Interferons in human papillomavirus infections

Human papillomavirus (HPV) infections usually present as benign warts (e.g., condyloma acuminatum, CA) but can also be responsible for dysplasia and carcinoma. Therapeutic options include chemotherapeutic agents, cryotherapy and surgery, but all these treatments are anti-tumor, not anti-viral. Interferons (IFNs) are the only anti-viral drugs approved for the therapy of benign HPV-related lesions. While IFN-alpha, IFN-beta and IFN-gamma have all been tested against CA, most information is available on IFN-alpha which appears efficacious via a number of routes of administration, schedules and dosages with an acceptable safety profile. The highest rate of success with IFN-alpha therapy, in terms of reduced recurrence rates of CA was reported from studies in which all visible lesions were surgically removed with subsequent administration of subcutaneous local IFN-alpha. Less data is available on the efficacy of IFNs in the treatment of HPV-related dysplasia and carcinoma, but combination therapy (e.g., IFN-alpha plus retinoids for cervical carcinoma) appears promising. Future advances in control of HPV-related lesions are expected to continue to involve IFN combined with non-antiviral therapies as well as the use of exogenous inducers of IFNs and other cytokines.