Evaluation of a Digene-recommended algorithm for human papillomavirus low-positive results present in a "retest zone"

The Digene Hybrid Capture 2 (hc2) high-risk human papillomavirus (HPV) DNA test (Digene, Gaithersburg, MD) is widely used for triage of women with atypical squamous cells of undetermined significance. Results in a "retest zone" (weakly positive tests) are repeated up to 2 times according to the Digene-recommended algorithm. We studied 56 cervical samples in the retest zone. Specimens were tested by a multiplex polymerase chain reaction (PCR)-based genotyping assay, and relevant cytopathologic results were reviewed. Digene results were compared with a reference standard that combined PCR genotyping and cytopathology results. The first repeated Digene assay yielded a sensitivity of 85.2% and a specificity of 62.1% with false-positive and false-negative rates of 40.0% and 15.4%, respectively. The 22 negative samples underwent a second retest and 18 (82%) were negative by the reference standard. The combined first and second retest sensitivity, specificity, and predictive values remained unchanged from the first retest alone. Repeating specimens in the retest zone is necessary, but a second retest does not offer advantages over the first retest.