Detection of SARS-CoV-2 Antibodies in Immunoglobulin Products

BACKGROUND: For patients with primary antibody deficiency, the first line of therapy is replacement with immunoglobulin (Ig) products. Prior to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, Ig products did not contain antibodies with specificity for this virus, and there have been limited data on the antibodies present in the Ig products in current use.OBJECTIVE: To quantitatively examine SARS-CoV-2 anti-bodies in current Ig products.METHODS: We examined 142 unique lots of 11 different Ig products intended for intravenous and/or subcutaneous delivery for IgG-binding activities against recombinant SARS-CoV-2 receptor binding domain, spike, and nucleocapsid proteins by enzyme-linked immunosorbent assays. In addition, to assess functionality, 48 of these unique lots were assessed for their ability to inhibit the variants SARS-CoV-2 Ancestral, Alpha, Beta, Delta, and Omicron spike binding to angiotensin-converting enzyme 2 (ACE2).RESULTS: Significantly increased antibody values were observed for products manufactured after the year 2020 (expiration dates 2023e2024), as compared with Ig products before 2020 (prepandemic). Sixty percent and 85% of the Ig products with

Automated summary

This study quantitatively examined SARS-CoV-2 antibodies in current Ig products and found significantly increased antibody values in products manufactured after 2020. Enzyme-linked immunosorbent assays were used to assess IgG-binding activities against recombinant SARS-CoV-2 proteins and the ability to inhibit SARS-CoV-2 variants from binding to receptors.