Detection of HPV Genotypes in Non-genital SeborrheicKeratosis by HPV DNA Chip Analysis

Lee, Un Ha; Choi, Woo Seok; Kim, Sung Woo; Park, Hyun Su; Jang, Sang Jai; Hwang, Seon Wook; Lee, Hye Kyung

Abstract

BACKGROUND
The precise etiology of seborrheic keratosis (SK) is unknown. Genetics, sun exposure and infection have all been implicated as possible factors. Because of its clinical and histopathological similarities to verrucae vulgaris and condyloma acuminatum, human papillomavirus (HPV) has been suggested as a possible causative agent. In the previous studies, HPV were frequently detected in the genital lesions or hair follicles of immunocompromised hosts.
OBJECTIVE
A newly introduced HPV detection technique, the HPV DNA Chip analysis, contains 24 HPV probes and it has the advantage of being able to detect 24 types of HPV at once. The purpose of this study was to evaluate the presence of HPV DNA in the nongenital SK of immunocompetant individuals.
METHODS
We analyzed 31 biopsy specimens that were taken from patients with nongenital SK, and these specimens were compared with genital warts (the positive control) and distilled water in place of DNA (the negative control) with using HPV DNA Chip analysis and a polymerase chain reaction-based DNA microarray system as the HPV genotyping method.
RESULTS
By polymerase chain reaction (PCR), HPV DNA was detected in 2 of the 31 nongenital SK biopsies (6.5%). HPV DNA Chip analysis revealed that 3 of 31 nongenital SKs (9.7%) contained HPV DNA. Two distinct HPV genotypes were detected: HPV type 16 (n=2) and HPV type 42 (n=1). The duration of SK in the HPV positive group was longer than that of the SK in the negative group. The mean age of the patients in the HPV positive group was also older than the mean age of the negative group. There were no different histopathologic findings between the HPV positive and negative SK.
CONCLUSION
This study did not provide any concrete evidence that HPV infection might directly play a part in the pathogenesis of nongenital SK. However, two distinct HPV DNA types were identified as types that have never been reported before. Further studies with a larger number of cases of SK are needed to confirm the presence of HPV DNA in nongenital SK and also to determine the role of HPV in the origin of nongenital SK.