title: Relationship of serum levels of TNF-α, IL-6 and IL-18 and schizophrenia-like symptoms in chronic ketamine abusers.
abstract: OBJECTIVE
  Exposing to NMDAR receptor antagonists, such as ketamine, produces schizophrenia-like symptoms in humans and deteriorates symptoms in schizophrenia patients. Meanwhile, schizophrenia is associated with alterations of cytokines in the immune system. This study aims to examine the serum TNF-α, IL-6 and IL-18 levels in chronic human ketamine users as compared to healthy subjects. The correlations between the serum cytokines levels with the demographic, ketamine use characteristics and psychiatric symptoms were also assessed.
  
  
  METHODS
  155 subjects who fulfilled the criteria of ketamine dependence and 80 healthy control subjects were recruited. Serum TNF-α, IL-6 and IL-18 levels were measured using an enzyme-linked immunosorbent assay (ELISA). The psychiatric symptoms of the ketamine abusers were assessed using the Positive and Negative Syndrome Scale (PANSS).
  
  
  RESULTS
  Serum IL-6 and IL-18 levels were significantly higher, while serum TNF-α level was significantly lower among ketamine users than among healthy controls (p<0.05). Serum TNF-α levels showed a significant negative association with PANSS total score (r=-0.210, p<0.01) and negative subscore (r=-0.300, p<0.01). No significant association was found between PANSS score and serum levels of IL-6 and IL-18.
  
  
  CONCLUSIONS
  Serum levels of TNF-α, IL-6 and IL-18 were altered in chronic ketamine abusers which may play a role in schizophrenia-like symptoms in chronic ketamine abusers.
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China. Electronic address: fanni2005@126.com.
authors.forename: Ni
authors.initials: N
authors.lastname: Fan
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China.
authors.forename: Yayan
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Department of Psychiatry, Yale School of Medicine, 300 George St, New Haven, CT, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China.
authors.forename: Minling
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China; Shenzhen Mental Health Center, 1080 Cuizhu Rd., Luohu District, Shenzhen, Guangdong 518020, China.
authors.forename: Xiaoyin
authors.initials: X
authors.lastname: Ke
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China.
authors.forename: Xini
authors.initials: X
authors.lastname: Huang
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China.
authors.forename: Daping
authors.initials: D
authors.lastname: Wang
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Ning
authors.affiliation: Guangzhou Baiyun Voluntary Drug Rehabilitation Hospital, 586 North of Baiyun Road, Baiyun District, Guangzhou, Guangdong 510440, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Deng
authors.affiliation: Guangzhou Brain Hospital (Guangzhou Huiai Hospital, the Affiliated Brain Hospital of Guangzhou Medical University), 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: He
mesh_terms: D000293:Adolescent; D000328:Adult; D001774:Blood Chemical Analysis; D004797:Enzyme-Linked Immunosorbent Assay; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects*; D020382:Interleukin-18 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007649:Ketamine / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000097:blood; D012565:Schizophrenic Psychology; D019966:Substance-Related Disorders / Q000097:blood* / Q000523:psychology*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D055815:Young Adult
chemical_list: D018691:Excitatory Amino Acid Antagonists; C000589760:IL18 protein, human; C508600:IL6 protein, human; D013287:Illicit Drugs; D020382:Interleukin-18; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D007649:Ketamine
keywords: Cytokines; IL-18; IL-6; Ketamine; Schizophrenia; TNF-α