RESUMO
BACKGROUND: hBoV, a recently discovered parvovirus, can be present in the respiratory tract of patients with acute respiratory diseases (ARD), but its etiologic involvement in the underlying diseases is still uncertain. OBJECTIVE: To determine in a retrospective study, the prevalence of hBoV, compared with common respiratory viruses (RV), in respiratory specimens from patients with ARD. STUDY DESIGN: A total of 335 specimens obtained over 7 years were examined. Two hundred were nasal swabs from infants hospitalized for ARD, 84 were nasal swabs or bronchoalveolar lavages from adults with pneumonia, bronchopneumonia or asthma, and 51 were nasal swabs from healthy children. RESULTS: The overall rate of hBoV detection in specimens from infants with ARD, which was 4.5%, varied slightly from year to year, except for the period 2000-2002, when no specimen was positive. Unlike other RV, no seasonal variation in hBoV incidence was noted. Infants with hBoV infection suffered either from bronchiolitis or from bronchopneumonia and 5 out of 9 cases yielded no co-infecting viral pathogen. Only one sample from an adult was hBoV positive. None of the nasal swabs from healthy subjects tested hBoV-positive. CONCLUSIONS: The findings indicate that hBoV can cause ARD in infants.
Assuntos
Bocavirus/classificação , Bocavirus/isolamento & purificação , Infecções por Parvoviridae/virologia , Doenças Respiratórias/virologia , Doença Aguda , Adolescente , Adulto , Idoso , Asma/virologia , Bocavirus/genética , Líquido da Lavagem Broncoalveolar/virologia , Broncopneumonia/virologia , Criança , Pré-Escolar , DNA Viral/química , DNA Viral/genética , Feminino , Humanos , Lactente , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Nariz/virologia , Infecções por Parvoviridae/epidemiologia , Filogenia , Pneumonia/virologia , Prevalência , Doenças Respiratórias/epidemiologia , Estudos Retrospectivos , Estações do Ano , Análise de Sequência de DNARESUMO
Active infection with torquetenovirus (TTV) has been associated with an increased severity of diseases in which inflammation plays a particularly important pathogenetic role. Here, we report that cloned DNA of a genogroup 4 TTV (ViPiSAL) is an activator of proinflammatory cytokine production by murine spleen cells and that the effect is mediated via toll-like receptor (TLR)9. The same DNA also increased the levels of proinflammatory cytokines induced by two well-characterized TLR9 stimulants. Finally, in silico analyses of the genomes of ViPiSAL and other TTVs revealed marked differences in the representation of CpG motifs known to be most effective at activating immune cells via TLR9. These findings demonstrate for the first time that at least one TTV isolate has the potential to stimulate and co-stimulate inflammatory responses.
Assuntos
Citocinas/biossíntese , DNA Viral/imunologia , Mediadores da Inflamação/metabolismo , Receptor Toll-Like 9/metabolismo , Torque teno virus/imunologia , Animais , Células Cultivadas , Ilhas de CpG , Citocinas/genética , DNA Viral/química , DNA Viral/genética , Expressão Gênica , Genoma Viral , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Interferon gama/biossíntese , Interferon gama/genética , Interleucina-10/biossíntese , Interleucina-10/genética , Interleucina-6/biossíntese , Interleucina-6/genética , Camundongos , Baço/citologia , Baço/imunologia , Baço/virologia , Torque teno virus/classificação , Torque teno virus/genética , Torque teno virus/patogenicidadeRESUMO
An apparently transient infection by a superimposed torquetenovirus (TTV) in a subject who already carried three different genotypes of the virus is described. The superinfection induced a rapid increase in the plasma TTV load and a decline in immunocomplexed virus. The superinfecting TTV was a novel group 2 genotype.