Detection of multiple human papillomavirus types in Condylomata acuminata lesions from otherwise healthy and immunosuppressed patients

Abstract

Condylomata acuminata, or genital warts, are proliferative lesions of genital epithelium caused by human papillomavirus (HPV) infection. HPV types 6 and 11 are most often detected in these lesions. Genital lesions consistent with exophytic condylomata acuminata were removed by excision biopsy from 65 patients, 41 of whom were otherwise healthy individuals (control group) and 24 of whom had conditions known to cause immunosuppression. Histologically, the majority of the lesions were typical condylomata acuminata. Three lesions removed from immunosuppressed individuals also contained foci of moderate to severe dysplasia (intraepithelial neoplasia grade II/III). A recently developed PCR and reverse blot strip assay was used to determine the specific HPV types present in the genital lesions. With a set of oligonucleotide primers based on the same primer binding regions used for the MY09 and MY11 primer pair, this PCR assay detects the presence of 27 HPV types known to infect the genital tract. All but two condylomata acuminata contained either HPV type 6 or 11. The predominant type in the lesions from control patients was HPV 6, while lesions from immunosuppressed types most often contained HPV 11. Condylomata acuminata from immunosuppressed patients contained significantly more overall HPV types than lesions from the control group. HPV types associated with an increased risk of dysplasia (high-risk types) were detected in 42 (64.6%) of the total of 65 specimens; 18 (43.9%) specimens were detected in the 41 otherwise healthy individuals, and 24 (100%) specimens were detected in the 24 immunosuppressed patients. HPV 16 was the most common high-risk type detected, found in 21 of 65 (32.3%) specimens. After HPV types 6 and 11, HPV types 53 and 54 were the most frequently detected low-risk HPV types. This study demonstrates that a high percentage of condylomata acuminata lesions contain multiple HPV types, including types associated with a high risk of dysplastic abnormalities. Further studies are needed to determine the influence these additional HPV types have on the epidemiology of genital tract HPV infections and the natural history of condylomata acuminata, especially in immunosuppressed patients.

FIG. 1

A representative PCR and reverse blot assay was performed on condylomata acuminata specimens from 15 patients. The numbers at the top of the figure represent the patients identified in Tables 1 and 2. Shown on the left side of the figure is a template identifying the probe specific for each HPV type in the assay, as well as the β-globin controls.

FIG. 2

Bar graph illustrating the type distribution of HPV types in condylomata acuminata lesions. Bars indicate the percentages of lesions from control and immunosuppressed patients containing particular HPV types.

FIG. 3

Quantitative analysis of PCR products by using cloned HPV 16 DNA added to HPV-free human DNA. Lane 1, PCR containing no template; lane 2, PCR containing 500 ng of DNA from a clinical specimen known to contain six different HPV types. The remaining lanes contain strips hybridized with serial 10-fold dilutions of cloned HPV 16 DNA made in 500 ng of HPV-negative human DNA and subjected to PCR. Lane 3, the equivalent of 10⁰ viral copies per cell; lane 4, 10⁻¹ viral copies per cell; lane 5, 10⁻² viral copies per cell; lane 6, 10⁻³ viral copies per cell; lane 7, 10⁻⁴ viral copies per cell; lane 8, 10⁻⁵ viral copies per cell; lane 9, 10⁻⁶ viral copies per cell; lane 10, 10⁻⁷ viral copies per cell. The upper arrow on the right side of the figure shows the position of the HPV 16 band, the first HPV type represented on these strips. The two bands just below the center of the strips are the high- and low-quantity β-globin amplification controls, respectively.