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Brain-Derived Neurotrophic Factor Levels in Autism: A Systematic Review and Meta-Analysis

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Abstract

Brain-derived neurotrophic factor (BDNF) plays an important role in activity-dependent synaptic plasticity. Altered blood BDNF levels have been frequently identified in people with autism spectrum disorders (ASD). There are however wide discrepancies in the evidence. Therefore, we performed the present systematic review and meta-analysis aimed at qualitative and quantitative synthesis of studies that measured blood BDNF levels in ASD and control subjects. Observational studies were identified through electronic database searching and also hand-searching of reference lists of relevant articles. A total of 183 papers were initially identified for review and eventually twenty studies were included in the meta-analysis. A meta-analysis of blood BDNF in 887 patients with ASD and 901 control subjects demonstrated significantly higher BDNF levels in ASD compared to controls with the SMD of 0.47 (95% CI 0.07–0.86, p = 0.02). In addition subgroup meta-analyses were performed based on the BDNF specimen. The present meta-analysis study led to conclusion that BDNF might play role in autism initiation/ propagation and therefore it can be considered as a possible biomarker of ASD.

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Acknowledgments

The study was supported by a Grant from Tehran University of Medical Sciences (Grant No. 32828).

Author Contributions

AS developed the concept and designed study, collected and analyzed data, and wrote the original draft of paper; AS and NR critically revised the paper; NR supervised the project. All authors read and approved the final manuscript.

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Authors and Affiliations

  1. Research Center for Immunodeficiencies, Children’s Medical Center, Tehran University of Medical Sciences, Tehran, Iran

    Amene Saghazadeh & Nima Rezaei

  2. MetaCognition Interest Group (MCIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran

    Amene Saghazadeh

  3. Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

    Nima Rezaei

  4. Systematic Review and Meta-analysis Expert Group (SRMEG), Universal Scientific Education and Research Network (USERN), Boston, MA, USA

    Nima Rezaei

  5. Children’s Medical Center Hospital, Dr. Qarib St, Keshavarz Blvd, Tehran, 14194, Iran

    Nima Rezaei

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  1. Amene Saghazadeh
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Correspondence to Nima Rezaei.

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Saghazadeh, A., Rezaei, N. Brain-Derived Neurotrophic Factor Levels in Autism: A Systematic Review and Meta-Analysis. J Autism Dev Disord 47, 1018–1029 (2017). https://doi.org/10.1007/s10803-016-3024-x

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