Perspective: Solving the Heterogeneity Conundrum of TSPO PET Imaging in Psychosis

Positron emission tomography using ligands targeting translocator protein 18 kDa (TSPO PET) is an innovative method to visualize and quantify glial inflammatory responses in the central nervous system in vivo. Compared to some other neuropsychiatric disorders, findings of TSPO PET in schizophrenia a...

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Main Authors: Livia De Picker, Manuel Morrens
Format: Article
Language:English
Published: Frontiers Media S.A. 2020-05-01
Series:Frontiers in Psychiatry
Subjects:
Online Access:https://www.frontiersin.org/article/10.3389/fpsyt.2020.00362/full
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author Livia De Picker
Livia De Picker
Manuel Morrens
Manuel Morrens
author_facet Livia De Picker
Livia De Picker
Manuel Morrens
Manuel Morrens
author_sort Livia De Picker
collection DOAJ
description Positron emission tomography using ligands targeting translocator protein 18 kDa (TSPO PET) is an innovative method to visualize and quantify glial inflammatory responses in the central nervous system in vivo. Compared to some other neuropsychiatric disorders, findings of TSPO PET in schizophrenia and related psychotic disorders have been considerably more heterogeneous. Two conflicting meta-analyses have been published on the topic within the last year: one asserting evidence for decreased TSPO uptake, while the other observed increased TSPO uptake in a selection of studies. In this paper, we review and discuss five hypotheses which may explain the observed variability of TSPO PET findings in psychotic illness, namely that (1) an inflammatory phenotype is only present in a subgroup of psychosis patients; (2) heterogeneity is caused by interference of antipsychotic medication; (3) interference of other clinical confounders in the study populations (such as age, sex, BMI, smoking, and substance use); or (4) methodological variability between studies (such as choice of tracer and kinetic model, genotyping, study power, and diurnal effects); and (5) the glial responses underlying changes in TSPO expression are themselves heterogeneous and dynamic. Finally, we propose four key recommendations for future research proposals to mitigate these different causes of heterogeneity.
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spelling doaj.art-8400819989dc495cb23a545cb1476ba72022-12-21T18:27:39ZengFrontiers Media S.A.Frontiers in Psychiatry1664-06402020-05-011110.3389/fpsyt.2020.00362510979Perspective: Solving the Heterogeneity Conundrum of TSPO PET Imaging in PsychosisLivia De Picker0Livia De Picker1Manuel Morrens2Manuel Morrens3Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, BelgiumSINAPS, University Psychiatric Hospital Campus Duffel, Duffel, BelgiumCollaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, BelgiumSINAPS, University Psychiatric Hospital Campus Duffel, Duffel, BelgiumPositron emission tomography using ligands targeting translocator protein 18 kDa (TSPO PET) is an innovative method to visualize and quantify glial inflammatory responses in the central nervous system in vivo. Compared to some other neuropsychiatric disorders, findings of TSPO PET in schizophrenia and related psychotic disorders have been considerably more heterogeneous. Two conflicting meta-analyses have been published on the topic within the last year: one asserting evidence for decreased TSPO uptake, while the other observed increased TSPO uptake in a selection of studies. In this paper, we review and discuss five hypotheses which may explain the observed variability of TSPO PET findings in psychotic illness, namely that (1) an inflammatory phenotype is only present in a subgroup of psychosis patients; (2) heterogeneity is caused by interference of antipsychotic medication; (3) interference of other clinical confounders in the study populations (such as age, sex, BMI, smoking, and substance use); or (4) methodological variability between studies (such as choice of tracer and kinetic model, genotyping, study power, and diurnal effects); and (5) the glial responses underlying changes in TSPO expression are themselves heterogeneous and dynamic. Finally, we propose four key recommendations for future research proposals to mitigate these different causes of heterogeneity.https://www.frontiersin.org/article/10.3389/fpsyt.2020.00362/fulltranslocator proteinschizophreniapsychosismicrogliapositron emission tomographyneuroinflammation
spellingShingle Livia De Picker
Livia De Picker
Manuel Morrens
Manuel Morrens
Perspective: Solving the Heterogeneity Conundrum of TSPO PET Imaging in Psychosis
Frontiers in Psychiatry
translocator protein
schizophrenia
psychosis
microglia
positron emission tomography
neuroinflammation
title Perspective: Solving the Heterogeneity Conundrum of TSPO PET Imaging in Psychosis
title_full Perspective: Solving the Heterogeneity Conundrum of TSPO PET Imaging in Psychosis
title_fullStr Perspective: Solving the Heterogeneity Conundrum of TSPO PET Imaging in Psychosis
title_full_unstemmed Perspective: Solving the Heterogeneity Conundrum of TSPO PET Imaging in Psychosis
title_short Perspective: Solving the Heterogeneity Conundrum of TSPO PET Imaging in Psychosis
title_sort perspective solving the heterogeneity conundrum of tspo pet imaging in psychosis
topic translocator protein
schizophrenia
psychosis
microglia
positron emission tomography
neuroinflammation
url https://www.frontiersin.org/article/10.3389/fpsyt.2020.00362/full
work_keys_str_mv AT liviadepicker perspectivesolvingtheheterogeneityconundrumoftspopetimaginginpsychosis
AT liviadepicker perspectivesolvingtheheterogeneityconundrumoftspopetimaginginpsychosis
AT manuelmorrens perspectivesolvingtheheterogeneityconundrumoftspopetimaginginpsychosis
AT manuelmorrens perspectivesolvingtheheterogeneityconundrumoftspopetimaginginpsychosis