The predictive value of serum interleukins in recurrent respiratory papillomatosis: a preliminary study.

Objective: IL-2 is the primary interleukin responsible for activation of the cell-mediated (Th1) arm of the immune response. Our objective was to determine whether a correlation existed between circulating levels of interleukin-2 as well as its soluble receptor (sIL-2R) and the clinical course of recurrent respiratory papillomatosis.
Methods and Materials: Fifteen children with a histological diagnosis of RRP were recruited. Age at the time of study, time since first diagnosis, and number of surgical interventions were recorded. The number of surgically treated recurrences per year was then calculated. We obtained serum samples from each of these 15 children and from 10 normal control subjects. We then performed in vitro determination of serum IL-2 and soluble IL-2 receptor levels using enzyme-linked immunosorbent assay (ELISA) techniques.
Results: IL-2 was significantly lower (136.6 vs. 199.9 pg/mL, P =.035) in papilloma patients than in control subjects. IL-2R was also lower in papilloma patients (531.7 vs. 785.8 U/mL, P =.025). There was no statistical age difference between the papilloma and control groups. Among patients with papillomatosis, IL-2 and sIL-2R levels were significantly higher in those with aggressive disease (>4 surgically treated recurrences per year) versus non-aggressive disease (179.2 vs. 99.2 pg/mL, P =.024; and 697 vs. 387 U/mL, P =.022). Age was also significantly lower in the aggressive papilloma group (P =.002).
Conclusions: Levels of interleukin-2 and IL-2 receptor were significantly lower in patients with recurrent respiratory papillomatosis compared with normal children. These data support the presence of an aberrant cell-mediated immune response in children with recurrent respiratory papillomatosis.