Impact of TT virus infection in acute and chronic, viral- and non viral-related liver diseases.
OBJECTIVE
The prevalence and pathogenicity of TT virus, recently identified in patients with non A-non G post-transfusional hepatitis, are questioned.


METHODS
We investigated the impact of this new viral infection in a large series of patients with non A-non G, cryptogenic, non-viral and viral-related, acute and chronic liver diseases (n=577) and blood donors (n=300). TTV DNA was detected in serum by hemi-nested polymerase chain reaction. Phylogenetic analysis was performed in 13 isolates.


RESULTS
TTV DNA was detected in 6/25 and 15/127 patients with cryptogenic non A-non G acute and chronic liver disease, respectively. TTV DNA positive subjects with post-transfusional acute hepatitis scored negative before transfusion. TTV prevalence was increased in patients with cryptogenic non A-non G acute and chronic liver disease compared to blood donors (6/300; p<0.001) and non-viral-related chronic liver diseases (6/137; p<0.05). TTV/HBV coinfection was frequently identified (35/147), but this was not the case for HCV-infected subjects (4/77). Transaminase activity or liver histological score was not significantly increased among TTV positive, HBV infected or non A-non G patients. The HBV infection and Mediterranean origin were the risk factors associated with TTV infection. The majority of analysed sequences clustered in genotype 1 (8=1b; 3=1a). Two isolates showed homology to genotype 2.


CONCLUSIONS
These results support the view that TTV is a widely spread infectious agent with a weak pathogenicity. It raises the possibility, however, that TTV might be implicated in a few cases of acute and chronic non A-non G hepatitis. TTV-DNA-analysed sequences are related to genotypes 1 and 2 described in Europe.
Tuveri
R
R
CNR on Viral Hepatitis, Necker Institute, Necker University, Paris, France.
Jaffredo
F
F
Lunel
F
F
Nalpa
B
B
Pol
S
S
Feray
C
C
Marcellin
P
P
Thibault
V
V
Delagneau
J F
JF
Opolon
P
P
Scarpa
B
B
Bréchot
C
C
Thiers
V
V
D000208:Acute Disease; D001782:Blood Donors; D002908:Chronic Disease; D004266:DNA Virus Infections / Q000150:complications* / Q000453:epidemiology; D004279:DNA, Viral / Q000032:analysis; D005602:France; D006509:Hepatitis B / Q000150:complications; D006526:Hepatitis C / Q000150:complications; D006525:Hepatitis, Viral, Human / Q000821:virology; D006801:Humans; D007558:Italy; D008107:Liver Diseases / Q000209:etiology / Q000821:virology*; D015995:Prevalence; D012189:Retrospective Studies; D022783:Torque teno virus / Q000235:genetics; D065227:Transfusion Reaction
D004279:DNA, Viral