Immunohistochemical evaluation of ProEx C in human papillomavirus-induced lesions of the cervix.

Abstract

Aims: Considering the sparse information about the clinical utility of the novel immunohistochemical marker ProEx C in histologic sections a decision was taken to study the pattern of ProEx C expression in normal/benign cervical epithelium (N/B), low-grade squamous intraepithelial lesion (LGSIL), and high-grade squamous intraepithelial lesion (HGSIL), as well as the association of ProEx C expression with human papillomavirus (HPV) genotypes.

Methods: One hundred cervical samples including 21 N/B cervices, 16 LGSIL, 61 HGSIL and 2 cervical invasive carcinomas obtained from conization and hysterectomy surgical specimens were arranged in three tissue microarrays and stained for ProEx C. Ninety-three samples were HPV genotyped. Genotypes were performed by DNA amplification and hybridization with genotype specific probes on a low density DNA array.

Results: ProEx C positive expression above the lower one third of the epithelium was observed in 14.3% of N/B, in 62.5% of LGSIL and in 90.2% of HGSIL. Seventy percent of HPV positivity was found in cases with expression above the lower one third of the epithelium. Of 31 cases that were positive for HPV16, 16.1% showed ProEx C expression restricted to 1-2 basal layers and 83.9% showed ProEx C expression above the lower one third of the epithelium.

Conclusions: ProEx C is significantly associated with HPV16 infection and is a useful adjunct in the identification of LGSIL and HGSIL in histologic sections when expressed in more than the lower one third of the epithelium.