Immune Pathological Mechanism Of WU Polyomavirus In Acute Respiratory Tract Infection In Children

Background and objective WU polyomavirus (WUPyV), a new member of the genus of Polyomavirus in the family Polyomaviridae, has been found and associated with respiratory tract infections recently. But the role of the WU polyomavirus as agents of human disease remains uncertain .We sought to investigate the immune pathological mechanism of WU polyomavirus (WUPyV) in acute respiratory tract infection in Children through the changes of cytokines in peripheral blood.Material and methodsMaterial From July 2008 through May 2010, throat swabs and peripheral blood were collected from 1253 children who were hospitalized with acute respiratory tract infection in Second Affiliated Hospital of Shantou University Medical College, and 82 were asymptomatic who visited the health checkup clinic.Methods WU Polyomaviruses and 9 commonly respiratory infectious viruses ( RSV; human bocavirus; human metapneumovirus; adenovirus ; influenza A and B; PIV 1 and 3; rhinovirus) were detected by using PCR or RT-PCR. The cytokines (IFN-γ,IL-1β,IL-1α,IL-2,IL-4,IL-6,IL-8,IL-10,IL-12p70,IL-12p40,IL-13,TNF-α) were detected in serum of peripheral blood, which collected from 22 healthy children,15 patients solely infected with WUPyV and 20 patients solely infected with RSV, using Luminxe simultaneously.Results1. In this study, 32 of the 1253 tested specimens with acute respiratory tract infection were positive for WU polyomavirus (2.55%). WU polyomavirus was the sole virus detected in 15 specimens (46.88%) from patients with acute respiratory tract infection, and 17of 32 (53.13%) specimens infected with WU polyomavirus were co-infected with other viruses, such as RSV, ADV, IVA, and HRV. Of the 158 tested specimens with acute respiratory tract infection were positive for RSV. RSV was the sole virus detected in 85 specimens (12.61%) from patients with acute respiratory tract infection, and 73 specimens(46.20%) infected with RSV were co-infected with other 9 viruses. All of the asymptomatic children who visited the well-being clinic were negative.2. Levels of IL-6,IL-8,IL-1β,TNF-α,IL-12p40 elevated in patients infected with WUPyV was all higher than heathy control subjects,and the differences were statistically significant(P<0.05). Levels of IL-6,IL-8,IL-1β,TNF-α,IL-12p40 elevated in patients infected with RSV was all higher than heathy control subjects,and the differences were statistically significant (P<0.01). The levels of those 5 cytokines in patients infected with WUPyV were lower than those in patients infected with RSV, but the differences had no statistical significance (P>0.05). The levels of IL-2,IL-4,IL-1α,INF-γof the two virus groups were higher than healthy control subjects, but the differences all had no statistical significance (P>0.05). Levels of IL-10,IL-12p70,IL-13 were not detected in serum nearly and therefore were not included in our analyses.Conclusions Infection with WU polyomavirus could made abnormal immune function in children with acute respiratory tract infection, and the pattern was similar to those children infected with RSV,but the degree of the changes of cytokines was lower than those infected with RSV.