Plasma levels of TNF superfamily molecules are increased in bipolar disorder
Izabela G Barbosa 1, Gabriela N Vaz 1, Natalia P Rocha 1, 2, Rodrigo Machado-Vieira 3, Marcio R Ventura 1, Rodrigo B Huguet 1, Moises E Bauer 4, Michael Berk 5, 6, Antonio L Teixeira 1, 2*
1Laboratório Interdisciplinar de Investigação Médica, Faculdade de Medicina, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil., 2Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston. Houston, USA. , 3Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, Bethesda, MD, USA., 4Laboratório de Imunologia do Envelhecimento, Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil., 5Deakin University, IMPACT Strategic Research Centre, School of Medicine, Geelong, Australia., 6Orygen, The National Centre of Excellence in Youth Mental Health, Department of Psychiatry and The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia.
Received: November 2, 2016; Revised: March 17, 2017; Accepted: April 9, 2017; Published online: April 9, 2017.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Objective: Patients with bipolar disorder (BD) exhibit peripheral low-grade inflammation. The aim of the current study was to investigate the involvement of hitherto unexplored components of the tumor necrosis factor (TNF) superfamily in BD.
Methods: Eighty patients with type I BD and 50 healthy controls matched for age and gender were enrolled in this study. All subjects were assessed with the Mini-Plus to evaluate psychiatric comorbidities; the Young Mania Rating Scale (YMRS) and the Hamilton Depression Rating Scale (HDRS) to evaluate manic and depressive symptoms severity, respectively. TNF superfamily molecules [TNF, TNF-related weak inducer of apoptosis (TWEAK), TNF-related apoptosis-inducing ligand (TRAIL), soluble TNF receptor type 1 (sTNFR1), and soluble TNF receptor type 2 (sTNFR2)] levels were measured by ELISA.
Results: Patients with BD, regardless of mood state, presented increased plasma levels of sTNFR1 and TWEAK in comparison with controls.
Conclusion: These findings corroborate the view that TNF superfamily may play a role in BD pathophysiology.
Keywords: Bipolar disorder, TWEAK, TNF-alpha, TRAIL, sTNFR