Hypereosinophilic Syndrome:a Case Report And Literature Review

Background:Hypereosinophilic syndromes (HES) are rare and agnogenic heamatology diseases characterized by persistent increase of peripheral eosinophils that is responsible for organ damage or dysfunction. In 1975, Chusid et al. proposed the diagnostic criteria for HES which has been recognized and used internationally. In 2011, the working conference on Eosinophil Disorders and Syndromes updated the diagnostic criteria. According to different classification methods, HES can be divided into different subtypes. Contrast to the classification of 2005, in 2011, the working conference on Eosinophil Disorders and Syndromes divided HES into 3 subtypes according to the etiology. Tissue infiltration usually involves the heart, skin, lungs, livers, spleen, central and peripheral nervous system, eyes, gastrointestinal tract, and so on. Due to the different organs and different levels of involvement, clinical manifestations of HES are various, which need detailed examinations to make comprehensive diagnosis, so as to avoid misdiagnosis and missed diagnosis. The classical therapy includes:corticosteroids, hydroxyurea, vincristine, other cytotoxic agents, IFN-α, other immunomodulatory agents, imatinib mesylate, bone marrow transplant, and so on. The first-line therapy for idiopathic HES is corticosteroids. Imatinib mesylate is a tyrosine kinase inhibitor with activity against the fusion kinase FIP1L1-PFGFRA (F/P) and has been the first-line therapy for FIP1L1-PFGFRA(+) HES. But its effect on idiopathic HES is different.·Objective:Here we report a case of idiopathic HES which was successfully treated with combination of corticosteroids and imatinib, and review the literature to improve the understanding of the clinical manigestations, diagnosis and treatment of HES.·Case report:A 44-year-old man presented with painfull and intumescent right axillary lymph node, left leg pain and swelling. Blood test showed normal leukocytosis and eosinophilia. B-mode ultrasound scan revealed left lower extremity venous thrombus. He was treated with antibiotics, anticoagulation and thrombolysis. One week after treatment, signs of thrombosis had improved.20 days later, he presented again with bilateral lower extremities pain and swelling. He also suffered from painful paresthesias and motor deficits of right ulnar ofrearm and muscle atrophy of hypothenar muscles. Evaluation revealed leukocytosis(8.53×109/L) with eosinophilia (1.54×109/L). B-mode ultrasound scan revealed right lower extremity deep venous thrombus. Lymph node biopsy demonstrated prominent eosinophilic infiltrations. A bone marrow biopsy showed increased number of mature eosinophils. Electromyography showed right median and ulnar nerve damage. The karyotype was normal and FIP1L1-PDGFRA fusion gene was negative. Flow cytometry showed polyconal CD3+ T lymphocytes (CD4+ 76% and CD8+ 22%), and Th/Ts(3.48) elevated. No CD3-CD4+T lymphocytes were detected, but CD3+CD4-CD8-T lymphocytes contained of 2.2%. The serum globin proteins was present with high IgE (170.43IU/ml) and normal IgA, IgM and IgG levels. Without causes of secondary eosinophilia, such as allergic, neoplastic, parasitic, or autoimmune disorders, a diagnosis of HES was made.Initial treatment was a high dose of corticosteroid and got symptomatic improvement. But the symptoms promptly relapsed with the tapering of the corticosteroid. Then we altered the treatment to imatinib 100mg/d and prednisone 5mg/d which showed significant effect. Howevere, treatment with imatinib alone showed no notable effect.* Conclusions:1. Because of different organs and different levels of involvement, clinical manifestations of HES are various, which need detailed examinations to make comprehensive diagnosis, so as to avoid misdiagnosis and missed diagnosis.2. Although corticosteroids is the first-line therapy for idiopathic HES, some cases need large doses for a long time, which will result in serious side effect.3. In some cases, treatment of idiopathic HES with imatinib alone showed no notable effect, but combination of corticosteroids and imatinib has significant effect in idiopathic HES, even in small doses.