Detection of Human Papillomavirus in Squamous Cell Carcinoma of Conjunctiva by Nested PCR: A Case Control Study in Iran

Squamous-cell carcinoma (SCC) of the eye conjunctiva is a rare tumor. Its link with immune impairment suggests that infectious agents such as human papillomavirus (HPV) may be involved in the etiology of SCC. We conducted a case-control study on 50 SCC cases (mean age: 65.2) and 50 age frequency-matched control patients with lesion-free, normal conjunctival biopsies (mean age: 63.8) obtained from the cancer registry archive at Pathology Department of Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran, where SCC has become the most common conjunctival malignancy. MY/GP nested PCR was performed for HPV detection and E6/E7 consensus primers in combination of type specific primers were used in another nested PCR series for HPV typing. HPV DNA was detected in 46 of 50 samples of squamous cell carcinoma and none of the normal biopsies by nested PCR using primer sets of the HPV consensus L1 region (MY/GP). Subsequently, specimens from the 46 positive cases were subjected to specific PCR. Although 630bp amplicon was produced in 44 of 46 samples (E6/E7 primers), none of the specific HPV PCR reactions for HPV DNA type 16, 18, 31 or 33 resulted in the detection of HPV DNA in the 44 SCC specimens of the conjunctiva. Current results confirm the role of HPV in the etiology of conjunctival SCC. The absence of HPV 16, 18, 31 and 33 in conjunctival SCC in this study raise doubts about the role of genital types of HPV in conjunctival carcinomas.