title: Intravenous immunoglobulin products contain specific antibodies to recombinant human tau protein.
abstract: Intravenous immunoglobulin (IVIG) products are prepared from plasma immunoglobulins from healthy donors. Pilot studies suggest that IVIG may stabilize cognitive functioning in patients with mild-to-moderate Alzheimer's disease. This study measured antibodies to recombinant human tau protein in the IVIG products Gammagard (Baxter), Gamunex (Talecris), and Flebogamma (Grifols). Anti-tau antibodies were measured by ELISA, subtracting IVIG's polyvalent binding from its binding to tau-coated wells to calculate specific anti-tau antibody levels. Because polyvalent binding of IVIG products may interfere with ELISA measurement of their specific antibody levels, the percentage of binding of each IVIG product to tau-coated wells that was specific for tau was also determined. Specific anti-tau antibodies were detected in all three IVIG products, with significant differences between these products (p<0.001) even when Flebogamma's anti-tau antibodies were doubled to account for its preparation as a 5% solution vs. 10% solutions for Gammagard and Gamunex (means: Gammagard, 3.1 μg/ml; Gamunex, 2.5 μg/ml; Flebogamma, 1.2 μg/ml). The percentages of each IVIG product's specific binding to tau-coated wells also varied between the various products (p<0.001) and between all pairs of IVIG products (means: Gammagard, 73.1%; Flebogamma, 54.5%; Gamunex, 37.4%; p<0.01 for all pairwise comparisons). These findings indicate that IVIG products contain specific anti-tau antibodies. The concentrations of these antibodies and the percentages of specific binding of IVIG to tau-coated wells vary between IVIG products. Further studies are indicated to determine if IVIG also contains antibodies to pathologic forms of tau.
authors.affiliation: Department of Neurology Research, Beaumont Research Institute, Beaumont Health System, 3811 West Thirteen Mile Road, Royal Oak, MI 48073, USA.
authors.forename: Lynnae M
authors.initials: LM
authors.lastname: Smith
authors.forename: Mary P
authors.initials: MP
authors.lastname: Coffey
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Klaver
authors.forename: David A
authors.initials: DA
authors.lastname: Loeffler
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000302:isolation & purification*; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000737:chemistry* / Q000276:immunology; D011485:Protein Binding; D011994:Recombinant Proteins; D016875:tau Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D016756:Immunoglobulins, Intravenous; D011994:Recombinant Proteins; D016875:tau Proteins