Dating of human bocavirus infection with protein-denaturing IgG-avidity assays-Secondary immune activations are ubiquitous in immunocompetent adults

作者：Hedman Lea; Soderlund Venermo Maria; Jartti Tuomas; Ruuskanen Olli; Hedman Klaus^*

来源：Journal of Clinical Virology, 2010, 48(1): 44-48.

DOI：10.1016/j.jcv.2010.02.003

• Anamnestic response
• Antibody affinity
• Immunoglobulin
• Parvovirus
• Serodiagnosis

Background: Humanbocavirus (HBoV) is a widespread human parvovirus causing acute respiratory illness in young children. The HBoV primary infections are viremic and can be diagnosed serologically.
Objectives: To set up HBoV-IgG-avidity enzyme immuno assays (EIAs) using as antigen recombinant VP2 virus-like particles (VLPs), for diagnosis and timing of primary infections and their distinction from secondary infections or immunoactivations by this recently found virus.
Study design: The VLPs were utilized in setting up HBoV-IgG-avidity-EIAs of two different types. Paired sera were available from 36 wheezing children with acute primary HBoV infection, single sera from 108 nonsymptomatic university students, and 84 single or follow-up sera from 38 adults with pre-existing HBoV immunity.
Results: HBoV-IgG avidity for the VP2-VLPs was measured successfully by protein-denaturing EIAs of two types, employing low concentrations of urea (4.7 M and 2.5 M). The diagnostic specificities were 99.1% and 90.7%, and diagnostic sensitivities, 94.4% and 91.7%, respectively. Interestingly, of the adults followed up 44% (4/9) exhibited significant titre increases of past-immunity HBoV-IgG.
Conclusions: Diagnosis of HBoV primary infection can be strengthened by measurement of IgG avidity. HBoV secondary infections or anamnestic antibody responses occur ubiquitously in immunocompetent adults.

• 出版日期2010-5