NanoString Technology for Human Papillomavirus Typing

High-throughput HPV typing assays with increased automation, faster turnaround and type-specific digital readout would facilitate studies monitoring the impact of HPV vaccination. We evaluated the NanoString nCounter® platform for detection and digital readout of 48 HPV types in a single reaction. NanoString (NS) used proprietary software to design CodeSets: type-specific probe pairs targeting 48 HPV types and the globin gene. We tested residual DNA extracts from epidemiologic specimens and defined samples (HPV plasmids at 10 to 104 copies/reaction) directly (No-PCR) as well as after L1 consensus PCR of 45 (PCR-45) or 15 cycles (PCR-15). Assay and interpretation followed NS recommendations. We evaluated analytic performance by comparing NanoString results for types included in prior assays: Roche Linear Array (LA) or HPV TypeSeq assay. No-PCR results on 40 samples showed good type-specific agreement with LA (k = 0.621) but sensitivity was 65% with lower limit of detection (LOD) at 104 plasmid copies. PCR-45 results showed almost perfect type-specific agreement with LA (k = 0.862), 82% sensitivity and LOD at 10 copies. PCR-15 results on 75 samples showed substantial type-specific agreement with LA (k = 0.796, 92% sensitivity) and TypeSeq (k = 0.777, 87% sensitivity), and LOD at 10 copies of plasmids. This proof-of-principle study demonstrates the efficacy of the NS platform with HPV CodeSet for type-specific detection using a low number of PCR cycles (PCR-15). Studies are in progress to evaluate assay reproducibility and analytic validation with a larger number of samples.

Oropharyngeal HPV infection: prevalence and sampling methods among HIV-infected men in South Africa

Worldwide, 96,000 cases of oropharyngeal cancer (OPC) occurred in 2012. Human papillomavirus (HPV) is a risk factor for OPC. Data on oropharyngeal HPV infection are limited. There is no consensus on the best sampling method for detecting the infection. We describe the prevalence of oropharyngeal HPV infection among HIV-infected men and compare the performance of oral rinses and swabs in detecting oropharyngeal HPV infection. Paired oral rinses and swabs for 181 men were tested for HPV DNA using the Roche Linear Array. Performance was determined by the number of infections detected and the percentage of samples with adequate DNA extraction. Agreement between sampling methods was assessed by the kappa statistic. Prevalence of oropharyngeal HPV infection with rinse samples was 1.8% (three infections) and 0.6% (one infection) with swabs (p = 0.06). Adequate cellular DNA extraction was more likely with rinse (93.4%) than swab samples (89.0%, p = 0.05). There was moderate agreement between the methods (kappa = 0.49). The prevalence of oropharyngeal HPV DNA infection among this predominantly heterosexual sample of men living with HIV was low and consistent with the infrequent oral sex practices. Oral rinse performed better than oral swab in detecting oropharyngeal HPV DNA infection and might contribute to screening for OPCs.

Prevalent high-risk HPV infection and vaginal microbiota in Nigerian women

SUMMARYIn this study, we evaluated the association between high-risk human papillomavirus (hrHPV) and the vaginal microbiome. Participants were recruited in Nigeria between April and August 2012. Vaginal bacterial composition was characterized by deep sequencing of barcoded 16S rRNA gene fragments (V4) on Illumina MiSeq and HPV was identified using the Roche Linear Array®HPV genotyping test. We used exact logistic regression models to evaluate the association between community state types (CSTs) of vaginal microbiota and hrHPV infection, weighted UniFrac distances to compare the vaginal microbiota of individuals with prevalent hrHPV to those without prevalent hrHPV infection, and the Linear Discriminant Analysis effect size (LEfSe) algorithm to characterize bacteria associated with prevalent hrHPV infection. We observed four CSTs: CST IV-B with a low relative abundance ofLactobacillusspp. in 50% of participants; CST III (dominated byL. iners) in 39·2%; CST I (dominated byL. crispatus) in 7·9%; and CST VI (dominated by proteobacteria) in 2·9% of participants. LEfSe analysis suggested an association between prevalent hrHPV infection and a decreased abundance ofLactobacillussp. with increased abundance of anaerobes particularly of the generaPrevotellaandLeptotrichiain HIV-negative women (P< 0·05). These results are hypothesis generating and further studies are required.