Predictive Value of Tenofovir Diphosphate in Dried Blood Spots for Future Viremia in Persons Living With HIV.
BACKGROUND
Tenofovir diphosphate (TFV-DP) in dried blood spots (DBS) is associated with viral suppression in persons living with HIV (PLWH) taking tenofovir disoproxil fumarate (TDF). However, its value as a predictor of future viremia remained unknown.


METHODS
Blood for plasma viral load (VL) and TFV-DP in DBS were collected (up to 3 visits within 48 weeks) in PLWH on TDF. TFV-DP cut points were selected using logistic prediction models maximizing the area under the receiver operation characteristic curve, and estimated adjusted odds ratio (aOR) of future viremia (≥20 copies/mL) were compared to the highest TFV-DP category.


RESULTS
Among all 451 participants in the analysis, aOR of future viremia for participants with TFV-DP <800 and 800 to <1650 fmol/punch were 4.7 (95% CI, 2.6-8.7; P < .0001) and 2.1 (95% CI, 1.3-3.3; P = .002) versus ≥1650 fmol/punch, respectively. These remained significant for participants who were virologically suppressed at the time of the study visit (4.2; 95% CI, 1.5-12.0; P = .007 and 2.2; 95% CI, 1.2-4.0; P = .01).


CONCLUSIONS
TFV-DP in DBS predicts future viremia in PLWH on TDF, even in those who are virologically suppressed. This highlights the utility of this biomarker to inform about adherence beyond VL. Clinical Trials Registration. NCT02012621.
['Morrow|Mary|M|', 'MaWhinney|Samantha|S|', 'Coyle|Ryan P|RP|', 'Coleman|Stacey S|SS|', 'Gardner|Edward M|EM|', 'Zheng|Jia-Hua|JH|', 'Ellison|Lucas|L|', 'Bushman|Lane R|LR|', 'Kiser|Jennifer J|JJ|', 'Anderson|Peter L|PL|', 'Castillo-Mancilla|Jose R|JR|']
D000225:Adenine D000328:Adult D019380:Anti-HIV Agents D015415:Biomarkers D005260:Female D006678:HIV D015658:HIV Infections D006801:Humans D008297:Male D055118:Medication Adherence D008875:Middle Aged D010755:Organophosphates D011237:Predictive Value of Tests D000068698:Tenofovir D019562:Viral Load D014766:Viremia
predictive value tenofovir diphosphate dried blood spots adherence antiretroviral therapy pharmacokinetics