Dual-Stained Cervical Cytology and Histology with Claudin-1 and Ki67

Several biomarkers are in use to improve the sensitivity and specificity of cervical cancer screening. Previously, increased expression of tight junction protein claudin-1 (CLDN1) was detected in premalignant and malignant cervical lesions and applied for cytology screening. To improve the specificity, a double immunoreaction with CLDN1/Ki67 was developed in the recent study. Parallel p16/Ki67 (CINtec® PLUS) and CLDN1/Ki67 dual-stained cytology and histology were performed and compared. p16/Ki67 immunoreaction showed positivity in 317 out of 1596 smears with negativity in 1072 and unacceptable reactions in 207 samples. CLDN1/Ki67 dual staining was positive in 200 of 1358 samples, negative in 962, whereas 196 smears could not be evaluated due to technical reasons. Considering the high-grade squamous intraepithelial lesion cytology as gold standard, sensitivity of CLDN1/Ki67 reaction was 76%, specificity was 85.67%, while for p16/Ki67 sensitivity was 74% and specificity was 81.38%. Comparison of CLDN1/Ki67 and p16/Ki67 dual stainings showed the results of the two tests not to be significantly different. Analysing histological slides from 63 cases, the results of the two tests agreed perfectly. As conclusion the sensitivity and specificity proved to be similar using p16/Ki67 and CLDN1/Ki67 double immunoreactions both on LBC samples and on histological slides.