title: Biologic and analytic components of variation of concentration values of selected serum proteins.
abstract: The magnitude and statistical significance of the various biologic and analytic sources of variation of the serum concentration values of seven proteins: albumin, alpha1-antitrypsin, transferrin, orosomucoid, IgG, IgM, and IgA, were evaluated in 12 healthy subjects. Blood specimens were obtained at 0800 h, 1100 h, and 1400 h on one particular day. The analytic error was partitioned into pre-instrumental and instrumental components; the biologic variation was separated into inter-subject variation of mean levels and intra-individual within-day variation. The mean levels of the subjects differed significantly for all seven proteins studied. For the group as a whole there were no consistent diurnal variations of significance. However, for all the proteins, except for IgM, significant individual within-day biologic fluctuations were noted. The within-day biologic variation was smaller than the total analytic variation for transferrin, IgG, orosomucoid, and IgM. When the total analytic variation was separated into pre-instrumental and instrumental components, it was found that the pre-instrumental sources of variation were of a relatively greater magnitude for albumin, IgG, IgA, alpha1-antitrypsin, and IgM.
mesh_terms: D000328:Adult; D001798:Blood Proteins / Q000032:analysis*; D002940:Circadian Rhythm; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008297:Male; D009961:Orosomucoid / Q000032:analysis; D012016:Reference Values; D012709:Serum Albumin / Q000032:analysis; D014168:Transferrin / Q000032:analysis; D000515:alpha 1-Antitrypsin / Q000032:analysis
chemical_list: D001798:Blood Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D009961:Orosomucoid; D012709:Serum Albumin; D014168:Transferrin; D000515:alpha 1-Antitrypsin