Validation of Cervista HPV16/18 Assay in Anal Swab Specimens
Haiying Zhang, Abha Khanna, Jie Feng, Shobha Patel, Gregg Staerkel, Ming Guo. University of Texas MD Anderson Cancer Center, Houston, TX
Background: High-risk human papillomavirus (HPV) infection, specifically HPV16 and/or HPV18, is the major etiologic factor (>90%) for the development of anal carcinoma. In high-risk populations, such as HIV-positive patients, anal smears have been used for the surveillance of anal precancerous lesions, i.e. anal intraepithelial neoplasia (AIN). Similar to Pap Test in cervical specimens, HPV 16/18 testing may be useful for anal precancerous lesion surveillance. In this validation study, we evaluated Cervista HPV16/18, an FDA-approved HPV testing assay for Pap Test specimens, in anal swab specimens and compared results to PCR-based HPV16/18 testing results in split anal swab samples.
Design: Residual anal swab specimens (ThinPrep) were collected retrospectively from 98 patients (92 males and 6 females) at the Banner MD Anderson Cancer Center, Gilbert, AZ from 2011 to 2012. Patient's age ranged from 20 to 75 years old with a mean age of 43 years old. We performed HPV DNA testing using the Cervista HR and Cervista HPV 16/18 assays. Genotyping for HPV16 and HPV18 using a PCR-based HPV 16/18 genotyping assay was performed in the split samples of the anal swab. Cervista HPV 16/18 assay results were compared with PCR 16/18 genotyping results.
Results: Among the 98 specimens, 36 had insufficient genomic DNA for both Cervista HR and Cervista HPV 16/18 assays and were excluded from the data analysis. Of the 62 cases qualified for analysis, Cervista HR was positive in 42 (68%) cases. Cervista HPV16/18 was positive in 26 cases which included 12 cases of HPV18, 10 cases of HPV16 and 4 cases of HPV16 and HPV18. In 39 cases, there was sufficient DNA for both the Cervista HPV16/18 assay and the PCR-based HPV 16/18 genotyping assay. The results demonstrated a good correlation between the two HPV genotyping assays (kappa=0.69, 95% CI 0.46-0.92) (Table 1).
|PCR HPV 16/18||Positive||Negative||Total|