Cytologic diagnosis of human papillomavirus infection: spindled nuclei

A morphological protocol and guide-list on uterine cervix cytology associated to Papillomavirus infection

The present study was designed to further assess the validity of the cytological description of morphological lesions said to be related to Papillomavirus (HPV) infections in senior women. The casuistic comprised 196 cervical smears from a group of women with no clinical or morphological evidence of neoplasia, collected simultaneously with samples submitted to detection of HPV DNA by PCR in a previous study. Three experienced cytologists studied each slide in two different conditions, with an interval of 20 months between them. The first approach was performed under routine laboratory standards, whereas the second was guided by a list of 16 well-defined parameters indicative of HPV-related cytological lesions. When suspicious cases of HPV-related alterations were grouped with positive cases, they showed on average: sensitivity of 25.5%, specificity of 84.4% and positive predictive value (PPV) of 26.8%. When suspicious cases were grouped with negative cases, sensitivity decreased, whereas specificity and PPV increased, as expected. In the second reading, which followed a "guide-list", a decrease in sensitivity was observed, contrasting with a sharp increase of positive predictive value. Among the 16 cytomorphological criteria tested, "koilocytosis", "mild koilocytosis" and "condylomatous parabasal cells" yielded the best predictive value for HPV DNA detection by PCR. In conclusion, despite the low sensitivity, cytopathologic assessment of cervico-vaginal smears leads to a highly specific diagnosis of HPV infection in menopausal women, with PPV of 91.0% when directed by a guide-list of well-defined morphologic criteria.

Correlation between histological criteria and human papillomavirus presence based on PCR assay in cervical biopsies

The aim was to correlate histological findings in cervix lesions to human papillomavirus (HPV), as detected by polymerase chain reaction (PCR). One hundred and seven women with atypical Pap smear were submitted to colposcopic examination, and suspicious images were biopsied. The PCR assay was performed with the primers MY09/11 and GP05/06+ and, as control, the beta-globin gene was amplified. The morphological findings were correlated to HPV positivity: parakeratosis, acanthosis, koilocytotic atypia (KA), binucleation, dyskeratosis, and number of mitoses. From 107 patients, 61 biopsies were taken: 11 chronic cervicitis (CC), 36 cervical intraepithelial neoplasia (CIN) (13 CIN I; 10 CIN II; 13 CIN III), and 14 suggestive for HPV (SHPV). DNA extraction was not possible in eight cases. HPV was found in 35% CC, 77% CIN, and 64% SHPV. The analysis did not indicate any morphological criteria strongly related to HPV. The findings with highest sensitivity for HPV were KA (88.89%) and binucleation (75%), but with low specificity of 29.41 and 52.94%, respectively. The higher predictive positive values (PV+) for HPV were also KA (72.73%) and binucleation (77.14%). Considering KA, dyskeratosis and binucleation together, PV+ was 72.41%.

CONCLUSION

Although indicative, none of the studied morphological criteria was always related to PCR virus detection, denoting some limitations for histological diagnosis.

Value of morphological criteria in diagnosing cervical HPV lesions confirmed by in situ hybridization and hybrid capture assay

The present study evaluated the value of morphological criteria (binucleation, multinucleation, koilocytosis, spindle koilocytes, abnormal mitosis and dyskeratosis) in the diagnosis of cervical human papillomavirus (HPV) lesions confirmed by in situ hybridization (ISH) and hybrid capture (HC) assay. Colposcopic punch biopsies from a series of 138 women with abnormal Pap smears were examined on light microscopy and in situ hybridization (DAKO widespectrum cocktail probe) for HPV-induced morphological changes and HPV DNA, respectively. Cervical swabs were analyzed for HPV DNA of the oncogenic types using Hybrid Capture. CIN 2 and CIN 3 were found in 44 biopsies, CIN 1 in 62, and no evidence of HPV in 32 cases. HPV was detected by ISH in 51/138 (37%) cases and by HC in 66/138 (48%) lesions. With both tests, HPV DNA detection increased parallel with lesion severity, up to 70% and 59% in CIN 2/3 by HC and ISH, respectively OR 4.6 (1.7-12.1) and 10.1 (3.0-33.8). Among the histological criteria, multinucleation, binucleation and abnormal mitoses were significantly associated with HPV DNA detection. Multinucleation proved to be the strongest predictor of HPV DNA-positivity. Binucleation, abnormal mitosis, koilocytosis and spindle koilocytes were also reliable criteria of HPV lesions. Minor nuclear atypia, and "mild koilocytosis" were of no value in making this diagnosis.

Pathogenesis of genital HPV infection

Clinical, subclinical, and latent human papillomavirus (HPV) infections are distinguished from HPV-associated neoplasia. Besides HPV additional cofactors are necessary to transform HPV infected tissue to intraepithelial or invasive neoplasia. Risk factors for the presence of HPV are high number of sexual partners, early cohabitarche, young age at first delivery, suppression and alteration of immune status, young age and hormonal influences. While the fact of a high number of sexual partners exclusively increases the risk of HPV infection, it is not known whether the other factors lead to either an increased risk for HPV infection and/or to HPV-associated neoplasia. Subclinical and latent genital HPV infections are highly prevalent. The prevalence rate depends on the sensitivity of the HPV detection system used, on age and sexual activity of the population screened, and on the number of subsequent examinations performed for each subject. Sexual transmission is the main pathway for genital HPV's, however, vertical, peripartal, and oral transmission are also possible. Seroreactivity against genital HPV may be due to an active infection or the result of contact with HPV earlier in life. Antibodies against the HPV 16 E7 protein indicate an increased risk for cervical cancer. Compared with humoral response cellular immune response is probably more important for regression of genital HPV infection: impaired cellular response is characterized by depletion of T helper/inducer cells and/or Langerhans cells and impaired function of natural killer cells and/or the infected keratinocyte. In condylomata replication and transcription of viral nucleic acids and antigen production coincide with cellular differentiation. However, the interaction between HPV and the keratinocyte on a molecular level in subclinical and latent disease is not well understood. Regression or persistence of subclinical and latent genital HPV infections as observed in longitudinal investigations show a constant come-and-go of HPV presence. Subclinical or latent cervical infections with high-risk HPV types (such as HPV 16 and 18) have an increased risk for the development of HPV-associated neoplasia.