TY - JOUR
T1 - Cognitive deterioration among bipolar disorder patients infected by Toxoplasma gondii is correlated to interleukin 6 levels
AU - Hamdani, Nora
AU - Daban-Huard, Claire
AU - Lajnef, Mohamed
AU - Gadel, Rémi
AU - Le Corvoisier, Philippe
AU - Delavest, Marine
AU - Carde, Soufiane
AU - Lépine, Jean Pierre
AU - Jamain, Stéphane
AU - Houenou, Josselin
AU - Galeh, Bijan
AU - Richard, Jean Romain
AU - Aoki, Masayuki
AU - Charron, Dominique
AU - Krishnamoorthy, Rajagopal
AU - Yolken, Robert
AU - Dickerson, Faith
AU - Tamouza, Ryad
AU - Leboyer, Marion
N1 - Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - Background Cognitive deficits are present in a large majority of Bipolar Disorder (BD) patients and known to be a marker of bad prognosis. Because, these deficits encompass several domains and no specific medical treatment seems to be effective, it is important to better understand the mechanisms underlying cognitive deterioration. As Toxoplasma gondii is known to induce the synthesis of pro-inflammatory cytokines such as IL-6, we will explore here the possible role of T. gondii in the cognitive decline observed in BD. Methods 42 euthymic BD patients and 36 controls were assessed for episodic verbal memory using the CVLT and for working memory and verbal ability using the WAIS III. Patients and controls were also screened for seropositivity to T. gondii and evaluated for the levels of IL-6 transcripts. Results The seropositivity for T. gondii was significantly higher in BD patients as compared to controls (p=0.005). The cognitive deterioration index (DI) was higher in BD patients (p=5.10-6) and correlated to high IL-6 mRNA expression only among those infected by T. gondii (rho=0.43, p=0.01). Among deteriorated patients (defined by scores above 0.10 according to Weschler's definition), the IL-6 mRNA expression was twice greater (p=0.01). Limitations Our results are to be interpreted with caution because of our small sample size and the cross-sectional design. Conclusions A long-term exposure to inflammation, measured here with IL-6 mRNA expression in T. gondii infected BD may alter cognitive functioning. IL-6 could thus be a useful predictive marker of cognitive deterioration in BD and may help to design personalized treatment.
AB - Background Cognitive deficits are present in a large majority of Bipolar Disorder (BD) patients and known to be a marker of bad prognosis. Because, these deficits encompass several domains and no specific medical treatment seems to be effective, it is important to better understand the mechanisms underlying cognitive deterioration. As Toxoplasma gondii is known to induce the synthesis of pro-inflammatory cytokines such as IL-6, we will explore here the possible role of T. gondii in the cognitive decline observed in BD. Methods 42 euthymic BD patients and 36 controls were assessed for episodic verbal memory using the CVLT and for working memory and verbal ability using the WAIS III. Patients and controls were also screened for seropositivity to T. gondii and evaluated for the levels of IL-6 transcripts. Results The seropositivity for T. gondii was significantly higher in BD patients as compared to controls (p=0.005). The cognitive deterioration index (DI) was higher in BD patients (p=5.10-6) and correlated to high IL-6 mRNA expression only among those infected by T. gondii (rho=0.43, p=0.01). Among deteriorated patients (defined by scores above 0.10 according to Weschler's definition), the IL-6 mRNA expression was twice greater (p=0.01). Limitations Our results are to be interpreted with caution because of our small sample size and the cross-sectional design. Conclusions A long-term exposure to inflammation, measured here with IL-6 mRNA expression in T. gondii infected BD may alter cognitive functioning. IL-6 could thus be a useful predictive marker of cognitive deterioration in BD and may help to design personalized treatment.
KW - Bipolar disorder
KW - Cognitive deterioration
KW - IL-6
KW - T. gondii
UR - http://www.scopus.com/inward/record.url?scp=84926621730&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84926621730&partnerID=8YFLogxK
U2 - 10.1016/j.jad.2015.03.038
DO - 10.1016/j.jad.2015.03.038
M3 - Article
C2 - 25863913
AN - SCOPUS:84926621730
SN - 0165-0327
VL - 179
SP - 161
EP - 166
JO - Journal of Affective Disorders
JF - Journal of Affective Disorders
ER -