A pilot study on immuno-psychiatry in the 22q11.2 deletion syndrome: A role for Th17 cells in psychosis?

Elfi Vergaelen; Carmen Schiweck; Kristof Van Steeland; Jacqueline Counotte; Wim Veling; Ann Swillen; Hemmo Drexhage; Stephan Claes

doi:10.1016/j.bbi.2018.03.022

A pilot study on immuno-psychiatry in the 22q11.2 deletion syndrome: A role for Th17 cells in psychosis?

Brain Behav Immun. 2018 May:70:88-95. doi: 10.1016/j.bbi.2018.03.022. Epub 2018 Mar 19.

Authors

Elfi Vergaelen¹, Carmen Schiweck², Kristof Van Steeland², Jacqueline Counotte³, Wim Veling⁴, Ann Swillen⁵, Hemmo Drexhage⁶, Stephan Claes²

Affiliations

¹ University Psychiatric Center KU Leuven, University Hospital Leuven, Leuven, Belgium; Center for Human Genetics, University Hospital Leuven, Leuven, Belgium. Electronic address: elfi.vergaelen@uzleuven.be.
² University Psychiatric Center KU Leuven, University Hospital Leuven, Leuven, Belgium.
³ Parnassia Psychiatric Institute, The Hague, The Netherlands.
⁴ University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands.
⁵ Center for Human Genetics, University Hospital Leuven, Leuven, Belgium; Department of Human Genetics, KU Leuven, Leuven, Belgium.
⁶ Department of Immunology, Erasmus MC, Rotterdam, The Netherlands.

Abstract

Background: A growing body of evidence supports a role for immune alterations in Schizophrenia Spectrum Disorders (SSD). A high prevalence (25-40%) of SSD has been found in patients with 22q11.2 deletion syndrome (22q11.2DS), which is known for T-cell deficits due to thymus hypoplasia. This study is the first to explore the association between the T-cell subsets and psychotic symptoms in adults with 22q11.2DS.

Methods: 34 individuals (aged 19-38 yrs.) with 22q11.2DS and 34 healthy age- and gender matched control individuals were included. FACS analysis of the blood samples was performed to define T-cell subsets. Ultra-high risk for psychosis or diagnosis of SSD was determined based on CAARMS interviews and DSM-5 criteria for SSD. Positive psychotic symptom severity was measured based on the PANSS positive symptoms subscale.

Results: A partial T-cell immune deficiency in 22q11.2DS patients was confirmed by significantly reduced percentages of circulating T and T-helper cells. Significantly higher percentages of inflammatory Th1, Th17, and memory T-helper cells were found in adults with 22q11.2DS. Most importantly an increased Th17 percentage was found in adults with psychotic symptoms as compared to non-psychotic adults with 22q11.2DS, and Th17 percentage were related to the presence of positive psychotic symptoms.

Conclusions: Given the literature on the role of T cells and in particular of Th17 cells and IL-17 in hippocampus development, cognition and behavior, these results support the hypothesis for a role of Th17 cells in the development and/or regulation of psychotic symptoms in 22q11.2DS. This pilot study underlines the importance to further study the role of T-cell defects and of Th17 cells in the development of psychiatric symptoms. It also supports the possibility to use 22q11.2DS as a model to study T-cell involvement in the development of SSD.

Keywords: 22q11.2 deletion syndrome; Neuro-inflammation; Psychosis; Schizophrenia spectrum disorder; T-cell immune deficiency; Th17 cells.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Adult
DiGeorge Syndrome / genetics
DiGeorge Syndrome / immunology*
Female
Humans
Male
Pilot Projects
Psychiatric Status Rating Scales
Psychotic Disorders / etiology
Psychotic Disorders / immunology*
Schizophrenia / immunology
Th17 Cells / metabolism
Th17 Cells / physiology*

Abstract

Publication types

MeSH terms

Grants and funding