Mass value assignment of total and subclass immunoglobulin G in a human standard anthrax reference serum

• Published in: Clinical and diagnostic laboratory immunology Vol. 11; no. 5; pp. 919 - 923
• Main Authors: Semenova, V A, Steward-Clark, E, Stamey, K L, Taylor, Jr, T H, Schmidt, D S, Martin, S K, Marano, N, Quinn, C P
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01-09-2004
• Subjects: Anthrax Vaccines - immunology; Antibodies and Mediators of Immunity; Antibodies, Bacterial - blood; Antibody Formation; Antigens, Bacterial - immunology; Bacterial Toxins - immunology; Enzyme-Linked Immunosorbent Assay - standards; Humans; Immunodiffusion - standards; Immunoglobulin G - blood; Immunoglobulin G - classification; Reference Standards
• ISSN: 1071-412X; 1098-6588
• DOI: 10.1128/CDLI.11.5.919-923.2004

An anti-Anthrax Vaccine Adsorbed (anti-AVA) standard human reference serum pool, AVR414, has been prepared, and the total and protective antigen (PA)-specific immunoglobulin G (IgG) were quantified. AVR414 was prepared by plasmapheresis of healthy adults who had received a minimum of four subcutaneous injections of AVA. Mass values (in milligrams per milliliter) for total IgG and IgG subclasses 1 to 4 were determined by radial immunodiffusion. Anti-PA-specific IgG assignment (in micrograms per milliliter) was done by consensus of two complementary approaches: homologous enzyme-linked immunosorbent assay (ELISA) with affinity-purified anti-PA IgG as a calibrator and summation of mean PA-specific IgG subclass concentrations determined by IgG subclass-specific ELISA using the United States National Reference Preparation for Human Serum Proteins as a standard. The total IgG concentration assigned to AVR414 reference serum was 8.33 mg/ml. IgG subclass concentrations were the following: for IgG1, 4.48 mg/ml; for IgG2, 3.35 mg/ml; for IgG3, 0.37 mg/ml; and for IgG4, 0.30 mg/ml. The assigned mass value for total anti-PA-specific IgG was 141.2 microg/ml. Anti-PA-specific IgG subclass concentrations were the following: for IgG1, 79.6 microg/ml; for IgG2, 35.3 microg/ml; for IgG3, 3.2 microg/ml; and for IgG4, 25.3 microg/ml. Human reference serum pool AVR414 will have direct application in the standardization of anthrax serological assays, in reagent qualification, and as a standard for quantification of PA-specific IgG in humans who have been vaccinated with or otherwise exposed to Bacillus anthracis PA.