Review article: consensus statements on therapeutic drug monitoring of anti-tumour necrosis factor therapy in inflammatory bowel diseases

BACKGROUND

Therapeutic drug monitoring (TDM) in inflammatory bowel disease (IBD) patients receiving anti-tumour necrosis factor (TNF) agents can help optimise outcomes. Consensus statements based on current evidence will help the development of treatment guidelines.

AIM

To develop evidence-based consensus statements for TDM-guided anti-TNF therapy in IBD.

METHODS

A committee of 25 Australian and international experts was assembled. The initial draft statements were produced following a systematic literature search. A modified Delphi technique was used with 3 iterations. Statements were modified according to anonymous voting and feedback at each iteration. Statements with 80% agreement without or with minor reservation were accepted.

RESULTS

22/24 statements met criteria for consensus. For anti-TNF agents, TDM should be performed upon treatment failure, following successful induction, when contemplating a drug holiday and periodically in clinical remission only when results would change management. To achieve clinical remission in luminal IBD, infliximab and adalimumab trough concentrations in the range of 3-8 and 5-12 μg/mL, respectively, were deemed appropriate. The range may differ for different disease phenotypes or treatment endpoints-such as fistulising disease or to achieve mucosal healing. In treatment failure, TDM may identify mechanisms to guide subsequent decision-making. In stable clinical response, TDM-guided dosing may avoid future relapse. Data indicate drug-tolerant anti-drug antibody assays do not offer an advantage over drug-sensitive assays. Further data are required prior to recommending TDM for non-anti-TNF biological agents.

CONCLUSION

Consensus statements support the role of TDM in optimising anti-TNF agents to treat IBD, especially in situations of treatment failure.

Workplace interventions for common mental disorders: a systematic meta-review

Depression and anxiety disorders are the leading cause of sickness absence and long-term work incapacity in most developed countries. The present study aimed to carry out a systematic meta-review examining the effectiveness of workplace mental health interventions, defined as any intervention that a workplace may either initiate or facilitate that aims to prevent, treat or rehabilitate a worker with a diagnosis of depression, anxiety or both. Relevant reviews were identified via a detailed systematic search of academic and grey literature databases. All articles were subjected to a rigorous quality appraisal using the AMSTAR assessment. Of the 5179 articles identified, 140 studies met the inclusion criteria, of which 20 were deemed to be of moderate or high quality. Together, these reviews analysed 481 primary research studies. Moderate evidence was identified for two primary prevention interventions; enhancing employee control and promoting physical activity. Stronger evidence was found for CBT-based stress management although less evidence was found for other secondary prevention interventions, such as counselling. Strong evidence was also found against the routine use of debriefing following trauma. Tertiary interventions with a specific focus on work, such as exposure therapy and CBT-based and problem-focused return-to-work programmes, had a strong evidence base for improving symptomology and a moderate evidence base for improving occupational outcomes. Overall, these findings demonstrate there are empirically supported interventions that workplaces can utilize to aid in the prevention of common mental illness as well as facilitating the recovery of employees diagnosed with depression and/or anxiety.

Dissociative responses to conscious and non-conscious fear impact underlying brain function in post-traumatic stress disorder

BACKGROUND

Dissociative reactions in post-traumatic stress disorder (PTSD) have been regarded as strategic responses that limit arousal. Neuroimaging studies suggest distinct prefrontal responses in individuals displaying dissociative and hyperarousal responses to threat in PTSD. Increased prefrontal activity may reflect enhanced regulation of limbic arousal networks in dissociation. If dissociation is a higher-order regulatory response to threat, there may be differential responses to conscious and automatic processing of threat stimuli. This study addresses this question by examining the impact of dissociation on fear processing at different levels of awareness.

METHOD

Functional magnetic resonance imaging (fMRI) with a 1.5-T scanner was used to examine activation to fearful (versus neutral) facial expressions during consciously attended and non-conscious (using backward masking) conditions in 23 individuals with PTSD. Activation in 11 individuals displaying non-dissociative reactions was compared to activation in 12 displaying dissociative reactions to consciously and non-consciously perceived fear stimuli.

RESULTS

Dissociative PTSD was associated with enhanced activation in the ventral prefrontal cortex for conscious fear, and in the bilateral amygdala, insula and left thalamus for non-conscious fear compared to non-dissociative PTSD. Comparatively reduced activation in the dissociative group was apparent in dorsomedial prefrontal regions for conscious fear faces.

CONCLUSIONS

These findings confirm our hypotheses of enhanced prefrontal activity to conscious fear and enhanced activity in limbic networks to non-conscious fear in dissociative PTSD. This supports the theory that dissociation is a regulatory strategy invoked to cope with extreme arousal in PTSD, but this strategy appears to function only during conscious processing of threat.

Cognitive development in macaques: Attentional set-shifting in juvenile and adult rhesus monkeys

In humans and nonhuman primates, the structure and function of frontal cortical regions of the brain are not completely developed until early adulthood. How this cortical development affects cognitive function continues to be elucidated. To that end, this experiment tested the ability of juvenile and adult rhesus monkeys to perform a cognitive task that is dependent upon intact frontal cortical function for optimal performance. Twenty-four juvenile (mean age 2.3 years) and 16 adult (mean age 10.3 years) rhesus monkeys were tested on the Cambridge Neuropsychological Test Automated Battery intradimensional/extradimensional set-shifting (ID/ED) task. Performance on the ID/ED task has been shown to be dependent upon frontal cortical function in both humans and nonhuman primates. Compared with adults, juveniles were impaired on the reversal of simple discrimination, intradimensional shift, reversal of intradimensional shift, and the extradimensional shift stages of the task. These results indicate juveniles committed more perseverative errors and more errors on the set-formation and set-shifting components of the ID/ED task. The developmental stage of the juvenile monkeys corresponds to roughly 5 to 6-year-old children, and these results are consistent with performance of human children and adults on similar ID/ED tests and on several other tests of attentional set-shifting or attentional flexibility. Furthermore, these results are consistent with the ongoing development of frontal cortical structures relating to ongoing cognitive development in nonhuman primates.

Re-assessing the relationship between cholesterol, statins and Alzheimer's disease

This communication integrates the purported role of cholesterol and statins in Alzheimer's disease (AD) with recent data. Meta-analysis of association studies relevant to AD indicates that apolipoprotein (apo)E4 is the only cholesterol-related polymorphism that shows clear association with AD. This suggests that the effect of apoE4 on the pathophysiology of AD occurs via a mechanism that is not directly related to cholesterol, such as fibrillization of Abeta. Despite the lack of genetic association, cholesterol and statins clearly modulate amyloid precursor protein (APP) processing in cell culture and animal models. Statins appear to act by a pleiotropic mechanism, involving both cholesterol (via lipid rafts) and isoprenylation. The pleiotropic mechanism of statin action clarifies conflicting data from clinical studies, where statins exert an action on Abeta and AD that might be dose dependent because of actions on both cholesterol and isoprenylation. Reduced isoprenylation can also inhibit inflammation. Our own studies of brains from Alzheimer subjects +/- statins indicate that statins inhibit inflammation in humans but might not reduce cerebral Abeta load. These results suggest that the primary action of statins in humans with AD might be to reduce inflammation rather than decrease Abeta load.