Prevalence of Human Papillomavirus Genotypes in Pterygia from Thai Individuals

ABSTRACT

Purpose

Pterygium, a common ocular growth, has an unknown pathogenesis and aetiology. Environmental factors such as ultraviolet light, genetic factors and viral infections may be implicated in the development of pterygia. Human papillomavirus (HPV), an oncogenic virus, has previous been detected in individuals with pterygia. The aim of this study was to assess the prevalence of HPV genotypes in pterygia from Thai individuals.

Methods

DNA was extracted from 389 pterygia. HPV was detected by nested PCR and HPV genotyping was conducted using reverse hybridization. The DNA sequences of HPV-L1 genes were analyzed.

Results

HPV was detected in only 6.8% (25/389) of pterygia from Thai individuals. The majority (16/25, 64%) of strains were genotyped as HPV-16 and the remainder (9/25, 36%) could not be typed. Four pterygia showed evidence of coinfection by HPV-16 and either HPV-18 (2/25, 8%) or HPV-58 (2/25, 8%). Nine of 11 samples showed the same HPV-16 L1 gene sequence that was identical to a HPV-16 reference sequence in GenBank. The remaining two samples each bore silent single nucleotide mutations (T1078G and T1081A) that did not result in amino acid changes.

Conclusion

HPV, especially HPV-16, may be one of the pathogens causing pterygia in Thai individuals. Genotyping data suggested that HPV-16 from pterygia may be similar in sequence to HPV-16 causing cervical cancer.

KEYWORDS:

• Pterygium
• human papillomavirus
• HPV
• Thailand
• genotyping

Acknowledgments

We are grateful for financial support from the Rachadapisek Sompoj Fund (RA21/53), Faculty of Medicine, Chulalongkorn University, Bangkok, 10330. We also thank Edanz Group (https://en-author-services.edanzgroup.com/ac) for editing a draft of this manuscript.

Declaration of conflicting interest

None of the authors have any proprietary interests or conflicts of interest related to this submission.

Ethical approval

This study was approved by the Institutional Review Board, Faculty of Medicine, Chulalongkorn University (COA No. 1085/2009: IRB No. 417/52).

Statement

This submission has not been published anywhere previously and that it is not simultaneously being considered for any other publication.

Additional information

Funding

This work was supported by the Rachadapisek Sompoj Fund, Faculty of Medicine, Chulalongkorn University [RA21/53].