PCR for the detection of cervical HPV16 infection: the need for standardization

Human papillomavirus findings in relation to cervical intraepithelial neoplasia grade: a study on 476 Stockholm women, using PCR for detection and typing of HPV

Among human papillomavirus (HPV) types found in humans, there is a strong association between HPV 16, 18, 31, and 33, and cervical cancer. The relationship between various grades of dysplasia and HPV type is less clear. To elucidate this point, the authors tested 476 cytological and histological samples from cervix with polymerase chain reaction (PCR) for HPV using consensus primer My 09-11 and type-specific primers. All cases were divided into groups on the basis of cytology: "normal cases" (ie, women with other disease than cervical intraepithelial neoplasia [CIN]), and CIN I, II, and III. Out of the "normal cases," in which women with a previous history of condyloma and dysplasia were included, 69% had HPV with type 6 as the most common one. Of all CIN I cases, 71% were HPV positive, and HPV type 6 and 16 were equally common. In CIN II cases, HPV 16 was the most common type, whereas HPV 6 accounted for only 7.5% of cases in this group as single virus type. HPV 16 was also the most common type in the CIN III group, followed by type 33. Double and even multiple infections occurred in all groups.

HPV detection in cytological cases with condylomatous or dysplastic changes: a study with PCR and in situ hybridization on cytological material

Cytobrush samples of 80 patients, who previously had a cytological or histopathological diagnosis of condyloma and/or dysplasia were investigated for human papillomavirus infection (HPV) by polymerase chain reaction (PCR) and in situ DNA hybridization technique (ISH). The results were compared with concomitantly obtained cytological Pap-stained smears or, in some cases, histological sections. The time between the diagnosis of the original and the concomitant cytology/histopathology was less than 1 yr. Six additional patients had similar morphological diagnoses 2-4 yr before. Five more cases were included on clinical diagnosis of HPV. Compared with the original morphological diagnoses, 70% of the cases were positive by PCR and/or ISH. The concomitant morphology was not diagnostic of HPV in 44 out of 80 cases (55%), showing a relatively high percentage of cases morphologically normalized in the interval since the first specimen was taken. After detection with PCR, 30 cases (37.5%) were negative for HPV. Only one of the patients with a previous disease 2-4 yr before was HPV positive by PCR and two out of five patients with a clinical diagnosis of HPV. ISH could be performed on 67/80 cases, 43 of which were positive for HPV. There was a good agreement between the results of ISH and PCR, but there were six cases positive by ISH and negative by PCR. In these cases, few infected cells may have escaped detection by PCR. Both methods seem to be able to detect silent HPV infections and comparison with concomitant cytology/histopathology shows that morphology alone is insufficient for HPV detection in these cases.