The current study was conducted to evaluate the efficacy of human papillomavirus (HPV) DNA testing of residual ThinPrep specimens, which were pretreated with acetic acid to optimize cellularity with a special focus on atypical squamous cells of undetermined significance (ASCUS) specimens.
A total of 120 ThinPrep gynecologic samples were chosen for a pilot study including cases with a normal or abnormal interpretation and those with or without blood. Each residual specimen was divided into two portions. One portion was treated with glacial acetic acid (GAA) and the other half remained untreated. Both aliquots were tested for high-risk HPV DNA using the Hybrid Capture 2 test. After internal validation, reflex HPV DNA testing was performed on all consecutive 1776 ASCUS specimens including 98 acid-washed bloody specimens in routine practice.
Of the 120 specimens with paired aliquots, 117 specimens had concordant HPV DNA test results in the treated and untreated groups with a squared correlation coefficient value of 0.97 and a kappa value of 0.95. Subsequently, in the clinical setting, 43 of 98 (43.9%) acid-washed specimens and 845 of 1676 (50.4%) routine specimens with an ASCUS interpretation tested positive for high-risk HPV DNA. There was no statistically significant difference noted between these two groups with regard to age, percentage HPV DNA positivity, or viral load.
The pretreatment of bloody specimens with GAA did not appear to significantly affect high-risk HPV DNA testing in specimens with an ASCUS interpretation.