Learned immunosuppressive placebo responses in renal transplant patients

Shaping Treatment Expectation to Optimize Efficacy of Interleukin 17A Antagonist Secukinumab in Psoriasis Patients

Purpose

Patients' treatment expectations significantly influence the effectiveness of medical and pharmacological treatments. This clinical proof-of-concept study aimed to enhance treatment outcomes by targeting positive treatment expectations of psoriasis patients beginning systemic anti-psoriatic therapy with secukinumab, an interleukin (IL)-17A antagonist.

Patients and Methods

We randomly assigned patients to three groups: a treatment as usual (TAU) group receiving the standard 300mg dose of secukinumab, a dose-control (DC) group with 75% dose reduction and an experimental (EXP) group receiving the same reduced dose along with a "cover story" designed to positively influence treatment expectations. We evaluated skin symptoms using the Psoriasis Area and Severity Index (PASI), the Dermatology Life Quality Index (DLQI), perceived itch, mood and plasma IL-17A levels at baseline and at 1, 2, 3, 4, 8, 12, and 16 weeks post intervention.

Results

The study included N = 120 patients (average age = 45.78 years, 34% female). A high baseline expectation level (8.1 of 10 points) was observed across all groups which could not be further increased by the EXP-group's "cover story". The EXP and DC groups did not differ with regard to reaching 75% improvement in PASI scores (PASI75), a DLQI score of 0 or 1 or at least 4 points improvement in itch. Over time, the EXP-group showed a faster decline in PASI scores and anxiety symptoms compared to the DC-group, but less improvement in quality of life. IL-17A levels significantly increased throughout the treatment, with no significant differences between groups despite the 75% dose reduction.

Conclusion

This study demonstrates an attempt to modify patients' treatment expectations to enhance the effectiveness of pharmacological therapy with secukinumab in psoriasis patients. However, verbal suggestion alone did not significantly improve clinical outcomes, suggesting that future studies should explore alternative approaches to leverage placebo effects to the benefit of patients with psoriasis.

"Powerful placebo": A teaching and learning concept addressing placebo and nocebo effects in competency-based communication training

Aim

Placebo and nocebo effects are based on expectations that are formed by how doctors communicate and can influence the efficacy of medical treatment. Given the implications for doctor-patient communication and the learning objectives listed in NKLM 2.0, we herein present a novel teaching and learning concept to impart competency-based knowledge about placebo and nocebo effects.

Method

The teaching and learning concept was piloted with N=324 third-semester medical students. It combines a self-guided, small-group component to gather communication strategies and apply them in a video-recorded conversation, followed by a classroom-based session to reflect on and discuss the videos and to learn basic scientific and theoretical knowledge. The evaluation involved written feedback from the students and lecturers (structure/process) and an analysis of the videos (students' learning success). To supplement this, the overall course evaluation was included since this new teaching concept was not specifically evaluated by the students.

Results

Course structure and process were rated positively. The active involvement of the students in the subject matter and the balance between theoretical, scientific and practical content was emphasized positively. Analysis of the learning success showed that the students were able to effectively transfer the knowledge gained about placebo and nocebo effects to conversational situations.

Conclusion

The topic of placebo/nocebo is optimally suited to teach communication skills with its many links to knowledge, translational approaches and added value for medical practice. When doing this, video-recorded conversations appear to be an effective tool to achieve learning objectives. This teaching and learning strategy offers possibilities for expanding communication curricula.

A social science: Using psychoneuroimmunology principles to promote career longevity, productivity, and meaning

Over the past several decades, psychoneuroimmunologists have uncovered key principles (e.g., social support and stress management) that can inform future research content and conduct. That is, psychoneuroimmunology (PNI) can inform how scientists from all disciplines engage in the scientific method in a more sustainable manner. Dr. Janice Kiecolt-Glaser, a PNI pioneer, recently ended her long and celebrated career. Her unique engagement in the scientific method, including her mentorship style, is worthy of closer examination. As her final graduate student, I observed Dr. Kiecolt-Glaser's science and mentorship style at their full maturity. Her scientific content, remarkable in its own right, is the subject of commentaries and accolades; yet, her scientific conduct - the foundation of her success and innovation - deserves further consideration. This article outlines ten research conduct principles that Dr. Kiecolt-Glaser explicitly and implicitly taught: (1) applying the literature to one's own health behaviors; (2) knowing and remembering "the why" behind the science; (3) developing and adhering to a vision; (4) creating a streamlined workflow; (5) embracing team science; (6) pursuing depth and breadth; (7) communicating ideas clearly; (8) engaging in a daily rhythm of science; (9) treating trainees like future primary investigators; and (10) working toward clinical meaningfulness. These principles correspond to PNI findings and account for her health and longevity as a scientist.

Working with patients' treatment expectations - what we can learn from homeopathy

The usual homeopathic remedy, "globules," does not contain any pharmacologically active ingredient. However, many patients and practitioners report beneficial effects of homeopathic treatment on various health outcomes. Experimental and clinical research of the last two decades analyzing the underlying mechanisms of the placebo effect could explain this phenomenon, with patients' treatment expectations as the predominant mechanism. Treatment expectations can be optimized through various factors, such as prior information, communication, and treatment context. This narrative review analyses how homeopathy successfully utilizes these factors. Subsequently, it is discussed what evidence-based medicine could learn from homeopathic practice to optimize treatment expectations (e.g., using an empathic, patient-centered communication style, deliberately selecting objects in practice rooms, or using clear treatment rituals and salient contextual stimuli) and thereby treatment effectiveness. Homeopathic remedy does not work beyond the placebo effect but is recommended or prescribed as an active treatment by those who believe in it. Thus, practitioners need to understand the manner in which homeopathy (as an example of inert treatment) works and are advised to reintegrate its underlying effective placebo mechanisms into evidence-based medicine. This promises to increase treatment efficacy, tolerability, satisfaction, and compliance with evidence-based treatments, and addresses the desires patients are trying to satisfy in homeopathy in an ethical, fully informed way that is grounded in evidence-based medicine.

The Effects of Fingolimod (FTY720) on Leukocyte Subset Circulation cannot be Behaviourally Conditioned in Rats

Suppression of immune functions can be elicited by behavioural conditioning using drugs such as cyclosporin A or rapamycin. Nevertheless, little is known about the underlying mechanisms and generalisability of this phenomenon. Against this background, the present study investigated whether the pharmacological properties of fingolimod (FTY720), an immunosuppressive drug widely applied to treat multiple sclerosis, can be conditioned in rats by means of taste-immune associative learning. For this purpose, a conditioned taste avoidance paradigm was used, pairing the presentation of a novel sweet drinking solution (saccharin or sucrose) as conditioned stimulus (CS) with therapeutically effective doses of FTY720 as unconditioned stimulus (US). Subsequent re-exposure to the CS at a later time point revealed that conditioning with FTY720 induced a mild conditioned taste avoidance only when saccharin was employed as CS. However, on an immunological level, neither re-exposure with saccharin nor sucrose altered blood immune cell subsets or splenic cytokine production. Despite the fact that intraperitonally administered FTY720 could be detected in brain regions known to mediate neuro-immune interactions, the present findings show that the physiological action of FTY720 is not inducible by mere taste-immune associative learning. Whether conditioning generalises across all small-molecule drugs with immunosuppressive properties still needs to be investigated with modified paradigms probably using distinct sensory CS. Moreover, these findings emphasize the need to further investigate the underlying mechanisms of conditioned immunomodulation to assess the generalisability and usability of associative learning protocols as supportive therapies in clinical contexts.

Learning by observing: a systematic exploration of modulatory factors and the impact of observationally induced placebo and nocebo effects on treatment outcomes

Introduction

Observational learning (OL) refers to learning through observing other people's behavior. OL has been suggested as an effective and simple tool to evoke treatment expectations and corresponding placebo and nocebo effects. However, the exact mechanisms by which OL shapes treatment outcomes, its moderating factors and possible areas of application remain unclear. We thus reviewed the existing literature with two different literature searches to answer the following questions: Which influencing factors contribute to OL-induced placebo and nocebo effects (in healthy volunteers and patients) and how large are these effects (search 1)? In which medical fields has OL been used so far to modulate treatment expectancy and treatment outcomes in patients, their caregivers, and at-risk groups (search 2)? We also aimed to explore whether and how the assessment of treatment expectations has been incorporated.

Methods

We conducted two independent and comprehensive systematic literature searches, both carried out on September 20, 2022.

Results

We identified 21 studies that investigated OL-mediated placebo and nocebo effects for pain and itch, the (placebo) efficacy of sham treatment on anxiety, and the (nocebo) induction of medication side effects (search 1). Studies showed that OL can efficiently induce placebo and nocebo effects across different presentation modes, with medium effect sizes on average: placebo effects, d = 0.79 (range: d = -0.36-1.58), nocebo effects, d = 0.61 (range: d = 0.04-1.5). Although several moderating factors have been investigated, their contribution to OL-induced effects remains unclear because of inconsistent results. Treatment expectation was assessed in only four studies. Regarding medical applications of OL (search 2), we found 12 studies. They showed that OL was effectively applied in preventive, therapeutic and rehabilitative interventions and that it was mainly used in the field of psychosomatics.

Discussion

OL effects on treatment outcomes can be both positive and negative. Future research should investigate which individuals would benefit most from OL and how OL can be implemented most effectively to induce placebo and avoid nocebo effects in clinical settings.

Systematic review registration

This work was preregistered at the Center for Open Science as open-ended registration (doi: 10.17605/OSF.IO/FVHKE). The protocol can be found here: https://archive.org/details/osf-registrations-fvhke-v1.

Can Pharmacological Conditioning as an Add-On Treatment Optimize Standard Pharmacological Treatment in Patients with Recent-Onset Rheumatoid Arthritis? A Proof-of-Principle Randomized Clinical Trial

Medication regimens using conditioning via variable reinforcement have shown similar or improved therapeutic effects as full pharmacological treatment, but evidence in patient populations is scarce. This proof-of-principle double-blind randomized clinical trial examined whether treatment effects in recent-onset rheumatoid arthritis (RA) can be optimized through pharmacological conditioning. After four months of standardized treatment (n = 46), patients in clinical remission (n = 19) were randomized to the Control group (C), continuing standardized treatment (n = 8), or the Pharmacological Conditioning (PC) group, receiving variable treatment according to conditioning principles (n = 11). After eight months, treatment was tapered and discontinued linearly (C) or variably (PC). Standard treatment led to large improvements in disease activity and HRQoL in both groups. The groups did not differ in the percentage of drug-free clinical remission obtained after conditioning or continued standard treatment. The PC group did show a larger decrease in self-reported disease activity (Cohen's d = 0.9) and a smaller increase in TNF-α levels (Cohen's d = 0.7) than the C group. During all phases, more differences between groups were found for the patients who followed protocol than for the intention-to-treat sample. Although the results are not conclusive, pharmacological conditioning may have some advantages in terms of disease progression and stability, especially during the conditioning phase, compared with standard clinical treatment. The effects may be particularly beneficial for patients who show a good initial response to increased medication dosages.

Placebo Effect and Its Determinants in Ocular Hypotensive Therapy: Meta-analysis and Multiple Meta-regression Analysis

TOPIC

The placebo effect and its potential determinants in ocular hypotensive therapy.

CLINICAL RELEVANCE

The placebo effect has been studied and documented within a wide clinical context. It remains unclear whether placebo is effective in glaucoma treatment or, if so, which factors are determinative of effect size (ES).

METHODS

Randomized controlled trials (RCTs) of topical ocular hypotensive therapy for patients with open-angle glaucoma or ocular hypertension, conducted through June 2, 2022, were included. First, a perceived placebo effect was measured as the overall intraocular pressure (IOP) change from the baseline. It was evaluated in terms of the ES (mean difference between the baseline and the end point) and then was compared with the ES, as obtained from the untreated control participant to obtain a true placebo effect. The primary outcome was ES based on 4 weeks of treatment. Meta-analysis-based statistical pooling was performed where appropriate, and 95% confidence intervals (CIs) were used for comparison. Potential placebo effect determinants were scrutinized using a multiple meta-regression model (PROSPERO identifier, CRD42022348098).

RESULTS

A total of 40 RCTs (7829 eyes) with 33 placebo groups (2055 eyes) along with 7 untreated groups (1184 eyes) were included. Among placebo-controlled trials, placebo was determined to be effective in lowering IOP (ES, -1.30 mmHg; 95% CI, -1.75 to -0.84 mmHg). Using NMA, the ES for placebo was -2.27 mmHg (95% CI, -3.52 to -1.01 mmHg) greater than ES for untreated control participants.. According to the multiple meta-regression model, the active treatment ES was a significant factor to predict the amount of placebo effect. Placebo additionally lowered IOP by -0.45 mmHg per -1 mmHg of active treatment effect. Add-on study design and larger sample size also were associated with greater amount of placebo effect. No publication bias was evident in either a funnel plot or the Begg and Mazumdar adjusted rank correlation test results (P = 0.24).

DISCUSSION

This meta-analysis indicated that placebo is effective in lowering IOP and is superior to the effect observed for the untreated control participants. However, caution is required in interpreting the results because of the small number of untreated controlled trials and potential bias from the lack of direct comparison between the placebo and untreated arms.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Placebo effects in osteoarthritis: implications for treatment and drug development

Osteoarthritis (OA) is the most common form of arthritis worldwide, affecting ~500 million people, yet there are no effective treatments to halt its progression. Without any structure-modifying agents, management of OA focuses on ameliorating pain and improving function. Treatment approaches typically have modest efficacy, and many patients have contraindications to recommended pharmacological treatments. Drug development for OA is hindered by the gradual and progressive nature of the disease and the targeting of established disease in clinical trials. Additionally, new medications for OA cannot receive regulatory approval without demonstrating improvements in both structure (pathological features of OA) and symptoms (reduced pain and/or improved function). In clinical trials, people with OA show high 'placebo responses', which hamper the ability to identify new effective treatments. Placebo responses refer to the individual variability in response to placebos given in the context of clinical trials and other settings. Placebo effects refer specifically to short-lasting improvements in symptoms that occur because of physiological changes. To mitigate the effects of the placebo phenomenon, we must first understand what it is, how it manifests, how to identify placebo responders in OA trials and how these insights can be used to improve clinical trials in OA. Leveraging placebo responses and effects in clinical practice might provide additional avenues to augment symptom management of OA.

Study protocol: randomised controlled trial of conditioned open-label placebo (COLP) for perioperative pain management in patients with head and neck cancer

INTRODUCTION

Patients with head and neck cancer have a substantial risk of chronic opioid dependence following surgery due to pain and psychosocial consequences from both the disease process and its treatments. Conditioned open-label placebos (COLPs) have been effective for reducing the dose of active medication required for a clinical response across a wide range of medical conditions. We hypothesise that the addition of COLPs to standard multimodal analgesia will be associated with reduced baseline opioid consumption by 5 days after surgery in comparison to standard multimodal analgesia alone in patients with head and neck cancer.

METHODS AND ANALYSIS

This randomised controlled trial will evaluate the use of COLP for adjunctive pain management in patients with head and neck cancer. Participants will be randomised with 1:1 allocation to either the treatment as usual or COLP group. All participants will receive standard multimodal analgesia, including opioids. The COLP group will additionally receive conditioning (ie, exposure to a clove oil scent) paired with active and placebo opioids for 5 days. Participants will complete surveys on pain, opioid consumption and depression symptoms through 6 months after surgery. Average change in baseline opioid consumption by postoperative day 5 and average pain levels and opioid consumption through 6 months will be compared between groups.

ETHICS AND DISSEMINATION

There remains a demand for more effective and safer strategies for postoperative pain management in patients with head and neck cancer as chronic opioid dependence has been associated with decreased survival in this patient population. Results from this study may lay the groundwork for further investigation of COLPs as a strategy for adjunctive pain management in patients with head and neck cancer. This clinical trial has been approved by the Johns Hopkins University Institutional Review Board (IRB00276225) and is registered on the National Institutes of Health Clinical Trials Database.

TRIAL REGISTRATION NUMBER

NCT04973748.

[Conditioning of the immune system-Already clinically usable?]

The brain and the immune system permanently exchange information via various neuronal and humoral signaling pathways. This communication network forms the basis for controlling peripheral immune functions via associative learning or conditioning processes. Establishing a learned immune reaction, an immunomodulatory drug that represents the unconditioned stimulus (US) is paired with a new odor or taste stimulus. Re-presentating this previously neutral odor or taste stimulus, its now functions as a conditioned stimulus (CS) and triggers reactions in the immune system similar to those formerly induced by the drug used as US. Using different learning protocols, it was possible to condition immunopharmacological effects in animal disease models, such as lupus erythematosus, contact allergy or rheumatoid arthritis, thereby reducing disease symptoms. Preliminary experimental studies in healthy volunteers and patients confirmed a possible clinical use of learned immune responses with the aim of using associative learning protocols as complementary measures to pharmacological interventions in clinical practice in order to reduce drug doses and thus undesirable drug side effects while maintaining therapeutic efficacy. However, there is still a great need for further research to understand the mechanisms of learned immune responses in preclinical studies and to optimize the associative learning processes for using them in the clinical routine in studies with healthy volunteers and patients.

Blinded Pain Cocktails: A Reliable and Safe Opioid Weaning Method

Weaning opioids in patients with noncancerous chronic pain often poses a challenge when psychosocial factors complicate the patient's chronic pain syndrome and opioid use. A blinded pain cocktail protocol used to wean opioid therapy has been described since the 1970s. At the Stanford Comprehensive Interdisciplinary Pain Program, a blinded pain cocktail remains a reliably effective medication-behavioral intervention. This review (1) outlines psychosocial factors that may complicate opioid weaning, (2) describes clinical goals and how to use blinded pain cocktails in opioid tapering, and (3) summarizes the mechanism of dose-extending placebos and ethical justification of its use in clinical practice.

The placebo effect in pharmacological treatment of obstructive sleep apnea, a systematic review and meta-analysis

OBJECTIVE

New drug treatments are under development in obstructive sleep apnea (OSA). The placebo effect is well recognized in various conditions, but its relevance in OSA is debated. In the current study we determined the influence of a placebo effect in studies of drug therapy in OSA.

METHODS

A systematic review and meta-analysis (PROSPERO CRD42021229410) with searches in MEDLINE, Scopus, Web of Science and Cochrane CENTRAL from inception to 2021-01-19. Inclusion criteria were (i) RCTs of adults with OSA, (ii) drug intervention with placebo baseline and follow-up sleep study (iii) outcomes: apnea hypopnea index (AHI), mean oxygen saturation (mSaO2), oxygen desaturation index (ODI) and/or Epworth Sleepiness Scale (ESS). Risk-of-bias was assessed with Cochrane RoB 2.

RESULTS

7436 articles were identified and 29 studies included (n = 413). Studies were generally small (median n = 14), with 78% men, baseline AHI range 9-74 events/h and treatment duration range 1-120 days. Meta-analyses were conducted for main outcomes. Mean change of the primary outcome, AHI, was -0.84 (95% CI -2.98 to 1.30); mSaO2 and ODI estimations were also non-significant. ESS showed a trend towards a reduction of -1 unit. Subgroup analysis did not show significant differences. Risk-of-bias assessment indicated mostly low risk but studies were small with wide confidence intervals.

CONCLUSIONS

In this meta-analysis we did not identify systematic placebo effects on the AHI, ODI or mSaO2 while ESS score showed a trend for a small reduction. These results have an impact on the design and interpretation of drug trials in OSA.

Effectiveness of Conditioned Open-label Placebo With Methadone in Treatment of Opioid Use Disorder: A Randomized Clinical Trial

Importance

Methadone treatment is the most effective evidence-based treatment for opioid use disorder (OUD), but challenges related to dosing and premature treatment dropout argue for adjunct interventions to improve outcomes. One potential behavioral intervention with low risk involves harnessing placebo effects.

Objective

To determine the effect of a pharmacologically conditioned open-label placebo (C-OLP) on 90-day methadone dose, retention, drug use, withdrawal, craving, quality of life, and sleep.

Design, Setting, and Participants

This 2-arm, open-label, single-blind randomized clinical trial was conducted between December 5, 2017, and August 2, 2019, in an academically affiliated community opioid treatment program. Analyses were conducted between October 1, 2019, and April 30, 2020. A total of 320 newly enrolled adults seeking treatment for moderate to severe OUD were assessed for study eligibility; 131 met eligibility criteria, provided informed consent, and were randomized to either C-OLP or treatment as usual (TAU) in an unequal-block (3:2) manner. Exclusion criteria were pregnancy, hospital/program transfers, and court-ordered treatment.

Interventions

Participants randomized to C-OLP received pharmacologic conditioning and a placebo pill and methadone, and participants randomized to TAU were given methadone only. Participants met with the study team 5 times: at baseline (treatment intake) and 2, 4, 8, and 12 weeks postbaseline. Interactions were balanced between the 2 groups.

Main Outcomes and Measures

Outcomes included 90-day methadone dose (primary) and treatment retention, drug use, withdrawal, craving, quality of life, and sleep quality (secondary). Analyses were conducted as intention-to-treat.

Results

Of the 131 people enrolled in the study, 54 were randomized to TAU and 77 to C-OLP. Mean (SD) age was 45.9 (11.2) years; most of the participants were Black or African American (83 [63.4%]) and male (84 [64.1%]). No significant group differences were observed in the mean (SD) 90-day methadone dose (83.1 [25.1] mg for group TAU, 79.4 [19.6] mg for group C-OLP; t = 0.621991; P = .43), but the groups differed significantly in their retention rates: 33 (61.1%) for TAU and 60 (77.9%) for C-OLP (χ21 = 4.356; P = .04; number needed to treat for the beneficial outcome of 3-month treatment retention, 6; 95% CI, 4-119). C-OLP participants also reported significantly better sleep quality.

Conclusions and Relevance

In this randomized clinical trial, C-OLP had no effect on the primary outcome of 90-day methadone dose. However, C-OLP participants were significantly more likely to remain in treatment. These findings support the use of C-OLP as a methadone treatment adjunct, but larger trials are needed to further examine the use of C-OLP.

Trial Registration

ClinicalTrials.gov Identifier: NCT02941809.

[Placebo effects in analgesia : Influence of expectations on the efficacy and tolerability of analgesic treatment]

Expectations of patients influence the perception and neuronal processing of acute and chronic pain and modulate the effectiveness of analgesic treatment. The expectation of treatment is not only the most important determinant of placebo analgesia. Expectations of treatment also influence the efficacy and tolerability of "active" pharmacological and non-pharmacological treatment of pain. Recent insights into the psychological and neurobiological mechanisms underlying the clinically relevant effects of treatment expectations enable and call for the systematic integration and modulation of treatment expectations into analgesic treatment concepts. Such a strategy promises to optimize analgesic treatment and to prevent or reduce the burden of unwanted side effects and the misuse of analgesics, particularly of opioids. This review highlights the current concepts, recent achievements and also challenges and key open research questions.

Behavioral factors to modulate immunotherapy efficacy in cancer

Immune checkpoint inhibitors, including anti-PD-1 and anti-CTLA-4 therapies, are used to (re)activate the immune system to treat cancer. Despite promising results, a large group of patients does not respond to checkpoint inhibition. In the vulnerability-stress model of behavioral medicine, behavioral factors, such as stress, exercise and classical pharmacological conditioning, predict cancer incidence, recurrence and the efficacy of conventional cancer treatments. Given the important role of the immune system in these processes, certain behavior may be promising to complement immune checkpoint inhibition therapy. Here, we discuss the preliminary evidence and suitability of three behavioral mechanisms, i.e. stress modulation, exercise and classical pharmacological conditioning for the benefit of immunotherapy. It is crucial to study the potential beneficial effects of behavioral strategies that support immunotherapeutic anti-tumor effects with rigorous experimental evidence, to exploit behavioral mechanisms in improving checkpoint inhibition efficacy.

Disgusting odors trigger the oral immune system

Recent research has characterized the behavioral defense against disease. In particular the detection of sickness cues, the adaptive reactions (e.g. avoidance) to these cues and the mediating role of disgust have been the focus. A presumably important but less investigated part of a behavioral defense is the immune system response of the observer of sickness cues. Odors are intimately connected to disease and disgust, and research has shown how olfaction conveys sickness cues in both animals and humans. This study aims to test whether odorous sickness cues (i.e. disgusting odors) can trigger a preparatory immune response in humans. We show that subjective and objective disgust measures, as well as TNFα levels in saliva increased immediately after exposure to disgusting odors in a sample of 36 individuals. Altogether, these results suggest a collaboration between behavioral mechanisms of pathogen avoidance in olfaction, mediated by the emotion of disgust, and mechanisms of pathogen elimination facilitated by inflammatory mediators. Disgusting stimuli are associated with an increased risk of infection. We here test whether disgusting odors, can trigger an immune response in the oral cavity. The results indicate an increase level of TNFα in the saliva. This supports that disease cues can trigger a preparatory response in the oral cavity.

Taste-immune associative learning amplifies immunopharmacological effects and attenuates disease progression in a rat glioblastoma model

Mechanistic target of rapamycin (mTOR)-signaling is one key driver of glioblastoma (GBM), facilitating tumor growth by promoting the shift to an anti-inflammatory, pro-cancerogenic microenvironment. Even though mTOR inhibitors such as rapamycin (RAPA) have been shown to interfere with GBM disease progression, frequently chaperoned toxic drug side effects urge the need for developing alternative or supportive treatment strategies. Importantly, previous work document that taste-immune associative learning with RAPA may be utilized to induce learned pharmacological placebo responses in the immune system. Against this background, the current study aimed at investigating the potential efficacy of a taste-immune associative learning protocol with RAPA in a syngeneic GBM rat model. Following repeated pairings of a novel gustatory stimulus with injections of RAPA, learned immune-pharmacological effects could be retrieved in GBM-bearing animals when re-exposed to the gustatory stimulus together with administering 10 % amount of the initial drug dose (0.5 mg/kg). These inhibitory effects on tumor growth were accompanied by an up-regulation of central and peripheral pro-inflammatory markers, suggesting that taste-immune associative learning with RAPA promoted the development of a pro-inflammatory anti-tumor microenvironment that attenuated GBM tumor growth to an almost identical outcome as obtained after 100 % (5 mg/kg) RAPA treatment. Together, our results confirm the applicability of taste-immune associative learning with RAPA in animal disease models where mTOR overactivation is one key driver. This proof-of-concept study may also be taken as a role model for implementing learning protocols as alternative or supportive treatment strategy in clinical settings, allowing the reduction of required drug doses and side effects without losing treatment efficacy.

Savor the flavor: A randomized double-blind study assessing taste-enhanced placebo analgesia in healthy volunteers

Placebo effects substantially contribute to analgesic treatment outcomes and might be leveraged to enhance gold-standard treatments. The taste of oral medications has been proposed to boost placebo effects. Here, we aimed at estimating how far the taste of an oral medication enhances placebo analgesia. We conducted a randomized, double-blind, between-group, single-visit study, with pre-treatment baseline. Over the course of three substudies, 318 healthy volunteers (297 included) were tested in a clinical trial setting. Participants were subjected to experimental tonic cold water pain (cold pressor test) before and after receiving taste-neutral (water), or bitter (quinine), or sweet (saccharin), or no placebo drops. Pre- versus post-treatment changes in area under the pain rating curve, the main outcome, indicated that placebo treatment showed a small analgesic effect versus no treatment. Added taste induced placebo enhancement in the very small effect size range, but accounted for a substantial portion of the overall placebo effect. No noteworthy advantage of sweet over bitter placebo was observed. An exploration of heart rate (HR) recordings indicated that placebo treatments were associated with an increase in peak HR-response to cold water, but these were not associated with placebo analgesia at an individual level. Placebo treatments were associated with minimal side effects. These results indicate that added taste may be an easy-to-implement, cost-effective, and safe way to optimize treatment outcomes and that taste-neutral preparations may reduce placebo-related outcome variance in clinical trials. Further studies are needed to test if these findings can be translated into clinical scenarios.

Experiences of Patients Taking Conditioned Open-Label Placebos for Reduction of Postoperative Pain and Opioid Exposure After Spine Surgery

BACKGROUND

Pain after spine surgery is difficult to manage, often requiring the use of opioid analgesics. While traditional "deceptive" or concealed placebo has been studied in trials and laboratory experiments, the acceptability and patient experience of taking honestly prescribed placebos, such as "open-label" placebo (non-deceptive placebo), or conditioned placebo (pairing placebo with another active pharmaceutical) is relatively unexamined.

METHODS

Qualitative thematic analysis was performed using semi-structured, post-treatment interviews with spine surgery patients (n = 18) who had received conditioned open-label placebo (COLP) during the first 2-3 weeks after surgery as part of a RCT. Interview transcripts were reviewed by 3 investigators using an immersion/crystallization approach, followed by iterative large-group discussions with additional investigators, to identify, refine, and codify emergent themes.

RESULTS

Patients' experiences and perceptions of COLP efficacy varied widely. Some emergent themes included the power of the mind over pain, how COLP might provide distraction from or agency over pain, bandwidth required and engagement with COLP, and its modulation of opioid tapering, as well as negative attitudes toward opioids and pill taking in general. Other themes included uncertainty about COLP efficacy, observations of how personality may relate to COLP efficacy, and a recognition of the greater impact of COLP on reduction of opioid use rather than on pain itself. Interestingly, participant uncertainty, disbelief, and skepticism were not necessarily associated with greater opioid consumption or worse pain.

CONCLUSION

Participants provided insights into the experience of COLP which may help to guide its future utilization to manage acute pain and tapering from opioids.

Even when you know it is a placebo, you experience less sadness: First evidence from an experimental open-label placebo investigation

BACKGROUND

Recent studies demonstrate substantial effects of deceptive placebo on experimentally induced sadness, even on autonomic activity. Whether deception is necessary, remains to be elucidated. We investigated the effect of an open-label placebo (OLP) treatment, i.e. an openly administered placebo delivered with a convincing rationale for its sadness-protecting effect.

METHODS

Eighty-four healthy females were randomized to an OLP group or a no-treatment control group. All participants received the same detailed information about the OLP effect, only the OLP group received an OLP nasal spray. Before and after the OLP intervention, participants underwent a sad mood induction procedure combining self-deprecating statements (Velten's method) and sad music. Sadness was assessed by the Positive and Negative Affect Schedule (PANAS-X). Autonomic activity was measured continuously.

RESULTS

Participants in the OLP group reported a significantly attenuated increase in sadness upon mood induction and less sadness after induction compared to the control group (d = 0.79). Regardless of intervention, heart rate decreased during mood inductions with a more pronounced deceleration in the second mood induction.

LIMITATIONS

Generalizability is limited due to the selective sample and the reliance on an experimentally controlled mood induction.

CONCLUSION

OLP treatment had a beneficial effect on perceived sadness, at least at the subjective level. Hence, deception may not necessarily be required for placebos to modulate experienced sad mood. Investigating the beneficial effects of OLP in (sub-)clinical samples would seem a promising and required next step towards a clinical use of placebo-associated positive treatment expectations.

Psycho-Neuro-Endocrine-Immunological Basis of the Placebo Effect: Potential Applications beyond Pain Therapy

The placebo effect can be defined as the improvement of symptoms in a patient after the administration of an innocuous substance in a context that induces expectations regarding its effects. During recent years, it has been discovered that the placebo response not only has neurobiological functions on analgesia, but that it is also capable of generating effects on the immune and endocrine systems. The possible integration of changes in different systems of the organism could favor the well-being of the individuals and go hand in hand with conventional treatment for multiple diseases. In this sense, classic conditioning and setting expectations stand out as psychological mechanisms implicated in the placebo effect. Recent advances in neuroimaging studies suggest a relationship between the placebo response and the opioid, cannabinoid, and monoaminergic systems. Likewise, a possible immune response conditioned by the placebo effect has been reported. There is evidence of immune suppression conditioned through the insular cortex and the amygdala, with noradrenalin as the responsible neurotransmitter. Finally, a conditioned response in the secretion of different hormones has been determined in different studies; however, the molecular mechanisms involved are not entirely known. Beyond studies about its mechanism of action, the placebo effect has proved to be useful in the clinical setting with promising results in the management of neurological, psychiatric, and immunologic disorders. However, more research is needed to better characterize its potential use. This review integrates current knowledge about the psycho-neuro-endocrine-immune basis of the placebo effect and its possible clinical applications.

Placebo and nocebo effects in transfusion medicine

BACKGROUND

Our own observations suggested that placebo and nocebo effects may occur with transfusions. However these effects seem to have been poorly studied.

OBJECTIVES

To examine published information on, and draw attention to the possibility of, placebo and nocebo effects with transfusion.

METHODS

Focused literature review.

RESULTS

There is some information on placebo effects with clotting factors and this effect appears modest at best. There is very little published information on this regarding other fresh blood components. Although unknown biologic effects cannot be ruled out, there are hints that placebo effects might operate - especially with red blood cell transfusions. There is practically no information on nocebo effects with transfusions.

CONCLUSIONS

There are ways of surmounting the practical and ethical difficulties involved, and obtaining better information on both types of effects. Individualised, contextualised, informed consenting of transfusion recipients may help to enhance placebo, and reduce nocebo, effects. This may be supportable ethically, and desirable clinically, and financially.

Placebo nasal spray protects female participants from experimentally induced sadness and concomitant changes in autonomic arousal

BACKGROUND

To investigate the powerful placebo effects in antidepressant drug trials and their mechanisms, recent pioneering experimental studies showed that expectation manipulation combined with an active placebo attenuated induced sadness. In the present study, we aimed at extending these findings by assessing the psychophysiological response in addition to mere self-report.

METHODS

One hundred and thirteen healthy female students were randomly assigned to a drug expectation group (active placebo, positive treatment expectation), placebo expectation group (active placebo, no treatment expectation), or a no-treatment group (no placebo, no treatment expectation). After placebo intake, sadness was induced by self-deprecating statements using the Velten method combined with sad music, including a rumination phase. Sadness was measured using the Positive and Negative Affect Schedule Expanded Form (PANAS-X). Heart rate and skin conductance were assessed continuously.

RESULTS

After mood induction and after rumination, self-reported sadness was significantly lower, and skin conductance level was significantly higher, in the drug expectation group than in the no-treatment group. The mood induction was further accompanied by a heart rate deceleration within all groups.

LIMITATIONS

Generalizability is limited by sample selectivity and focusing on sadness as a symptom of depression, exclusively.

CONCLUSION

Expectation-induced placebo effects significantly influenced sadness-correlated changes in autonomic arousal, and not only subjectively reported sadness, indicating that placebo effects in the context of affect are not merely due to subjective response bias. The systematic modification of treatment expectation could be utilized in clinical practice to optimize current therapeutic approaches to improve mood regulation.

Expectation-induced enhancement of pain, itch and quality of life in psoriasis patients: study protocol of a randomised controlled trial

INTRODUCTION

Experimental and clinical data demonstrate that skin diseases like psoriasis are affected by psychological factors and can be modulated by interventions other than conventional drug therapy. The expectation of patients towards the benefit of a forthcoming treatment as well as treatment pre-experiences have been demonstrated as crucial factors mediating placebo responses in inflammatory skin diseases. However, it is unknown whether and to what extent treatment outcomes of psoriasis patients under therapy with monoclonal antibodies like secukinumab can be experimentally modulated at subjective and physiological levels by modifying the expectation of patients via verbal instruction or prior experience.

METHODS AND ANALYSIS

Treatment expectations will be modulated in patients with moderate-to-severe psoriasis undergoing treatment with the anti-interleukin-17A monoclonal antibody secukinumab. Patients with a Psoriasis Area and Severity Index (PASI) >12 will be randomly allocated to one of three groups (N=40 each). As a standard schedule, patients in the pharmacological control group (group 1) will be treated weekly with 300 mg secukinumab, while patients in groups 2 and 3 will receive only 75 mg secukinumab (75% dose reduction) during all treatment weeks. In addition to the injections, patients in group 3 will ingest a novel tasting drink, with a cover story explaining that previous studies showed additional beneficial effects of this combination (drug and drink). Patients will be assessed and treated at nine visits over a 16-week period, during which the severity of pain and itch symptoms, skin lesions and quality of life will be analysed with standardised questionnaires and the PASI.

ETHICS AND DISSEMINATION

This study was approved by the Ethics committee of the Medical Faculty of the University Duisburg-Essen. Study outcomes will be published in peer-reviewed scientific journals.

Escalating morphine dosage fails to elicit conditioned analgesia in a preclinical chronic neuropathic pain model

Many people with chronic pain escalate their opioid dosage to counteract tolerance effects. A treatment regimen consisting of placebos admixed with opioids has been suggested as a possible therapeutic option that could reduce the harm of long-term opioid use. However, the analgesic efficacy of such a regimen requires further investigation before widespread adoption. We have recently reported that a 4-day pharmacological conditioning procedure, which paired morphine (6 mg/kg) with contextual cues, elicited placebo analgesia in subpopulations of male (35%) and female (25%) rats with sciatic nerve chronic constriction injury (CCI). Here, we investigated how an escalating morphine dosage during conditioning affects the incidence and strength of placebo analgesia. Forty-four male, Sprague-Dawley rats received CCI. Thirty-eight (86%) rats developed strong cold allodynia by day 6 post-surgery, as measured by hind paw withdrawal (HPW) behaviour on a 5°C cold plate (120 s). In this experiment, pharmacological conditioning consisted of an escalating morphine dose over 4 days (8/9/10/12 mg/kg). This dosing regimen produced strong reductions in HPW behaviour and counteracted the effects of morphine tolerance during conditioning. However, none of the rats given the placebo treatment (n = 12) demonstrated reductions in HPW behaviour when morphine was substituted for saline (i.e. placebo analgesia), but instead showed a strong behavioural response (rearing). These results demonstrate that a high, escalating dose of morphine failed to produce conditioned placebo analgesia in rats with CCI. It is possible that admixing placebos with opioids may be similarly ineffective in chronic pain patients when the opioids regimen is high or escalating.

[Treatment expectations for postoperative pain]

Hintergrund

Präoperative Behandlungserwartungen haben einen deutlichen Einfluss auf die postoperativen Schmerzen und Behandlungsergebnisse. Positive Erwartungen sind ein wichtiger Mechanismus von Placeboeffekten und negative Erwartungen ein wichtiger Mechanismus von Noceboeffekten.

Fragestellung

Welchen Einfluss haben Behandlungserwartungen, wie werden diese im klinischen Setting erhoben und wie können diese Erkenntnisse in der klinischen Praxis umgesetzt werden?

Material und Methoden

Es wurde eine Literatursuche für klinische Studien mit den Schlagwörtern „expectation“ AND („postoperative“ OR „surgery“) durchgeführt. Ausgewählt wurden alle aktuellen englischen und deutschen Artikel. Zusätzlich wurden die Literaturverzeichnisse der gefundenen Artikel untersucht und mit aufgenommen.

Ergebnisse

Insgesamt 158 Artikel wurden gefunden, von denen 49 Artikel Erwartungen erheben und ein postoperatives Behandlungsergebnis einbeziehen. Die meisten Artikel untersuchen Erwartungen in der Baseline-Erhebung, um nachzuweisen, dass sich Gruppen in Gruppenvergleichen präoperativ nicht voneinander unterscheiden. Die Studien, die den Einfluss von Erwartungen prospektiv untersuchen, verwenden sehr unterschiedliche Messverfahren, um das Konstrukt „Erwartung“ zu erheben. Somit ist ein Vergleich zwischen den Studien schwer möglich. Es gibt wenige Studien, die untersuchen, ob und wie die Erwartungen perioperativ beeinflusst werden können, und die praxisrelevante Interventionen zu deren Veränderung entwickelt haben.

Schlussfolgerung

Für eine fundierte Untersuchung der Behandlungserwartung sollten in klinischen Studien valide und reliable Messverfahren verwendet werden. Weitere Studien sollten sich mit Interventionsmöglichkeiten auseinandersetzen, damit Behandlungserwartungen auch in die klinische Standardbehandlung einbezogen werden können.

Conditioned open-label placebo for opioid reduction after spine surgery: a randomized controlled trial

ABSTRACT

Placebo effects have traditionally involved concealment or deception. However, recent evidence suggests that placebo effects can also be elicited when prescribed transparently as "open-label placebos" (OLPs), and that the pairing of an unconditioned stimulus (eg, opioid analgesic) with a conditioned stimulus (eg, placebo pill) can lead to the conditioned stimulus alone reducing pain. In this randomized control trial, we investigated whether combining conditioning with an OLP (COLP) in the immediate postoperative period could reduce daily opioid use and postsurgical pain among patients recovering from spine surgery. Patients were randomized to COLP or treatment as usual, with both groups receiving unrestricted access to a typical opioid-based postoperative analgesic regimen. The generalized estimating equations method was used to assess the treatment effect of COLP on daily opioid consumption and pain during postoperative period from postoperative day (POD) 1 to POD 17. Patients in the COLP group consumed approximately 30% less daily morphine milligram equivalents compared with patients in the treatment as usual group during POD 1 to 17 (-14.5 daily morphine milligram equivalents; 95% CI: [-26.8, -2.2]). Daily worst pain scores were also lower in the COLP group (-1.0 point on the 10-point scale; 95% CI: [-2.0, -0.1]), although a significant difference was not detected in average daily pain between the groups (-0.8 point; 95% CI: [-1.7, 0.2]). These findings suggest that COLP may serve as a potential adjuvant analgesic therapy to decrease opioid consumption in the early postoperative period, without increasing pain.

Explaining placebo effects in an online survey study: Does 'Pavlov' ring a bell?

OBJECTIVES

Despite the increasing knowledge about placebo effects and their beneficial impact on treatment outcomes, strategies that explicitly employ these mechanisms remain scarce. To benefit from placebo effects, it is important to gain better understanding in how individuals want to be informed about placebo effects (for example about the underlying mechanisms that steer placebo effects). The main aim of this study was to investigate placebo information strategies in a general population sample by assessing current placebo knowledge, preferences for different placebo explanations (built around well-known mechanisms involved in placebo effects), and attitudes and acceptability towards the use of placebo effects in treatment.

DESIGN

Online survey.

SETTING

Leiden, The Netherlands.

PARTICIPANTS

444 participants (377 completers), aged 16-78 years.

MAIN OUTCOME MEASURES

Current placebo knowledge, placebo explanation preferences, and placebo attitudes and acceptability.

RESULTS

Participants scored high on current placebo knowledge (correct answers: M = 81.15%, SD = 12.75). Comparisons of 8 different placebo explanations revealed that participants preferred explanations based on brain mechanisms and positive expectations more than all other explanations (F(7, 368) = 3.618, p = .001). Furthermore, attitudes and acceptability for placebos in treatment varied for the type of the condition (i.e. more acceptant for psychological complaints) and participants indicated that physicians do not always have to be honest while making use of placebo effects for therapeutic benefit.

CONCLUSION

Our results brought forth new evidence in placebo information strategies, and indicated that explanations based on brain mechanisms and positive expectations were most preferred. These results can be insightful to construct placebo information strategies for both clinical context and research practices.

The placebo phenomenon and the underlying mechanisms

The clinical role of the placebo effect is a topic of increasing interest for the scientific community. Focus is shifting from the inert role of placebos in randomized controlled trials (RCTs) to potential effects in clinical applications, since the phenomenon is thought to be inherent in routine clinical practice, affecting therapy success rates. Mediation of the mind-brain-body relationship involves both psychosocial and neurobiological factors, the interaction of which comprises the placebo mechanisms. Psychosocial factors include environmentally induced expectations, reward expectations, and even conditioned responses to certain stimuli. Expectations also depend on previous experience of the patient with a similar procedure and can affect future responses. Moreover, the supportive bedside behavior of the clinician and the positive framing of information provided to the patient have proven to be of great importance, setting the foundations for reconsideration of standardized practices. Neurobiological mechanisms mediate these effects through neurotransmitter and neuromodulator pathways. The best understood mechanisms are those regulating non-opioid- and opioid-mediated analgesic responses that implicate specific brain regions of pain control and activation of endogenous opioids. Other responses concern, among others, hormonal control, motor performance, and antidepressant responses. Although mechanisms underlying placebo responses are not as yet completely elucidated, there is substantial evidence suggesting that placebo effects are indicative of healthy functioning of intact brain structures and occur through actual functional changes, and are not simply subjective symptom reports. These effects can be utilized in treatment optimization while maintaining an ethical and respectful manner toward the patient and the standardized disclosure procedures.

Effects of Patients' Expectation in Dermatology: Evidence from Experimental and Clinical Placebo Studies and Implications for Dermatologic Practice and Research

Patients' expectations towards the benefit of a treatment are key determinants of placebo responses and can affect the development and course of medical conditions and the efficacy and tolerability of active medical treatment. The mechanisms mediating these placebo and nocebo effects have been best described in the field of experimental pain and placebo analgesia. However, also in dermatology experimental and clinical studies demonstrate that various skin diseases such as inflammatory dermatoses and allergic reactions can be modulated by patients' expectations. Dermatologists should consider the important modulatory role of patients' expectations on the efficacy and tolerability of specific treatments and the key role of verbal information, patients' prior treatment experiences (associative learning), and the quality and quantity of doctor-patient communication in shaping treatment expectation. As a consequence, techniques aiming at maximizing patients' expectation effects should be implemented into daily clinical routine. By contrast, in clinical studies expectation effects should be maximally controlled and harmonized to improve the "assay sensitivity" to detect new compounds. Further translational studies, also in dermatoses that have not been investigated yet, are needed to better characterize the mechanisms underlying patients' expectation and to gain further insights into potential clinical implications of these effects in dermatologic conditions. Therefore, in this review, we provide a brief overview on the concept of expectation effects on treatment outcome in general, summarize what is already known about this topic for dermatologic diseases, and finally present the relevance of this topic in clinical dermatology.

Research priorities for neuroimmunology: identifying the key research questions to be addressed by 2030

Neuroimmunology in the broadest sense is the study of interactions between the nervous and the immune systems. These interactions play important roles in health from supporting neural development, homeostasis and plasticity to modifying behaviour. Neuroimmunology is increasingly recognised as a field with the potential to deliver a significant positive impact on human health and treatment for neurological and psychiatric disorders. Yet, translation to the clinic is hindered by fundamental knowledge gaps on the underlying mechanisms of action or the optimal timing of an intervention, and a lack of appropriate tools to visualise and modulate both systems. Here we propose ten key disease-agnostic research questions that, if addressed, could lead to significant progress within neuroimmunology in the short to medium term. We also discuss four cross-cutting themes to be considered when addressing each question: i) bi-directionality of neuroimmune interactions; ii) the biological context in which the questions are addressed (e.g. health vs disease vs across the lifespan); iii) tools and technologies required to fully answer the questions; and iv) translation into the clinic. We acknowledge that these ten questions cannot represent the full breadth of gaps in our understanding; rather they focus on areas which, if addressed, may have the most broad and immediate impacts. By defining these neuroimmunology priorities, we hope to unite existing and future research teams, who can make meaningful progress through a collaborative and cross-disciplinary effort.

Der Placeboeffekt in der Schmerztherapie – für den klinischen Alltag nutzbar? Ja, unbedingt!

Als Placeboeffekte bezeichnet man positive physiologische oder psychologische Veränderungen, die nach einer Einnahme von Medikamenten ohne spezifischen Wirkstoff oder Scheineingriffen auftreten und durch Erwartungs- und Konditionierungsprozesse induziert werden. Die mit Placeboeffekten einhergehenden neurobiologischen und peripher-physiologischen Vorgänge können auch bei der Vergabe von wirkstoffhaltigen Medikamenten eine wichtige Rolle spielen und sind somit nicht zwingend an die Gabe eines Scheinmedikamentes gebunden. Die Darreichung von „traditionellen“ Placebos ist im klinischen Alltag aus juristischen und ethischen Gründen höchst problematisch. Dieser Beitrag zeigt neben neuen Erkenntnissen zu offenen Placebo-Anwendungen (Open-Label Placebos) Wege auf, wie die zugrundeliegenden Mechanismen von Placeboantworten dennoch gezielt im schmerztherapeutischen Alltag genutzt werden können, um die Wirksamkeit, Verträglichkeit und Compliance bestehender pharmakologischer und anderer Therapien zum Wohle des Patienten zu optimieren.

Placebos in chronic pain: evidence, theory, ethics, and use in clinical practice

Despite their ubiquitous presence, placebos and placebo effects retain an ambiguous and unsettling presence in biomedicine. Specifically focused on chronic pain, this review examines the effect of placebo treatment under three distinct frameworks: double blind, deception, and open label honestly prescribed. These specific conditions do not necessarily differentially modify placebo outcomes. Psychological, clinical, and neurological theories of placebo effects are scrutinized. In chronic pain, conscious expectation does not reliably predict placebo effects. A supportive patient-physician relationship may enhance placebo effects. This review highlights "predictive coding" and "bayesian brain" as emerging models derived from computational neurobiology that offer a unified framework to explain the heterogeneous evidence on placebos. These models invert the dogma of the brain as a stimulus driven organ to one in which perception relies heavily on learnt, top down, cortical predictions to infer the source of incoming sensory data. In predictive coding/bayesian brain, both chronic pain (significantly modulated by central sensitization) and its alleviation with placebo treatment are explicated as centrally encoded, mostly non-conscious, bayesian biases. The review then evaluates seven ways in which placebos are used in clinical practice and research and their bioethical implications. In this way, it shows that placebo effects are evidence based, clinically relevant, and potentially ethical tools for relieving chronic pain.

Learned Immunosuppressive Placebo Response Attenuates Disease Progression in a Rodent Model of Rheumatoid Arthritis

OBJECTIVE

Patients with chronic inflammatory autoimmune diseases benefit from a broad spectrum of immunosuppressive and antiproliferative medication available today. However, nearly all of these therapeutic compounds have unwanted toxic side effects. Recent knowledge about the neurobiology of placebo responses indicates that associative learning procedures can be utilized for dose reduction in immunopharmacotherapy while simultaneously maintaining treatment efficacy. This study was undertaken to examine whether and to what extent a 75% reduction of pharmacologic medication in combination with learned immunosuppression affects the clinical outcome in a rodent model of type II collagen-induced arthritis.

METHODS

An established protocol of taste-immune conditioning was applied in a disease model of chronic inflammatory autoimmune disease (type II collagen-induced arthritis) in rats, where a novel taste (saccharin; conditioned stimulus [CS]) was paired with an injection of the immunosuppressive drug cyclosporin A (CSA) (unconditioned stimulus [US]). Following conditioning with 3 CS/US pairings (acquisition), the animals were immunized with type II collagen and Freund's incomplete adjuvant. Fourteen days later, at the first occurrence of clinical symptoms, retrieval was started by presenting the CS together with low-dose CSA as reminder cues to prevent the conditioned response from being extinguished.

RESULTS

This "memory-updating" procedure stabilized the learned immune response and significantly suppressed disease progression in immunized rats. Clinical arthritis score and histologic inflammatory symptoms (both P < 0.05) were significantly diminished by learned immunosuppression in combination with low-dose CSA (25% of the full therapeutic dose) via β-adrenoceptor-dependent mechanisms, to the same extent as with full-dose (100%) pharmacologic treatment.

CONCLUSION

These results indicate that learned immunosuppression appears to be mediated via β-adrenoceptors and might be beneficial as a supportive regimen in the treatment of chronic inflammatory autoimmune diseases by diminishing disease exacerbation.

[The learned placebo response in the immune system]

The learned placebo response of the immune system is based on the mutual interaction between the brain and the immune system; both systems continually exchange information via humoral and neural communication pathways. This communication network enables the modification, i.e. suppression or stimulation, of peripheral immune functions by classical or Pavlov's conditioning. The present article provides an overview of the results of recent experimental animal studies, which also document the potential clinical relevance of learned immune responses. Learned immunological responses mediated by classical conditioning have also been demonstrated in humans. The knowledge gained from experimental data and clinical observations paves the way for a potential implementation of learned immune responses as supportive measures to standard immunopharmacological treatment strategies to reduce drug dosage as well as adverse side effects while simultaneously maximizing the therapeutic effect.

Conditioning open-label placebo: a pilot pharmacobehavioral approach for opioid dose reduction and pain control

Opioid consumption for those in comprehensive inpatient rehabilitation units is high because of the complexity of their injuries. Notably, pain in rehabilitation leads to worsened clinical outcomes because of maladaptive behaviors and poor engagement during therapies. It is critical to developing evidence-based pharmacobehavioral interventions. Based on principles of classical conditioning, conditioning open-label placebo (COLP) is a promising approach for reducing opioid use in comprehensive inpatient rehabilitation, and this technique takes advantage of the possibility of association learning and opioid pharmacology to promote evoked placebo-driven analgesia.

OBJECTIVES

In this brief report, we evaluate the feasibility of COLP as a pharmacobehavioral intervention to decrease total opioid consumption in patients with pain hospitalized at Spaulding Rehabilitation Hospital.

METHODS

Inpatients with spinal cord injury and polytrauma (n = 20) with moderate to severe pain were randomized to receive COLP (n = 10) or treatment-as-usual for 6 consecutive days. Opioid utilization was measured by morphine equivalents using the morphine equivalent dose conversion; pain severity was assessed using the numerical visual analog scale.

RESULTS

Conditioning open-label placebo significantly reduced total opioid consumption by the end of the intervention period (P ≤ 0.001). Pain reduction was also significant for the COLP group (P = 0.005), whereas the treatment-as-usual group demonstrated a trend towards pain reduction (P = 0.05).

CONCLUSIONS

This study presents the first data in the use of a pharmacobehavioral intervention that capitalize on the benefits of open-label placebo and classical drug conditioning for opioid dose reduction in a population with moderate to severe pain exposed to intensive inpatient rehabilitation.

Dose-Dependent Acute Effects of Everolimus Administration on Immunological, Neuroendocrine and Psychological Parameters in Healthy Men

The rapamycin analogue everolimus (EVR) is a potent inhibitor of the mammalian target of rapamycin (mTOR) and clinically used to prevent allograft rejections as well as tumor growth. The pharmacokinetic and immunosuppressive efficacy of EVR have been extensively reported in patient populations and in vitro studies. However, dose-dependent ex vivo effects upon acute EVR administration in healthy volunteers are rare. Moreover, immunosuppressive drugs are associated with neuroendocrine changes and psychological disturbances. It is largely unknown so far whether and to what extend EVR affects neuroendocrine functions, mood, and anxiety in healthy individuals. Thus, in the present study, we analyzed the effects of three different clinically applied EVR doses (1.5, 2.25, and 3 mg) orally administered 4 times in a 12-hour cycle to healthy male volunteers on immunological, neuroendocrine, and psychological parameters. We observed that oral intake of medium (2.25 mg) and high doses (3 mg) of EVR efficiently suppressed T cell proliferation as well as IL-10 cytokine production in ex vivo mitogen-stimulated peripheral blood mononuclear cell. Further, acute low (1.5 mg) and medium (2.25 mg) EVR administration increased state anxiety levels accompanied by significantly elevated noradrenaline (NA) concentrations. In contrast, high-dose EVR significantly reduced plasma and saliva cortisol as well as NA levels and perceived state anxiety. Hence, these data confirm the acute immunosuppressive effects of the mTOR inhibitor EVR and provide evidence for EVR-induced alterations in neuroendocrine parameters and behavior under physiological conditions in healthy volunteers.

Primary care providers' use of and attitudes towards placebos: An exploratory focus group study with US physicians

OBJECTIVE

To examine how primary care physicians define placebo concepts, use placebos in clinical practice, and view open-label placebos (OLPs).

DESIGN

Semi-structured focus groups that were audio-recorded and content-coded.

METHODS

Two focus groups with a total of 15 primary care physicians occurred at medical centres in the New England region of the United States. Prior experience using placebo treatments and attitudes towards open-label placebos were explored. Themes were analysed using an inductive data-driven approach.

RESULTS

Physicians displayed a nuanced understanding of placebos and placebo effects in clinical contexts which sometimes focused on relational factors. Some respondents reported that they prescribed treatments with no known pharmacological effect for certain conditions and symptoms ('impure placebos') and that such prescriptions were more common for pain disorders, functional disorders, and medically unexplained symptoms. Opinions about OLP were mixed: Some viewed OLPs favourably or considered them 'harmless'; however, others strongly rejected OLPs as disrespectful to patients. Other issues in relation to OLPs included the following: lack of guidelines, legal and reputational concerns, and the notion that such treatments would run counter to customary medical practice.

CONCLUSIONS

A number of physicians reported prescribing impure placebos in clinical care. Although some primary care physicians were resistant to the possibility of recommending OLPs, others regarded OLPs more favourably, viewing them as potential treatments, albeit with restricted potential. Statement of contribution What is already known? Many physicians report prescribing drugs for the purposes of eliciting a placebo effect. Initial evidence for the efficacy of open-label placebos is promising. What does this study add? A more nuanced description of the circumstances under which primary care physicians report placebo prescribing. A qualitative account of physician attitudes about using open-label placebos in clinical practice.

Behavioral Conditioning, the Placebo Effect, and Emergency Department Pain Management

Animals and humans can be readily conditioned to associate a novel stimulus (often a unique taste) by pairing it with the effects of a drug or other agent. When later presented with the stimulus alone, their body's systems respond as if the drug or agent were given. The earliest clinical applications demonstrated both conditioned suppression and enhancement of immune processes. Unique benign stimuli, paired with chemotherapy, come to elicit T-cell suppression when administered alone. The beneficial immune responses to an antigen can be conditioned in the same manner. Further study of what came to be called "psychoneuroimmunology" led to the understanding that the familiar placebo effect, previously attributed to suggestion and expectation, is at least equally dependent on the same sorts of behavioral conditioning. The demonstrated ability to manipulate the immune system by a conditioned taste stimulus is, by definition, a placebo: a therapeutic effect caused by an inactive agent. The purpose of this analysis was to stimulate research in, and the application of, placebo-response conditioning to emergency medicine. Clinical and experimental studies confirm the usefulness of conditioned placebos in analgesia and in placebo-controlled dose reduction. Such conditioning paradigms demonstrate "one-trial learning," making them potentially useful in pain and addiction management within a single emergency department encounter.

Human sleep consolidates allergic responses conditioned to the environmental context of an allergen exposure

Allergies are highly prevalent, and allergic responses can be triggered even in the absence of allergens due to Pavlovian conditioning to a specific cue. Here we show in humans suffering from allergic rhinitis that merely reencountering the environmental context in which an allergen was administered a week earlier is sufficient to trigger an allergic response-but only if participants had slept after allergen exposure. This context-conditioning effect was entirely absent when participants stayed awake the night after allergen exposure or were tested in a different context. Unlike in context conditioning, cue conditioning (to an odor stimulus) occurred independently of sleep, a differential pattern that is likewise observed for conditioning in the behavioral domain. Our findings provide evidence that allergic responses can be conditioned to contextual information alone, even after only a single-trial conditioning procedure, and that sleep is necessary to consolidate this rapidly acquired maladaptive response. The results unravel a mechanism that could explain part of the strong psychological impact on allergic responses.

Effects of oxytocin administration and conditioned oxytocin on brain activity: An fMRI study

It has been demonstrated that secretion of several hormones can be classically conditioned, however, the underlying brain responses of such conditioning have never been investigated before. In this study we aimed to investigate how oxytocin administration and classically conditioned oxytocin influence brain responses. In total, 88 females were allocated to one of three groups: oxytocin administration, conditioned oxytocin, or placebo, and underwent an experiment consisting of three acquisition and three evocation days. Participants in the conditioned group received 24 IU of oxytocin together with a conditioned stimulus (CS) during three acquisition days and placebo with the CS on three evocation days. The oxytocin administration group received 24 IU of oxytocin and the placebo group received placebo during all days. On the last evocation day, fMRI scanning was performed for all participants during three tasks previously shown to be affected by oxytocin: presentation of emotional faces, crying baby sounds and heat pain. Region of interest analysis revealed that there was significantly lower activation in the right amygdala and in two clusters in the left superior temporal gyrus in the oxytocin administration group compared to the placebo group in response to observing fearful faces. The activation in the conditioned oxytocin group was in between the other two groups for these clusters but did not significantly differ from either group. No group differences were found in the other tasks. Preliminary evidence was found for brain activation of a conditioned oxytocin response; however, despite this trend in the expected direction, the conditioned group did not significantly differ from other groups. Future research should, therefore, investigate the optimal timing of conditioned endocrine responses and study whether the findings generalize to other hormones as well.

Pharmacological conditioning for juvenile idiopathic arthritis: a potential solution to reduce methotrexate intolerance

BACKGROUND

Methotrexate (MTX) therapy has proven to be a successful and safe treatment for Juvenile Idiopathic Arthritis (JIA). Despite the high efficacy rates of MTX, treatment outcomes are often complicated by burdensome gastro-intestinal side effects. Intolerance rates for MTX in children are high (approximately 50%) and thus far no conclusive effective treatment strategies to control for side effects have been found. To address this need, this article proposes an innovative research approach based on pharmacological conditioning, to reduce MTX intolerance.

PRESENTATION OF THE HYPOTHESIS

A collaboration between medical psychologists, pediatric rheumatologists, pharmacologists and patient groups was set up to develop an innovative research design that may be implemented to study potential improved control of side effects in JIA, by making use of the psychobiological principles of pharmacological conditioning. In pharmacological conditioning designs, learned positive associations from drug therapies (conditioning effects) are integrated in regular treatment regimens to maximize treatment outcomes. Medication regimens with immunosuppressant drugs that made use of pharmacological conditioning principles have been shown to lead to optimized therapeutic effects with reduced drug dosing, which might ultimately cause a reduction in side effects.

TESTING THE HYPOTHESIS

This research design is tailored to serve the needs of the JIA patient group. We developed a research design in collaboration with an interdisciplinary research group consisting of patient representatives, pediatric rheumatologists, pharmacologists, and medical psychologists.

IMPLICATIONS OF THE HYPOTHESIS

Based on previous experimental and clinical findings of pharmacological conditioning with immune responses, we propose that the JIA patient group is particularly suited to benefit from a pharmacological conditioning design. Moreover, findings from this study may potentially also be promising for other patient groups that endure long-lasting drug therapies.

Pavlovian Conditioning of Immunological and Neuroendocrine Functions

The phenomenon of behaviorally conditioned immunological and neuroendocrine functions has been investigated for the past 100 yr. The observation that associative learning processes can modify peripheral immune functions was first reported and investigated by Ivan Petrovic Pavlov and his co-workers. Their work later fell into oblivion, also because so little was known about the immune system’s function and even less about the underlying mechanisms of how learning, a central nervous system activity, could affect peripheral immune responses. With the employment of a taste-avoidance paradigm in rats, this phenomenon was rediscovered 45 yr ago as one of the most fascinating examples of the reciprocal functional interaction between behavior, the brain, and peripheral immune functions, and it established psychoneuroimmunology as a new research field. Relying on growing knowledge about efferent and afferent communication pathways between the brain, neuroendocrine system, primary and secondary immune organs, and immunocompetent cells, experimental animal studies demonstrate that cellular and humoral immune and neuroendocrine functions can be modulated via associative learning protocols. These (from the classical perspective) learned immune responses are clinically relevant, since they affect the development and progression of immune-related diseases and, more importantly, are also inducible in humans. The increased knowledge about the neuropsychological machinery steering learning and memory processes together with recent insight into the mechanisms mediating placebo responses provide fascinating perspectives to exploit these learned immune and neuroendocrine responses as supportive therapies, the aim being to reduce the amount of medication required, diminishing unwanted drug side effects while maximizing the therapeutic effect for the patient’s benefit.