Pediatr Infect Vaccine.  2021 Apr;28(1):21-30. 10.14776/piv.2021.28.e4.

Opsonophagocytic Antibodies of Intravenous Immunoglobulin Preparations against Seven Streptococcus agalactiae Serotypes

  • 1Department of Pediatrics, Ewha Womans University Seoul Hospital, Seoul, the Republic of Korea
  • 2Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University College of Medicine, Seoul, the Republic of Korea
  • 3Department of Pediatrics, Hallym University Sacred Heart Hospital, Anyang, the Republic of Korea
  • 4Department of Pediatrics, Ewha Womans University Mokdong Hospital, Seoul, the Republic of Korea
  • 5Department of Pediatrics, Ewha Womans University College of Medicine, Seoul, the Republic of Korea


Group B streptococcus (GBS) is a causative organism of invasive infections in neonates and pregnant women as well as in non-pregnant adults. Among 10 known serotypes of GBS, uncommon serotypes, such as IV and VI to IX, can cause invasive infections in immunocompromised patients. However, opsonophagocytic antibodies against these serotypes in human sera and intravenous immunoglobulin (IVIG) have not yet been studied. IVIG therapy is used to treat or prevent invasive infections in patients with primary antibody deficiencies. Here, we analyzed the activity of opsonophagocytic antibodies against GBS in IVIG preparations.
Opsonophagocytic antibody activity (opsonic index [OI]) against seven GBS serotypes (II and IV to IX) was evaluated in 16 commercially available IVIG preparations using the opsonophagocytic assay (OPA) in HL-60 cells and baby rabbit complement assay during 2015–2016 in South Korea (UAB GBS OPA, at
The estimated serum trough levels of OIs against GBS exceeded the limit of detection (≥4) in all IVIG preparations. For serotype VII, the serum levels of OIs were 6–136, the lowest among all serotypes. An IVIG dose of 400 mg/kg was found to be appropriate for immunocompromised individuals to prevent invasive GBS infections.
Most immunoglobulin products displayed high levels of opsonophagocytic activity against GBS, except for serotype VII. IVIG preparations could serve as a therapeutic or immunomodulatory agent for immunocompromised individuals.


Streptococcus agalactiae; Opsonin; Phagocytosis; Immunoglobulins; Immunocompromised host
Full Text Links
  • PIV
export Copy
  • Twitter
  • Facebook
Similar articles
    DB Error: unknown error