Koilocytic changes are not elicited by human papillomavirus genotypes with higher oncogenic potential

Koilocytes are considered a common cytopathological effect in patients with human papillomavirus (HPV) infection. Thus, we aimed to elucidate whether koilocytes are common to all HPV infections. Liquid-based cytology samples from 651 patients with abnormal Papanicolaou (Pap) test results were used to analyze the presence of koilocytes and HPV genotype. HPV genotype was determined in complete liquid cytology samples and microdissected cell samples from Pap smear slides using the uniplex E6/E7 polymerase chain reaction method, which can detect 39 mucosal HPV genotypes. Koilocytes were found in 29.3% (191) of all patients. Logistical regression analysis of diverse HPV genotypes revealed that infections with low-risk HPV types (HPV-6b, HPV-40, HPV-42, HPV-61, HPV-74, HPV-89, and HPV-90), probably high-risk HPV types (HPV-53 and HPV-66), and high-risk types (HPV-39 and HPV-56) were significantly associated with the presence of koilocytes. However, HPV-16, HPV-18, and HPV-52, which have higher oncogenic potential, were not found to be associated with koilocytes. These results were confirmed by HPV genotyping using microdissected koilocytes in 27 patients.Most common high-risk types belonging to α-9 and α-7 genotypes appear to rarely induce koilocytic changes. Therefore, koilocytes may provide additional useful information for predicting the risk of progression to high-grade lesions.