Immunogenicity, reactogenicity and safety of 2 doses of an adjuvanted herpes zoster subunit vaccine administered 2, 6 or 12 months apart in older adults: Results of a phase III, randomized, open-label, multicenter study

BACKGROUND

In phase III trials, 2 doses of a herpes zoster (HZ) subunit vaccine (HZ/su; 50 µg varicella-zoster virus glycoprotein E [gE] and AS01_B Adjuvant System) administered 2-months apart in older adults (≥50 and ≥70 years) demonstrated >90% efficacy in preventing HZ and had a clinically acceptable safety profile. Here we report immunogenicity, reactogenicity and safety following administration of 2 HZ/su doses at intervals longer than 2 months.

METHODS

In this Phase III, open-label trial conducted in the US and Estonia, 354 adults ≥50 years were randomized 1:1:1 to receive 2 HZ/su doses 2, 6, or 12 months apart. gE-specific humoral immune responses were evaluated at pre-vaccination, 1 and 12 months post-dose 2. Co-primary objectives were to compare immune responses to HZ/su 1 month post-dose 2 when given 6-months or 12-months apart to those administered 2-months apart. For each participant, safety information was collected from dose 1 to 12 months post-dose 2.

RESULTS

346 participants completed the study and 343 were included in the according-to-protocol cohort for immunogenicity. One month post-dose 2, vaccine response rates were 96.5% (97.5% confidence interval [CI]: 90.4; 99.2) and 94.5% (97.5% CI: 87.6; 98.3) for the 0, 6- and 0, 12-month schedules, respectively, both schedules meeting the pre-defined criterion. Non-inferiority of anti-gE geometric mean concentrations was demonstrated for HZ/su administered on 0, 6-month compared to a 0, 2-month schedule; however, HZ/su administered on a 0, 12-month schedule did not meet the non-inferiority criterion. Injection site pain was the most commonly reported solicited adverse event (AE). 26 participants each reported at least 1 serious AE; none were assessed as related to vaccination.

CONCLUSIONS

Immune responses to HZ/su administered at 0, 6-month were non-inferior to those elicited by a 0, 2-month schedule. HZ/su exhibited a clinically acceptable safety profile for all dosing intervals.

CLINICAL TRIALS REGISTRATION

Clinicaltrials.gov (NCT01751165).

Progression of HPV infection to detectable cervical lesions or clearance in adult women: Analysis of the control arm of the VIVIANE study

The control arm of the phase III VIVIANE (Human PapillomaVIrus: Vaccine Immunogenicity ANd Efficacy; NCT00294047) study in women >25 years was studied to assess risk of progression from cervical HPV infection to detectable cervical intraepithelial neoplasia (CIN). The risk of detecting CIN associated with the same HPV type as the reference infection was analysed using Kaplan–Meier and multivariable Cox models. Infections were categorised depending upon persistence as 6‐month persistent infection (6MPI) or infection of any duration. The 4‐year interim analysis included 2,838 women, of whom 1,073 (37.8%) experienced 2,615 infections of any duration and 708 (24.9%) experienced 1,130 6MPIs. Infection with oncogenic HPV types significantly increased the risk of detecting CIN grade 2 or greater (CIN2+) versus non‐oncogenic types. For 6MPI, the highest risk was associated with HPV‐33 (hazard ratio [HR]: 31.9 [8.3–122.2, p < 0.0001]). The next highest risk was with HPV‐16 (21.1 [6.3–70.0], p < 0.0001). Similar findings were seen for infections of any duration. Significant risk was also observed for HPV‐18, HPV‐31, and HPV‐45. Concomitant HPV infection or CIN grade 1 or greater associated with a different oncogenic HPV type increased risk. Most women (79.3%) with an HPV infection at baseline cleared detectable infections of any duration, and 69.9% cleared a 6MPI. The risk of progression of HPV infection to CIN2+ in women >25 years in this study was similar to that in women 15–25 years in PATRICIA.

What's New?

Which HPV infections lead to cancer in women over 25 years? Most cervical cancer follows persistent oncogenic HPV infection, but most HPV infections clear naturally. Thus, to best predict patient outcomes, it's imperative to understand how HPV infections progress to CINs. This study confirmed that in women over 25 years, persistent infection with HPV‐33 or HPV‐16 meant the greatest chance of developing a CIN—the same as was found in women 15–25 years, in an earlier analysis.

Sustained efficacy, immunogenicity, and safety of the HPV-16/18 AS04-adjuvanted vaccine: final analysis of a long-term follow-up study up to 9.4 years post-vaccination

HPV-023 (NCT00518336; ClinicalTrial.gov) is a long-term follow-up of an initial double-blind, randomized (1:1), placebo-controlled study (HPV-001, NCT00689741) evaluating the efficacy against human papillomavirus (HPV)-16/18 infection and associated cyto-histopathological abnormalities, persistence of immunogenicity, and safety of the HPV-16/18 AS04-adjuvanted vaccine. Among the women, aged 15-25 years, enrolled in HPV-001 and who participated in the follow-up study HPV-007 (NCT00120848), a subset of 437 women from five Brazilian centers participated in this 36-month long-term follow-up (HPV-023) for a total of 113 months (9.4 years). During HPV-023, anti-HPV-16/18 antibodies were measured annually by enzyme-linked immunosorbent assay (ELISA) and pseudovirion-based neutralisation assay (PBNA). Cervical samples were tested for HPV DNA every 6 months, and cyto-pathological examinations were performed annually. During HPV-023, no new HPV-16/18-associated infections and cyto-histopathological abnormalities occurred in the vaccine group. Vaccine efficacy (VE) against HPV-16/18 incident infection was 100% (95%CI: 66.1, 100). Over the 113 months (9.4 years), VE was 95.6% (86.2, 99.1; 3/50 cases in vaccine and placebo groups, respectively) against incident infection, 100% (84·1, 100; 0/21) against 6-month persistent infection (PI); 100% (61·4, 100; 0/10) against 12-month PI; 97·1% (82.5, 99.9; 1/30) against ≥ ASC-US; 95·0% (68.0, 99.9; 1/18) against ≥ LSIL; 100% (45.2, 100; 0/8) against CIN1+; and 100% (-128.1, 100; 0/3) against CIN2+ associated with HPV-16/18. All vaccinees remained seropositive to HPV-16/18, with antibody titers remaining several folds above natural infection levels, as measured by ELISA and PBNA. There were no safety concerns. To date, these data represent the longest follow-up reported for a licensed HPV vaccine.

Efficacy, safety, and immunogenicity of the human papillomavirus 16/18 AS04-adjuvanted vaccine in women older than 25 years: 4-year interim follow-up of the phase 3, double-blind, randomised controlled VIVIANE study

BACKGROUND

Although adolescent girls are the main population for prophylactic human papillomavirus (HPV) vaccines, adult women who remain at risk of cervical cancer can also be vaccinated. We report data from the interim analysis of the ongoing VIVIANE study, the aim of which is to assess the efficacy, safety, and immunogenicity of the HPV 16/18 AS04-adjuvanted vaccine in adult women.

METHODS

In this phase 3, multinational, double-blind, randomised controlled trial, we randomly assigned healthy women older than 25 years to the HPV 16/18 vaccine or control (1:1), via an internet-based system with an algorithm process that accounted for region, age stratum, baseline HPV DNA status, HPV 16/18 serostatus, and cytology. Enrolment was age-stratified, with about 45% of participants in each of the 26-35 and 36-45 years age strata and 10% in the 46 years and older stratum. Up to 15% of women in each age stratum could have a history of HPV infection or disease. The primary endpoint was vaccine efficacy against 6-month persistent infection or cervical intraepithelial neoplasia grade 1 or higher (CIN1+) associated with HPV 16/18. The primary analysis was done in the according-to-protocol cohort for efficacy, which consists of women who received all three vaccine or control doses, had negative or low-grade cytology at baseline, and had no history of HPV disease. Secondary analyses included vaccine efficacy against non-vaccine oncogenic HPV types. Mean follow-up time was 40·3 months. This study is registered with ClinicalTrials.gov, number NCT00294047.

FINDINGS

The first participant was enrolled on Feb 16, 2006, and the last study visit for the present analysis took place on Dec 10, 2010; 5752 women were included in the total vaccinated cohort (n=2881 vaccine, n=2871 control), and 4505 in the according-to-protocol cohort for efficacy (n=2264 vaccine, n=2241 control). Vaccine efficacy against HPV 16/18-related 6-month persistent infection or CIN1+ was significant in all age groups combined (81·1%, 97·7% CI 52·1-94·0), in the 26-35 years age group (83·5%, 45·0-96·8), and in the 36-45 years age group (77·2%, 2·8-96·9); no cases were seen in women aged 46 years and older. Vaccine efficacy against atypical squamous cells of undetermined significance or greater associated with HPV 16/18 was also significant. We also noted significant cross-protective vaccine efficacy against 6-month persistent infection with HPV 31 (79·1%, 97·7% CI 27·6-95·9) and HPV 45 (76·9%, 18·5-95·6]) Serious adverse events occurred in 285 (10%) of 2881 women in the vaccine group and 267 (9%) of 2871 in the control group; five (<1%) and eight (<1%) of these events, respectively, were believed to be related to vaccination.

INTERPRETATION

In women older than 25 years, the HPV 16/18 vaccine is efficacious against infections and cervical abnormalities associated with the vaccine types, as well as infections with the non-vaccine HPV types 31 and 45.

FUNDING

GlaxoSmithKline Biologicals SA.

Immune responses elicited by a fourth dose of the HPV-16/18 AS04-adjuvanted vaccine in previously vaccinated adult women

BACKGROUND

Vaccines are now available for the prevention of HPV-16/18-related cervical infections and pre-cancers, primarily targeting adolescent girls. Since the risk of HPV exposure potentially persists throughout a woman's sexual life, vaccine-derived immunity should be long-term. The current study, HPV-024 (NCT00546078, http://clinicaltrials.gov), assessed the immune memory in North American women who received three doses of HPV-16/18 AS04-adjuvanted vaccine 7 years earlier in HPV-001 (NCT00689741).

METHODS

Women vaccinated in HPV-001 received a 4th-dose of the HPV-16/18 vaccine (024-4DV group, N=65). Post 4th-dose immune responses were compared with post 1st-dose immune responses in cross-vaccination controls (024-3DV group, N=50). Reactogenicity was compared between the 4th-dose and the 1st-dose administration.

RESULTS

Pre 4th-dose, 100% of subjects in the 024-4DV group remained seropositive for anti-HPV-16/18 antibodies (ELISA). Compared to pre 4th-dose, GMTs for anti-HPV-16 and anti-HPV-18 antibodies were respectively 9.3-fold and 8.7-fold higher at day 7, and 22.7-fold and 17.2-fold higher at month 1. Compared to post 1st-dose, GMTs for anti-HPV-16 and anti-HPV-18 were respectively 80.5-fold and 205.4-fold higher at day 7, and 11.8-fold and 20.5-fold higher at month 1. Furthermore, 68.2% and 77.3% of women had HPV-16/18 specific memory B-cells, respectively, pre 4th-dose, rising to 100% one month post 4th-dose vaccination. The 4th-dose was generally well tolerated.

CONCLUSION

A 4th-dose of HPV-16/18 AS04-adjuvanted vaccine triggered a rapid and strong anamnestic response in previously vaccinated women, demonstrating vaccine-induced immune memory.

Sustained immunogenicity and efficacy of the HPV-16/18 AS04-adjuvanted vaccine: up to 8.4 years of follow-up

Prophylactic human papillomavirus (HPV) vaccines are now available and vaccination programs are being widely implemented, targeting adolescent girls prior to sexual debut. Since the risk of HPV exposure persists throughout a woman's sexual life, the duration of protection provided by vaccination is critical to the overall vaccine effectiveness. We report the long-term efficacy and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine (Cervarix (®) ) up to 8.4 y after the first vaccine dose.   In an initial placebo-controlled study performed in US, Canada and Brazil, women aged 15-25 y with normal cervical cytology, HPV-16/18 seronegative by ELISA, DNA-negative for 14 oncogenic HPV types by PCR, received either the HPV-16/18 vaccine or placebo (n = 1,113). Subjects were followed up to 6.4 y after the first dose (n = 776). We report an additional 2-y follow-up for women enrolled from the Brazilian centers from the initial study (n = 436). During the current follow-up study (HPV-023, NCT00518336), no new infection or lesions associated with HPV-16/18 occurred in the vaccine group. Vaccine efficacy over the entire follow-up (up to 8.4 y) was 95.1% (84.6, 99.0) for incident infection, 100% (79.8, 100) for 6-mo persistent infection, 100% (56.1, 100) for 12-mo persistent infection and 100% (< 0, 100) for CIN2+ associated with HPV-16/18. All women in the vaccine group remained seropositive to both HPV-16/18, with antibody titers for total and neutralizing antibodies remaining several-folds above natural infection levels. The safety profile was clinically acceptable for both vaccine and control groups. This is, to date, the longest follow-up study for a licensed cervical cancer vaccine.

Different regional brain activity during physiological gastric distension compared to balloon distension: a H2 15O-PET study

BACKGROUND

Stepwise gastric balloon distension progressively activates a 'visceral pain neuromatrix', ultimately inducing discomfort and pain. On the other hand, normal meal ingestion requires gastric volume expansion without induction of pain. The aim was to test the hypothesis that physiological gastric distension (liquid meal infusion) until maximal satiation elicits brain responses similar to balloon distension at discomfort threshold.

METHODS

Brain H(2) (15) O-positron emission tomography (PET) was performed in two different groups of healthy volunteers (both n=14) during continuous and stepwise infusion of a liquid meal through a nasogastric tube, until maximal satiation. Brain (de)activation patterns were compared with historical controls in which discomfort was elicited using gastric balloon distension. This latter reference group was acquired on the same scanner using the same acquisition protocol; all data were analyzed using statistical parametric mapping (SPM2). Within each group, brain activity at maximal distension was compared to baseline activity and between-group comparisons were made.

KEY RESULTS

Intragastric volumes and satiation/gastric sensation scores at endpoint were similar in all groups. Continuous and stepwise nutrient infusion was associated with progressive deactivations in key areas of the 'visceral pain neuromatrix' that were activated during balloon distension. Additionally, stepwise infusion progressively activated prefrontal areas and showed deactivations in 'default network' brain regions also found to be deactivated during balloon distension.

CONCLUSIONS & INFERENCES

Compared to gastric balloon distension, physiological gastric distension using nutrient infusion elicits opposite brain responses in the 'visceral pain neuromatrix', but similar responses in other areas. We interpret this finding as a prerequisite for tolerance of normal meal volumes in health.

Influence of acute tryptophan depletion on gastric sensorimotor function in humans

Peripheral serotonin (5-hydrodytryptamine; 5-HT) is involved in the regulation of gastrointestinal motility and sensation, whereas centrally it plays a role in mood regulation. A dysfunctional serotonergic system may provide a plausible link between functional dyspepsia symptoms and its high psychosocial comorbidity such as anxiety and depression. The aim of this study was to evaluate the effect of decreased 5-HT synthesis by acute tryptophan depletion (ATD) on gastric sensorimotor function and nutrient tolerance, anxiety scores, and gastrointestinal mucosal 5-HT concentrations in healthy volunteers. All subjects were studied under a control condition and during ATD. Gastric sensorimotor function and nutrient tolerance were assessed using a barostat (n = 16, mean age 28.8 ± 1.4 yr) and a satiety drinking test (n = 13, mean age 27.3 ± 1.4 yr). Anxiety during the barostat was evaluated using State-Trait Anxiety Inventory (STAI) questionnaire. 5-HT concentrations were measured in fundic and duodenal mucosal biopsies by means of ELISA and immunohistochemistry. ATD significantly decreased plasma tryptophan levels compared with control in every experiment. ATD did not affect gastric sensitivity and compliance but decreased the sensation of nausea during balloon distension (AUC: 17.4 ± 4.3 vs. 11.4 ± 3.4 mm·mmHg, P = 0.030). ATD enhanced the postprandial volume increase (ANOVA, P < 0.05), but this was not accompanied by augmented nutrient tolerance (848 ± 110 vs. 837 ± 99 ml, nonsignificant). ATD had no effect on STAI state anxiety scores. No evidence was found for an effect on the number of enterochromaffin cells, but ATD reduced 5-HT levels in the duodenal mucosa. ATD alters gastric postprandial motor function and distension-induced nausea. These findings confirm involvement of 5-HT in the control of gastric accommodation and sensitivity.

Regional brain activity in functional dyspepsia: a H(2)(15)O-PET study on the role of gastric sensitivity and abuse history

BACKGROUND & AIMS

Differences in brain activity between health and functional dyspepsia (FD) have been reported; it is unclear whether this is influenced by gastric hypersensitivity or abuse history. Therefore, we aimed to determine the influence of gastric sensitivity and abuse history on gastric sensation scores and brain activity in homeostatic-afferent, emotional-arousal, and cortical-modulatory brain regions in FD.

METHODS

Abuse history was assessed using a validated self-report questionnaire. H(2)(15)O positron emission tomography was performed in 25 FD patients (13 hypersensitive and 8 abused) during 3 conditions, that is, no distension, gastric distension at discomfort threshold, and sham distension. Data were analyzed in SPM2. Region of interest analysis was used to confirm differences in prehypothesized regions.

RESULTS

No association between hypersensitivity and abuse history was found. Gastric hypersensitivity was associated with significantly higher gastric sensation scores during baseline and sham. A condition-independent difference in ventral posterior cingulate activity was found between groups, as well as distension and sham-specific differences in brainstem and cingulate areas. Abuse history was associated with higher gastric sensation scores in all conditions and with differences in insular, prefrontal, and hippocampus/amygdala activity.

CONCLUSIONS

Gastric sensitivity and abuse history independently influence gastric sensation as well as brain activity in FD.

Influence of naloxone on rectal sensorimotor function in health

Abnormal rectal motor physiology and visceral hypersensitivity are implicated in the pathogenesis of irritable bowel syndrome. Endogenous opioids are involved in both the regulation of gut motility and the processing of sensory information. Our aim was to study the effect of suppression of endogenous opioid function by naloxone on rectal sensorimotor function in health. Eighteen healthy subjects participated in a rectal barostat study. Sensorimotor function was evaluated during two consecutive stepwise distensions separated by 30 min of basal tone recording, and with perception scoring on a 0-6 graded scale. Naloxone was administered, after 15 min of basal tone measurements, as an intravenous bolus (0.4 mg), followed by continuous infusion (20 microg kg(-1) h(-1)) in a placebo-controlled, single-blinded and randomized fashion. Naloxone did not alter rectal sensitivity. Comparison of visual analogue scale scores between naloxone and saline did not reveal altered intensities of pain or discomfort. Compared to the baseline distension, a significant adaptive increase in compliance occurred during the second distension after saline (7.8 +/- 0.7 vs 11.0 +/- 0.6 mL mmHg(-1), P = 0.0016). This dynamic change in rectal compliance did not occur after naloxone administration (8.8 +/- 0.7 vs 10.1 +/- 0.8 mL mmHg(-1), ns). Low intensity tonic distension induced a rectal adaptive relaxation, which was absent after naloxone. Naloxone does not alter rectal sensitivity but abolishes rectal adaptation in response to repeated balloon distention. These observations suggest that the endogenous opioid system is involved in control of rectal tone rather than rectal sensitivity.

Cortical deactivations during gastric fundus distension in health: visceral pain-specific response or attenuation of 'default mode' brain function? A H2 15O-PET study

Gastric distension activates a cerebral network including brainstem, thalamus, insula, perigenual anterior cingulate, cerebellum, ventrolateral prefrontal cortex and potentially somatosensory regions. Cortical deactivations during gastric distension have hardly been reported. To describe brain areas of decreased activity during gastric fundus distension compared to baseline, using data from our previously published study (Gastroenterology, 128, 2005 and 564). H(2) (15)O-brain positron emission tomography was performed in 11 healthy volunteers during five conditions (random order): (C(1)) no distension (baseline); isobaric distension to individual thresholds for (C(2)) first, (C(3)) marked, (C(4)) unpleasant sensation and (C(5)) sham distension. Subtraction analyses were performed (in SPM2) to determine deactivated areas during distension compared to baseline, with a threshold of P(uncorrected_voxel_level) < 0.001 and P(corrected_cluster_level) < 0.05. Baseline-maximal distension (C(1)-C(4)) yielded significant deactivations in: (i) bilateral occipital, lateral parietal and temporal cortex as well as medial parietal lobe (posterior cingulate and precuneus) and medial temporal lobe (hippocampus and amygdala), (ii) right dorsolateral and dorso- and ventromedial PFC, (iii) left subgenual ACC and bilateral caudate head. Intragastric pressure and epigastric sensation score correlated negatively with brain activity in similar regions. The right hippocampus/amygdala deactivation was specific to sham. Gastric fundus distension in health is associated with extensive cortical deactivations, besides the activations described before. Whether this represents task-independent suspension of 'default mode' activity (as described in various cognitive tasks) or an visceral pain/interoception-specific process remains to be elucidated.

Influence of abuse history on gastric sensorimotor function in functional dyspepsia

Patients with functional gastrointestinal disorders have elevated rates of sexual or physical abuse, which may be associated with altered rectal sensorimotor function in irritable bowel syndrome. The aim was to study the association between abuse history and gastric sensorimotor function in functional dyspepsia (FD). We studied gastric sensorimotor function with barostat (sensitivity, compliance and accommodation) and gastric emptying test in 233 consecutive FD patients from a tertiary care centre (162 women, mean age 41.6 +/- 0.9). Patients filled out self-report questionnaires on history of sexual and physical abuse during childhood or adulthood. Eighty-four patients (out of 198, 42.4%) reported an overall history of abuse [sexual and physical in respectively 30.0% (60/200) and 20.3% (42/207)]. FD patients reporting general as well as severe childhood sexual abuse have significantly lower discomfort thresholds during gastric distension [respectively 10.5 +/- 0.4 vs 7.5 +/- 1.0 mmHg above minimal distending pressure (MDP), P = 0.014 and 10.5 +/- 0.4 vs 6.6 +/- 1.2 mmHg above MDP, P = 0.007]. The corresponding intra-balloon volume was also significantly lower (respectively 579 +/- 21 vs 422 +/- 59 mL, P = 0.013 and 579 +/- 19 vs 423 +/- 79 mL, P = 0.033). Gastric accommodation was significantly more pronounced in patients reporting rape during adulthood (91 +/- 12 vs 130 +/- 40 mL, P = 0.016). Abuse history was not associated with differences in gastric emptying. A history of abuse is associated with alterations in gastric sensorimotor function in FD. Particularly sexual abuse, rather than physical abuse, may influence gastric sensitivity and motor function.

Determinants of symptoms in functional dyspepsia: gastric sensorimotor function, psychosocial factors or somatisation?

BACKGROUND

Gastric sensorimotor dysfunction, psychosocial factors and somatisation are all implicated in symptom generation in functional dyspepsia (FD).

AIM

To determine the relative contribution of each of these factors to overall dyspeptic symptom severity and weight loss in FD.

METHODS

In 201 consecutive tertiary care patients with FD (mean age 40.1 (SD 12.6) years), gastric sensorimotor function was studied using barostat (sensitivity, compliance and accommodation). Psychosocial factors (depression and anxiety disorders, positive and negative affect, perceived stress, alexithymia and history of abuse), somatisation and co-morbid irritable bowel syndrome (IBS) and chronic fatigue symptoms were assessed using self-report questionnaires. Variables were correlated with dyspepsia symptom severity (DSS) and weight loss. Hierarchical multiple linear regression was used to identify determinants of DSS and weight loss.

RESULTS

Multiple linear regression identified the following determinants of DSS: gastric sensitivity (beta = 0.77, p = 0.25), depression (beta = 0.12, p = 0.06) and somatisation (beta = 0.48, p<0.0001) (controlling for age and occupation, R(2) = 0.29, p<0.0001). The effect of depression on DSS is partially mediated by somatisation. Gastric sensitivity (beta = 2.87, p = 0.08), history of childhood sexual abuse (beta = 9.37, p = 0.0006), depression (beta = 0.19, p = 0.24) and somatisation (beta = 0.67, p = 0.01) are independent determinants of weight loss (controlling for gender and occupation, R(2) = 0.42, p<0.0001). The effect of depression on weight loss is fully mediated by somatisation.

CONCLUSION

Symptom severity and weight loss in FD are determined by psychosocial factors (depression, abuse history) and somatisation, and only to a lesser extent by gastric sensorimotor function. The importance of psychosocial factors and somatisation compared to gastric sensorimotor function is most pronounced in hypersensitive patients.

Influence of experimentally induced anxiety on rectal sensorimotor function in healthy humans

Psychological processes, especially anxiety, may have an influence on visceral perception and gastrointestinal (GI) motor function, thereby eliciting or aggravating GI symptoms. Anxiety has been shown to affect gastric sensorimotor function but it is conceivable that anxiety affects not only the stomach but also other parts of the GI tract, such as the rectum. The aim of this study was to investigate whether experimentally induced anxiety would alter rectal sensorimotor function in health. Eighteen healthy subjects (mean age 26.97 +/- 1.75 years) underwent a rectal barostat study. To assess sensitivity to rectal distension and rectal compliance, stepwise isobaric distension was performed during anxious and neutral emotional state. Two methods of emotion induction were used simultaneously: audiotape assisted recall of a neutral or anxious autobiographical experience and viewing of a set of validated neutral or fearful facial expressions. Anxiety levels were assessed by means of the Spielberger State-Trait Anxiety Inventory (STAI) and anxiety scores on a Likert scale. Anxiety scores (AUC: 2.11 +/- 1.45 vs 42.78 +/- 6.17 mm mmHg, P < 0.0001) and STAI scores (36.06 +/- 2.09 vs 45.56 +/- 2.52, P = 0.005) confirmed the efficacy of anxiety induction. Rectal compliance was not different during anxious compared with neutral emotional state (11.62 +/- 0.93 vs 10.61 +/- 0.96 mL mmHg(-1), P = NS). Pressure and volume thresholds inducing discomfort during rectal distension were not significantly different during anxious and neutral emotional state (29.33 +/- 1.41 vs 29.78 +/- 1.49 mmHg, P = NS and 249.26 +/- 16.22 vs 231.38 +/- 21.19 mL, P = NS respectively). Contrary to its influence on gastric sensorimotor function, experimentally induced anxiety does not affect rectal sensitivity or rectal compliance in healthy subjects.

Role of endogenous opioids in the control of gastric sensorimotor function

Endogenous opioids have been implicated not only in the process of feeding but also in the control of gastric sensitivity and gastric motor responses, and impairment of antinociceptive opioid pathways has been hypothesized to contribute to the pathogenesis of functional dyspepsia. Our aim was to study the effect of suppression of endogenous opioid action by naloxone on gastric sensorimotor function in healthy volunteers. During intravenous administration of saline or naloxone (0.4 mg intravenous bolus followed by continuous infusion 20 microg kg(-1) h(-1)), sensitivity to gastric distension, gastric accommodation and fundic phasic contractility were evaluated by barostat in 15 subjects. Nutrient tolerance and meal-related symptoms were assessed using a satiety drinking test (n = 13), and solid and liquid gastric emptying were evaluated by breath test (n = 14). Naloxone did not influence gastric compliance and sensitivity. No effect on preprandial gastric tone was found but meal-induced accommodation was significantly inhibited by naloxone (P = 0.031). Subjects receiving naloxone demonstrated a higher motility index before (20.8 +/- 2.4 vs 28.0 +/- 1.9 mL s(-1), P = 0.007) and after (15.2 +/- 2.0 vs 22.7 +/- 1.5 mL s(-1), P = 0.0006) the meal. Naloxone significantly decreased the amount of food ingested at maximum satiety (715.4 +/- 77.7 vs 617.3 +/- 61.3 mL, P = 0.03). No effect of naloxone on gastric emptying was observed and intensity of postprandial symptoms was unchanged. These observations suggest that endogenous opioids are involved in the control of gastric accommodation and phasic contractility but not in the control of sensitivity to gastric distension or gastric emptying in healthy volunteers.

Functional dyspepsia: past, present, and future

Functional dyspepsia (FD) is a highly prevalent gastrointestinal disorder characterized by symptoms originating from the gastroduodenal region in the absence of underlying organic disease that readily explains the symptoms. The Rome II consensus, which defined FD as the presence of unexplained pain or discomfort in the epigastrium, had a number of drawbacks, including an unjustified focus on pain, inclusion of a large number of nonspecific symptoms, and an unclear position on overlap with gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS). The Rome III consensus redefined FD as the presence of epigastric pain or burning, postprandial fullness or early satiation in the absence of underlying organic disease. Frequent overlap with GERD and IBS is acknowledged but does not exclude a diagnosis of FD. A subgroup classification into postprandial distress syndrome and epigastric pain syndrome was proposed. Ongoing studies will clarify the impact of this subdivision on clinical management and treatment outcomes.

The role of somatosensory cortical regions in the processing of painful gastric fundic distension: an update of brain imaging findings

Painful gastric distension is processed in a network consisting of brainstem, thalamus, insula, anterior cingulate cortex, (lateral) orbitofrontal and prefrontal cortex, superior temporal cortex and cerebellum. However, the role of primary and secondary somatosensory cortical regions (SI/SII) in the processing of visceral sensation or pain in general and gastric sensation in particular remains unclear. The aim of this study was to localize activations in the SI/SII area from our previously published functional brain imaging studies on gastric distension more precisely, using newly available cytoarchitectonic probability maps of SI/SII, implemented in the SPM Anatomy toolbox. In healthy volunteers, we found two clusters to be overlapping with SII (mainly the OP4 subregion) and, to a lesser extent, SI, although this overlap was small in size. In functional dyspepsia patients, we found two clusters to be overlapping with SII (mainly OP4), of which the cluster in the right hemisphere also overlapped with SI. These findings were confirmed in a conjunction analysis of both groups. Activation in right SI/SII was significantly higher in healthy volunteers when formally compared to patients. These results provide more detailed information on the brain processing of gastric sensation, supporting the hypothesis that SI/SII are involved. This is in line with some previously published studies on visceral sensation, but at variance with some other studies. Methodological differences between the brain imaging studies on gastric distension may account for these somewhat discrepant findings.

Deguelin inhibits expression of IκBα protein and induces apoptosis of B-CLL cells in vitro

We investigated if deguelin, a naturally occurring rotenoid, was able to inhibit nuclear factor kappa B (NF-kappaB)-binding protein (IkappaBalpha) expression and to induce apoptosis in B-cell chronic lymphocytic leukemia (B-CLL) cells in vitro. Deguelin-induced cell death in the majority of B-CLL cells and was found to be more toxic toward B-CLL cells than to the normal mononuclear or B-cells, suggesting selectivity towards the malignant cells. Deguelin was found to reduce IkappaBalpha protein expression, and thus interacts with the NFkappaB pathway. The induced apoptosis was characterized by processing of caspase-9 and -3 and poly-(ADP)-ribose-polymerase cleavage. Exposure of B-CLL cells to deguelin resulted in Bcl2-associated protein (Bax) conformational changes and downregulation of the key survival protein myeloid cell leukemia sequence 1 (Mcl-1), which is associated with response to treatment in B-CLL patients. Deguelin retained its ability to induce apoptosis in B-CLL cells in the presence of interleukin-4, a pro-survival cytokine in B-CLL, and when cultured with 50% human serum. These data indicate that deguelin is able to induce apoptosis in B-CLL cells in the presence of pro-survival signals and thus merits further investigation for clinical application either as a single agent or in combination with other anticancer agents.

Relationship between anxiety and gastric sensorimotor function in functional dyspepsia

OBJECTIVE

To investigate the relationship between anxiety and gastric sensorimotor function in patients with (hypersensitive) functional dyspepsia (FD). Comorbidity between FD and anxiety disorders is high. In FD, epigastric pain is associated with gastric hypersensitivity and neuroticism, a personality trait related to anxiety. Experimentally induced anxiety in healthy volunteers is associated with changes in sensorimotor function of the proximal stomach.

METHODS

A total of 139 patients with FD (n = 102 women) underwent a barostat investigation to determine gastric compliance, meal accommodation, and thresholds for discomfort and pain. Anxiety was measured by the State-Trait Anxiety Inventory (STAI) scale (anxiety as a stable personality trait) and the STAI-State scale (momentary anxiety). The anxiety subscale of the Hospital Anxiety and Depression Scale (HADS-A) was filled out to detect comorbid anxiety disorders.

RESULTS

Hyper- and normosensitive patients had similar anxiety scores, but gastric compliance was significantly lower in hypersensitive patients (11.4 versus 32.8 ml/mm Hg; p < .001). In the whole patient group, no significant correlations between STAI scores and gastric sensorimotor function were found. In hypersensitive patients (n = 53, 43 women), state anxiety was negatively correlated with discomfort threshold (rho = -.49; p = .001), pain threshold (rho = -.48; p = .02), and gastric compliance (rho = -.46; p = .002). These results were confirmed by multiple linear and logistic regression analyses.

CONCLUSION

In hypersensitive patients with FD, state anxiety is significantly and negatively correlated with discomfort threshold, pain threshold, and compliance. These results strengthen the hypothesis that anxiety is important in FD, especially in hypersensitive patients.

Regional cerebral blood flow during gastric balloon distention in functional dyspepsia

BACKGROUND & AIMS

Hypersensitivity to proximal gastric distention as a result of abnormal central nervous system processing of visceral stimuli is a possible pathophysiologic mechanism in functional dyspepsia (FD). Increasing evidence suggests involvement of both lateral and medial pain systems in normal visceral sensitivity and aberrant brain activation patterns in visceral hypersensitivity. We hypothesized that there is involvement of aberrant brain activation in FD with hypersensitivity to gastric distention. Our aim was to investigate regional cerebral blood flow during painful proximal gastric distention in hypersensitive FD.

METHODS

Brain (15)O-water positron emission tomography was performed in 13 FD patients with symptoms of gastric hypersensitivity during 3 conditions: no distention, sham distention, and isobaric distention to unpleasant or painful sensation. Pain, discomfort, nausea, and bloating during maximal distention were rated on visual analogue scales. Data were analyzed using statistical parametric mapping.

RESULTS

The threshold for painful distention was 6.6 +/- 3.8 mm Hg greater than the minimal distending pressure. At the corrected P level of less than .05, subtraction analysis (painful distention - no distention) showed activations in bilateral gyrus precentralis, bilateral gyrus frontalis inferior, bilateral gyrus frontalis medialis, bilateral gyrus temporalis superior, bilateral cerebellar hemisphere, and left gyrus temporalis inferior. Sham distention minus no distention showed no activations.

CONCLUSIONS

Similar to healthy volunteers, proximal stomach distention in FD activates components of the lateral pain system and bilateral frontal inferior gyri, putatively involved in regulation of hunger and satiety. In hypersensitive FD, these activations occur at significantly lower distention pressures. In contrast to findings in normosensitivity, none of the components of the medial pain system were significantly activated.

Influence of experimentally induced anxiety on gastric sensorimotor function in humans

BACKGROUND & AIMS

Unexplained dyspeptic symptoms are associated with changes in gastric sensorimotor function and several psychopathologic dimensions, including anxiety. It is unclear whether this reflects common predisposition or a causal relationship. The aim of this study was to investigate whether experimentally induced anxiety would alter gastric sensorimotor function in health.

METHODS

Fourteen subjects underwent a gastric barostat study to assess gastric sensitivity and accommodation. Eighteen subjects underwent a 10-minute satiety drinking test (30 mL/min) with registration of epigastric symptoms on a visual analogue scale (VAS) at 2-minute intervals. Emotional context was modulated for 10 minutes at the start of each experiment by combined projection of validated facial expressions and an audiotape recalling a neutral or an anxious autobiographical experience. Anxiety levels were assessed using a VAS and the Spielberger State-Trait Anxiety Inventory (STAI).

RESULTS

VAS and STAI scores confirmed efficacy of anxiety induction. During the anxiety condition, gastric compliance was significantly decreased (57 +/- 5 vs 40 +/- 5 mL/mm Hg; P < .01). Intraballoon pressures inducing discomfort during gastric distention were not altered, but the corresponding volume (630 +/- 47 vs 489 +/- 39 mL; P < .005) was significantly lower. Meal-induced relaxation was inhibited during the anxiety condition and this persisted for the 60-minute measurement (157 +/- 29 vs 100 +/- 24 mL; P < .05). During the satiety drinking test, the anxiety condition was associated with significantly higher scores for satiety, fullness, and bloating.

CONCLUSIONS

Experimentally induced anxiety alters gastric sensorimotor function, suggesting that psychological factors may play a causal role in the pathogenesis of some dyspeptic symptoms and mechanisms.

Electrical impedance tomography systems based on voltage drive

At the ESAT-MICAS research facility in Leuven, several EIT systems have been designed and realised. The latest hardware set-up makes use of a PC to control the data collection and to reconstruct the images. A voltage drive strategy and no common-mode feedback are some of its specific characteristics. The function-generator produces signals with a frequency between 10 and 100 kHz, so multifrequency images can also be produced. Static images have already been obtained and (semi-)real time imaging is possible with our latest mark IV system. This system has 16 bit analogue-to-digital convertors and is capable of taking 50 x 10(3) samples/s.