Dove L, Phung Y, Bzowej N, Kim M, Monto A, Wright T L
Department of Veterans Affairs Medical Center and University of California, San Francisco, CA, USA.
J Viral Hepat. 2005 Nov;12(6):574-83. doi: 10.1111/j.1365-2893.2005.00640.x.
Injection drug users represent the largest cohort of patients with established hepatitis C virus (HCV) infection as well as the group that is at highest risk for new infections. Most published studies have focused on the clinical consequences of established HCV infection and have not examined the consequences of new infection. The aim of the current study was to measure the virological consequences of HCV in patients with ongoing injection drug use that might pose a risk for new and/or for superinfection with additional strains of HCV. We examined the following groups: (a) those with resolved HCV infection with ongoing injection drug use, (b) those with chronic infection who continued to inject and (c) those with chronic infection who no longer injected. Our study demonstrated a spectrum of responses. The majority of patients appeared to be 'protected' from new infection. None of six patients with resolved infection had detectable HCV RNA by quantitative or qualitative PCR when followed for 1 year. Similarly, despite ongoing injection drug use, no patient with persistent infection had a 'switch' in HCV genotype indicative of possible superinfection. Virological analysis of HCV quasispecies to detect possible infection with new variants of HCV in patients with apparently 'stable' infection, indicated divergence of virus over time, divergence that was unrelated to injection drug behaviour. Thus, patients with ongoing or prior HCV infection appear to develop immunity that protects against further infection with HCV despite repeated exposure.
注射吸毒者是已感染丙型肝炎病毒（HCV）患者中最大的群体，也是新感染风险最高的群体。大多数已发表的研究都集中在已确诊的HCV感染的临床后果上，而没有研究新感染的后果。本研究的目的是测量正在注射吸毒的患者中HCV的病毒学后果，这些患者可能面临新感染和/或感染其他HCV毒株的双重感染风险。我们检查了以下几组：（a）已治愈HCV感染但仍在注射吸毒的患者，（b）持续感染且继续注射的患者，以及（c）持续感染但不再注射的患者。我们的研究显示了一系列反应。大多数患者似乎对新感染具有“免疫力”。6例已治愈感染的患者在随访1年时，通过定量或定性PCR均未检测到可检测的HCV RNA。同样，尽管持续注射吸毒，但没有持续感染的患者出现HCV基因型“转换”，提示可能发生双重感染。对HCV准种进行病毒学分析，以检测明显“稳定”感染患者中是否可能感染HCV新变种，结果表明病毒随时间发生了变异，这种变异与注射吸毒行为无关。因此，无论是正在感染还是既往感染HCV的患者，尽管反复接触病毒，似乎都会产生免疫力，从而防止再次感染HCV。
