Epidermodysplasia verruciformis (EV) is a rare genetic disorder characterized by development of lesions associated with human papillomavirus in early childhood and malignant transformation in approximately half of individuals during adulthood. The persistence of human papillomavirus infection in EV is thought to be a result of an immunogenetic defect, which determines the generation of several cytokines capable of down-regulating cell-mediated immunity.

We sought to study the prevalence of interleukin 10 (IL-10) promoter polymorphisms in skin biopsy specimens of patients with EV compared with DNA samples from healthy individuals.

DNA samples extracted from normal skin of 22 patients from Brazil with EV and blood samples from 27 healthy Brazilian individuals were studied for IL-10 promoter polymorphisms using restriction fragment length polymorphism analysis.

The patients with EV showed an increased rate of low-production genotypes of IL-10 compared with control subjects (P = .003). Patients with EV and skin cancer were more likely to have low-production IL-10 genotypes than patients with benign forms of EV.

IL-10 genotypes associated with low levels of IL-10 production may have an important role in the pathogenesis of EV, including the susceptibility for development of skin cancer in patients with EV.