Differential cytokine profiles in pediatric patients with PFAPA syndrome and recurrent tonsillitis

Objective : An attempt was made to identify characteristic cytokine profiles to distinguish periodic fever with aphthous stomatitis, pharyngitis and cervical adenitis syndrome (PFAPAS) from recurrent tonsillitis, of which clinical manifestations are similar to those of PFAPAS in children. Methods : Serum concentrations of IL-6, IL-4 and IFN-γ were measured during febrile episodes in pediatric patients. Results : The levels of IL-6 during febrile episodes were markedly increased above the upper limit of normal ranges in patients with both PFAPAS and recurrent tonsillitis, but there were no significant differences between groups. The levels of IL-4 during febrile episodes in PFAPAS patients were significantly lower than those in recurrent tonsillitis patients. The levels of IFN-γ during febrile episodes in PFAPAS patients were significantly higher than those in recurrent tonsillitis patients. Conclusion : In pediatric patients with PFAPAS, despite an increase of IL-6, IL-4 was suppressed with a marked increase of IFN-γ during febrile episodes. On the contrary, in febrile pediatric patients with recurrent tonsillitis, both IL-6 and IL-4, but not IFN-γ were increased. The characteristic cytokine profiles of IL-6, IL-4 and IFN-γ can be used for differential diagnosis of PFAPAS from recurrent tonsillitis in children in clinical ear, nose and throat (ENT) settings.