title: Serum measurements of human neutrophil lipocalin (HNL) discriminate between acute bacterial and viral infections.
abstract: Human neutrophil lipocalin (HNL) is a recently identified protein from human neutrophil granules. The concentrations of HNL in the circulation were measured, in a group of patients with acute infections, using a radioimmunoassay. The concentrations of HNL in patients infected by viruses and bacteria were 93.78 +/- 45.30 micrograms l-1 (SD), 404.14 +/- 355.02 micrograms l-1 (SD) in serum, and 47.81 +/- 18.18 micrograms l-1 (SD), 145.46 +/- 194.32 micrograms l-1 (SD) in plasma, respectively. The differences between the two patient groups were highly significant. There was a significant correlation between serum HNL and plasma HNL levels in bacterial infections (r = 0.73, p < 0.0001). The HNL serum levels also correlated with those of C-reactive protein (CRP) (r = 0.59, p < 0.0001). Determination of HNL in serum was more specific and sensitive than CRP in the distinction between viral and bacterial infections. At a cut-off of 155 micrograms l-1 (HNL in serum), the positive and negative predictive values for the diagnosis of bacterial infections were 92 and 96%, respectively, which were superior to the optimal predictive values of CRP. Thus, the determination of HNL level is useful in the diagnosis of acute bacterial infections.
authors.affiliation: Department of Clinical Chemistry, University Hospital, Uppsala, Sweden.
authors.forename: S Y
authors.initials: SY
authors.lastname: Xu
authors.forename: K
authors.initials: K
authors.lastname: Pauksen
authors.forename: P
authors.initials: P
authors.lastname: Venge
mesh_terms: D000209:Acute-Phase Proteins; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000097:blood / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D002352:Carrier Proteins / Q000097:blood*; D002648:Child; D003594:Cytoplasmic Granules / Q000737:chemistry*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000737:chemistry* / Q000648:ultrastructure; D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins; D011863:Radioimmunoassay; D012680:Sensitivity and Specificity; D013997:Time Factors; D014777:Virus Diseases / Q000097:blood / Q000175:diagnosis*
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; D002352:Carrier Proteins; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins; D002097:C-Reactive Protein