Ruizhi Mao1, Chen Zhang2, Jun Chen1, Guoqing Zhao3, Rubai Zhou1, Fan Wang1, Jingjing Xu1, Tao Yang1, Yousong Su1, Jia Huang1, Zhiguo Wu1, Lan Cao1, Yong Wang1, Yingyan Hu1, Chengmei Yuan1, Zhenghui Yi1, Wu Hong1, Zuowei Wang4, Daihui Peng1, Yiru Fang5. 1. Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China. 2. Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China. Electronic address: zhangchen645@gmail.com. 3. Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; Department of Psychology, Provincial Hospital Affiliated to Shandong University, Jinan, 250021, China. 4. Division of Mood Disorders, Hongkou District Mental Health Center of Shanghai, Shanghai, 200083, China. 5. Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; CAS Center for Excellence in Brain Science and Intelligence Technology, China; Shanghai Key Laboratory of Psychotic Disorders, China. Electronic address: yirufang@aliyun.com.
Abstract
BACKGROUND: Immune system dysregulation is critical in the physiopathology of major depressive disorder (MDD) and bipolar disorder (BD). However, it is unclear whether both diseases present the same inflammatory patterns during depressive episodes. We explored the differences in pro- and anti-inflammatory cytokines between unipolar and bipolar depression (BDD) and the trajectory of these cytokines after acute-phase treatment. METHODS: Sixty-four MDD patients, 61 BDD patients, and 62 healthy controls (HCs) were enrolled. We assessed the clinical features and cytokines plasma levels at baseline and week 12. The pro-inflammatory cytokines (IL-6, TNF-α) and anti-inflammatory cytokines (IL-4, IL-13) of all subjects were assessed by multiplexed sandwich ELISA-based quantitative arrays. RESULTS: Before acute-phase treatment, the initial levels of TNF-α and IL-13 were significantly lower in the BDD patients than in the MDD patients. The results demonstrated that there was no relationship between each cytokine level and clinical features of unipolar and bipolar depressions. After 12 weeks, TNF-α, IL-4, and IL-13 levels became lower in MDD patients than in the other two groups regardless of the patients' response to treatment while the levels of TNF-α and IL-4 increased only in the BDD responders. LIMITATIONS: The effects of different drugs on inflammatory cytokines in MDD or BDD could not be explored further due to the relatively small sample size. CONCLUSION: Even within the same depressive states, MDD and BDD patients present different inflammatory features, particularly in regard to pro-inflammatory TNF-α and anti-inflammatory IL-13. In addition, the fluctuations of cytokines induced by medication may provide a hint regarding the prediction of treatment response.
BACKGROUND: Immune system dysregulation is critical in the physiopathology of major depressive disorder (MDD) and bipolar disorder (BD). However, it is unclear whether both diseases present the same inflammatory patterns during depressive episodes. We explored the differences in pro- and anti-inflammatory cytokines between unipolar and bipolar depression (BDD) and the trajectory of these cytokines after acute-phase treatment. METHODS: Sixty-four MDDpatients, 61 BDD patients, and 62 healthy controls (HCs) were enrolled. We assessed the clinical features and cytokines plasma levels at baseline and week 12. The pro-inflammatory cytokines (IL-6, TNF-α) and anti-inflammatory cytokines (IL-4, IL-13) of all subjects were assessed by multiplexed sandwich ELISA-based quantitative arrays. RESULTS: Before acute-phase treatment, the initial levels of TNF-α and IL-13 were significantly lower in the BDD patients than in the MDDpatients. The results demonstrated that there was no relationship between each cytokine level and clinical features of unipolar and bipolar depressions. After 12 weeks, TNF-α, IL-4, and IL-13 levels became lower in MDDpatients than in the other two groups regardless of the patients' response to treatment while the levels of TNF-α and IL-4 increased only in the BDD responders. LIMITATIONS: The effects of different drugs on inflammatory cytokines in MDD or BDD could not be explored further due to the relatively small sample size. CONCLUSION: Even within the same depressive states, MDD and BDD patients present different inflammatory features, particularly in regard to pro-inflammatory TNF-α and anti-inflammatory IL-13. In addition, the fluctuations of cytokines induced by medication may provide a hint regarding the prediction of treatment response.