An assay for parvovirus B19 neutralizing antibodies based on human hepatocarcinoma cell lines.
BACKGROUND
Although intravenous immune globulin (IVIG) is used widely for managing parvovirus B19 infections, IVIG products are not monitored routinely for the presence of parvovirus B19 neutralizing antibody.


METHODS
An assay has been developed to measure parvovirus B19 infectivity and neutralization activity based on two hepatocarcinoma cell lines (HepG2 and HuH7). The sources of parvovirus B19 were B19-DNA-containing plasma samples. Neosynthesized progeny in supernatants of infected cells were quantified by nested polymerase chain reaction. To validate the model, purified rabbit antibodies to different capsid protein sequences and IVIG preparations were tested.


RESULTS
The number of parvovirus B19 infectious neovirions in supernatants of infected cells increased with infection time. Both rabbit antibodies and IVIG products inhibited parvovirus B19 infectivity when incubated overnight with virus. The efficacy of IVIG to neutralized parvovirus B19 was product-related.


CONCLUSIONS
This assay for parvovirus B19 neutralization activity provides an improved and more specific method for selecting donors to produce IVIG with a high titer of parvovirus B19 neutralizing activity.
Laboratory of Molecular Virology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium. pcaillet@ulb.ac.be
Perrine
P
Caillet-Fauquet
Mario
M
Di Giambattista
Marie-Louise
ML
Draps
Vincent
V
Hougardy
Yvan
Y
de Launoit
Ruth
R
Laub
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis*; D000956:Antigens, Viral / Q000276:immunology; D036022:Capsid Proteins / Q000276:immunology; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D045744:Cell Line, Tumor; D017077:Culture Media, Conditioned; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D016756:Immunoglobulins, Intravenous / Q000276:immunology*; D008113:Liver Neoplasms / Q000473:pathology; D009500:Neutralization Tests; D016732:Parvovirus B19, Human / Q000254:growth & development / Q000276:immunology* / Q000302:isolation & purification / Q000502:physiology; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D016133:Polymerase Chain Reaction; D011817:Rabbits; D014776:Virus Cultivation; D014779:Virus Replication
D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; D017077:Culture Media, Conditioned; D007074:Immunoglobulin G; D016756:Immunoglobulins, Intravenous; D010446:Peptide Fragments; C095547:capsid protein VP1, parvovirus B19