Characteristics and Outcomes of Patients with Hypereosinophilia on Haemodialysis

Background: Hypereosinophilia we defined as persistently raised eosinophil count of > 1.5 x 109/l on at least 2 occasions 1 month apart. Hyperesinophilia is a rare but potentially serious condition in patients undergoing haemodialysis (HD). It can be transient and benign, but persistent cases have been associated with inflammatory complications, vascular access dysfunction and increased mortality. Objective: Our aim was to characterise the clinical course of hypereosinophilia in the HD population, evaluate interventions employed to treat itiand assess associated outcomes. Methods: Retrospective cohort study of adult patients on HD between 2010 to April 2025 who developed hypereosinophilia. Data were collected from the Renal and Pathology databases, and the parameters of interest included demographic data, mode of dialysis, peak eosinophil count, mortality, diabetes status and whether the hypereosinophilia resolved. Resolution of the hypereosinophilia was defined as a fall below 1.5 x 109/L sustained over at least 3 months. Patients were also stratified according to peak eosinophil count: Group A: 1.5-5 x109/L, Group B: 5.1-10 x109/L and Group C >10 X109/L. Results: The total number of patients who met the criteria was 205. 13 (6.3%) had documented episodes of haemodynamic instability on dialysis. The demographic data and other details are shown in table 1. Patients with haemodynamic instability and hypereosinophilia fared worse that the rest of the cohort with regard to mortality. Conclusion: In this cohort of patients, most of the patients who had haemodynamic instablity had the highest peak eosinophilia. The combination of severe hypereosinophilia and haemodynamic instability appears to portend a poor outcome and these patients. The use of steroids helped with symptom resolution, but did not always lead to resolution of hypereosinophilia, and switching dialysers did not make a difference to the outcome. Funding: Government Support – Non-U.S.