Yang Xu, Lei Jianhua, Zhang Yonghong, Luo Hongyu, Huang Li, Zheng Yuhuang, Tang Xiaopeng, Li Liangyou
Liver Diseases Research Center, Xiang ya Second Hospital, Central South University, Changsha 410011, China.
Zhonghua Yi Xue Za Zhi. 2002 Mar 25;82(6):400-2.
To explore the pathogen and molecular basis of cryptogenic cirrhosis in a patient.
Serum was collected from a patient, male, aged 56, with cryptogenic cirrhosis. HBV serologic markers were qualitatively tested, and HBsAg, HBeAg, and anti-HBc were quantitatively determined again. HBV DNA in serum was qualitatively tested using PCR, and quantified using fluorescence quantitative PCR. S gene was amplified, cloned, and sequenced.
HbsAg and anti-Hbe were negative, and anti-HBs, HBeAg, anti-HBc, and HBV DNA were all positive. HBsAg (S/N) was 0.77 (cutoff of S/N: >/= 2.00), HbeAg (S/N) was 56.43 (cutoff of S/N: >/= 2.10), anti-HBc (S/C(O)) was 0.03 (cutoff of S/C(O): </= 1.00); HBV DNA was 1.54 x 10(9) copies/ml. An uncommon point mutation at nucleotide 336 (C to A) in S gene was found, resulting in the change of the 61st codon into a novel stop codon and failure of synthesis of HbsAg.
HBV proves the pathogen of this case. This special mutation well explains the patient's unusual serologic pattern. Moreover, this finding possesses important clinical and theoretical significance.
探讨1例隐源性肝硬化患者的病原体及分子基础。
收集1例56岁男性隐源性肝硬化患者的血清。对乙肝血清学标志物进行定性检测，并再次定量检测HBsAg、HBeAg和抗-HBc。采用PCR对血清中的HBV DNA进行定性检测，并用荧光定量PCR进行定量。扩增、克隆并测序S基因。
HBsAg和抗-HBe阴性，抗-HBs、HBeAg、抗-HBc和HBV DNA均阳性。HBsAg（S/N）为0.77（S/N临界值：≥2.00），HBeAg（S/N）为56.43（S/N临界值：≥2.10），抗-HBc（S/C（O））为0.03（S/C（O）临界值：≤1.00）；HBV DNA为1.54×10⁹拷贝/ml。在S基因的核苷酸336处发现一个罕见的点突变（C突变为A），导致第61位密码子变为新的终止密码子，HbsAg合成失败。
HBV是该病例的病原体。这种特殊突变很好地解释了患者不寻常的血清学模式。此外，这一发现具有重要的临床和理论意义。
