title: Evaluation of leucocyte esterase reagent strip test for the rapid bedside diagnosis of spontaneous bacterial peritonitis.
abstract: BACKGROUND
  Spontaneous bacterial peritonitis (SBP) is a common serious complication of cirrhosis, and carries a high morbidity and mortality. Rapid diagnosis and prompt treatment of this condition may improve survival of such patients.
  
  
  OBJECTIVE
  To validate the diagnostic efficacy of a leukocyte esterase reagent (LER) strip test for rapid, bedside diagnosis of SBP.
  
  
  METHODS
  We prospectively studied 175 patients with liver cirrhosis and ascites [mean age 48 (SD 16.4) years; 146 men] between August 2007 and December 2008. Alcohol was the most common (124 of 175; 70.8%) cause of liver cirrhosis. All patients underwent abdominal paracentesis, and the ascitic fluid was processed for cell count, LER strip (Magistik 10) test and culture. Two different cut-offs for calling the LER strip test positive were tried, namely when the color turned light blue [grade 2: >125 polymorphonuclear leucocytes (PMNL)/microL] or it turned purple (grade 3: >500 PMNL/microL). Sensitivity, specificity, positive predictive value, negative predictive value were calculated, using PMN count by microscopy exceeding 250 PMNL/microL.
  
  
  RESULTS
  LER strip using the more stringent purple-color cut off to diagnose SBP had a sensitivity of 92% and specificity of 100%. The corresponding figures using the light-blue color cut-off were 97% and 89%, respectively.
  
  
  CONCLUSIONS
  LER strip testing of ascitic fluid is a rapid, cheap and sensitive bed side tool for the diagnosis of SBP.
authors.affiliation: Department of Gastroenterology, Calicut Medical College, Kerala, India.
authors.forename: Sithara K
authors.initials: SK
authors.lastname: Balagopal
authors.forename: Ashik
authors.initials: A
authors.lastname: Sainu
authors.forename: Varghese
authors.initials: V
authors.lastname: Thomas
mesh_terms: D000328:Adult; D001202:Ascitic Fluid / Q000201:enzymology*; D001424:Bacterial Infections / Q000175:diagnosis* / Q000201:enzymology / Q000209:etiology; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications / Q000201:enzymology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010538:Peritonitis / Q000175:diagnosis* / Q000201:enzymology / Q000382:microbiology; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D012372:ROC Curve; D011934:Reagent Strips
chemical_list: D011934:Reagent Strips; C021443:leukocyte esterase; D002265:Carboxylic Ester Hydrolases