Maggiolo Franco, Callegaro Annapaola, Cologni Giuliana, Bernardini Claudia, Velenti Daniela, Gregis Giampietro, Quinzan Giampaolo, Soavi Laura, Iannotti Nathalie, Malfatto Emanuele, Leone Sebastiano
Division of Infectious Diseases, pedali Riuniti, Bergamo, Italy.
J Acquir Immune Defic Syndr. 2012 Aug 15;60(5):473-82. doi: 10.1097/QAI.0b013e3182567a57.
Low-level viremia (LLV) is measurable, with enhanced assays, in many subjects with HIV RNA levels <50 copies per milliliter. The clinical consequences of LLV are unknown.
In a prospective study in HIV-1-infected adults, HIV RNA levels were determined with an ultrasensitive test (3 copies/mL) based on a real time polymerase chain reaction. The primary end point was to evaluate LLV prediction of virological failure, defined as a confirmed plasma HIV RNA level >50 copies per milliliter.
One thousand two hundred fourteen patients were followed for (mean) 378 days. At baseline, 71.5% were <3 copies per milliliter below the limit of detection (BLD). The risk of failing highly active antiretroviral therapy in the following 4 months for patients BLD was 0.4% compared with a 3.2% risk for those with LLV (P < 0.0001; odds ratio: 7.52). There was a significant (P < 0.0001) linear relationship between the HIV RNA and the risk of virologic failure. LLV receiver operating curve analysis showed an area under the curve of 0.76 (95% confidence interval: 0.68 to 0.84) that significantly (P < 0.0001) predicted the risk of failure. The risk of an unconfirmed viral blip was higher in patients with LLV (3.9%) than in those BLD (1.1%) (P < 0.0001; odds ratio: 3.56). Longer exposure to antiretrovirals, current use of nonnucleoside reverse transcriptase inhibitors, longer time BLD, and current HIV RNA <3 copies per milliliter were independent predictors of a positive outcome.
Viral replication may be the cause of LLV, at least in some patients. A LLV >3 copies per milliliter is linked to a significant increment of risk of virological failure leading to drug resistance. Patients with measurable LLV should be managed to better evaluate, over time, the risk of failure and to limit its consequences.
在许多HIV RNA水平低于每毫升50拷贝的受试者中，通过增强检测方法可检测到低水平病毒血症（LLV）。LLV的临床后果尚不清楚。
在一项针对HIV-1感染成人的前瞻性研究中，使用基于实时聚合酶链反应的超灵敏检测方法（检测下限为每毫升3拷贝）测定HIV RNA水平。主要终点是评估LLV对病毒学失败的预测情况，病毒学失败定义为确诊血浆HIV RNA水平高于每毫升50拷贝。
1214名患者接受了（平均）378天的随访。基线时，71.5%的患者低于检测下限（BLD）每毫升3拷贝。BLD患者在接下来4个月中高效抗逆转录病毒治疗失败的风险为0.4%，而LLV患者的风险为3.2%（P<0.0001；比值比：7.52）。HIV RNA与病毒学失败风险之间存在显著的（P<0.0001）线性关系。LLV的受试者工作特征曲线分析显示曲线下面积为0.76（95%置信区间：0.68至0.84），显著（P<0.0001）预测了失败风险。LLV患者未确诊病毒波动的风险（3.9%）高于BLD患者（1.1%）（P<0.0001；比值比：3.56）。更长时间使用抗逆转录病毒药物、当前使用非核苷类逆转录酶抑制剂、更长时间处于BLD状态以及当前HIV RNA低于每毫升3拷贝是阳性结果的独立预测因素。
病毒复制可能是LLV的原因，至少在一些患者中是这样。LLV高于每毫升3拷贝与导致耐药的病毒学失败风险显著增加有关。对于可检测到LLV的患者，应进行管理，以便随着时间推移更好地评估失败风险并限制其后果。
