Enzyme-linked immunosorbent assay for p16(INK4a) - a new triage test for the detection of cervical intraepithelial neoplasia?

Objective: To evaluate enzyme-linked immunosorbent assay (ELISA) for cyclin-dependent kinase inhibitor 2A protein (p16(INK4a) ) on self-collected cervicovaginal lavage samples as an additional triage test to identify women with high-grade cervical intraepithelial neoplasia (CIN).

Design: Retrospective feasibility, sensitivity and specificity study.

Setting: University Medical School, Germany.

Sample: One hundred and fifty-two patients from the colposcopy clinic were included.

Methods: All women used a cervico-vaginal lavage device (Delphi Screener) for self-sampling and had gynecological examinations with Pap smears, cervical smears in ThinPrep PreservCyt solution and Cervatec medium for human papillomavirus (HPV) testing (Qiagen Hybrid Capture 2) and colposcopic examinations with biopsies if abnormalities were detected (72 women; 51%). All cytological samples were examined by p16(INK4a) ELISA.

Main outcome measures: Sensitivity and specificity of p16(INK4a) ELISA for high-grade CIN.

Results: Complete data were available for 140 women. Among these, 62 women (46%) presented with an atypical Pap smear and 65 (46.4%) were high-risk HPV positive in the reference smear sample. Seventeen women (12%) had CIN 3+. Twenty-seven (19%) physician-collected samples were p16(INK4a) ELISA positive. In contrast, p16(INK4a) ELISA turned out to be positive in only one (1%) vaginal lavage sample.

Conclusions: Our study shows that self-sampling with cervicovaginal lavage followed by p16(INK4a) ELISA is not suitable for the detection of high-grade CIN.