Detection of human papillomavirus in pterygium and conjunctival papilloma by hybrid capture II and PCR assays

Human papilloma virus presence and its physical status in primary pterygium

Pterygium is one of the most frequent pathologies in ophthalmology, and is a benign, overgrowth of fibrovascular tissue, often with a wing-like appearance, from the conjunctiva over the cornea. It is composed of an epithelium and highly vascular, sub-epithelial, loose connective tissue. There is much debate surround the pathogenesis of pterygium and a number of theories have been put forward including genetic instability, cellular proliferation, inflammatory influence, and degeneration of connective tissue, angiogenesis, aberrant apoptosis and viral infection. At present, the involvement of human papillomavirus (HPV) in the genesis of pterygium is controversial, as have reported that HPV is present in 58% of cases, while others have failed to detect HPV in pterygium. In this study, we evaluated the presence and viral genotype of HPV DNA in pterygia and healthy conjunctiva sample, and virus integration into the cellular genome. Forty primary pterygia samples and 12 healthy conjunctiva samples were analyzed to HPV DNA presence by polymerase chain reaction, using MY09/MY11 primers of HPV-L1 gene. Viral genotype was identified by DNA sequence analysis of this amplicon. HPV integration into the cellular genome was analyzed by western blot detecting HPV-L1 capsid protein. Presence of HPV was observed in 19 of the 40 pterygia samples. In contrast, healthy conjunctiva samples were negative. To determine virus type, sequence analyses were performed. Interestingly, 11 out of the 19-pterygium samples were identified as HPV-11 type, meanwhile, the remaining 8 pterygium samples were identified as HPV-18. HPV-L1 capsid protein were found only in 3 out of the 10 samples studied. In conclusion, our study identified the presence of HPV DNA exclusively in pterygium samples and described HPV-11 and -18 genotypes. Our results suggest that HPV may be involved in the pathogenesis of pterygium. On the other hand, the expression of the L1-HPV protein suggests viral integration into the cellular genome.

Human Papillomavirus Related Neoplasia of the Ocular Adnexa

Human papillomaviruses (HPV) are a large group of DNA viruses that infect the basal cells of the stratified epithelium at different anatomic locations. In the ocular adnexal region, the mucosa of the conjunctiva and the lacrimal drainage system, as well as the eyelid skin, are potential locations for HPV-related neoplasia. The role of HPV in squamous cell neoplasia of the ocular adnexa has been debated for several decades. Due to the rarity of all these tumors, large studies are not available in the scientific literature, thereby hampering the precision of the HPV prevalence estimates and the ability to conclude. Nevertheless, increasing evidence supports that defined subsets of conjunctival papillomas, intraepithelial neoplasia, and carcinomas develop in an HPV-dependent pathway. The role of HPV in squamous cell tumors arising in the lacrimal drainage system and the eyelid is still uncertain. Further, the potential of HPV status as a diagnostic, prognostic, or predictive biomarker in these diseases is a topic for future research.

Prevalence of Human Papillomavirus Genotypes in Pterygia from Thai Individuals

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.

Ocular Human Papillomavirus Infections

CONTEXT

- Human papillomavirus (HPV) has a well-known role in the pathogenesis of squamous cell carcinoma and precursor lesions of the cervix, anogenital region, and head and neck, but its role in the development of squamous neoplasms of the eye, particularly the conjunctiva, remains unclear.

OBJECTIVE

- To review recent evidence implicating HPV in the pathophysiology of ocular lesions.

DATA SOURCES

- Published articles obtained from a PubMed search of the English literature were the primary sources for this review.

CONCLUSIONS

- The low-risk HPV types 6 and 11 appear to play a role in the development of at least a subset of conjunctival squamous papillomas. The role of HPV in the pathogenesis of pterygium and ocular surface squamous neoplasia is less well defined. There is evidence to suggest that HPV may be a cofactor in the development of these lesions, acting in concert with ultraviolet radiation and/or human immunodeficiency virus infection in a subgroup of cases.

Update on Diagnosis and Management of Conjunctival Papilloma

Conjunctival papilloma is an acquired benign squamous cell tumor that can present at any age, but most frequently in the third and fourth decades of life. Papillomas have been associated with human papilloma virus (HPV) infection, usually types 6 and 11.

Although histopathological diagnosis remains the gold standard, the advent of newer non-invasive imaging modalities such as optical coherence tomography (OCT) is transforming the way we diagnose and treat ocular surface tumors, including conjunctival papilloma. Management of these lesions can prove a challenge to the treating physician since not all lesions respond to medical and/or surgical therapy and in fact may worsen after surgical manipulation.

In this review, the epidemiology, pathophysiology, clinical characteristics, and diagnosis of conjunctival papilloma including the use of OCT are discussed. Indications, efficacy, and side effects of currently available management options are also reviewed to guide the selection of the best treatment approach.

Human papillomavirus infection and ocular surface disease (Review)

Human papillomavirus (HPV) infection has been implicated as a primary cause of lesions in the anogenital region, skin, oropharynx and respiratory tract. Additionally, the role of HPV in the pathogenesis of ocular surface disease has also been extensively studied. Conjunctival papilloma development has been strongly associated with the HPV infection of certain subtypes. On the other hand, the role of HPV in conjunctival pterygium, conjunctival intraepithelial neoplasia (CIN) and ocular surface squamous neoplasia (OSSN) remains controversial. Genetic predisposition and environmental factor is important in HPV hosts as regards the pathogenesis of ocular surface disease. Several studies have indicate a synergic role of HPV with ultraviolet radiation in pterygium establishment. A higher recurrence risk rate and more aggressive disease of ophthalmic pterygium is observed in cases of HPV infection. The purpose of this review was to provide a systematic review of the literature and to assist in a better understanding of the role of HPV in ocular surface disease.

Identification of human papillomavirus in pterygium

PURPOSE

The purpose of this study was to evaluate the involvement of human papillomavirus in the pathogenesis of primary and recurrent pterygium in northern Israel.

METHODS

A retrospective study examined 100 randomly chosen pterygium specimens with solar elastosis, from 100 patients who underwent pterygium surgery during 2012-2013 at the Emek Medical Center. All the specimens were analysed for evidence of human papillomavirus infection by immunohistochemistry.

RESULTS

Human papillomavirus was not detected in any of the 100 pterygia samples by immunohistochemistry. These used samples were taken from 100 patients with mean age of 51.5 years and a primary: recurrent ratio of 8.09:1.

CONCLUSION

We conclude from our study that human papillomavirus infection does not appear to be an important pathogenic factor of pterygium in Israel.

human adenoviruses role in ophthalmic pterygium formation

Background:

Ophthalmic pterygium is a common benign lesion of unknown origin and the pathogenesis might be vision-threatening. This problem is often associated with exposure to solar light. Recent evidence suggests that potentially oncogenic viruses such as human papillomavirus and Epstein-Barr virus may be involved in the pathogenesis of pterygia. Expression of specific adenovirus genes such as E1A and E1B, which potentially have many functions, may contribute to their oncogenic activity as well as relevance to cellular immortalization.

Objectives:

For the first time, we aimed to investigate involvement of adenoviruses in pterygium formation.

Patients and Methods:

Fifty tissue specimens of pterygium from patients undergoing pterygium surgery (as cases), 50 conjunctival swab samples from the same patients and 10 conjunctival biopsy specimens from individuals without pterygium such as patients undergoing cataract surgery (as controls) were analyzed for evidence of adenovirus infection with polymerase chain reaction using specific primers chosen from the moderately conserved region of the hexon gene. Furthermore, β-globin primers were used to access the quality of extracted DNA. Data was analyzed using SPSS (version 16) software.

Results:

Of 50 patients, 20 were men and 30 women with mean age of 61.1 ± 16.9 years ranged between 22 and 85 years. All samples of pterygia had positive results for adenoviruses DNA with polymerase chain reaction, but none of the negative control groups displayed adenoviruses. The pterygium group and the control groups were β-globin positive. Direct sequencing of PCR products confirmed Adenovirus infection.

Conclusions:

Adenoviruses might act as a possible cause of pterygium formation and other factors could play a synergistic role in the development. However, further larger studies are required to confirm this hypothesis.

Morphological characteristics of conjunctival squamous papillomas in relation to human papillomavirus infection

OBJECTIVE

To determine the prevalence of a broad spectrum of human papillomavirus (HPV) types in conjunctival papillomas and a possible difference in clinical and histopathological presentation of HPV-positive and HPV-negative papillomas.

METHODS

Formalin-fixed, paraffin-embedded papilloma tissue specimens obtained from 25 patients were analysed using six different PCR-based methods targeting 87 HPV types from four different papillomavirus (PV) genera: α-PV, β-PV, γ-PV and µ-PV, and in situ hybridisation for HPV-6/HPV-11. Slides were reviewed for pedunculated or sessile growth, the presence of goblet cells, keratinising or non-keratinising epithelium, elastosis, atypia and koilocytes.

RESULTS

α-PV types HPV-6 and HPV-11 were detected in 19/25 (76%) conjunctival papilloma tissue specimens, 9 (47%) of which were also HPV-6/HPV-11 positive with in situ hybridisation. Six different β-PV types-HPV-9, HPV-12, HPV-20, HPV-21, HPV-22, HPV-24-were additionally detected in four cases, all of which were also HPV-6/HPV-11 positive. No γ-PVs or µ-PVs were found in any of the tested tissues samples. Extralimbal location (p=0.021), presence of goblet cells (p=0.005), non-keratinising squamous epithelium (p=0.005), and absence of elastosis (p=0.005) were associated with the presence of HPV-6/HPV-11.

CONCLUSIONS

We demonstrated that certain clinical and histological features are more frequently associated with HPV infection and that HPV genera other than α-PV are most probably not significant factors in conjunctival papilloma occurrence.

Molecular Basis of Pterygium Development

Pterygium pathogenesis is mainly related to UV light exposure. However, the exact mechanisms by which it is formed have not been elucidated. Clinical advances in surgical treatment use conjunctival autografts and amniotic membranes in combination with adjuvant therapies, including mitomycin C, β-radiation, and 5-fluoroacil, to reduce recurrence. Several studies aim to unveil the molecular mechanisms underlying pterygium growth and proliferation. They demonstrate the role of different factors, such as viruses, oxidative stress, DNA methylation, apoptotic and oncogenic proteins, loss of heterozygosity, microsatellite instability, inflammatory mediators, extracellular matrix modulators, lymphangiogenesis, cell epithelial-mesenchymal transition, and alterations in cholesterol metabolism in pterygium development. Understanding the molecular basis of pterygium provides new potential therapeutic targets for its prevention and elimination. This review focuses on providing a broad overview of what is currently known regarding molecular mechanisms of pterygium pathogenesis.

Papilloma development and long-term ciclosporin use in chronic ocular allergy with associated keratoconus

PURPOSE

Conjunctival papillomata are squamous epithelial tumors with a strong association with human papilloma virus (HPV) types 6 and 11. They are benign conjunctival tumors that can be treated by surgical excision. We report a case where topical immunosuppressive therapy modified the local T-cell immunity in the conjunctiva resulting in papilloma development in a patient with keratoconus and a strong atopic history.

METHODS

A case report of a 44-year-old man with a history of severe ocular and generalized atopy is presented. We present the problems encountered in management of his severe ocular allergy and how these impeded the management of his keratoconus.

RESULTS

Conventional antiallergy topical medication was not producing symptom relief in this patient, and so topical immunosuppression was commenced using ciclosporin ointment 0.2%. This therapy modified the local T-cell immunity in the conjunctiva resulting in the development of papillomata which contributed to the intolerance of contact lens wear for visual rehabilitation of the keratoconus in the patient. These lesions were surgically removed but typically recurred and required further surgical excision. Adjunct cryotherapy was also performed at the time of the surgery to try to stem the recurrence of the papillomas.

CONCLUSIONS

To the best of our knowledge and following a review of the published literature using key databases that include Medline and PubMed, this is the first report confirming the development of conjunctival papillomas secondary to HPV type 6 in a ciclosporin-treated patient.

Viral involvement in the pathogenesis and clinical features of ophthalmic pterygium (Review)

Pterygium is a potentially vision-threatening fibrovascular lesion originating from the conjunctiva that often extends on the corneal surface. Although it has been extensively studied, its pathogenesis has yet to be fully elucidated. Recent evidence on molecular genetic abnormalities in pterygium suggested neoplastic changes of limbal stem cells potentially associated with exposure to ultraviolet (UV) light. Human papillomavirus (HPV) is an oncogenic virus, associated with squamo-proliferative lesions of the anogenital region, skin and oropharynx. Several studies have shown HPV involvement in the pathogenesis of conjunctival neoplastic lesions, including papilloma and squamous cell carcinoma. The involvement of HPV as a co-factor in the pathogenesis of pterygium, although suggested by several studies using PCR and immunohistochemical techniques, remains controversial. Moreover, a marked variation in the prevalence of HPV in ophthalmic pterygium has been reported by different studies. Ethnic susceptibility and methodological differences in the detection of HPV may account for this variation. Surgical excision, often using sophisticated techniques, is the standard current method of therapy for pterygium. However, recurrences are frequent and recurrent lesions tend to be more aggressive. If indeed HPV is involved in pterygium pathogenesis or recurrence, anti-viral medications or vaccination may be new options in pterygium therapy.

Association of human papilloma virus with pterygia and ocular-surface squamous neoplasia

There are more microorganisms that colonize the human body than resident cells; some are commensal whereas others are pathogenic. Pathogenic microorganisms are sensed by the innate or adaptive immune system, an immune response is initiated, and the infection is often cleared. Some microorganisms have developed strategies to evade immune defenses, ensuring their long-term survival with potentially devastating consequences for the host. Approximately 18% of all cancers can be attributed to infective agents; the most common being Helicobacter pylori, Human papilloma virus (HPV) and Hepatitis B and C virus in causing stomach, cervical and liver carcinoma, respectively. This review focuses on whether HPV infection is necessary for initiating pterygia, a common benign condition and ocular-surface squamous neoplasia (OSSN), a rare disease with metastatic potential. The search engine PubMed was used to identify articles from the literature related to HPV and pterygium or conjunctival neoplasia. From 34 investigations that studied HPV in pterygia and OSSN, a prevalence rate of 18.6% (136/731) and 33.8% (144/426), respectively, was recorded. The variation in HPV prevalence (0-100%) for both disease groups may have arisen from study-design faults and the techniques used to identify the virus. Overall, the data suggest that HPV is not necessary for initiating either condition but may be a co-factor in susceptible hosts. Currently, over 60 million people worldwide have been immunized with HPV vaccines, but any effect on pterygium and OSSN development may not be known for some time as these lesions can evolve over decades or occur in older individuals.

Presence of human papillomavirus in pterygium in Taiwan

PURPOSE

To evaluate the prevalence and possible role of human papillomavirus (HPV) in the formation of pterygia in patients in Taiwan, a tropical country with high prevalence of pterygium.

METHODS

A total of 62 patients with 65 pterygia were retrospectively examined. Ten normal conjunctiva, 8 conjunctival nevi, and 2 malignant conjunctival melanomas served as controls. HPV detection and typing were accomplished using polymerase chain reaction amplification of the viral sequences. HPV-positive specimens underwent further investigation with fluorescence in situ hybridization. Clinical histories were recorded for each patient.

RESULTS

Based on polymerase chain reaction analysis, 2 of 65 pterygia harbored HPV type 18, and they were also fluorescence in situ hybridization positive. No conjunctival control had HPV. There was no statistically significant correlation between pterygium and the presence of HPV. The presence of HPV was not significantly different between primary and recurrent pterygia.

CONCLUSIONS

The limited presence of HPV DNA in pterygium does not conclude that HPV is necessary or acting alone in the formation of pterygium, but HPV may still be implicated to play a role in some pterygia in Taiwan.