Assignment of immunoglobulin G1 and G2 concentrations to pneumococcal capsular polysaccharides 3, 6B, 14, 19F, and 23F in pneumococcal reference serum 89-SF.
We describe standardization of an enzyme-linked immunosorbent assay (ELISA) for measuring immunoglobulin G1 (IgG1) and IgG2 concentrations of antibodies to pneumococcal capsular polysaccharide (Pnc PS). The ELISA uses a human pneumococcal reference serum pool, lot 89-SF, as a reference. IgG1 and IgG2 concentrations were assigned to antibodies to Pnc PS serotypes 3, 6B, 14, 19F, and 23F in 89-SF by ELISA using affinity-purified monoisotypic IgG1 and IgG2 preparations. The sum of IgG1 and IgG2 concentrations in 89-SF agrees well with the previously assigned IgG concentrations. The IgG1 and IgG2 values in 89-SF were used to measure antibodies to Pnc PS 6B, 14, and 23F in adult pre- and postimmunization sera and the sum of IgG1 and IgG2 concentrations correlated well with the IgG values. Furthermore, the IgG2/IgG1 ratio did not affect the detection of IgG1, the isotype usually represented by a lower concentration.
Department of Vaccines, National Public Health Institute (KTL), Helsinki, Finland. anu.soininen@ktl.fi
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Soininen
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Seppälä
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Wuorimaa
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Käyhty
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines / Q000008:administration & dosage; D001667:Binding, Competitive; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000592:standards*; D005069:Evaluation Studies as Topic; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012015:Reference Standards; D013296:Streptococcus pneumoniae / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D007074:Immunoglobulin G; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate