title: Opsonophagocytic Antibodies to Serotype Ia, Ib, and III Group B Streptococcus among Korean Infants and in Intravenous Immunoglobulin Products.
abstract: Group B streptococcus (GBS) infection is a leading cause of sepsis and meningitis among infants, and is associated with high rates of morbidity and mortality in many countries. Protection against GBS typically involves antibody-mediated opsonization by phagocytes and complement components. The present study evaluated serotype-specific functional antibodies to GBS among Korean infants and in intravenous immunoglobulin (IVIG) products. An opsonophagocytic killing assay (OPA) was used to calculate the opsonization indices (OIs) of functional antibodies to serotypes Ia, Ib, and III in 19 IVIG products from 5 international manufacturers and among 98 Korean infants (age: 0-11 months). The GBS Ia, Ib, and III serotypes were selected because they are included in a trivalent GBS vaccine formulation that is being developed. The OI values for the IVIG products were 635-5,706 (serotype Ia), 488-1,421 (serotype Ib), and 962-3,315 (serotype III), and none of the IVIG lots exhibited undetectable OI values (< 4). The geometric mean OI values were similar for all 3 serotypes when we compared the Korean manufacturers. The seropositive rate among infants was significantly lower for serotype Ia (18.4%), compared to serotype Ib and serotype III (both, 38.8%). Infant age of ≥ 3 months was positively correlated with the seropositive rates for each serotype. Therefore, only a limited proportion of infants exhibited protective immunity against serotype Ia, Ib, and III GBS infections. IVIG products that exhibit high antibody titers may be a useful therapeutic or preventive measure for infants. Further studies are needed to evaluate additional serotypes and age groups.
authors.affiliation: Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Han Wool
authors.identifier: http://orcid.org/0000-0003-3463-3060
authors.initials: HW
authors.lastname: Kim
authors.affiliation: Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea.|Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Ji Hyen
authors.identifier: http://orcid.org/0000-0002-2234-1055
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gachon University, Incheon, Korea.
authors.forename: Hye Kyung
authors.identifier: http://orcid.org/0000-0003-0990-1350
authors.initials: HK
authors.lastname: Cho
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyunju
authors.identifier: http://orcid.org/0000-0003-0107-0724
authors.initials: H
authors.lastname: Lee
authors.affiliation: Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Korea.
authors.forename: Ho Seong
authors.identifier: http://orcid.org/0000-0002-7103-1344
authors.initials: HS
authors.lastname: Seo
authors.affiliation: Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Soyoung
authors.identifier: http://orcid.org/0000-0001-9627-6607
authors.initials: S
authors.lastname: Lee
authors.affiliation: Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea.|Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea. kaykim@ewha.ac.kr.
authors.forename: Kyung Hyo
authors.identifier: http://orcid.org/0000-0002-0333-6808
authors.initials: KH
authors.lastname: Kim
mesh_terms: D000907:Antibodies, Bacterial / Q000276:immunology; D044466:Asian People; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000494:pharmacology / Q000627:therapeutic use*; D007223:Infant; D007231:Infant, Newborn; D009895:Opsonin Proteins / Q000276:immunology / Q000378:metabolism; D056910:Republic of Korea; D065288:Serogroup; D013290:Streptococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000907:Antibodies, Bacterial; D016756:Immunoglobulins, Intravenous; D009895:Opsonin Proteins
keywords: Antibodies; Immunoglobulins; Infant; Intravenous; Opsonin Proteins; Streptococcus agalactiae