Human Papillomavirus in Atypical Squamous Cervical Cytology: The Invader HPV Test as a New Screening Assay

Divisions of Microbiology and Cytopathology, Department of Pathology and Laboratory Medicine, and the George Burns and Gracie Allen Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048

^* To whom correspondence should be addressed. Email: Shikha.bose{at}cshs.org.

	Abstract

In surveillance for cervical neoplasia, cytologically atypical cells of undetermined significance (ASCUS) present a significant clinical issue, often dependent on high risk (HR) human papilloma virus (HPV) testing for triage of patients. HPV type 16 now appears as a critical concern in the follow-up of ASCUS patients.

The Invader HPV test (Inv2) by Third Wave Technologies, Inc. is a recently developed analyte specific reagents (ASRs) assay employing probe sets for detection of 14 HR HPV subtypes, and grouped as probe sets A5/A6 (HPV 51,56,66), A7 (HPV 18,39,45,59,68) and A9 (HPV 16,31,33,35,52,58). This report describes performance characteristics of the Inv2 test in screening ASCUS cervical cytology specimens with correlation to the results of the Hybrid Capture II HPV test (HC2) by Digene. The Linear Array HPV Genotyping Test (PCR-LA) (Roche Molecular Systems) was employed as a reference method for discordant results.

Ninety-four Pap smear samples with cytologic diagnosis of ASCUS, and 39 samples with a negative diagnosis were tested. The Inv2 HPV test demonstrated good (86.6%) concordance when compared to the HC2 HPV test with an overall sensitivity and specificity of 96% Additionally, the Inv2 assay with high throughput, semi-automated DNA extraction offers subgrouping of HPV types by differential probe sets, and could provide a useful test for HPV screening with potential for improved risk stratification and selection of patients for further HPV subtyping.