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.

STUDY DESIGN AND 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.

CONCLUSION

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.