BACKGROUND: Intravenous immunoglobulin G (IVIG) replacement therapy is used to prevent invasive infections in patients with primary antibody deficiency (PAD). However, few studies have functionally evaluated specific antibodies against encapsulated bacteria that cause invasive infection in patients with PAD. In this study, functional antibodies against Haemophilus influenzae type b (Hib), Streptococcus pneumoniae (pneumococci), and Neisseria meningitidis (meningococci) in IVIG therapy were evaluated. STUDY DESIGN AND METHODS: Sixteen lots of IVIG products prepared by two Korean manufacturers (Products A and B) were evaluated. The functional antibodies were measured by serum bactericidal assay for Hib and four meningococcal serogroups and by multiplexed opsonophagocytic assay for 26 pneumococcal serotypes. The estimated trough levels of antibodies against Hib, pneumococcus, and meningococcus were calculated to determine whether the usual IVIG dose is appropriate for protecting patients with PAD. RESULTS: The functional antibody levels for Hib were similar in all of the IVIG products. In contrast, serum bacterial indices of meningococcal serogroups A and Y showed significant differences between products A and B. Opsonic indices to pneumococci varied depending on the serotype in each IVIG product. The estimated trough levels of antibodies against Hib, pneumococcus, and meningococcus exceeded the protective levels in most of the IVIG products except for the antibodies against two pneumococcal serotypes. CONCLUSION: Most of the tested commercial IVIG products had sufficient functional antibodies against Hib, pneumococcus, and meningococcus to protect patients with PAD receiving IVIG treatment. Regular and continuous evaluation of IVIG products is necessary to maintain an optimal therapeutic effect.
Bibliographical noteFunding Information:
We appreciate Green Cross Corp. (Yongin-si, Republic of Korea) and SK Chemicals (Seongnam-si, Republic of Korea) for providing the IVIG products. We thank Dr Moon Nahm (Birmingham, AL) for providing the target pneumococcal strains for the multiplexed opsonophagocytic assay (MOPA). The University of Alabama at Birmingham (UAB) owns intellectual property rights to the reagents used for the MOPA studies. We also thank the serologic laboratory teams at the Ewha Center for Vaccine Evaluation and Study and, in particular, Je Eun Cha and Soo Young Lim for laboratory support. Research conception and design—SL, HWK, and KHK; data acquisition—SL and HWK; data analysis and interpretation—SL and HWK; statistical analysis—SL and HWK; drafting of the manuscript—SL and HWK; critical revision of the manuscript—KHK; receiving grant—KHK; and approval of final manuscript—LS, HWK, and KHK.
© 2016 AABB