Human Papillomatosis Genotyping and Severity in Patients with Recurrent Respiratory Papillomatosis
Pavinee Intakorn MD*, Nuntigar Sonsuwan MD**
Affiliation : * Department of Otolaryngology, Queen Sirikit National Institute of Child Health, Bangkok, Thailand ** Department of Otolaryngology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Background : Recurrent respiratory papillomatosis (RRP) is caused by human papilloma virus (HPV) and is the most
common benign laryngeal neoplasm in children. Although RRP is rarely fatal, the disease requires prolonged, extensive
medical and surgical treatment, leading to physical and emotional suffering in affected children and their families. Previous
studies show HPV type 11 and type 6 in the lesion of Thai subjects with RRP. There is currently no published data available
from Thailand that compares staging and severity with RRP genotypes.
Objective : To identify the genotypes of human papilloma virus (HPV) isolated from patients with RRP and compare the
staging and severity with human papilloma virus genotype.
Material and Method: This prospective study was designed to assess population characteristics and follow the clinical
course of RRP from January 2011 to January 2013. At each endoscopic evaluation or debridement, all surgeons to stage each
patient’s disease severity used a consistent scoring system. The samples were analyzed for HPV genotype.
Results : Fifteen Thai children (7 female, 8 male) with respiratory papillomatosis were enrolled. Results showed that HPV type
6 and HPV type 11 caused RRP in 6 (40%) and 9 (60%) of the children, respectively. No co-infection between HPV type 6 and
type 11 was found. Overall mean age at diagnosis of patients with RRP was 2.65+0.82 years. The age at diagnosis was
significantly different between both HPV genotypes (p = 0.008). The mean disease severity score for HPV type 6 infection was
13.83+9.94, and that of HPV type 11 infection was 27.44+8.24. The mean disease severity score of HPV type 11 infection was
significantly higher than that of HPV type 6 infection (p = 0.013).
Conclusion : HPV type 6 and type 11 caused RRP in Thai children. RRP attributable to infection with HPV type 11 is more
aggressive in disease severity and has a shorter life time than HPV type 6 at time of first diagnosis. RRP is an incurable
disease that requires long-term medical management. Improved awareness and understanding amongst the Thai population
should be promoted to limit the spread of the disease. In addition, further research on the treatment of RRP would benefit
patients.
Keywords : Recurrent respiratory papillomatosis, Human papilloma virus, Human papilloma virus genotype
