Clinical characteristics of 148 cases of patients with hypereosinophilia of unknown origin

doi:10.16352/j.issn.1001-6325.2026.11.1539

Abstract

Abstract: Objective To improve the recognition of hypereosinophilia (HE) of unknown origin and provide a reference for its clinical diagnosis and management. Methods Patients with HE of unknown origin admitted to the Department of General Medicine at Peking Union Medical College Hospital between February 2012 and April 2025 were retrospectively enrolled. Baseline characteristics, laboratory findings, organ system involvement, etiological classification, treatment, and follow-up data were collected. Clinical characteristics and outcomes were compared between patients with secondary HE and those with idiopathic HE. Results Total of 148 patients with HE of unknown origin were included, predominantly young and middle-aged men, with median disease duration of 7.5 months; 98.0% had sought medical care at other hospitals before admission. Severe HE was observed in 60.8% of patients and 98.6% had organ involvement, most commonly affecting the skin, respiratory, and digestive systems. An etiological diagnosis was established in 82 patients (55.4%), with secondary HE accounting for 54.1% of the total cohort and autoimmune diseases being the most common cause; Idiopathic HE accounted for 44.6%. Compared with patients with idiopathic HE, those with secondary HE had higher hypersensitive C-reactive protein(sharp) levels and a higher incidence of lymphadenopathy, as well as more frequent involvement of the nervous system, vasculature/thrombotic system, kidneys, and ear, nose, and throat(ENT) system(P＜0.05). Following etiology-directed treatment, patients with secondary HE had a lower long-term relapse rate. Conclusions HE of unknown origin is mainly found in young and middle-aged males with multisystem involvement and diagnostic challenges. Autoimmune diseases represent the most common underlying causes of secondary HE. The hsCRP level and patterns of organ involvement may help differentiate HE of unknown origin subtypes. Etiology-directed treatment should be emphasized in secondary HE, while patients with idiopathic HE require long-term follow-up.

Key words: hypereosinophilia, unknown origin, etiological distribution, system involvement

CLC Number:

CHEN Chunyue, YIN Yue, ZHANG Yun, CHEN Jialin, ZENG Xuejun. Clinical characteristics of 148 cases of patients with hypereosinophilia of unknown origin[J]. Basic & Clinical Medicine, 2026, 46(11): 1539-1545.

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