Pseudovirion-binding and neutralizing antibodies to cutaneous Human Papillomaviruses correlated to presence of HPV DNA in skin.

We compared seroreactivity to Human papillomavirus (HPV) antigens measured with two different high-throughput assays. One method used GST-L1 fusion proteins and the other heparin-bound HPV pseudovirions as antigens and both methods used multiplexed fluorescent beads for detection. For six HPV types (5, 6, 15, 16, 32 and 38), seroreactivity could be measured in parallel for 434 serum samples from non-immunosuppressed patients with skin lesions (squamous cell carcinoma of the skin, basal cell carcinoma of the skin, actinic keratosis and benign skin lesions). Biopsies from the skin lesions were tested for presence of HPV DNA using three different PCR methods, with typing by sequencing. Among the types included in the serological tests, HPV DNA of types HPV5, 15, 38 and 76 were most frequently detected in the tumours. Serum samples from subjects with HPV DNA positive biopsies and randomly selected serum samples from subjects with HPV DNA negative biopsies were also tested with neutralization assays with HPV5, 38 and 76 pseudovirions. Agreement of the three serological methods varied from poor to moderate and showed limited consistency. Type-specific seroprevalences among patients positive for the same type of HPV DNA (sensitivity of serology) was improved with the pseudovirion-based method (average of 40%, maximum 63%) compared to the GST-L1 method (average of 20%, maximum of 25%). Neutralization was the most sensitive assay for HPV38 (50%). In summary, the pseudovirion-based methods appeared to have an improved sensitivity.