Two year sublingual immunotherapy affects serum leptin.

It has been demonstrated that serum leptin is elevated in females with allergic rhinitis. Recently, it has been reported that one course of sublingual immunotherapy (SLIT) does not affect serum leptin levels.The aim of this study was to evaluate the serum leptin levels in a cohort of patients with pollen-induced allergic rhinitis, before and after two pre-seasonal SLIT courses.Forty-one patients (22 males and 19 females, median age 39 years) with AR, due to pollen allergy, and 34 healthy subjects (16 males and 18 females, median age 43 years) were included in the study. Blood sampling for assessing serum leptin was performed in all subjects before and after the second SLIT course.All patients were responders to SLIT. Serum leptin was significantly increased only in males (p=0.0056) after the second SLIT course.This preliminary study shows that at least two pre-seasonal SLIT courses were required to induce significant modifications in serum leptin levels, but it occurred only in males. Some hypotheses might be outlined, including a leptin protective effect, however further studies must clarify this issue.