicates. The verification of these results by quantitative RT-PCR including a detailed time-course revealed an up to 15-fold transient over-expression of miR-634, miR-1246, miR-1290 and miR-487b compared with the basal level. For these miRNAs, in silico mRNA target prediction yielded numerous target transcripts involved in the regulation of cell stress, apoptosis, cell adherence and proliferation. This study provides the first comprehensive miRNome analysis after PDT treatment and may help to develop novel miRNA-based therapeutic approaches to further increase the efficiency of PDT.

Transcutaneous vaccination via laser microporation.

Driven by constantly increasing knowledge about skin immunology, vaccine delivery via the cutaneous route has recently gained renewed interest. Considering its richness in immunocompetent cells, targeting antigens to the skin is considered to be more effective than intramuscular or subcutaneous injections. However, circumvention of the superficial layer of the skin, the stratum corneum, represents the major challenge for cutaneous immunization. An optimal delivery method has to be effective and reliable, but also highly adaptable to specific demands, should avoid the use of hypodermic needles and the requirement of specially trained healthcare workers. The P.L.E.A.S.E. (Precise Laser Epidermal System) device employed in this study for creation of aqueous micropores in the skin fulfills these prerequisites by combining the precision of its laser scanning technology with the flexibility to vary the number, density and the depth of the micropores in a user-friendly manner. We investigated the potential of transcutaneous immunization via laser-generated micropores for induction of specific immune responses and compared the outcomes to conventional subcutaneous injection. By targeting different layers of the skin we were able to bias polarization of T cells, which could be modulated by addition of adjuvants. The P.L.E.A.S.E. device represents a highly effective and versatile platform for transcutaneous vaccination.

Clazosentan, an endothelin receptor antagonist, in patients with aneurysmal subarachnoid haemorrhage undergoing surgical clipping: a randomised, double-blind, placebo-controlled phase 3 trial (CONSCIOUS-2).

BACKGROUND: Clazosentan, an endothelin receptor antagonist, significantly and dose-dependently reduced angiographic vasospasm after aneurysmal subarachnoid haemorrhage (aSAH). We investigated whether clazosentan reduced vasospasm-related morbidity and all-cause mortality. METHODS: In this randomised, double-blind, placebo-controlled, phase 3 study, we randomly assigned patients with aSAH secured by surgical clipping to clazosentan (5 mg/h, n=768) or placebo (n=389) for up to 14 days (27 countries, 102 sites, inpatient and outpatient settings) using an interactive web response system. The primary composite endpoint (week 6) included all-cause mortality, vasospasm-related new cerebral infarcts, delayed ischaemic neurological deficit due to vasospasm, and rescue therapy for vasospasm. The main secondary endpoint was dichotomised extended Glasgow outcome scale (GOSE; week 12). This trial is registered with ClinicalTrials.gov, number NCT00558311. FINDINGS: In the all-treated dataset, the primary endpoint was met in 161 (21%) of 764 clazosentan-treated patients and 97 (25%) of 383 placebo-treated patients (relative risk reduction 17%, 95% CI -4 to 33; p=0·10). Poor functional outcome (GOSE score ≤4) occurred in 224 (29%) clazosentan-treated patients and 95 (25%) placebo-treated patients (-18%, -45 to 4; p=0·10). Lung complications, anaemia, and hypotension were more common with clazosentan. Mortality (week 12) was 6% in both groups. INTERPRETATION: Clazosentan at 5 mg/h had no significant effect on mortality and vasospasm-related morbidity or functional outcome. Further investigation of patients undergoing endovascular coiling of ruptured aneurysms is needed to fully understand the potential usefulness of clazosentan in patients with aSAH. FUNDING: Actelion Pharmaceuticals.

Acute hemodynamic effects of single-dose sildenafil when added to established bosentan therapy in patients with pulmonary arterial hypertension: results of the COMPASS-1 study.

This study investigated the acute pharmacodynamic effects of sildenafil in patients with pulmonary arterial hypertension (PAH) and concomitant bosentan treatment, in view of a mutual pharmacokinetic interaction between the 2 drugs. This prospective, open-label, noncomparative, multicenter, phase II study enrolled 45 patients (>or=18 years) with stable PAH (idiopathic, familial, or related to corrected congenital systemic-to-pulmonary shunts, drugs, or toxins) and on bosentan treatment for at least 3 months. Patients underwent right heart catheterization to evaluate the acute hemodynamic effects of (a) inhaled nitric oxide (iNO) and (b) a single oral dose of sildenafil (25 mg). Mean pulmonary vascular resistance (PVR) decreased from baseline following iNO (-15%; 95% confidence limits: -21%, -8%; P = .0001). A statistically significant decrease from baseline in mean PVR was also observed 60 minutes following sildenafil administration (-15%; 95% confidence limits: -21%, -10%; P < .0001). The reduction in PVR following sildenafil was comparable to that resulting from iNO. There were no unexpected safety findings. The pharmacodynamic effect suggests that addition of sildenafil to bosentan treatment can elicit additional hemodynamic benefits. These data represent a rationale for long-term combination studies with the 2 compounds.

Comparative immunogenicity of a PreS/S hepatitis B vaccine in non- and low responders to conventional vaccine.

Conventional hepatitis B vaccines do not elicit adequate antibody production in 5-10% vaccinees. This trial tests the ability of a third-generation vaccine, containing PreS1 and PreS2 antigens in addition to the S antigen, to elicit seroprotective titres in documented non- and low-responders, compared with those to a conventional vaccine. In the primary population of non-responders (<10 IU/l anti-HBs antibodies after > or = 4 previous injections of conventional vaccine) an enhanced antibody response was seen to additional injections of the third-generation vaccine compared with a conventional vaccine (absolute difference 14.9%; P = 0.006). Enhanced antibody responses were also found in a population that included low responders.