Human papillomavirus detection in cervical intraepithelial neoplasia by the second-generation hybrid capture microplate test, comparing two different cervical specimen collection methods

Abstract

Background: The second generation Hybrid Capture microplate-based human papillomavirus (HPV) test (HC II) was examined to determine its sensitivity for identification of cervical intraepithelial neoplasia (CIN) by two different cervical specimen collection methods.

Objectives: A cohort of 115 women with a mean age of 34.6 years (SD 9.1), referred to colposcopy with a history of abnormal cytology, was studied to compare HPV prevalence and viral load in low grade CIN vs. high grade CIN.

Study design: Prior to the application of acetic acid, cervical specimens were obtained by either method 1 or 2, as follows: method 1: A cotton-tipped swab was applied to the ectocervix and endocervix for a Papanicolaou (Pap) smear. Next, a special cone-shaped cervical brush was applied to the endocervix, the ectocervix, and to the posterior vaginal vault and suspended in 1.0 ml of transport medium for HPV testing. Method 2: a Pap smear was taken with a cyto standard cylindrical cytology brush from the endocervix, and ectocervix, and the remaining cells were suspended in 3 ml phosphate-buffered saline (PBS) for HPV testing. Next, a Dacron-tipped swab was used to take a specimen from the ectocervix and posterior fornix and suspended in the same PBS solution.

Results and conclusions: Histological evaluation of cervical punch biopsies or conization specimens showed CIN I in 39 cases, CIN II in 32 cases, and CIN III in 44 cases. High risk (HR) HPVs were detected with collection method 1 vs. collection method 2 in 70 (14/20) vs. 74% (14/19) of CIN I; 100 (17/17) vs. 87% (13/15) of CIN II; and 96 (25/26) vs. 94% (17/18) of CIN III (all differences not statistically significant). The estimated viral load of each collection method was significantly higher in patients with CIN II or III compared with CIN I, independent of the collection method used (P≤0.03). Collection method 1 gave higher relative HPV viral load estimates than method 2 for CIN II/III, but this difference was not statistically significant. We conclude that HC II has a high clinical sensitivity for CIN II/III (over 90%) and that high grade disease (CIN II/III) has a greater relative HPV viral load than low grade disease (CIN I). Method 1 appears to be better than method 2 for collecting cervical specimens, especially if viral load is considered a useful risk marker for high grade CIN or in cases of low-level HPV infection.