Immunocompetency in children with recurrent respiratory papillomatosis: prospective study

OBJECTIVES: We sought to investigate the immunologic status of children with recurrent respiratory papillomatosis and to evaluate possible correlations between the patients' immunocompetency and the clinical course of the disease. METHODS: Twenty children with recurrent respiratory papillomatosis underwent immunologic evaluation every 6 months for determination of complete blood count, serum immunoglobulin levels, lymphocyte subpopulations, lymphocyte response to mitogen stimulation, and natural killer cell function. The patients were observed prospectively (42 to 56 months), and their clinical course was recorded. The findings were compared with those in healthy age-matched controls. RESULTS: The CD4/CD8 ratio and the lymphocyte response to mitogen stimulation were significantly reduced in the study children compared to normal controls. A reduction in lymphocyte response to mitogen stimulation was significantly correlated to a high number of papilloma sites and more frequent recurrences. Abnormal natural killer cell function was significantly correlated to more frequent recurrences. CONCLUSIONS: A compromised cell-mediated immune response may be associated with repeated or persistent human papillomavirus infections, leading to the development of recurrent respiratory papillomatosis. Patients with an aggressive clinical course may have underlying cell-mediated immunodeficiency. Long-term prospective investigations are needed to establish the role of the host immune system in the pathogenesis of recurrent respiratory papillomatosis in children.