Cross-reactive Antibodies against Avian Influenza Virus A (H5N1)

摘要

To the Editor: Intravenous im-munoglobulin (IVIg) is used to treat bacterial and viral infections in pa-tients with primary immunodeficiency disease and those with autoimmune and inflammatory disorders (1). IVIg contains pooled IgG from >1,000 blood donors and antibodies against various common human pathogens, including influenza virus A.We tested the efficacy of commer-cial preparations of IVIg (50 mg/mL of highly purified immunoglobulin) against homosubtypic influenza virus-es A (H1N1 and H3N2) and their cross-reactivity against avian influenza virus A (H5N1). IVIg preparations (Octag-am; Octapharma, Vienna, Austria and Flebogamma; Instituto Grifols, Bar-celona, Spain) had hemagglutination inhibition (HI) titers against subtypes H1N1 and H3N2 ranging from 20 to 40. Human Immunoglobulin, pH 4.0, (Harbin Sequel Bio-Engineering Phar-maceutical, Harbin, People's Republic of China) had lower HI titers against avian influenza viruses (10 for subtype H3N2 and <10 for subtype H1N1). As expected, we did not detect antibodies against hemagglutinin (HA) of sub-type H5N1 (A/open-billed/stork/Nah-konsawan/BBD0104F/2004) in any of the IVIg preparations (HI titer <10).