Performance evaluation of a self-administered point-of-care test for anal HPV screening in PrEP users: data from a community-based PrEP service.

OBJECTIVES: In this study, we compared the performance of a self-administered point-of-care test (POCT) for anal human papillomavirus (HPV) screening with laboratory gold-standard test in pre-exposure prophylaxis (PrEP) users and evaluated its feasibility. METHODS: We enrolled PrEP users from a local community-based PrEP service. Each participant self-collected an anal swab to test anal HPV with a PCR POCT capable of detecting 14 high-risk HPV genotypes. Anonymous questionnaires on self-sampling feasibility were completed. Participants were then referred to local clinics to undergo standard viral genotyping. Concordance between POCT and gold-standard test was measured with absolute agreement and Cohen's kappa. Receiver operating characteristic (ROC) curves were used to calculate POCT sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: 179 subjects got a valid POCT result, most of them men (98.3%) and men who have sex with men (90.4%). 68.2% tested positive for at least one high-risk HPV genotype on POCT. 150 feasibility questionnaires were collected: 92.7% of compilers found the self-swab easy to perform. For 178 subjects, a gold-standard test valid result was also available: 77% tested positive for at least one high-risk HPV genotype. The median time elapsed between the two tests was 9.8 months, due to COVID-19-related service interruptions. Agreement between POCT and gold-standard test was 79.3% (Cohen's kappa=0.49). POCT showed a sensitivity of 81.0%, a specificity of 73.8%, a PPV of 91.0% and an NPV of 54.4%. CONCLUSIONS: POCT showed a moderate agreement with gold-standard test and a discrete sensitivity and specificity, suggesting that it could be a useful and feasible additional tool for HPV screening, especially in low-resource and community-based settings.

A Comparison of Tenofovir Predose Concentrations in Generic Pre-exposure Prophylaxis Formulations: A Short Communication.

BACKGROUND: There is extensive evidence to show that pre-exposure prophylaxis (PrEP) using tenofovir disoproxil fumarate (TDF)-based formulations dramatically reduces the risk of HIV acquisition among individuals without HIV infection. Here, the authors aim to compare tenofovir plasma predose concentrations in subjects taking PrEP daily versus on demand and using different TDF-based generic formulations. METHODS: Subjects providing informed signed consent for the measurement of tenofovir plasma levels were included in the study. Predose drug concentrations were stratified according to PrEP administration and the type of TDF-based formulation. The control group consisted of patients with HIV infection who were matched for renal function and were administered branded TDF that was not combined with boosted-antiretroviral drugs. RESULTS: The study consisted of 100 subjects (mean age, 39 ± 10 years; body weight, 77 ± 11 kg). A wide distribution in tenofovir predose concentrations was observed, with values ranging from 17 to 297 ng/mL (coefficient of variation 77%). No significant differences were noted in tenofovir predose concentrations between subjects who were administered PrEP daily (n = 75) or on demand (n = 25) [94 (35-255) versus 104 (37-287) ng/mL; P = 0.476]. Comparable tenofovir predose concentrations were found between patients with HIV infection (n = 220) who were administered branded TDF and those without HIV infection who were treated with 5 different generic TDF-based formulations with generics-to-branded ratios. These were always within the range of 80%-125% and were used to define bioequivalence. CONCLUSIONS: The marketed generic formulations of TDF delivered tenofovir plasma predose concentrations comparable with those delivered by branded formulations.