title: Quantitative analysis of complement receptors, CR1 (CD35) and CR3 (CD11b), on neutrophils improves distinction between bacterial and viral infections in febrile patients: comparison with standard clinical laboratory data.
abstract: There is an ongoing need for sensitive and specific markers of bacterial infection. In this prospective study, standard clinical laboratory data (neutrophil count, serum C reactive protein level, erythrocyte sedimentation rate) and quantitative flow cytometric analysis of neutrophil complement receptors, CR1 and CR3, were obtained from 289 hospitalized febrile patients. After microbiological confirmation or clinical diagnosis, 135 patients were found to have either bacterial (n = 89) or viral (n = 46) infection. The patient data was compared to 60 healthy controls. In bacterial infections, all measured variables were significantly increased, particularly the average amounts of CR1 and CR3 on neutrophils were over three-fold and two-fold higher, respectively, compared to viral infections and controls. We described a novel marker of local and systemic bacterial infections designated 'clinical infection score (CIS) point', which incorporates quantitative analysis of complement receptors on neutrophils and standard clinical laboratory data. CIS point varied between 0 and 8, and displayed 98% sensitivity and 97% specificity in distinguishing between bacterial and viral infections [average (S.D.); CIS points: 6.2 (1.7) vs. 0.6 (1.0); p < 0.001]. These findings suggest that the proposed CIS-based diagnostic test could potentially assist physicians in deciding whether antibiotic treatment is necessary.
authors.affiliation: Department of Biochemistry, University of Turku, Arcanum, Vatselankatu 2, 20014 Turku, Finland. jarnuu@utu.fi
authors.forename: Jari
authors.initials: J
authors.lastname: Nuutila
authors.forename: Ulla
authors.initials: U
authors.lastname: Hohenthal
authors.forename: Iina
authors.initials: I
authors.lastname: Laitinen
authors.forename: Pirkko
authors.initials: P
authors.lastname: Kotilainen
authors.forename: Allan
authors.initials: A
authors.lastname: Rajamäki
authors.forename: Jukka
authors.initials: J
authors.lastname: Nikoskelainen
authors.forename: Esa-Matti
authors.initials: EM
authors.lastname: Lilius
mesh_terms: D001424:Bacterial Infections / Q000097:blood / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D003627:Data Interpretation, Statistical; D003937:Diagnosis, Differential; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005334:Fever / Q000097:blood*; D006801:Humans; D016177:Macrophage-1 Antigen / Q000032:analysis / Q000097:blood*; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism*; D011446:Prospective Studies; D017463:Receptors, Complement 3b / Q000032:analysis / Q000097:blood*; D014777:Virus Diseases / Q000097:blood / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D016177:Macrophage-1 Antigen; D017463:Receptors, Complement 3b