Detection of high-risk human papillomavirus infection in tonsillar specimens using 2 commercially available assays

Prevalence and characteristics of tonsillar human papillomavirus infection in tumor-free patients undergoing tonsillectomy

OBJECTIVE

This study evaluated the prevalence and characteristics of tonsillar human papillomavirus (HPV) infection in tumor-free patients undergoing tonsillectomy.

METHODS

We prospectively enrolled healthy patients who underwent tonsillectomy for tumor-free tonsillar disease. Their tonsillar HPV infections were evaluated using CLART HPV2, and subsequent p16 immunohistochemistry was performed in patients with positive HPV infection. Moreover, the results of tonsillar HPV infection were analyzed according to sex, age, and indication of tonsillectomy.

RESULTS

A total of 362 patients were included. HPV test was positive in 8 patients, with an overall prevalence of 2.2%. All detected HPV types were high-risk, including HPV 16 in six patients, HPV 52 in one patient, and HPV 58 in one patient. P16 was negative in all 8 patients with HPV infection. The prevalence of tonsillar HPV infection in males and females was 2.4% (6/246) and 1.7% (2/116), respectively (P > 0.999), and in pediatric and adult patients, 2.2% (5/228) and 2.2% (3/134), respectively (P > 0.999). The prevalence showed a bimodal peak at 1st and 6th decades, with the prevalence of 2.6% (5/194) and 7.9% (3/38), respectively. The prevalence of tonsillar HPV infection in tonsillitis and non-tonsillitis groups were 0.0% (0/104) and 3.1% (8/258), respectively (P = 0.111).

CONCLUSION

The prevalence of tonsillar HPV infection in tumor-free patients was low, but all detected HPV infections were high-risk types. Our results support using a 9-valent vaccine which covers all high-risk HPV types found in this study.

Detection of high-risk human papillomavirus in the tonsils of galilee region adults and young adults undergoing tonsillectomy

INTRODUCTION

The presence of high-risk HPV in non-malignant tonsil tissues from patients who underwent tonsillectomy in the Galilee area might explain the low incidence of HPV-related oropharyngeal malignancy in the country. The aim of this retrospective study was to study the prevalence of human papillomavirus (HPV) in non-malignant tonsillectomy specimens of adults in the Galilee area.

MATERIALS AND METHODS

We conducted a retrospective analysis of all tonsil samples in our medical center. Tonsils from patients over 20 years of age who underwent tonsillectomy for the indication of recurrent tonsillitis and sleep apneas were eligible. Samples of formalin-fixed paraffin-embedded (FFPE) tonsillar tissue were tested for the presence of HPV DNA using polymerase chain reaction and by p16 immunohistochemistry.

RESULTS

Of the 71 tonsil samples, age range 20-65, none were positive for HPV DNA. Fifty-two FFPE specimens of tonsil with HPV-positive cancer tested positive by the same method served as positive controls.

CONCLUSIONS

HPV DNA is rare in non-malignant tonsil tissues of young adults and adults who underwent tonsillectomy in the Galilee area. Further research should be done in larger cohorts.

Mapping of human papilloma virus, p16, and epstein-barr virus in non-malignant tonsillar disease

Objectives

Due to their location in the entrance of the aero-digestive tract, tonsils are steadily exposed to viruses. Human papilloma virus (HPV) and Epstein-Barr virus (EBV) are two potentially oncogenic viruses that tonsils encounter. The incidence of HPV positive tonsillar cancer is on the rise and it is unknown when infection with HPV occurs.

Aim

To investigate if tonsils are infected with HPV and EBV, to study the co-expression of HPV and its surrogate marker p16, and to evaluate the number of EBV positive cells in benign tonsillar disease.

Materials and Methods

Tonsils from 40 patients in a university hospital were removed due to hypertrophy, chronic or recurrent infection. These were analyzed for presence of HPV, its surrogate marker p16, and EBV. HPV was studied using PapilloCheck (a PCR method), while p16 was identified in epithelial and lymphoid tissue with immunohistochemistry and EBV using EBER-ISH (Epstein-Barr encoding region-in situ hybridization).

Results

HPV was not detected, and p16 was present at low numbers in all epithelial samples as well as in 92.5% of the lymphoid tonsillar samples. At least one EBER-positive cell was seen in 65% of cases. Larger numbers of EBER-expressing cells were only seen in two cases.

Conclusion

These findings demonstrate that EBV and HPV infect tonsils independently, but further studies are warranted to confirm their infectious relationship.

Level of Evidence

Cross-sectional study.

Human papillomavirus in tonsillectomy specimen from China and Pakistan - Prevalence and genotype distribution

BACKGROUND

The expected corresponding increase in tonsillar human papillomavirus (HPV) infection associated with increasing incidence of oropharyngeal squamous cell carcinoma (OPSCC) substantiate the evaluation of normal tonsillar tissue in different population. The epidemiology of HPV in tonsillar tissue varies geographically. This study evaluated samples from two countries to determine the prevalence in respective samples.

OBJECTIVE

To characterize HPV infection in non-malignant tonsillar tissue from Shaanxi, China (herein after referred to as China) and Punjab, Pakistan (herein after referred to as Pakistan).

METHODOLOGY

The DNA extracted from formalin-fixed, paraffin-embedded tumor free tonsillar tissue was evaluated using polymerase chain reaction (PCR). A total of 367 cases from China and 139 cases from Pakistan were screened for HPV DNA using GP5+/GP6+ consensus primer. Genotype of the positive cases was determined for common HPV types (6, 11, 16, 18, 52, 58) simultaneously by type-specific PCR.

RESULTS

The mean age of cohorts in China was 13.42 (Median age 7, Range 2-72 years) while in Pakistan it was 10.77 (Median age 8, Range 3-42 years) the gender distribution was 61.6% male in China and in Pakistan they were 56.8%, rest were females. The overall prevalence of HPV in China was 2.45% and 2.16% in Pakistan. High risk human papillomavirus was 1.63% in China with 5 cases positive for HPV 16 and HPV 58 in 1 case. In Pakistan, 2 cases (1.43%) of HPV 16 were detected. Low-risk types include HPV 11 present in 2 cases from China, while HPV 6 was detected in 1 case each from both the countries.

CONCLUSION

A low prevalence of HPV was found in China and Pakistan; high-risk and low-risk HPV were detectable in tonsillar tissue from both countries. Age stratification (< 5 years, 5-14 years, 15-25 years, > 25 years) suggest that sexual and non-sexual transmission of the virus can occur. The difference in the genotype distribution geographically within China and with Pakistan was observed in the case of HPV 58. The most common type in both the countries was HPV 16.

The prevalence of human papillomavirus in pediatric tonsils: a systematic review of the literature

BACKGROUND

HPV-related head and neck cancer rates have been increasing in recent years, with the tonsils being the most commonly affected site. However, the current rate of HPV infection in the pediatric population remains poorly defined. The objective of this study was to systematically review and evaluate the prevalence and distribution of HPV in the tonsils of pediatric patients undergoing routine tonsillectomy.

METHODS AND RESULTS

The literature was searched using PubMed, EMBASE, Scopus, CINAHL, Cochrane Library, and ProQuest Dissertations & Theses Global databases (inception to December 2017) by two independent review authors. Inclusion criteria included articles which evaluated the prevalence of HPV in a pediatric cohort without known warts or recurrent respiratory papillomatosis, those which used tonsil biopsy specimens for analysis, and those with six or more subjects and clear outcomes reported. Eleven studies met the inclusion criteria. Using the Oxford Clinical Evidence-based Medicine (OCEBM) guidelines, two reviewers appraised the level of evidence of each study, extracted data, and resolved discrepancies by consensus. The systematic review identified 11 articles (n = 2520). Seven studies detected HPV in the subject population, with prevalence values ranging from 0 to 21%. The level of evidence for all included studies was OCEBM Level 3.

CONCLUSIONS

HPV may be present in pediatric tonsillectomy specimens; however, the largest included study demonstrated a prevalence of 0%. Future testing should be performed using methods with high sensitivities and specificities, such as reverse transcript real-time PCR or digital droplet PCR.

Prevalence of human papillomavirus in tonsil brushings and gargles in cancer-free patients: The SPLIT study

OBJECTIVE

To evaluate human papillomavirus (HPV) prevalence in the tonsil using extensive ex vivo brushing and gargling in a large age-stratified sample of cancer-free patients.

MATERIALS AND METHODS

From 2012 to 2016, consecutive patients undergoing tonsillectomy for benign indications in 19 French University Hospitals were invited to participate in the SPLIT study. Immediately after resection, half-tonsils were extensively brushed at the pathology laboratories on the surface epithelium and in tonsil crypts to collect exfoliated cells. In 11 centers, patients aged 15 and over (adults) were also asked to provide gargle samples before surgery. HPV-DNA detection used a very sensitive Luminex technology to evaluate 21 HPV types.

RESULTS

Tonsil brushings from 692 patients aged 1-70 years and gargles from 268 adults were tested for HPV. Among adults, overall HPV prevalence was 3.6% in tonsil brushings and 13.1% in gargles and HPV16 prevalence was 2.2% and 4.1%, respectively. Among 139 children, tonsil brushings were positive in two girls (1.4%). Percent agreement in HPV detection in paired tonsil brushings and gargles in adults was 85.8% and positive agreement 9.5%. HPV prevalence in gargles significantly varied by sex (prevalence ratio in men vs women=2.1; 95% confidence interval; 1.1-4.1) and tonsillectomy indication (non-infectious vs. infectious=4.9; 1.4-17.0).

CONCLUSION

HPV infection is infrequent in tonsil brushings of cancer-free children and adults. In contrast, HPV infection in gargles in adults is rather common. Low agreement in paired tonsil brushings and gargles suggests that gargle is not representative of HPV prevalence in the tonsil.