Human papillomavirus (HPV) is the most common sexually transmitted infection worldwide. Evidence linking HPV to cervical carcinoma is extensive. High risk HPV (hrHPV) testing is recommended for cervical cancer screening. This is a prospective study that enrolled women of all ages screened for cervical cancer who showed atypical squamous cells of undetermined significance (ASCUS). The study aim to compare the performance of Xpert® HPV assay (Cepheid, Sunnyvale) and Hybrid Capture® 2 (HC2) assay (Qiagen, Gaithersburg, MD) for detection of hrHPV infection in cervical smear samples. Also we determined the prevalence of hrHPV among women in area where no previous studies took place
Cervical cells, Pap specimens, from 168 subjects were collected with a Cytobrush that was washed into the PreservCyt collection medium (Hologic, Inc., Marlborough, and MA) kept at room temperature waiting for a liquid base cytology conventional cytology. All samples were reviewed by cyto-technologists and the final diagnosis was confirmed by the pathologists. The cervical cancer screening program in our institution states that, routinely, only samples showing atypical squamous cells of undetermined significance (ASCUS) cytology will be referred for hrHPV testing by Hybrid Capture® 2 (HC2) assay (Qiagen, Gaithersburg, MD). All samples tested by the latter were also tested by the Xpert® HPV assay. Both assays were performed in the molecular diagnostic laboratory at Johns Hopkins ARAMCO healthcare between January and July 2014.
A total of 168 ASCUS samples were enrolled in the study. Among them, 134 (79.8%) were from Saudi patients. The mean age + SD were 40.6 + 11.6 years, ranging from 20-83 years. Xpert® HPV assay reported 30 samples as positive (17.6%; 95% CI, 12.6 to 24.1), compared to 36 for the Hybrid Capture® 2 (HC2) assay (21.2%; 95% CI, 15.7- 27.9). The positive rates did not differ statistically among Saudi and non-Saudi patients. The overall concordance rate between the two tests was 98.2% with a positive concordance rate of 91%. There were three samples that tested positive on Hybrid Capture® 2 (HC2) assay were reported negative by Xpert® HPV assay. HPV others types, HPV 16 and HPV 18/45 types constituted the most common types in a decreasing order
Positive concordance was reasonable between the Xpert® HPV and Hybrid Capture® 2 (HC2) assays. Further investigation is needed to resolve discrepant cases. Overall, the Xpert® HPV assay has a faster turnaround time in comparison with conventional cytology and Hybrid Capture® 2 (HC2) and can be used as a point of care method to detect hrHPV on ASC-US samples.