Neutralization of human parvovirus B19 by plasma and intravenous immunoglobulins

Abstract

BACKGROUND:Human parvovirus B19 (B19V) is a highly prevalent pathogen, and plasma pools for manufacturing of plasma-derived products have been shown to contain antibodies against B19V (B19V immunoglobulin G [IgG]). STUDY DESIGN AND METHODS:The megakaryoblastic cell line UT7/Epo-S1 can be infected with B19V Genotype 1 and as demonstrated here by immunocytochemistry, Western blot, and reverse transcriptionpolymerase chain reaction (RT-PCR) of B19V-specific mRNA, also with the more recently discovered Genotype 2. Based on B19V RT-PCR analysis of infected UT7/Epo-S1 cells, an infectivity assay was established and implemented for a B19V neutralization assay. To investigate the role of B19V neutralization in relation to B19V IgG titers, more than 1000 manufacturing plasma pools were tested by enzyme-linked immunosorbent assay. RESULTS: Plasma pools were found to contain a mean B19V IgG titer of 33 Ϯ 9 IU per mL, with the lowest titer at 11 IU per mL. These 11 IU per mL B19V IgG neutralized 4.6 log B19V Genotype 1 and greater than 3.9 log Genotype 2 infectivity. Accordingly, a 10 percent intravenous immunoglobulin (IVIG) product prepared from such pools was found to contain an even higher B19V neutralization capacity. CONCLUSION: A high capacity of B19V Genotypes 1 and 2 neutralization was demonstrated in plasma pools for fractionation, an inherent feature based on the constantly high titer of B19V IgG in these pools. The neutralizing activity of B19V IgG was shown to be maintained in the 10 percent IVIG product tested.

Peptides Designed To Spatially Depict the Epstein-Barr Virus Major Virion Glycoprotein gp350 Neutralization Epitope Elicit Antibodies That Block Virus-Neutralizing Antibody 72A1 Interaction with the Native gp350 Molecule

“…The determination of human IgG reactivity against each of the three peptides could serve as a surrogate indicator of whether the gp350 mimetic peptides would be immunogenic or capable of generating an anti-gp350 antibody response. When the mimetic peptides were assayed with human EBV immune serum derived from 39 unique lots of IVIG, each of which was representative of Ͼ1,000 healthy blood donor units (32,33), all three peptides were found to be recognized (Fig. 6).…”

Hepatitis A virus antibodies in immunoglobulin preparations

“…They are therefore valuable seroepidemiologic tools, as recently shown through a demonstration of the gradual US seroconversion after introduction of the West Nile virus in 1999 6 or through the determination of population segments with increased human parvovirus B19 antibody levels. 7 Infection with HAV has variable outcomes, ranging from asymptomatic infection to fulminant hepatitis. The disease occurs worldwide and remains of economic importance; a recent analysis estimated costs of US$133.5 million during the lifetime of a single age cohort of children born in 2005 in the US.…”

Characterizing Viral Exanthems

“…This is even more likely in patients with illnesses that have already shortened the lifespan of erythrocytes, such as iron-deficiency anemia, HIV, sickle cell disease, thalassemia and sphero cytosis. Although treatment is supportive, at-risk patients may require transfusions or intravenous immunoglobulin therapy [15,16].…”