title: Clinical relevance of plasma miR-21 in new-onset systemic lupus erythematosus patients.
abstract: BACKGROUND
  Plasma miR-21 is widely investigated as biomarker in many diseases. Recent studies show that miR-21 participates in the development of systemic lupus erythematosus (SLE). The aim of this study was to evaluate the expression profile of miR-21 in the plasma of SLE patients.
  
  
  METHODS
  Relative quantities of plasma miR-21 both in SLE patients and healthy controls were determined by relative qRT-PCR under endogenous and exogenous controls. The diagnostic value of plasma miR-21 was evaluated in SLE patients. Data of some SLE-associated clinical parameters were collected.
  
  
  RESULTS
  Eighty participants from Central China were recruited. Forty-four participants were new-onset SLE patients and the others were healthy controls. Plasma miR-21 level in SLE patients was higher than that of healthy controls (P = 0.031). Receiver operating characteristic analysis of plasma miR-21 revealed an Area Under Curve (AUC) of 0.64 ± 0.06 (95% CI: 0.51-0.76, P = 0.03854) when differentiating SLE from healthy controls. The level of plasma miR-21 was not associated with the level of white blood cells (P = 0.4284), red blood cells (P = 0.4079), and platelets (P = 0.4961), but significantly correlated with the level of plasma complement C3 (r = -0.5297, P = 0.0004), C4 (r = -0.4732, P = 0.0020), and serum uric acid (r = 0.3932, P = 0.0121) in SLE patients.
  
  
  CONCLUSIONS
  Plasma miR-21 in SLE patients from Central China is overexpressed. Since circulating miR-21 is aberrantly expressed in many diseases, the applying of it as a disease biomarker should be considered carefully.
authors.affiliation: Department of Laboratory Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Zhao Ming
authors.initials: ZM
authors.lastname: Tang
authors.forename: Min
authors.initials: M
authors.lastname: Fang
authors.forename: Jin Ping
authors.initials: JP
authors.lastname: Wang
authors.forename: Peng Cheng
authors.initials: PC
authors.lastname: Cai
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Li Hua
authors.initials: LH
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001772:Blood Cell Count; D003176:Complement C3 / Q000378:metabolism; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D035683:MicroRNAs / Q000097:blood*; D008875:Middle Aged; D012372:ROC Curve; D014527:Uric Acid / Q000097:blood
chemical_list: D015415:Biomarkers; D003176:Complement C3; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D014527:Uric Acid
keywords: biomarker; miR-21; plasma; real-time polymerase chain reaction; systemic lupus erythematosus