Recurrent Respiratory Papillomatosis: A Longitudinal Study Comparing Severity Associated With Human Papilloma Viral Types 6 and 11 and Other Risk Factors in a Large Pediatric Population

Abstract

A database was developed for prospective, longitudinal study of recurrent respiratory papillomatosis (RRP) in a large population of pediatric patients. Data recorded for each patient included epidemiological factors, human papilloma virus (HPV) type, clinical course, staged severity of disease at each surgical intervention, and frequency of surgical intervention. The study hypothesizes that patients with HPV type 11 (HPV-11) and patients younger than 3 years of age at diagnosis are at risk for more aggressive and extensive disease. The 10-year prospective epidemiological study used disease staging for each patient with an original scoring system. Severity scores were updated at each surgical procedure. Parents of children with RRP referred to the authors' hospital completed a detailed epidemiological questionnaire at the initial visit or at the first return visit after the study began. At the first endoscopic debridement after study enrollment, tissue was obtained and submitted for HPV typing using polymerase chain reaction techniques and in situ hybridization. Staging of disease severity was performed in real time at each endoscopic procedure using an RRP scoring system developed by one of the authors (B.J.W.). The frequency of endoscopic operative debridement was recorded for each patient. Information in the database was analyzed to identify statistically significant relationships between extent of disease and/or HPV type, patient age at diagnosis, and selected epidemiological factors. The study may represent the first longitudinal prospective analysis of a large pediatric RRP population. Fifty-eight of the 73 patients in the study underwent HPV typing. Patients infected with HPV-11 were significantly more likely to have higher severity scores, require more frequent surgical intervention, and require adjuvant therapy to control disease progression. In addition, patients with HPV-11 RRP were significantly more likely to develop tracheal disease, to require tracheotomy, and to develop pulmonary disease. Patients receiving a diagnosis of RRP before 3 years of age had significantly higher severity scores, higher frequencies of surgical intervention, and greater likelihood of requiring adjuvant medical therapy. Patients with Medicaid insurance had significantly higher severity scores and required more frequent surgical debridement. Birth by cesarean section appeared to be a significant risk factor for more severe disease and necessity of more frequent surgical intervention. Statistical analysis of the relationships among epidemiological factors, HPV type, and clinical course revealed that patients with HPV-11 and patients younger than 3 years of age at RRP diagnosis are prone to develop more aggressive disease as represented by higher severity scores at endoscopic debridement, more frequent operative debridement procedures per year, a greater requirement for adjuvant therapy, and greater likelihood of tracheal disease with tracheotomy.