title: LDH concentration in nasal-wash fluid as a biochemical predictor of bronchiolitis severity.
abstract: OBJECTIVE
  Because the decision to hospitalize an infant with bronchiolitis is often supported by subjective criteria and objective indicators of bronchiolitis severity are lacking, we tested the hypothesis that lactate dehydrogenase (LDH), which is released from injured cells, is a useful biochemical indicator of bronchiolitis severity.
  
  
  METHODS
  We retrospectively analyzed a study of children <24 months old presenting to the emergency department with bronchiolitis. Demographic, clinical information, nasal wash (NW), and serum specimens were obtained. NW samples were analyzed for respiratory viruses, caspase 3/7 activity, and a panel of cytokines and chemokines. Total LDH activity was tested in NW samples and sera.
  
  
  RESULTS
  Of 101 enrolled children (median age: 5.6 months), 98 had NW specimens available. A viral etiology was found for 82 patients (83.6%), with respiratory syncytial virus (RSV) (66%) and rhinovirus (19%) being the most common viruses detected. Concentrations of LDH in NW specimens were independent from those in sera and were higher in children with RSV infection or with dual infection. Significant correlations were found between NW LDH and NW cytokines/chemokines. Similarly, NW LDH correlated with NW-caspase 3/7 activity (r = 0.75; P < .001). In a multivariate analysis, NW LDH concentration in the upper quartile was significantly associated with a reduced risk of hospitalization (odds ratio: 0.19 [95% confidence interval: 0.05-0.68]; P = .011).
  
  
  CONCLUSIONS
  NW LDH levels in young children with bronchiolitis varied according to viral etiology and disease severity. Values in the upper quartile were associated with approximately 80% risk reduction in hospitalization, likely reflecting a robust antiviral response. NW LDH may be a useful biomarker to assist the clinician in the decision to hospitalize a child with bronchiolitis.
authors.affiliation: Baylor College of Medicine, Department of Pediatrics, One Baylor Plaza, Room 248E (MS280), Houston, TX 77030, USA. laham@bcm.edu
authors.forename: Federico R
authors.initials: FR
authors.lastname: Laham
authors.forename: Amanda A
authors.initials: AA
authors.lastname: Trott
authors.forename: Berkeley L
authors.initials: BL
authors.lastname: Bennett
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Kozinetz
authors.forename: Alan M
authors.initials: AM
authors.lastname: Jewell
authors.forename: Roberto P
authors.initials: RP
authors.lastname: Garofalo
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Piedra
mesh_terms: D017209:Apoptosis / Q000502:physiology; D001988:Bronchiolitis / Q000378:metabolism* / Q000821:virology; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007770:L-Lactate Dehydrogenase / Q000032:analysis*; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D017817:Nasal Lavage Fluid / Q000737:chemistry*; D018357:Respiratory Syncytial Virus Infections / Q000150:complications / Q000378:metabolism; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D016207:Cytokines; D007770:L-Lactate Dehydrogenase