title: New sensitive method for the measurement of lysozyme and lactoferrin for the assessment of innate mucosal immunity. part I: time-resolved immunofluorometric assay in serum and mucosal secretions.
abstract: Mucous peristalsis, mucus and immunity proteins, such as lysozyme and lactoferrin, are part of humoral innate immunity. The aim of this study was to develop a quantitative method, a time-resolved-immunofluorometric assay, to measure lysozyme and lactoferrin in sera, saliva, stools and cervico-vaginal secretions. This method was validated in 51 healthy subjects. Linearity for lysozyme was between 1.02 and 25 microg/l and for lactoferrin between 1.02 and 100 microg/l. The detection limit was 0.5 microg/l for lysozyme and 1 microg/l for lactoferrin. Albumin and alpha1-antitrypsin were measured by immuno-nephelometry to calculate salivary, intestinal and cervico-vaginal coefficients of excretion. Lysozyme and lactoferrin were present in all types of mucosal surfaces. Very high concentrations of lysozyme and lactoferrin were found in cervico-vaginal fluid (166.2 and 72.7 mg/l, respectively), compared to the concentrations found in the other mucosal fluids. Lysozyme in stools was produced at the rate of 0.42 mg/d compared to 0.02 mg/d lactoferrin production. Lysozyme and lactoferrin greatly exceeded the values expected from the molecular weight-affected seepage from plasma, suggesting primarily local synthesis in healthy subjects. Quantitative measurement of lysozyme and lactoferrin can aid in the assessment of the activity of mucus-associated lymphoid tissues in innate immunity, and can help in further understanding of the role of these proteins in mucosal diseases.
authors.affiliation: Laboratoires de Parasitologie-Mycologie (EA 482) et Immunologie (EA 3181), Faculté de Médecine-Pharmacie, Besançon, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bard
authors.forename: Sophy
authors.initials: S
authors.lastname: Laibe
authors.forename: Dominique
authors.initials: D
authors.lastname: Bettinger
authors.forename: Didier
authors.initials: D
authors.lastname: Riethmuller
authors.forename: Sabeha
authors.initials: S
authors.lastname: Biichlé
authors.forename: Estelle
authors.initials: E
authors.lastname: Seilles
authors.forename: Dominique
authors.initials: D
authors.lastname: Meillet
mesh_terms: D000293:Adolescent; D000328:Adult; D000418:Albumins / Q000032:analysis; D012634:Bodily Secretions / Q000378:metabolism; D005243:Feces; D005260:Female; D015200:Fluoroimmunoassay / Q000379:methods*; D006801:Humans; D007781:Lactoferrin / Q000097:blood* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism*; D009113:Muramidase / Q000097:blood* / Q000378:metabolism*; D015203:Reproducibility of Results; D012463:Saliva / Q000378:metabolism; D012680:Sensitivity and Specificity; D013997:Time Factors; D000515:alpha 1-Antitrypsin / Q000032:analysis
chemical_list: D000418:Albumins; D000515:alpha 1-Antitrypsin; D009113:Muramidase; D007781:Lactoferrin