输血传播病毒（TTV）基因变异的临床意义

Clinical significance of gene quasispecies of transfusion transmitted virus]

OBJECTIVE: To investigate the clinical significance of gene variant of transfusion transmitted virus (TTV). METHODS: A nested polymerase chain reaction (nested-PCR) assay with specific primers from open reading frame one (ORF1) of TTV genome was established to detect TTV DNA in the serum samples from patients with hepatitis B and blood donors. Asymmetric PCR was established to get single strand DNA in the TTV DNA positive cases, and then single strand conformation polymorphism (SSCP) was applied. RESULTS: 1.25 +/- 0.50, 1.60 +/- 0.55, 3.36 +/- 1.36 and 4.59 +/- 1.83 SSCP bands were detected in the blood donors, chronic HBV carriers, chronic hepatitis B patients and chronic severe hepatitis B patients respectively. SSCP bands were much more complicated in chronic hepatitis patients and chronic severe hepatitis than those of chronic HBV carriers and blood donors (P < 0.05). CONCLUSION: There is gene variant in TTV infection. The complication of gene variant strain or quasispecies infection of TTV may be one of the causes responsible for clinical exacerbation of TTV superinfection in chronic hepatitis patients.