title: Increased β-glucuronidase activity in bronchoalveolar lavage fluid of children with bacterial lung infection: A case-control study.
abstract: OBJECTIVE
  β-Glucuronidase is a lysosomal enzyme released into the extracellular fluid during inflammation. Increased β-glucuronidase activity in the cerebrospinal and peritoneal fluid has been shown to be a useful marker of bacterial inflammation. We explored the role of β-glucuronidase in the detection of bacterial infection in bronchoalveolar lavage fluid (BALF) of paediatric patients.
  
  
  METHODS
  In this case-control study, % polymorphonuclear cell count (PMN%), β-glucuronidase activity, interleukin-8 (IL-8), tumour necrosis factor-α (TNF-α) and elastase were measured in culture-positive (≥10(4) cfu/mL, C+) and -negative (C-) BALF samples obtained from children.
  
  
  RESULTS
  A total of 92 BALF samples were analysed. The median β-glucuronidase activity (measured in nanomoles of 4-methylumbelliferone (4-MU)/mL BALF/h) was 246.4 in C+ (interquartile range: 71.2-751) and 21.9 in C- (4.0-40.8) (P < 0.001). The levels of TNF-α and IL-8 were increased in C+ as compared with C- (5.4 (1.7-12.6) vs 0.7 (0.2-6.2) pg/mL, P < 0.001 and 288 (76-4300) vs 287 (89-1566) pg/mL, P = 0.042, respectively). Elastase level and PMN% did not differ significantly (50 (21-149) vs 26 (15-59) ng/mL, P = 0.051 and 20 (9-40) vs 18 (9-34) %, P = 0.674, respectively). The area under the curve of β-glucuronidase activity (0.856, 95% confidence interval (CI): 0.767-0.920) was higher than that of TNF-α (0.718; 95% CI: 0.614-0.806; P = 0.040), IL-8 (0.623; 95% CI: 0.516-0.722; P = 0.001), elastase (0.645; 95% CI: 0.514-0.761; P = 0.008) and PMN% (0.526; 95 % CI: 0.418-0.632; P < 0.001).
  
  
  CONCLUSIONS
  This study demonstrates a significant increase of β-glucuronidase activity in BALF of children with culture-positive bacterial inflammation. In our population β-glucuronidase activity showed superior predictive ability for bacterial lung infection than other markers of inflammation.
authors.affiliation: Respiratory Unit, Department of Paediatrics, University General Hospital of Patras, Rion-Patras, Greece.
authors.forename: Evgenia C
authors.initials: EC
authors.lastname: Panagiotopoulou
authors.affiliation: Respiratory Unit, Department of Paediatrics, University General Hospital of Patras, Rion-Patras, Greece.|Paediatric Pulmonology and Allergy Research Group, University of Patras, Rion-Patras, Greece.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Fouzas
authors.affiliation: Respiratory and Allergy Unit, Third Department of Paediatrics, 'Attikon' University General Hospital, Athens, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Douros
authors.affiliation: Biochemistry, Biochemical Analysis, Matrix Pathobiology Research Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, Rion-Patras, Greece.
authors.forename: Irene-Eva
authors.initials: IE
authors.lastname: Triantaphyllidou
authors.affiliation: Biochemistry, Biochemical Analysis, Matrix Pathobiology Research Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, Rion-Patras, Greece.
authors.forename: Christina
authors.initials: C
authors.lastname: Malavaki
authors.affiliation: Paediatric Pulmonology and Allergy Research Group, University of Patras, Rion-Patras, Greece.|Respiratory and Allergy Unit, Third Department of Paediatrics, 'Attikon' University General Hospital, Athens, Greece.|Department of Allergology-Pulmonology, Penteli Children's Hospital, Athens, Greece.
authors.forename: Kostas N
authors.initials: KN
authors.lastname: Priftis
authors.affiliation: Biochemistry, Biochemical Analysis, Matrix Pathobiology Research Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, Rion-Patras, Greece.
authors.forename: Nikos K
authors.initials: NK
authors.lastname: Karamanos
authors.affiliation: Respiratory Unit, Department of Paediatrics, University General Hospital of Patras, Rion-Patras, Greece.|Paediatric Pulmonology and Allergy Research Group, University of Patras, Rion-Patras, Greece.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Anthracopoulos
mesh_terms: D000293:Adolescent; D019540:Area Under Curve; D001424:Bacterial Infections / Q000175:diagnosis / Q000201:enzymology*; D015415:Biomarkers / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000166:cytology / Q000382:microbiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005966:Glucuronidase / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000382:microbiology; D016209:Interleukin-8 / Q000032:analysis; D007958:Leukocyte Count; D008168:Lung / Q000473:pathology; D008171:Lung Diseases / Q000201:enzymology* / Q000382:microbiology; D008297:Male; D009504:Neutrophils; D010196:Pancreatic Elastase / Q000032:analysis; D012372:ROC Curve; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000201:enzymology* / Q000382:microbiology; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D015415:Biomarkers; C508606:CXCL8 protein, human; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D005966:Glucuronidase; D010196:Pancreatic Elastase
keywords: airway inflammation; bacterial infection; bronchoalveolar lavage; child; β-glucuronidase