JOURNAL OF BIOLOGICAL REGULATORS & HOMEOSTATIC AGENTS 0393-974X (2017) Copyright © by BIOLIFE, s.a.s. This publication and/or article is for individual use only and may not be further reproduced without written permission from the copyright holder. Unauthorized reproduction may result in fnancial and other penalties DISCLOSURE: ALL AUTHORS REPORT NO CONFLICTS OF INTEREST RELEVANT TO THIS ARTICLE. Vol. 31, no. 4 (S1), 1-5 (2017) Osteoarthritis is a whole-joint disease and its pathogenesis remains poorly understood. Recent evidence proposed the importance of the innate immune system as trigger of synovium infammation following the degeneration of cartilage. Moreover, synovial mast cells (MCs) might be correlated with pain and disability reported by patients. Anti IgE therapy represents a new class of MCs stabilizing agent, licensed for people with asthma and chronic urticaria. Therefore, we studied if the stabilizing effect of anti IgE would improve the pain and disability in patients affected by knee osteoarthritis and atopic disease. This pilot study provides the frst evidence that anti IgE treatment induces a short-term clinical improvement supporting the role of MCs in osteoarthritis. THE EFFECT OF ANTI-IGE THERAPY IN KNEE OSTEOARTHRITIS: A PILOT OBSERVATIONAL STUDY A. AQUILI 1 , L. FARINELLI 1 , C. BOTTEGONI 1 , L. ANTONICELLI 2 and A. GIGANTE 1 1 Clinical Orthopaedics, Università Politecnica delle Marche, Ancona, Italy; 2 Allergy Unit, Department of Internal Medicine, Ospedali Riuniti, Ancona, Italy