Background There are few data on the utility of tenofovir diphosphate (TFV-DP) in dried blood spots to predict future viral load (VL) in postpartum women with HIV on antiretroviral therapy (ART). Methods We conducted a nested case-control study within a trial of postpartum ART delivery strategies. Participants started ART containing tenofovir disoproxil fumarate (TDF) in pregnancy, were <10 weeks postpartum and had a VL <400 copies/mL. VL and TFV-DP samples were taken 3-6 monthly over 24 months. Cases had >1 VL >20 copies/mL; controls were randomly sampled from women with persistent viral suppression (VS; VL <20 copies/mL). Generalized estimating equations were used to calculate likelihood odds ratios (LORs) for future VL >20 copies/mL by TFV-DP concentration at the preceding visit. Results Sixty-one cases and 20 controls contributed 365 DBS-VL pairs (median ART duration 16 months). Sensitivity and specificity of TFV-DP <700 fmol/punch to detect future viremia were 62.9% (95% CI, 54.7%–70.6%) and 89.7% [95% CI, 84.9%–93.4%], respectively. Adjusting for age, ART duration, previous VL and duration between the TFV-DP and VL measures, LORs of viremia for TFV-DP concentrations 350–699 and <350 fmol/punch versus TFV-DP >1850 fmol/punch were 3.5 (95% CI, 1.1–10.8; P=0.033) and 12.9 (95% CI, 3.6–46.6; P<0.0001), respectively. Including only samples taken during VS, the LOR of future viremia for TFV-DP concentration <350 fmol/punch versus TFV-DP >1850 fmol/punch was 9.5 (95% CI, 1.9–47.0). Conclusions TFV-DP concentrations in DBS were strongly associated with future viremia and appear useful to identify non-adherence and predict future elevated VL.

中文翻译：

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使用二磷酸替诺福韦水平预测感染 HIV 的妇女产后病毒血症：一项巢式病例对照研究

背景 关于干血斑中替诺福韦二磷酸盐 (TFV-DP) 预测接受抗逆转录病毒治疗 (ART) 的产后 HIV 感染妇女未来病毒载量 (VL) 的效用的数据很少。方法 我们在产后 ART 递送策略试验中进行了巢式病例对照研究。参与者在怀孕期间开始使用含有富马酸替诺福韦二吡呋酯 (TDF) 的 ART，产后小于 10 周并且 VL 小于 400 拷贝/mL。VL 和 TFV-DP 样本在 24 个月内每月采集 3-6 次。病例 >1 VL >20 拷贝/mL；对照是从具有持续病毒抑制(VS；VL <20拷贝/mL)的女性中随机抽取的。使用广义估计方程计算前一次访问时 TFV-DP 浓度的未来 VL ＞ 20 拷贝/mL 的似然比值比 (LOR)。结果 61 个病例和 20 个对照贡献了 365 个 DBS-VL 对（中位 ART 持续时间 16 个月）。TFV-DP <700 fmol/punch 检测未来病毒血症的敏感性和特异性分别为 62.9%（95% CI，54.7%–70.6%）和 89.7% [95% CI，84.9%–93.4%]。调整年龄、ART 持续时间、既往 VL 以及 TFV-DP 和 VL 测量之间的持续时间，TFV-DP 浓度为 350-699 和 <350 fmol/punch 与 TFV-DP >1850 fmol/punch 的病毒血症 LOR 为 3.5 (95% CI, 1.1–10.8; P=0.033) 和 12.9 (95% CI, 3.6–46.6; P<0.0001)。仅包括在 VS 期间采集的样本，TFV-DP 浓度 <350 fmol/punch 与 TFV-DP >1850 fmol/punch 的未来病毒血症的 LOR 为 9.5（95% CI，1.9-47.0）。