Souza L O, Pinho J R R, Carrilho F J, da Silva L C
Serviço de Virologia, Instituto Adolfo Lutz, São Paulo, SP, Brasil.
Braz J Med Biol Res. 2004 Nov;37(11):1665-8. doi: 10.1590/s0100-879x2004001100011. Epub 2004 Oct 26.
Occult hepatitis B virus (HBV) infection has been reported as cases in which HBV DNA was detected despite the absence of any HBV serological markers or in cases in which anti-HBc antibody was the sole marker. The aim of the present study was to determine, using the polymerase chain reaction (PCR), whether HBV infection occurs in hepatitis C and non-A-E hepatitis patients without serological evidence of hepatitis B infection in Sao Paulo State. Two different populations were analyzed: 1) non-A-E hepatitis patients, including 12 patients with acute and 50 patients with chronic hepatic disorders without serological evidence of infection with known hepatitis viruses; 2) 43 patients previously diagnosed as hepatitis C with positive results for anti-HCV and HCV RNA. Among hepatitis C patients, anti-HBc was detected in 18.6% of the subjects. Three different sets of primers were employed for HBV DNA detection by nested PCR, covering different HBV genes: C, S and X. HBV-DNA was not detected in any sample, whereas the positive controls did produce signals. The lack of HBV DNA detection with these pairs of primers could be due to a very low viral load or to the presence of mutations in their annealing sites. The latter is unlikely as these primers were screened against an extensive dataset of HBV sequences. The development of more sensitive methods, such as real time PCR, to detect circular covalent closed DNA is necessary in order to evaluate this question since previous studies have shown that cryptic hepatitis B might occur.
隐匿性乙型肝炎病毒（HBV）感染被报道为尽管缺乏任何HBV血清学标志物但仍检测到HBV DNA的病例，或抗-HBc抗体为唯一标志物的病例。本研究的目的是使用聚合酶链反应（PCR）来确定在圣保罗州没有乙型肝炎感染血清学证据的丙型肝炎和非甲-戊型肝炎患者中是否发生HBV感染。分析了两个不同的人群：1）非甲-戊型肝炎患者，包括12例急性和50例慢性肝病患者，他们没有已知肝炎病毒感染的血清学证据；2）43例先前被诊断为丙型肝炎且抗-HCV和HCV RNA检测结果为阳性的患者。在丙型肝炎患者中，18.6%的受试者检测到抗-HBc。采用三组不同的引物通过巢式PCR检测HBV DNA，覆盖不同的HBV基因：C、S和X。在任何样本中均未检测到HBV-DNA，而阳性对照确实产生了信号。使用这些引物未检测到HBV DNA可能是由于病毒载量极低或其退火位点存在突变。由于这些引物是针对大量HBV序列数据集筛选的，所以后者不太可能。由于先前的研究表明可能发生隐匿性乙型肝炎，因此有必要开发更灵敏的方法，如实时PCR，来检测环状共价闭合DNA，以便评估这个问题。
