1
|
Skvortsova A, Meeuwis SH, Derksen S, Kerkkänen K, Sutter E, Evers AWM, Veldhuijzen DS. The role of self-reported and physiological stress in nocebo hyperalgesia. Biol Psychol 2024; 190:108818. [PMID: 38762001 DOI: 10.1016/j.biopsycho.2024.108818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 05/03/2024] [Accepted: 05/14/2024] [Indexed: 05/20/2024]
Abstract
Negative expectations can increase pain sensitivity, leading to nocebo hyperalgesia. However, the physiological and psychological factors that predispose individuals to this phenomenon are still not well understood. The present study examined whether stress induced by a social stressor affects nocebo hyperalgesia, and whether this effect is mediated by self-reported and physiological stress responses. We recruited 52 healthy participants (15 men) who were randomly assigned to either the Trier Social Stress Test (TSST) or a control condition (a friendly version of the TSST). Nocebo hyperalgesia was induced using negative suggestions combined with a validated pain conditioning paradigm. We assessed self-reported (anxiety and stress) and physiological (cortisol, alpha-amylase, heart rate, and skin conductance) responses to stress. Both groups exhibited significant nocebo hyperalgesia. The stress group showed higher levels of anxiety, self-reported stress, and cortisol levels compared to the control group while no significant differences were found in other physiological markers. The stress and control groups did not differ in the magnitude of nocebo hyperalgesia, but anxiety levels partially mediated the effects of the stress test on nocebo hyperalgesia. Our findings suggest that an external social stressor does not directly affect nocebo hyperalgesia, but that increased anxiety due to the stressor enhances its magnitude. Thus, it may be worthwhile to investigate whether reducing stress-related anxiety in clinical settings would help alleviate nocebo effects.
Collapse
Affiliation(s)
- A Skvortsova
- Health, Medical and Neuropsychology unit, Faculty of Social and Behavioural Sciences, Leiden University, the Netherlands.
| | - S H Meeuwis
- Health, Medical and Neuropsychology unit, Faculty of Social and Behavioural Sciences, Leiden University, the Netherlands.
| | - S Derksen
- Health, Medical and Neuropsychology unit, Faculty of Social and Behavioural Sciences, Leiden University, the Netherlands.
| | - K Kerkkänen
- Health, Medical and Neuropsychology unit, Faculty of Social and Behavioural Sciences, Leiden University, the Netherlands.
| | - E Sutter
- Health, Medical and Neuropsychology unit, Faculty of Social and Behavioural Sciences, Leiden University, the Netherlands.
| | - A W M Evers
- Health, Medical and Neuropsychology unit, Faculty of Social and Behavioural Sciences, Leiden University, the Netherlands; Department of Psychiatry, Leiden University Medical Center, Leiden, the Netherlands; Medical Delta, Leiden University, Technical University Delft and Erasmus University, the Netherlands.
| | - D S Veldhuijzen
- Health, Medical and Neuropsychology unit, Faculty of Social and Behavioural Sciences, Leiden University, the Netherlands.
| |
Collapse
|
2
|
Bavbek S, Ozyigit LP, Baiardini I, Braido F, Roizen G, Jerschow E. Placebo, Nocebo, and Patient-Reported Outcome Measures in Drug Allergy. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2023; 11:371-379. [PMID: 36521832 DOI: 10.1016/j.jaip.2022.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 11/24/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022]
Affiliation(s)
- Sevim Bavbek
- Division of Allergy and Clinical of Immunology, Department of Chest Diseases, Ankara University, School of Medicine, Ankara, Turkey.
| | - Leyla Pur Ozyigit
- Adult Allergy Service, Glenfield Hospital, University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
| | - Ilaria Baiardini
- Istituti di Ricovero e Cura a Carattere Scientifico, Ospedale Policlinico San Martino, Genova, Italy; Università di Genova, (DIMI), Genova, Italy
| | - Fulvio Braido
- Istituti di Ricovero e Cura a Carattere Scientifico, Ospedale Policlinico San Martino, Genova, Italy; Università di Genova, (DIMI), Genova, Italy
| | - Gigia Roizen
- Department of Immunology, Clinica Alemana De Santiago, Santiago, Chile
| | | |
Collapse
|
3
|
Meeuwis SH, van Middendorp H, Pacheco-Lopez G, Ninaber MK, Lavrijsen APM, van der Wee N, Veldhuijzen DS, Evers AWM. Antipruritic Placebo Effects by Conditioning H1-antihistamine. Psychosom Med 2020; 81:841-850. [PMID: 31490841 PMCID: PMC6844655 DOI: 10.1097/psy.0000000000000743] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/15/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Allergic rhinitis symptoms can be reduced by behaviorally conditioning antihistamine. It is unclear whether these findings extend to histamine-induced itch or work when participants are informed about the conditioning procedure (open-label conditioning). The current study aims to investigate the efficacy of (open-label) antipruritic behavioral conditioning for histamine-induced itch. METHODS Healthy participants (n = 92; 84% female) were randomized to I) an open-label conditioned, II) closed-label conditioned, III) conditioned-not-evoked control, or IV) nonconditioned control group. A two-phase conditioning paradigm was used. During acquisition, a conditioned stimulus (CS; distinctively tasting beverage) was repeatedly paired with the H1-antihistamine levocetirizine (groups I-III). During evocation, the CS was paired with placebo (I, II), or instead of the CS, water was paired with placebo (III). The nonconditioned control group (IV) received CS with placebo in both phases. Itch after histamine iontophoresis and physiological data (i.e., spirometry, heart rate, skin conductance) were assessed. Combined conditioned and combined control groups were first compared, and analyses were repeated for separate groups. RESULTS Marginally lower itch was reported in the combined conditioned compared with the control groups (F(1,88) = 2.10, p = .076, ηpartial = 0.02); no differences between separate groups were found. No effects on physiological data were found, except for heart rate, which reduced significantly and consistently for control groups, and less consistently for conditioned groups (group by time interaction: F(7,80) = 2.35, p = .031, ηpartial = 0.17). CONCLUSION Limited support was found for the efficacy of antipruritic behavioral conditioning, regardless of whether participants were informed about the conditioning procedure. The application of open-label conditioning in patient populations should be further researched. TRIAL REGISTRATION www.trialregister.nl; ID NTR5544.
Collapse
Affiliation(s)
- Stefanie H Meeuwis
- From the Health, Medical and Neuropsychology Unit, Institute Psychology, Faculty of Social and Behavioural Sciences, (Meeuwis, van Middendorp, Pacheco-Lopez, Veldhuijzen, Evers), Leiden University; Leiden Institute for Brain and Cognition (Meeuwis, van Middendorp, Veldhuijzen, Evers), Leiden University Medical Center, Leiden, The Netherlands; Health Sciences Department, Campus Lerma (Pacheco-Lopez), Metropolitan Autonomous University, Lerma, Edo Mex, Mexico; and Departments of Pulmonology (Ninaber), Dermatology (Lavrijsen), and of Psychiatry (van der Wee, Evers), Leiden University Medical Center, Leiden, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
4
|
Meeuwis SH, van Middendorp H, van Laarhoven AIM, van Leijenhorst C, Pacheco-Lopez G, Lavrijsen APM, Veldhuijzen DS, Evers AWM. Placebo and nocebo effects for itch and itch-related immune outcomes: A systematic review of animal and human studies. Neurosci Biobehav Rev 2020; 113:325-337. [PMID: 32240668 DOI: 10.1016/j.neubiorev.2020.03.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/24/2020] [Indexed: 12/19/2022]
Abstract
Placebo and nocebo effects can influence somatic symptoms such as pain. For itch and other dermatological symptoms these effects have been far less investigated. This review systematically integrates evidence from both animal (mainly rodents) and human trials on placebo and nocebo effects in itch, itch-related symptoms and conditions of the skin and mucous membranes, and related immune outcomes (e.g., histamine). Thirty-one animal studies, and fifty-five human studies (k = 21 healthy participants, k = 34 patients) were included. Overall, studies consistently show that placebo and nocebo effects can be induced by various methods (e.g., suggestions, conditioning and social cues), despite high heterogeneity across studies. Effects of suggestions were found consistently across subjective and behavioral parameters (e.g., itch and scratching in humans), whereas conditioning was likely to impact physiological parameters under certain conditions (e.g., conditioning of histamine levels in stressed rodents). Brain areas responsible for itch processing were associated with nocebo effects. Future research may investigate how variations in methods impact placebo and nocebo effects, and whether all symptoms and conditions can be influenced equally.
Collapse
Affiliation(s)
- Stefanie H Meeuwis
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands.
| | - Henriët van Middendorp
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands
| | - Antoinette I M van Laarhoven
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands; Department of Psychiatry, Leiden University Medical Center, P.O. Box 9600, 2300RC, Leiden, the Netherlands
| | - Cora van Leijenhorst
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands
| | - Gustavo Pacheco-Lopez
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Metropolitan Autonomous University (UAM), Campus Lerma, Health Sciences Department, Lerma, 52005, Edo Mex, Mexico
| | - Adriana P M Lavrijsen
- Department of Dermatology, Leiden University Medical Center, P.O. Box 9600, 2300RC, Leiden, the Netherlands
| | - Dieuwke S Veldhuijzen
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands
| | - Andrea W M Evers
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands; Department of Psychiatry, Leiden University Medical Center, P.O. Box 9600, 2300RC, Leiden, the Netherlands
| |
Collapse
|
5
|
Hadamitzky M, Lückemann L, Pacheco-López G, Schedlowski M. Pavlovian Conditioning of Immunological and Neuroendocrine Functions. Physiol Rev 2020; 100:357-405. [DOI: 10.1152/physrev.00033.2018] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
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.
Collapse
Affiliation(s)
- Martin Hadamitzky
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Laura Lückemann
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Gustavo Pacheco-López
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
6
|
C. Knibb R. Why Do People Misdiagnose Themselves with Food Hypersensitivity? An Exploration of the Role of Biopsychosocial Factors. EUROPEAN MEDICAL JOURNAL 2019. [DOI: 10.33590/10.33590/emj/10313340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Up to 35% of people self-diagnose food allergy or intolerance (food hypersensitivity [FH]), or diagnose it in their child, and self-manage the condition rather than seek a clinical diagnosis. This is much higher than the latest FH prevalence rate, estimated to affect 2–5% of the general population. The actual prevalence rate may be underestimated due to the lack of diagnostic services; however, this can only account for a small proportion of the discrepancy because only a small percentage of self-reported FH can be clinically confirmed. Many people are therefore misdiagnosing their or their child’s symptoms as FH and needlessly removing foods from their or their child’s diet. There are a number of possible reasons for this misdiagnosis, which can be considered from a biopsychosocial perspective. Psychological factors include a confusion over the diagnosis, coincidental pairing of food and symptom, psychological or psychosomatic reactions, and taste aversions. There are also biological mechanisms that have not been fully considered in food allergy research that may be relevant, such as conditioning of the immune system or stress responses. A social context pertains to a greater awareness of FH due to media coverage and changes in food labelling laws. Any of these theories are plausible, but the research to date has a number of methodological issues. Most studies report on small self-selected samples recruited from clinics and there is a lack of general population data. Studies also tend to be cross-sectional, which does not allow cause and effect to be established. Future research needs to include longitudinal designs that incorporate qualitative elements to enable a detailed exploration of reasons why people self and misdiagnose FH.
Collapse
Affiliation(s)
- Rebecca C. Knibb
- Department of Psychology, School of Life and Health Sciences, Aston University, Birmingham, UK
| |
Collapse
|
7
|
C. Knibb R. Why Do People Misdiagnose Themselves with Food Hypersensitivity? An Exploration of the Role of Biopsychosocial Factors. EUROPEAN MEDICAL JOURNAL 2019. [DOI: 10.33590/emj/10313340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Up to 35% of people self-diagnose food allergy or intolerance (food hypersensitivity [FH]), or diagnose it in their child, and self-manage the condition rather than seek a clinical diagnosis. This is much higher than the latest FH prevalence rate, estimated to affect 2–5% of the general population. The actual prevalence rate may be underestimated due to the lack of diagnostic services; however, this can only account for a small proportion of the discrepancy because only a small percentage of self-reported FH can be clinically confirmed. Many people are therefore misdiagnosing their or their child’s symptoms as FH and needlessly removing foods from their or their child’s diet. There are a number of possible reasons for this misdiagnosis, which can be considered from a biopsychosocial perspective. Psychological factors include a confusion over the diagnosis, coincidental pairing of food and symptom, psychological or psychosomatic reactions, and taste aversions. There are also biological mechanisms that have not been fully considered in food allergy research that may be relevant, such as conditioning of the immune system or stress responses. A social context pertains to a greater awareness of FH due to media coverage and changes in food labelling laws. Any of these theories are plausible, but the research to date has a number of methodological issues. Most studies report on small self-selected samples recruited from clinics and there is a lack of general population data. Studies also tend to be cross-sectional, which does not allow cause and effect to be established. Future research needs to include longitudinal designs that incorporate qualitative elements to enable a detailed exploration of reasons why people self and misdiagnose FH.
Collapse
Affiliation(s)
- Rebecca C. Knibb
- Department of Psychology, School of Life and Health Sciences, Aston University, Birmingham, UK
| |
Collapse
|
8
|
Lückemann L, Unteroberdörster M, Kirchhof J, Schedlowski M, Hadamitzky M. Applications and limitations of behaviorally conditioned immunopharmacological responses. Neurobiol Learn Mem 2017; 142:91-98. [PMID: 28216206 DOI: 10.1016/j.nlm.2017.02.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 02/10/2017] [Accepted: 02/15/2017] [Indexed: 12/17/2022]
Abstract
The importance of placebo responses for the treatment of various medical conditions has increasingly been recognized, whereas knowledge and systematic application in clinical settings are still sparse. One possible application for placebo responses in pharmacotherapy is given by learning paradigms, such as behaviorally conditioned immunosuppression, aiming at drug dose reduction while maintaining therapeutic efficacy of drug treatment. In an established learning paradigm of conditioned taste aversion/avoidance (CTA) in both, rats and humans, respectively, a novel-tasting drinking solution (conditioned stimulus, CS) is paired with an injection of the immunosuppressive drug cyclosporine A (CsA) as unconditioned stimulus (US). The conditioned response, evoked by re-presenting the CS alone at a later time, is reflected by avoidance behavior of consuming the solution (conditioned taste aversion; CTA) and a diminished interleukin (IL)-2 and interferon (IFN)-γ cytokine production as well as mRNA expression of rat splenic T cells or human peripheral T lymphocytes, closely mimicking the immunosuppressive effects of CsA. However, due to unreinforced CS-re-exposure conditioned responses progressively decreases over time (extinction), reflecting a considerable challenge for potential clinical applications of this learned immunosuppression. The present article discusses and critically reviews actual approaches, applications but also limitations of learning paradigms in immune pharmacotherapy.
Collapse
Affiliation(s)
- Laura Lückemann
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Meike Unteroberdörster
- Department of Neurosurgery, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Julia Kirchhof
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Martin Hadamitzky
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany.
| |
Collapse
|
9
|
Wendt L, Albring A, Schedlowski M. Learned placebo responses in neuroendocrine and immune functions. Handb Exp Pharmacol 2014; 225:159-181. [PMID: 25304532 DOI: 10.1007/978-3-662-44519-8_10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The phenomenon of learned placebo responses in neuroendocrine and immune functions is a fascinating example of communication between the brain and both the endocrine and peripheral immune systems. In this chapter, we will give a short overview of afferent and efferent communication pathways, as well as the central mechanisms, which steer the behavioral conditioned immune response. Subsequently, we will focus on data that provides evidence for learned immune responses in experimental animals and learned neuroendocrine and immune placebo responses in humans. Finally, we will take a critical look at these learning protocols, to determine whether or not they can be considered a viable additional treatment option to pharmacological regimens in clinical routine. This is fundamental, since there are still a number of issues, which need to be solved, such as the potential reproducibility, predictability, and extinction of the learned neuroendocrine and immune responses. Together, these findings not only provide an excellent basis to increase our understanding of human biology but may also have far reaching clinical implications. They pave the way for the ultimate aim of employing associative learning protocols as supportive treatment strategies in pharmacological regimens. As a result, medication levels may be reduced, as well as their unwanted side effects, providing a maximized therapeutic outcome to the benefit of the patient.
Collapse
Affiliation(s)
- Laura Wendt
- Institute of Medical Psychology and Immunobiology, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, D-45122, Essen, Germany
| | | | | |
Collapse
|
10
|
Vits S, Cesko E, Enck P, Hillen U, Schadendorf D, Schedlowski M. Behavioural conditioning as the mediator of placebo responses in the immune system. Philos Trans R Soc Lond B Biol Sci 2011; 366:1799-807. [PMID: 21576137 DOI: 10.1098/rstb.2010.0392] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Current placebo research postulates that conditioning processes are one of the major mechanisms of the placebo response. Behaviourally conditioned changes in peripheral immune functions have been demonstrated in experimental animals, healthy subjects and patients. The physiological mechanisms responsible for this 'learned immune response' are not yet fully understood, but some relevant afferent and efferent pathways in the communication between the brain and the peripheral immune system have been identified. In addition, possible benefits and applicability in clinical settings have been demonstrated where behaviourally conditioned immunosuppression attenuated the exacerbation of autoimmune diseases, prolonged allograft survival and affected allergic responses. Here, we summarize data describing the mechanisms and the potential clinical benefit of behaviourally conditioned immune functions, with particular focus on learned placebo effects on allergic reactions.
Collapse
Affiliation(s)
- Sabine Vits
- Institute of Medical Psychology and Behavioral Immunobiology, University Clinic Essen, Essen, Germany.
| | | | | | | | | | | |
Collapse
|
11
|
Schedlowski M, Pacheco-López G. The learned immune response: Pavlov and beyond. Brain Behav Immun 2010; 24:176-85. [PMID: 19698779 DOI: 10.1016/j.bbi.2009.08.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 08/10/2009] [Accepted: 08/14/2009] [Indexed: 01/26/2023] Open
Abstract
The ability to associate physiological changes with a specific flavor was most likely acquired during evolution as an adaptive strategy aimed at protecting the organism while preparing it for danger. The behaviorally conditioned or learned immune response is an exquisite example of the bidirectional communication between the central nervous system (CNS) and the peripheral immune system. How is it possible that specific immuno-modulating properties of a drug or substance (unconditioned stimulus) can be re-enlisted just by the mere re-exposure to a particular taste, odor or environment (conditioned stimulus)? To answer this key question, we review the neurobiological mechanism mediating this type of associative learning, as well as the pathways and mechanisms employed by the brain to harness the immune system during the execution of the conditioned immune response. Finally, we focus on the potential therapeutic relevance of such learned immune responses, and their re-conceptualization within the framework of "learned placebo effects".
Collapse
Affiliation(s)
- Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University of Duisburg-Essen, Medical Faculty, 45122 Essen, Germany.
| | | |
Collapse
|
12
|
Abstract
PURPOSE OF REVIEW In the century since the discovery of anaphylaxis, research has yet to identify the mechanisms that cause a localized allergic response to become rapidly generalized, and particularly why only some sensitized individuals develop the clinical reaction on exposure. The possible components and steps in the process (proven and hypothetical) are reviewed with respect to their variation and regulation and their potential for therapeutic intervention. RECENT FINDINGS Studies of insect sting allergy have revealed some of the gaps in our understanding, the relatively poor predictive value of our diagnostic tests, and more recently the early evidence for 'priming' of basophils and mast cells as a precursor or predictor of clinical reactivity. Recent literature has elucidated some of the products and regulatory pathways of the cells involved in the initiation of the anaphylactic response, the role of neurologic pathways, and the possible 'on-off switches' at the level of the immunoglobulin E receptors and their related signaling pathways. SUMMARY This review incorporates old and new observations that may be related to the puzzling characteristics of anaphylaxis. Recognizing the gaps in our understanding helps to identify many areas that require further study and presents promising targets for future treatment and prevention of anaphylaxis.
Collapse
Affiliation(s)
- David Bk Golden
- Johns Hopkins Asthma and Allergy Center, Baltimore, Maryland 21224, USA.
| |
Collapse
|