Objective: Determination of early prognostic factors in patients with recurrent respiratory papillomatosis is extremely important, so the major goal of our prospective, multicentre study was to evaluate (1) the feasibility of various factors to determine prognosis of the clinical course,as well as (2) the response to interferon-alpha therapy in recurrent respiratory papillomatosis.

Methods: Forty-two patients with recurrent respiratory papillomatosis were treated with interferon-alpha (3 MU/m2 three times per week; mean therapy duration was 2.7 ± 1.8 years)in 1983–1994 and followed-up until 2003. Human papilloma virus (HPV) type, recurrent respiratory papillomatosis severity and 2′,5′-oligoadenylate synthetase activity were determined by standard methods and analysed for correlation with the results of long-term clinical outcome.

Results and conclusion: Patients with HPV type 11, a severity score >4, a high number of surgical procedures prior to interferon-alpha therapy and a high basal 2′,5′-oligoadenylate synthetase activity should be considered at high risk of an aggressive clinical course, often with spread to lower airway passages, malignant transformation and death. Human papilloma virus type, score for recurrent respiratory papillomatosis severity, number of surgical procedures and 2′,5′-oligoadenylate synthetase activity showed significant association with response to interferon-alpha therapy and the long-term clinical course, so these factors have value in predicting prognosis in recurrent respiratory papillomatosis.