Microorganisms (Feb 2023)

Cross-Reactivity of Antibodies in Intravenous Immunoglobulin Preparation for Protection against SARS-CoV-2

  • Toshifumi Osaka,
  • Yoko Yamamoto,
  • Takehisa Soma,
  • Naoko Yanagisawa,
  • Satoru Nagata

DOI
https://doi.org/10.3390/microorganisms11020471
Journal volume & issue
Vol. 11, no. 2
p. 471

Abstract

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Severe cases of COVID-19 continue to put pressure on medical operations by prolonging hospitalization, occupying intensive care beds, and forcing medical personnel to undergo harsh labor. The eradication of SARS-CoV-2 through vaccine development has yet to be achieved, mainly due to the appearance of multiple mutant-incorporating strains. The present study explored the utility of human intravenous immunoglobulin (IVIG) preparations in suppressing the aggravation of any COVID-19 infection using a SARS-CoV-2 pseudovirus assay. Our study revealed the existence of IgG antibodies in human IVIG preparations, which recognized the spike protein of SARS-CoV-2. Remarkably, the pretreatment of ACE2/TMPRSS2-expressing host cells (HEK293T cells) with IVIG preparations (10 mg/mL) inhibited approximately 40% entry of SARS-CoV-2 pseudovirus even at extremely low concentrations of IgG (0.16–1.25 mg/mL). In contrast, the antibody-dependent enhancement of viral entry was confirmed when SARS-CoV-2 pseudovirus was treated with some products at an IgG concentration of 10 mg/mL. Our data suggest that IVIG may contribute to therapy for COVID-19, including for cases caused by SARS-CoV-2 variants, since IVIG binds not only to the spike proteins of the virus, but also to human ACE2/TMPRSS2. An even better preventive effect can be expected with blood collected after the start of the COVID-19 pandemic.

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