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

目的 :研究TTV基因变异与其致病性的关系。方法 :采用巢式多聚酶链式反应 (PCR)扩增TTVDNA ,收集TTVDNA阳性病例 5 2例 ,其中献血员 4例 ,乙型肝炎病毒携带者 5例 ,慢性乙型肝炎患者 11例 ,慢性重型乙型肝炎患者 32例 ,采用单链构象多态性 (SSCP)方法进行TTV基因变异检测。结果 :献血员、乙型肝炎病毒携带者、慢性乙型肝炎、慢性重型乙型肝炎患者中 ,SSCP电泳条带数分别为 1.2 5± 0 .5 0 ,1.6 0± 0 .5 5 ,3.36± 1.36 ,4 .5 9± 1.83;慢性乙型肝炎和慢性重型乙型肝炎患者组中SSCP电泳条带数显著多于其他组 (P <0 .0 5 ) ;慢性重型乙型肝炎患者中SSCP电泳条带数显著多于慢性乙型肝炎患者 (P <0 .0 5 )。结论 :TTV存在基因变异 。

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 superinfecion in chronic hepatitis patients.