Torquetenovirus infection and ciliary dysmotility in children with recurrent pneumonia.
BACKGROUND
The aim of the study was to assess Torquetenovirus (TTV) loads within respiratory ciliated cells and to verify the existence of a correlation between TTV loads and functional or structural ciliary abnormalities, in a group of children with recurrent or persistent pneumonia.


METHODS
Nasal brushing samples of 55 children (28 male) were evaluated for ciliary motion and ultrastructural assessment, as well as for detection and quantification of TTV. Moreover, presence and load of TTV within ciliated cells, obtained from 5 patients by laser capture microdissection, were determined.


RESULTS
The nasal samples of 47 (85%) children with persistent or recurrent pneumonia resulted positive for TTV (loads = 2.1-7.3 log10 copies/microg total DNA). TTV were demonstrated also within microdissected ciliated cells. No significant difference between primary (11 subjects) and secondary ciliary dyskinesia (44 subjects) for TTV prevalence and mean loads were found. A significant correlation was observed between nasal TTV loads and ciliary beat frequency score (r = 0.305; P < 0.05), but not between TTV loads and presence of abnormal motion patterns, in patients with secondary ciliary abnormalities. As expected no correlations were found between nasal TTV loads and ciliary motion analysis in primary ciliary dyskinesia.


CONCLUSIONS
The presence of TTV in nasal samples demonstrates TTV ability to infect respiratory ciliated cells and suggests that these cells are potentially able to support virus replication. Moreover, TTV may behave in respiratory cells in a similar way to other viruses, that is, they disrupt the mucociliary escalator.
Pifferi
Massimo
M
Department of Pediatrics, Division of Surgical, Molecular and Ultrastructural Pathology, University of Pisa, Pisa, Italy. m.pifferi@med.unipi.it
Maggi
Fabrizio
F
Di Cristofano
Claudio
C
Cangiotti
Angela M
AM
Nelli
Luca Ceccherini
LC
Bevilacqua
Generoso
G
Macchia
Pierantonio
P
Bendinelli
Mauro
M
Boner
Attilio L
AL
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002925:Ciliary Motility Disorders / Q000473:pathology*; D004266:DNA Virus Infections / Q000473:pathology* / Q000821:virology*; D004847:Epithelial Cells / Q000648:ultrastructure / Q000821:virology; D005260:Female; D006801:Humans; D007223:Infant; D007619:Kartagener Syndrome / Q000821:virology; D008297:Male; D011014:Pneumonia / Q000473:pathology* / Q000821:virology*; D020545:Respiratory Mucosa / Q000473:pathology / Q000648:ultrastructure / Q000821:virology*; D022783:Torque teno virus / Q000302:isolation & purification*