The preferred workflow for high-risk human papillomavirus (hrHPV) testing in the majority of laboratories involves cytology processing of samples collected in liquid-based cytology medium followed by hrHPV testing. The cobas HPV Test received approval from the US Food and Drug Administration in April 2011, and the supporting clinical trial design necessitated prealiquoting the sample used for hrHPV testing from the PreservCyt primary vial into a secondary vial that was placed on the cobas 4800 System.
To validate use of the postcytology residual sample in the primary vial, the authors presented the results of cross-contamination studies and a comparison of the cobas HPV Test results from the prealiquot in the secondary vial with results obtained from the postcytology primary vial on samples processed on either the Hologic ThinPrep 2000 System (T2000) or ThinPrep 3000 System (T3000).
Cross-contamination checkerboard studies with 100 samples processed on the T2000 system and 120 samples processed on the T3000 system indicated no conversion of primary vial results from positive to negative or from negative to positive. For clinical samples, approximately 1100 archived specimens from the ATHENA (Addressing the Need for Advanced HPV Diagnostics) study and 1100 combined archived and fresh primary vial specimens that had been processed on the T2000 and T3000 processors, respectively, were compared. The overall percentage agreement between the primary and secondary vials was at least 93.5%.
The postcytology residual of samples collected in PreservCyt primary vials and run on the T2000 and T3000 processors provided reliable cobas HPV Test results that were comparable to results from the precytology secondary vial, without any evidence of contamination.