Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology
Hypereosinophilic syndrome (HES) is a heterogeneous group of rare disorders defined by:
- persistent blood eosinophilia greater than 1.5 x 10(9)/L
- absence of a secondary cause
- eosinophil-associated pathology
A 2009 analysis showed that 11% of patients with HES were Fip1-like 1-platelet-derived growth factor receptor alpha (FIP1L1-PDGFRA) mutation-positive, and 17% had an aberrant or clonal T-cell population.
Corticosteroid monotherapy induced complete or partial responses at 1 month in 85% of patients with most remaining on maintenance doses (median, 10 mg prednisone daily for 2 months to 20 years).
Hydroxyurea and IFN-alpha were also effective, but their use was limited by toxicity. Hydrea and interferon are equally effective for idiopathic HES ( about 30%) (AAAAI, 2012).
Imatinib was more effective in patients with the FIP1L1-PDGFRA mutation (88%) than in those without (23%).
Mepolizumab (anti-IL-5 mAb) is awaiting FDA approval.
Hypereosinophilic syndrome: A multicenter, retrospective analysis of clinical characteristics and response to therapy. Ogbogu PU, Bochner BS, Butterfield JH, Gleich GJ, Huss-Marp J, Kahn JE, Leiferman KM, Nutman TB, Pfab F, Ring J, Rothenberg ME, Roufosse F, Sajous MH, Sheikh J, Simon D, Simon HU, Stein ML, Wardlaw A, Weller PF, Klion AD. J Allergy Clin Immunol. 2009 Nov 10.