Evaluation of a novel multiplex human papillomavirus (HPV) genotyping assay for HPV types in skin warts

Skin surface material for detecting human papillomavirus infection of skin warts

Warts, caused by human papillomavirus (HPV) infection, have various clinical presentations, making them difficult to differentiate from clavus, callus, and sometimes, squamous cell carcinoma. Although skin biopsies are the gold standard, a less-invasive method of examining these lesions is desired. Ninety patients with warts and related diseases, such as clavus and callus, were recruited to explore new differentiation methods using the surface of the warts. DNA was extracted from three types of specimens in each case: surface swab, shaved hyperkeratotic scale, and post-shaved surface swab. Total DNA was successfully extracted from these three specimens and was sufficient for subsequent HPV DNA detection. We analyzed samples for the HPV type and HPV viral load using polymerase chain reaction (PCR). Fifty-five cases were PCR-positive, and HPV1a, 2a, 4, 27, 57, and 65 were detected. The amount of HPV1a DNA produced was significantly greater than that of other HPV types. Regarding the correlation between the clinical diagnosis and HPV detection, the positive agreement rate was 90.9%, the negative agreement rate was 40.0%, and the overall agreement rate was 71.1%. Ten of the 21 cases clinically diagnosed as plantar warts were PCR-negative, especially in elderly patients. This suggests that it is difficult to distinguish plantar warts from clavus and callus in clinical practice. Although the amount of HPV DNA in the removed keratinization scale was highest for all HPV types, HPV detection by swabbing before and after shaving is also useful for follow-up as well as for differential diagnosis.

Characterization of type-specific HPV prevalence in a population of persistent cutaneous warts in Flanders, Belgium

Cutaneous warts are benign skin lesions caused by the human papillomavirus (HPV). Even though they are considered benign, they can have a considerable impact on the quality of life and cause serious illness in certain immunocompromised populations. Studies have shown that the efficacy of wart treatment is dependent on the causative HPV type. Therefore, in this article, we aim to determine the HPV genotype-specific prevalence in cutaneous warts of a Flemish population as part of the Omnivirol-Salycilic acid randomized controlled trial. Swab samples of cutaneous warts (n = 269) were collected during enrollment. The DNA extraction was performed on the automated NucliSENS® easyMAG® system (bioMérieux). The samples were analyzed with two separate in-house PCR assays capable of detecting the most prevalent cutaneous HPV types (i.e. wart-associated HPV qPCR) as well as the most relevant mucosal types (i.e. RIATOL qPCR assay). In total, the type-specific prevalence of 30 distinct HPV genotypes was determined. The beta-globin gene was used as a cellularity control and for viral load quantification. Data concerning wart persistence, previous treatment, wart type, and other relevant wart and patient characteristics was collected through a baseline questionnaire. The study population consisted mostly of persistent warts considering that 98% (n = 263) of the sampled skin lesions were older than six months and 92% (n = 247) had undergone previous treatment. The most prominent wart type was the mosaic verruca plantaris (42%, n = 113). The most prevalent HPV types were cutaneous HPV types 27 (73%, n = 195), 57 (63%, n = 169), and 2 (42%, n = 113). Only 2% (n = 6) of the lesions was HPV negative. The highest median viral loads were observed with HPV27 and 57 (i.e. 6.29E+04 and 7.47E+01 viral copies per cell respectively). The multivariate analysis found significant associations between wart persistence and certain wart types, the number of warts, and HPV genotypes. Based on these findings, persistent warts are more likely to: (1) be verruca vulgaris, verruca plantaris simple or mosaic, (2) to manifest as multiple warts, (3) and to be negative for HPV type 2 or 4. These characteristics can be useful in the clinical setting for future risk stratification when considering treatment triage and management. Trial registration: NCT05862441, 17/05/2023 (retrospectively registered).

Development and validation of a wart-associated human papilloma virus genotyping assay for detection of HPV in cutaneous warts

Cutaneous warts are infectious disorders caused by human papillomavirus (HPV). A recent study revealed that the HPV genotype influences the natural course and response to treatment for plantar warts, suggesting that HPV genotyping could potentially be used to optimize wart treatment schemes. For this purpose, a wart-associated HPV genotyping assay was developed. The assay was subjected to an intensive validation process including, i.a., empiric determination of the annealing temperature, primer-probe optimization, evaluation of the analytical specificity and sensitivity, viral load quantification, and qualitative as well as quantitative analysis of intra-run repeatability and inter-run reproducibility. The newly developed assay was employed in a small-scale HPV genotyping study of wart biopsies (n = 50). The assay exhibited an analytical type-specific sensitivity and specificity of 100% (95% confidence interval [CI]: 83.9%-100%). The limit of quantification of the tested sequences corresponded to less than 17 viral copies/µl, while the limit of detection was less than 5 copies/µl. Very good to excellent agreements were gained between intra- and inter-run measurements (κ = 0.85-1.00) and coefficients of variation of the quantitative agreements were less then 3%. 22.5% (95% CI: 11%-39%) of the analyzed biopsies were negative for the tested HPV types, while 35% (95% CI: 21%-52%) contained multiple infections. The wart-associated HPV quantitative polymerase chain reaction assay was proven to be highly sensitive and specific. Multiple HPV infections were detected in 35% of lesions, contradicting the current literature claiming that in immunocompetent patients only 4%-16% of warts exhibit multiple HPV infections. This assay is qualified to be implemented in development of future genotype specific wart treatment strategies.

Determination of Causative Human Papillomavirus Type in Tissue Specimens of Common Warts Based on Estimated Viral Loads

Background: Assessment of human papillomavirus (HPV) type-specific viral load (VL) is a valid tool for determining the etiology of HPV-related skin tumors, especially when more than one HPV type is detected within one lesion.

Methods: The causative HPV type was determined in 185 fresh-frozen tissue specimens of histologically confirmed common warts (CWs) collected from 121 immunocompetent patients. All tissues were tested using the type-specific quantitative real-time polymerase chain reactions (PCR) for the most common wart-associated Alpha-PV (HPV2/27/57) and Mu-PV types (HPV1/63/204). The presence of 23 additional low-risk HPVs was evaluated using a conventional wide-spectrum PCR.

Results: HPV DNA was detected in 176/185 (95.1%) CWs and multiple HPV types in 71/185 (38.4%) lesions. Using the VL approach and a robust cutoff of one viral copy/cell established in this study, HPV2/27/57 were determined as causative agents in 41/53 (77.3%) and 53/71 (74.7%) CWs with single and multiple HPVs, respectively.

Conclusions: CWs are mostly etiologically associated with HPV2/27/57 and only rarely with HPV1. In the majority of CWs containing multiple HPVs, a single HPV type was present in high concentration, indicating etiological association. No significant differences in VLs of lesion-causing HPV types in CWs containing single or multiple HPVs were found.

[Low-dose prophylactic oral isotretinoin treatment for 18 years in a patient with epidermodysplasia verruciformis and numerous squamous cell carcinomas]

Epidermodysplasia verruciformis (also known as Lewandowsky-Lutz dysplasia) is an extremely rare autosomal recessive genodermatosis, in which the skin is unusually sensitive to human papilloma viruses (HPV). It is associated with a high risk of developing non-melanocytic skin tumors. Treatment with keratolytic retinoids is currently considered to be the most effective therapy. Retinoids have a broad spectrum of activity and inhibit the growth of squamous cell carcinoma and other malignant tumors. We report the case of an 81-year-old woman who had been receiving prophylactic treatment with oral isotretinoin at a daily dose of 1.0-0.33 mg/kg bodyweight for about 18 years because of her epidermodysplasia verruciformis (HPV types 9 & 57 detected). We observed a reduction of the incidence of squamous cell carcinomas of the skin and presume a causal relationship between the treatment with this retinoid and the reduction of squamous cell carcinomas of the skin in this patient.

Detection of High-Risk Human Papillomavirus Genotypes 16 and 18 in Head and Neck Squamous Cell Carcinomas in Jordan

Background:

Recently, associations of the human papillomavirus (HPV) with head and neck cancer have become well established. Of particular concern, the severity and pathological outcomes of squamous cell carcinomas are remarkably affected by the genotypes of HPV present in such lesions. This study was conducted to investigate the occurrence of HPV genotypes, particularly high risk 16 and 18, among oral and laryngeal squamous cell carcinomas in Jordan.

Methods:

During the period of May 2015 to March 2016, we evaluated a total of 108 paraffin-embedded tissue samples, histologically confirmed as SCC, of both oral and laryngeal tumors for the presence of HPV DNA. DNA was extracted using a Zymogen commercial kit. HPV genotypes were detected by nested PCR using consensus primers followed by primer-specific PCR for HPV-16 and HPV-18 genotypes. The genotypes were confirmed by DNA sequencing methods.

Results:

Sixteen samples were positive for HPV DNA (14.8%) with higher rates in oral tumors compared to their laryngeal counterparts (20% and 6% respectively). The HPV-16 genotype predominated, being detected in 81.3% of the cases as a single infection and in 18.7% in combination with HPV-18. A significant association between the anatomical location and the HPV-16 genotype was observed (p < 0.05). In contrast, no significant associations could be established with tumor grade and gender or age.

Conclusions:

A relatively high rate of high-risk HPV genotypes, especially HPV 16, is evident in head and neck cancers SCCs in Jordan. Genotyping of HPV might be of considerable value for evaluation of progression.

Comparison of molecular multiplex assays for the detection of human papillomaviruses from clinical gynecological tissue samples

ABSTRACT: 

Papillomavirus-associated cervical cancer remains a major disease burden for young women. Therefore, it plays an important role in the pathological diagnosis. Besides cytological and classical pathological methods, molecular biology tests are used for the analysis of HPV status. Here we compare three PCR assays for the detection of human papillomavirus DNA from 50 gynecological samples, namely the HPV Genotyping Kit HPVsign® (Qiagen, Germany), a novel HPV-genotyping kit based on pyrosequencing, the LCD array HPV Type 3.5 (Chipron, Germany) and an in-house PCR of the National Reference Center for Papilloma- and Polyomaviruses at the Institute for Virology of the University Cologne (Germany). The HPVsign assay mainly detected the assumed leading HPV type, while both the in-house PCR and the Chipron HPV Assay 3.5 reproducibly detected single and multiple infections.

Genomic diversity of human papillomaviruses (HPV) and clinical implications: an overview in adulthood and childhood

During the last years, several researchers have highlighted the importance of characterizing more than one genomic region in order to detect recombination and classify variants of human papillomaviruses (HPVs) properly. HPVs variants differ in their biological, molecular and chemical properties. Therefore, this genomic diversity can present differences in the natural history and pathogenicity of HPVs. Different 'high-risk' HPVs variants of the genotypes HPV 16 and 18 can confer varied risks of viral persistence in the human cervix and influence HPVs progression to cervical cancer. Moreover, different 'low-risk' HPVs variants of the genotypes HPV 6 and 11 can play a unique role in the development of anogenital and cutaneous warts, recurrent respiratory papillomatosis (RRP) and ophthalmic pterygium. In future, the precise impact of genomic HPVs diversity to the clinical course of HPVs-associated diseases as well as to the efficacy of the current HPVs vaccines remains to be elucidated.

Human papillomavirus (HPV) genotyping of cutaneous warts in Greek children

The human papillomavirus (HPV) infects the squamous epithelium of the skin and produces common warts, plantar warts, and flat warts, which occur commonly on the hands, face, and feet. The objective of this study was to determine the presence of HPV in warts in children in order to associate the virus with the disease. Sixty-eight children with clinically diagnosed cutaneous warts were recruited. Skin biopsy samples were examined and DNA was extracted using a commercially available kit. To distinguish between the HPV types, we used a specific pair of primers to amplify the HPV DNA. Polymerase chain reaction amplification of the L1 region was followed by restriction fragment length polymorphism analysis and Luminex xMAP technology. HPV 57 was the predominant type in our study, although the detection of the high-risk HPV type 16 in 33% of our positive samples indicates the presence of mucosal high-risk HPV types in the skin of children. It seems that the newly introduced Luminex assay maximized the discrimination of genotypes even in the case of multiple HPV infections. Or findings also suggest the presence of high-risk HPV types in cutaneous warts.

Diversity of human papillomaviruses in skin lesions

Pools of frozen biopsies from patients with squamous cell carcinoma (SCC) (n=29) actinic keratosis (AK) (n=31), keratoacanthoma (n=91) and swab samples from 84 SCCs and 91 AKs were analysed with an extended HPV general primer PCR and high-throughput sequencing of amplimers. We found 273 different HPV isolates (87 known HPV types, 139 previously known HPV sequences (putative types) and 47 sequences from novel putative HPV types). Among the new sequences, five clustered in genus Betapapillomavirus and 42 in genus Gammapapillomavirus. Resequencing of the three pools between 21 to 70 times resulted in the detection of 283 different known or putative HPV types, with 156 different sequences found in only one of the pools. Type-specific PCRs for 37 putative types from an additional 296 patients found only two of these putative types. In conclusion, skin lesions contain a large diversity of HPV types, but most appeared to be rare infections.

Improved detection of human papillomavirus harbored in healthy skin with FAP6085/64 primers

FAP59/64, FAP6085/6319, and CUT primer sets were designed for detecting cutaneous HPV and have been used in many clinical and epidemiology studies. The FAP6085/64 primer set was first evaluated in this study and the FAP6085/64 combination was found to be much more sensitive than all three original primer sets by using HPV plasmids as a template. To confirm further the effectiveness of the FAP6085/64 primer set in human DNA templates, 90 palmar exfoliated cell DNA samples were used to detect the cutaneous HPV by both the FAP59/64 and FAP6085/64 primer sets. The overall proportion of HPV detection in those skin samples was 77.8% (70/90) using FAP6085/64, as compared to 55.6% (50/90) using FAP59/64. The FAP6085/64 primer set was also applied in a population based study. The proportion of HPV detection was 73.96% (2076/2807) in skin samples collected from healthy individuals, and a total of 336 different PV types were found. Sixty (17.9%) of them were fully characterized HPV types, 127 (37.8%) were putative HPV types which had been described previously, 149 (44.3%) were novel putative HPV types, and two animal PVs were also detected. These results suggest that the FAP6085/64 primer set was sensitive and effective for detection of cutaneous HPV in healthy skin samples.

Bead-based multiplex genotyping of 58 cutaneous human papillomavirus types

Cutaneous human papillomaviruses (HPVs) are a heterogeneous, nonmonophyletic assembly, comprising about 50 characterized types and at least 133 isolates putatively representing new types. Their natural history of infection and potential association with nonmelanoma skin cancer are not well understood. Several PCR systems have been developed that amplify a broad spectrum of cutaneous HPVs. However, amplicon genotyping by sequencing or reverse line blot assays are complex and not well suited for high-throughput analyses. We developed a novel multiplex cutaneous papillomavirus genotyping (McPG) assay for 38 defined and 20 putative cutaneous HPVs of the beta, gamma, mu, and nu genera. Viral DNA was amplified by the use of a modified single-tube nested "hanging-droplet" FAP PCR. The amplifiable papillomavirus (PV) spectrum was enlarged by the use of 9 outer and 13 inner primers. Biotinylated PCR products were hybridized to type-specific oligonucleotide probes coupled to fluorescence-labeled polystyrene beads and analyzed using Luminex technology. Analytical sensitivity was analyzed for 38 defined HPVs and was ≤100 genome copies for all types. Integrated β-globin primers allow for simultaneous DNA quality control. McPG is characterized by high reproducibility (κ= 0.84, 95% confidence interval = 0.79 to 0.88), good concordance with the original nested FAP PCR, followed by sequencing (70.2% complete or partial agreement) when 322 skin biopsy DNA samples were analyzed, and improved ability to detect multiple infections (on average 2.5 HPV types per HPV-positive sample compared to 1.7 HPV types with nested FAP-PCR). In conclusion, McPG is a powerful tool for genotyping multiple cutaneous HPVs in a high-throughput format and is thus suitable for large-scale epidemiological studies.