“Idiopathic eosinophilic vasculitis”: another side of hypereosinophilic syndrome? A comprehensive analysis of 117 cases in asthma-free patients

Abstract Background The absence of asthma may rule out a diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA) in patients with hypereosinophilic syndrome (HES) and features of vasculitis. Objective To describe eosinophilic vasculitis (EoV) as a possible manifestation of HES in asthma-free patients. Methods We screened our hospital database and the literature for patients with HES who met the following four criteria: (i) histopathologic or clinical features of EoV (biopsy-proven vasculitis with predominant eosinophilic infiltration of the vessel wall and/or features of vasculitis with tissue and/or blood hypereosinophilia (>1.5 G/L)), (ii) no other obvious causes of reactive eosinophilia, organ damage, and vasculitis, (iii) the absence of antineutrophil cytoplasmic antibodies, and (iv) the absence of current asthma. Results Ten of our 83 (12%) asthma-free patients with HES and 107 additional cases in the literature met the criteria for EoV. After a critical analysis of the patients’ clinical and laboratory characteristics and outcomes, we identified 41 cases of single-organ EoV (coronary arteritis: n=29; temporal arteritis: n=8; cerebral vasculitis: n=4). Of the 76 remaining patients with EoV, the most frequent manifestations (>10%) were cutaneous vasculitis (56%), peripheral neuropathy (24%), thromboangiitis-obliterans-like disease (16%), fever (13%), central nervous system involvement (13%), deep venous thrombosis (12%), and nonasthma lung manifestations (12%). Blood hypereosinophilia >1.5 G/L was observed in 79% of patients and necrotizing vasculitis was observed in 44%. Conclusions Our results suggest that idiopathic EoV (HES-associated vasculitis) can be classified as an eosinophilic-rich, necrotizing, systemic form of vasculitis that affects vessels of various sizes in asthma-free patients.