title: Red blood cell distribution width and neutrophil to lymphocyte ratio are correlated with disease activity of dermatomyositis and polymyositis.
abstract: BACKGROUND
  Previous studies indicated that both red blood cell distribution width (RDW) and neutrophil to lymphocyte ratio (NLR) were useful indices in assessing the disease activity of autoimmune diseases. However, the evidence for the association between RDW, NLR and dermatomyositis (DM) and polymyositis (PM) is limited. The aim of this study is to investigate the association between the disease activity of PM/DM and both RDW and NLR.
  
  
  METHODS
  Medical records of 114 PM/DM patients and 114 healthy controls were retrospectively reviewed, and their RDW, NLR and myositis disease activity assessment visual analogue scale (MYOACT) on admission were extracted. The correlations between RDW, NLR and MYOACT were analyzed using the Spearman approach and multivariable model.
  
  
  RESULTS
  PM/DM patients had significantly higher RDW and NLR. Increased RDW in PM/DM patients was not completely attributed to decreased hemoglobin or therapeutic agents. Both RDW and NLR are independently and positively correlated MYOACT.
  
  
  CONCLUSIONS
  Both RDW and NLR are useful indices in assessing the disease activity of PM/DM.
authors.affiliation: Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi, China.
authors.forename: Ming-Zhu
authors.identifier: http://orcid.org/0000-0002-8556-1792
authors.initials: MZ
authors.lastname: Gao
authors.affiliation: Department of Laboratory Medicine, No.455 Hospital of the Chinese People's Liberation Army, Shanghai, China.
authors.forename: Yuan-Lan
authors.initials: YL
authors.lastname: Huang
authors.affiliation: Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi, China.
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Wu
authors.affiliation: Department of Rheumatology, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi, China.
authors.forename: Qiang-Wei
authors.initials: QW
authors.lastname: Xu
authors.affiliation: Department of Rheumatology, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Ji
authors.affiliation: Department of Laboratory Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Gu
authors.affiliation: Department of Laboratory Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.
authors.forename: Ai-Yan
authors.initials: AY
authors.lastname: Zhang
authors.affiliation: Department of Laboratory Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Hao
authors.affiliation: Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi, China.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Han
authors.affiliation: Department of Rheumatology, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi, China.
authors.forename: Tian-Li
authors.initials: TL
authors.lastname: Ren
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003882:Dermatomyositis / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology; D004909:Erythrocyte Indices / Q000502:physiology*; D005260:Female; D006801:Humans; D007958:Leukocyte Count / Q000706:statistics & numerical data*; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology*; D017285:Polymyositis / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology
keywords: dermatomyositis; disease activity; neutrophil to lymphocyte ratio; polymyositis; red blood cell distribution width