High prevalence of antibodies against polyomavirus WU, polyomavirus KI, and human bocavirus in German blood donors

Florian Neske,Andreas Opitz,Moritz Ewald,Christiane Prifert,Jörg Schubert,Benedikt Weissbrich,Barbara Scheiner

doi:10.1186/1471-2334-10-215

Abstract

BackgroundDNA of the polyomaviruses WU (WUPyV) and KI (KIPyV) and of human bocavirus (HBoV) has been detected with varying frequency in respiratory tract samples of children. However, only little is known about the humoral immune response against these viruses. Our aim was to establish virus-specific serological assays and to determine the prevalence of immunoglobulin G (IgG) against these three viruses in the general population.MethodsThe capsid proteins VP1 of WUPyV and KIPyV and VP2 of HBoV were cloned into baculovirus vectors and expressed in Sf9 insect cells. IgG antibodies against WUPyV VP1, KIPyV VP1, and HBoV VP2 were determined by immunofluorescence assays in 100 plasma samples of blood donors.ResultsThe median age of the blood donors was 31 years (range 20 - 66 yrs), 52% were male. 89% of the samples were positive for WUPyV IgG (median age 31 yrs, 49.4% male), 67% were positive for KIPyV IgG (median age 32 yrs, 46.3% male), and 76% were positive for HBoV IgG (median age 32 yrs, 51.3% male). For WUPyV and HBoV, there were no significant differences of the seropositivity rates with respect to age groups or gender. For KIPyV, the seropositivity rate increased significantly from 59% in the age group 20 - 29 years to 100% in the age group > 50 years.ConclusionsHigh prevalences of antibodies against WUPyV, KIPyV, and HBoV were found in plasma samples of healthy adults. The results indicate that primary infection with these viruses occurs during childhood or youth. For KIPyV, the seropositivity appears to increase further during adulthood.

Highlights

DNA of the polyomaviruses WU (WUPyV) and KI (KIPyV) and of human bocavirus (HBoV) has been detected with varying frequency in respiratory tract samples of children
To determine the frequency of past exposure with WUPyV, KIPyV, and HBoV in healthy adults, 100 blood donor plasma samples were tested for the presence of immunoglobulin G (IgG) against WUPyV VP1, KIPyV VP1, and HBoV VP2 using an immunofluorescence assay (IFA) based on Sf9 cells infected with the recombinant baculoviruses (Figure 2)
In order to further confirm the specificity of positive IFA results, three plasma samples were studied in an absorption assay

Summary

Introduction

DNA of the polyomaviruses WU (WUPyV) and KI (KIPyV) and of human bocavirus (HBoV) has been detected with varying frequency in respiratory tract samples of children. Infections of the respiratory tract are a major cause of human morbidity They are most often caused by respiratory viruses, which include the well-known pathogens respiratory syncytial virus, influenza viruses A and B, adenoviruses, parainfluenza viruses, rhinoviruses, and coronaviruses. A number of unknown viruses have been identified in the respiratory tract by molecular methods, including the human metapneumovirus, several corona viruses, the human bocavirus (HBoV), and most recently the polyomaviruses WU (WUPyV) and KI (KIPyV) [1,2,3,4]. Initial studies on WUPyV and KIPyV have looked at genome detection rates using polymerase chain reaction (PCR) methods. One study describing the seroepidemiology of polyomaviruses including WUPyV and KIPyV in adults has recently been published [12]

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