Genital warts do not respond to systemic recombinant interferon alfa-2a treatment during cannabis consumption

The case of a 22-year-old man suffering from genital warts is described. The lesions responded completely to recombinant interferon alfa-2a only after discontinuation of cannabis consumption. Cannabis was detected using the enzyme immunoassay/1-trans-tetrahydrocannabinoid method in urine. Southern blotting of frozen genital wart biopsy material revealed papillomavirus type 11 DNA, the amount of which increased significantly during interferon treatment. The final clearing of lesions after discontinuation of cannabis consumption implicates that the drug-induced impairment of cellular immunity was reversible. It is concluded that drug abuse and especially cannabis consumption may play some role in the world-wide increase in genital papillomavirus disease and in the high number of recalcitrant courses of genital warts.