title: Circulating human leucine-rich α-2-glycoprotein 1 mRNA and protein levels to detect acute appendicitis in patients with acute abdominal pain.
abstract: BACKGROUND
  Elevated levels of circulating plasma and urine leucine-rich-2-glycoprotein-1 (LRG1) protein has been found in patients with acute appendicitis (AA) and may be useful for diagnosis. This study aimed to investigate whether combined tests including circulating LRG1 mRNA levels improve the early diagnosis of AA.
  
  
  METHODS
  Between December 2011 and October 2012, a prospective study was conducted on patients aged 18years or older presenting to the ED with acute abdominal pain (<7days of symptom onset). Levels of whole blood LRG1 mRNA and plasma LRG1 protein taken from these patients within 24h of arrival (mean 12.4h) were analyzed. The primary outcome was AA.
  
  
  RESULTS
  Eighty-four patients (40 (47.6%) with AA and 44 (52.4%) without AA; mean age 35years; 41.6% males) were recruited. Median whole blood LRG1 mRNA and plasma LRG1 levels were higher in AA patients than in non-AA. Of 40 AA patients, 13 (32.5%) were diagnosed as complicated AA. In ROC analysis of LRG1 mRNA (normalized to GAPDH), LRG1 protein and Alvarado score for discriminating AA and non-AA, the areas under the curve (AUC) were 0.723, 0.742 and 0.805 respectively. The AUC of combination of normalized LRG1 mRNA, LRG1 protein and Alvarado score was 0.845.
  
  
  CONCLUSIONS
  A combination of modified whole blood LRG1 mRNA levels, plasma LRG1 protein and Alvarado score at the ED may be useful to diagnose simple and complicated AA from other causes of abdominal pain.
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong.
authors.forename: T H
authors.initials: TH
authors.lastname: Rainer
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong.
authors.forename: L Y
authors.initials: LY
authors.lastname: Leung
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Cpy
authors.initials: C
authors.lastname: Chan
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Y K
authors.initials: YK
authors.lastname: Leung
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong.
authors.forename: N M
authors.initials: NM
authors.lastname: Cheng
authors.affiliation: Department of Surgery, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Pbs
authors.initials: P
authors.lastname: Lai
authors.affiliation: Department of Surgery, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Y S
authors.initials: YS
authors.lastname: Cheung
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong. Electronic address: cagraham@cuhk.edu.hk.
authors.forename: C A
authors.initials: CA
authors.lastname: Graham
mesh_terms: D015746:Abdominal Pain / Q000097:blood*; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D001064:Appendicitis / Q000097:blood*; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012333:RNA, Messenger / Q000097:blood*
chemical_list: D006023:Glycoproteins; C015246:LRG1 protein, human; D012333:RNA, Messenger
keywords: Abdominal pain; Acute abdomen; Acute appendicitis; Diagnosis; mRNA