慢性 B 型肝炎感染被認為是肝硬化或肝炎的危險因子之一。在慢性 B 型肝炎治療中, Lamivudine 為其中之一。它可以有效的抑制 B 型肝炎病毒複製,但是使用 lamivudine 卻會隨著時間的長短而造成有抗藥病毒株的出現。我們希望能夠藉由分析在接受抗病毒藥物病人體內的病毒演化因素上,病毒株所扮演的角色;並更進一步的設計對於抗藥病毒株早期偵測的方法。為了能夠及早的在病人體內發現抗藥病毒株的產生,我們設計了 PCR-enriched RFLP 的偵測方法, 並依據病毒的基因圖譜設計一些引子及核酸內切脢的位置。結果顯示在定性方面, PCR-enriched RFLP 所採用的去除病毒野生株的策略可以有效的在早期偵測出抗藥病毒株的存在,並且將其敏感度提高100倍。更進一步分析,此方法的敏感度可達到 101copies/ml。而根據隨機抽取的病人結果,將 PCR-enriched RFLP 和定序方法及病人服藥的就醫紀錄做比較,都可以得到相當高的相似結果。目前對於病毒及宿主角力的過程的了解仍需要多方面的開發及努力。這個方法能夠有效的偵測出對於 lamivudine 產生抗藥性的病毒株,並且能夠早期偵測出抗藥株的出現。對於臨床治療 B 型肝炎病人上能夠提供一個監控抗病毒藥物治療的機制。

　　Chronic infection of hepatitis B virus (HBV) is considered as an increasing risk factor developing cirrhosis and hepatocellular carcinoma. In the treatment of chronic hepatitis B patients, the use of lamivudine is effective to suppress viral replication; however, durable suppression of viral replication is limited by development of drug-resistant strains upon prolonged therapy. In the present study, we aimed to analyze the influences of virological factors involved in the viral fitness during antiviral therapies, and develop sensitive methods for early detections of HBV YMDD mutations. Several primers and restriction enzyme cutting sites were designed for the detection of the appearance of viral mutants. The PCR-enriched RFLP results showed that strategies for eliminating the co-existed wild type viruses were effective, and the detecting sensitivity were enhanced by about 100 folds. The sensitivity of this method is evaluated to 101 copies/ml, with identical results between nucleotide sequence analyses. This method is thus effective for early detection of the developing lamivudine-resistant mutants, and monitoring of the entire antiviral therapies. Despite for the fact that only incomplete understanding of the factors involved in the viral-host interactions, this method is valuable and useful for the detecting of drug-resistant mutants for clinical implications.

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