title: Efficacy of Stem Cell Therapy in Amyotrophic Lateral Sclerosis: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  Published studies seeking to improve survival in amyotrophic lateral sclerosis (ALS) have poor results in humans, although there are several studies in animal models with positive results.
  
  
  METHODS
  We conducted a systematic review and meta-analysis of studies that were published between March 2009 and March 2015 on stem cell therapy and survival in animal models and patients with ALS. A total of 714 articles were identified, and from these, we selected preclinical in vivo studies and retrospective clinical studies.
  
  
  CONCLUSIONS
  A meta-analysis confirmed the efficacy of stem cell therapy in improving survival in preclinical trials, where a mean difference of 9.79 days (95% confidence interval: 4.45 - 15.14) in lifespan favored stem cell therapy. In contrast, the number of clinical studies is still insufficient to assess their effectiveness, and these studies only demonstrate the absence of serious adverse events. However, even this conclusion should be interpreted with caution because clinical studies are retrospective and heterogeneous and have an unsatisfactory quality.
authors.affiliation: Hospital Regional da Asa Norte, State Secretariat of Health of the Federal District, DF, Brazil.
authors.forename: Mirian Conceicao
authors.initials: MC
authors.lastname: Moura
authors.affiliation: School of Health Sciences, DF, and University of Brasilia, Brazil.
authors.forename: Maria Rita Carvalho Garbi
authors.initials: MR
authors.lastname: Novaes
authors.affiliation: School of Medicine, School of Health Sciences, DF, Brazil.
authors.forename: Yuri S S P
authors.initials: YS
authors.lastname: Zago
authors.affiliation: School of Medicine, School of Health Sciences, DF, Brazil.
authors.forename: Emanoel Junio
authors.initials: EJ
authors.lastname: Eduardo
authors.affiliation: University Hospital of Brasilia, DF, Brazil.
authors.forename: Luiz Augusto
authors.initials: LA
authors.lastname: Casulari
keywords: ALS; Amyotrophic lateral sclerosis; Cell therapy; Motor neuron; Survival