Impact of peripheral levels of chemokines, BDNF and oxidative markers on cognition in individuals with schizophrenia Elson Asevedo a, b, * , Ary Gadelha a, b , Cristiano Noto a, b , Rodrigo B. Mansur b , André Zugman b , Síntia I.N. Belangero b , Arthur A. Berberian a, b , Bruno S. Scarpato b , Emilie Leclerc b , Antônio L. Teixeira c , Clarissa S. Gama d , Rodrigo A. Bressan a, b , Elisa Brietzke b a Schizophrenia Program (PROESQ), Department of Psychiatry, Universidade Federal de São Paulo, Rua Machado Bittencourt, 222, São Paulo, SP CEP 04044- 000, Brazil b Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Universidade Federal de São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, Third Floor, São Paulo, SP CEP 04039-032, Brazil c Translational Psychoneuroimmunology Group, Universidade Federal de Minas Gerais, Avenida Antonio Carlos, 6627, Pampulha, Belo Horizonte, MG CEP 31270-901, Brazil d Laboratoryof Molecular Psychiatry, Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2350, Prédio Anexo, CEP 90035-903 Porto Alegre, RS, Brazil article info Article history: Received 25 January 2013 Received in revised form 11 April 2013 Accepted 31 May 2013 Keywords: Schizophrenia Cognition BDNF Chemokines Oxidative stress Biomarkers abstract Objective: To investigate possible differences in peripheral levels of chemokines, BDNF and oxidative markers between patients with Schizophrenia (SZ) and matched healthy controls, and investigate the correlation of these biomarkers with cognitive performance. Methods: Thirty individuals with SZ and 27 healthy controls were included and the following plasmatic biomarkers’ levels were determined according to manufacturers’ instructions: BDNF, TBARS, protein carbonyl content (PCC) and the chemokines CXCL-10/IP-10, CXCL-8/IL-8, CCL-11, CCL-24/Eotaxin-2, CCL- 2/MCP-1, CCL-3/MIP-1. Selected neuropsychological tasks were administered to assess verbal learning (Hopkins Verbal Learning Test), verbal fluency (FAS test), working memory (Visual Working Memory Task, Keep Track Task, Letter Memory Task), set shifting (Pluseminus task, Numbereletter task), inhi- bition (Computerized Stroop Task, Semantic Generation Task) and complex executive function tasks (Tower of London and the shortened version of the WCST-64). Results: Compared with the healthy control group, individuals with SZ presented significantly higher levels of BDNFand the chemokine CCL-11, and lower levels of TBARS and the chemokine CXCL-10/IP-10. When we examined only the SZ group, BDNF levels were positively correlated with semantic generation tasks. Working memory ability was negatively correlated with PCC. Regarding chemokines, CCL-11 was negatively correlated to performance in working memory test, and positively correlated with cognitive flexibility task. CXCL-8/IL-8 was positively correlated with verbal fluency. CCL-24/Eotaxin-2 was posi- tively correlated with semantic generation ability and letter memory task. Conclusions: Our results indicate that cognitive performance in SZ is associated with mediators of neu- roplasticity that can be measured peripherally. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Cognitive deficits are a core characteristic of schizophrenia (SZ) and have been associated with functional impairment in domains like work, interpersonal relationships and daily life (Goff et al., 2011; Green et al., 2004). Individuals with SZ have deficits in several domains of cognition, such as episodic memory, processing speed, attention, inhibition, language and executive functions (Barch and Ceaser, 2012). * Corresponding author. Universidade Federal de São Paulo (UNIFESP), Rua Machado Bittencourt, 222, São Paulo, SP, Brazil. Tel./fax: þ55 11 55764845. E-mail addresses: elsonmed@gmail.com (E. Asevedo), aryararipe@gmail.com (A. Gadelha), crisnoto@hotmail.com (C. Noto), rodrigomansur71@uol.com.br (R.B. Mansur), andre.zugman@gmail.com (A. Zugman), sinogueira@gmail.com (S.I.N. Belangero), arthur.berberian@gmail.com (A.A. Berberian), brunosini@ yahoo.com.br (B.S. Scarpato), emilie.leclerc@gmail.com (E. Leclerc), altexr@ gmail.com (A.L. Teixeira), csgama@yahoo.com (C.S. Gama), rodrigoabressan@ gmail.com (R.A. Bressan), elisabrietzke@hotmail.com (E. Brietzke). Contents lists available at SciVerse ScienceDirect Journal of Psychiatric Research journal homepage: www.elsevier.com/locate/psychires 0022-3956/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jpsychires.2013.05.032 Journal of Psychiatric Research xxx (2013) 1e7 Please cite this article in press as: Asevedo E, et al., Impact of peripheral levels of chemokines, BDNF and oxidative markers on cognition in individuals with schizophrenia, Journal of Psychiatric Research (2013), http://dx.doi.org/10.1016/j.jpsychires.2013.05.032