LINEAR ARRAY Human Papillomavirus Genotyping Test Amenable to Automation by Implementation of GT-Blot 48 – A Pilot Study

Persistent infection with high-risk human papillomavirus is associated with the development of cervical intraepithelial neoplasia and a key factor in progression to invasive cancer. The Linear Array HPV genotyping test (LA) is a valuable diagnostic tool enabling type-specific detection of DNA from 37 anogenital high- and low-risk HPV genotypes. Its value, however, is hampered by the underlying labour-intensive manual line blot technology. This study was designed to improve the suitability of LA in routine use by implementing the GT-Blot 48 instrument as an alternative instead of using the proposed manual detection protocol.

Automation of LA processing was evaluated by comparing GT-blot 48 processed strips to the manufacturer recommended manual protocol. For type-specificity we compared the performance of GT-blot 48 processed strips with that of PapilloCheck, another PCR-based HPV typing assay. Furthermore, the performance of HPV DNA detection by GTblot 48 processed strips to that by Hybrid Capture 2 (hr-HC2) assay was compared, using samples from 122 women attending routine cervical examination.

GT-blot 48 processed strips and the manual method demonstrate equal performance. The overall agreement of HPV prevalence between automated LA and PapilloCheck was 96.6% (kappa = 0.92). A 91.2% concordance was observed between automated LA and hr-HC2 (kappa = 0.82).

Automated LA processing is a valuable alternative to the manual method. Results are highly comparable with those obtained by hr-HC2 and PapilloCheck. Implementation of GT-blot 48 is a reliable easy-to-use format, which offers increased time efficiency and the additional benefit of high-throughput with standardized processing.