Department of Medicine, University of California San Francisco.
Department of Psychiatry, John Stroger Hospital of Cook County, Chicago, Illinois.
Clin Infect Dis. 2018 Jan 6;66(2):213-219. doi: 10.1093/cid/cix755.
Young men-who-have-sex-with-men (MSM) are disproportionately impacted by human immunodeficiency virus (HIV). Preexposure prophylaxis (PrEP) could reduce HIV acquisition among youth, but suboptimal adherence threatens effectiveness. Optimal metrics of PrEP adherence among adolescents have remain undefined.
The Adolescent Trials Network 110/113 studies provided daily oral PrEP with tenofovir (TFV) disoproxil fumarate/emtricitabine over 48 weeks to a diverse population of MSM (aged 15-22 years). Self-reported adherence was assessed and PrEP drug concentrations measured from hair and dried blood spot (DBS) samples; 23% of participants received Wisepill electronic monitoring devices. The average number of PrEP doses per week taken was estimated, and concordance between measures assessed.
Among 243 participants, hair samples were collected at 1186/1238 (96%) person-visits. The concordance of TFV levels in hair and TFV-diphosphate in DBS around thresholds consistent with taking ≥4 and 7 PrEP doses/week was high (76% and 80%). Hair and DBS concentrations correlated poorly with self-report and Wisepill metrics. Through week 12, 40%-60% of participants (by hair and DBS), ≤31% (Wisepill), and >85% (self-report) were estimated to have taken ≥4 PrEP doses/week (a threshold associated with protection among MSM). For all measures except self-report, adherence declined over time, with half of participants taking <2 doses/week by week 48.
Among youth on PrEP, adherence waned over time. Self-report overestimated adherence, and use of Wisepill was limited. Hair collection was highly acceptable and provided similar interpretations to DBS. Incorporation of either metric in future PrEP studies among youth could identify suboptimal adherence and trigger interventions.
男男性行为者（MSM）青年人群受人类免疫缺陷病毒（HIV）影响过大。暴露前预防（PrEP）可降低青年人群的 HIV 感染率，但不理想的依从性会威胁其效果。青少年 PrEP 依从性的最佳衡量标准仍未确定。
青少年试验网络 110/113 研究在 48 周内为不同人群的 MSM（年龄 15-22 岁）提供每日口服替诺福韦（TFV）二异丙基富马酸酯/恩曲他滨，共 110/113 项研究。自我报告的依从性得到评估，并通过毛发和干血斑（DBS）样本测量 PrEP 药物浓度；23%的参与者接受了 Wisepill 电子监测设备。每周服用 PrEP 的平均剂量进行了估计，并评估了各种措施之间的一致性。
在 243 名参与者中，1186/1238（96%）人次就诊时采集了毛发样本。在与每周服用≥4 剂和 7 剂 PrEP 一致的阈值下，头发中 TFV 水平和 DBS 中 TFV-二磷酸盐的一致性较高（76%和 80%）。头发和 DBS 浓度与自我报告和 Wisepill 指标相关性差。到第 12 周时，通过头发和 DBS 估计有 40%-60%的参与者（Wisepill 为≤31%，自我报告为>85%）每周服用≥4 剂 PrEP（这是 MSM 中预防的阈值）。除自我报告外，所有措施的依从性均随时间下降，一半的参与者在第 48 周时每周服用<2 剂。
在接受 PrEP 的青年人群中，依从性随时间推移而减弱。自我报告高估了依从性，而 Wisepill 的使用受到限制。毛发采集非常容易接受，与 DBS 提供了相似的解释。在未来的青少年 PrEP 研究中纳入这两种指标中的任何一种都可以发现不理想的依从性并触发干预措施。
