Abstract: 【Abstract】 Objective To investigate the association between serum IgE levels and chronic kidney disease-associated pruritus （CKD-aP） in patients on maintenance hemodialysis. Methods A cross-sectional study was conducted among patients with chronic kidney disease who had been on maintenance hemodialysis for at least 3 months at the Hemodialysis Center of Zhujiang Hospital, Southern Medical University, from June to December 2024. The patients were divided into a pruritus group and a non-pruritus group according to the presence of CKD-aP, and patients with CKD-aP were further classified into a mild pruritus group and a moderate-to-severe pruritus group based on the Worst Itch Numeric Rating Scale. Serum IgE levels were measured before and after the first dialysis session after enrollment. Intergroup differences were compared using the Mann-Whitney U test and the Kruskal-Wallis H test. Multivariable logistic regression was used to identify factors associated with CKD-aP. Receiver operating characteristic （ROC） curve analysis was performed to assess the discriminative ability of pre-dialysis serum IgE levels for moderate-to-severe CKD-aP. Results A total of 104 patients on maintenance hemodialysis were enrolled, including 71 males （68.3%）and 33 females （31.7%), aged 57.66 ± 12.64 years. CKD-aP was present in 60 patients （57.7%), of whom 27 （45.0%） had mild pruritus and 33 （55.0%） had moderate-to-severe pruritus. Serum IgE levels were significantly higher in the pruritus group than in the non-pruritus group both before dialysis （median ［first quartile, third quartile］: 90.25 ［35.70, 130.50］ IU/ml vs. 37.55 ［12.38, 102.75］ IU/ml; Z = -2.96, P = 0.003） and after dialysis （94.40 ［36.45, 151.50］ IU/ml vs. 36.80 ［13.80, 111.25］ IU/ml; Z = -2.98, P = 0.003）. Significant differences in pre- and post-dialysis IgE levels were observed among patients with different pruritus severity （H = 22.74 and 24.57, respectively, both P < 0.001）, with the moderate-to-severe pruritus group showing significantly higher pre- and post-dialysis IgE levels than the non-pruritus and mild-pruritus groups （all P < 0.001）. Multivariable logistic regression analysis showed that the pre-dialysis IgE level （per 10-IU/ml increase: OR = 1.116, 95% CI: 1.030 - 1.207, P = 0.006） and male sex（OR = 2.951，95% CI: 1.086 - 8.019，P = 0.034） were associated with increased odds of CKD-aP, while the serum creatinine level was associated with decreased odds of CKD-aP （per 10-μmol/L increase: OR = 0.977，95% CI：0.958 - 0.995，P = 0.014）. ROC curve analysis showed that the area under the curve for pre-dialysis serum IgE levels in discriminating moderate-to-severe CKD-aP was 0.791 （95% CI: 0.700 - 0.882, P < 0.001）, with a sensitivity of 72.7% and a specificity of 78.9%. Conclusion Elevated serum IgE levels were associated with the severity of CKD-aP in patients on maintenance hemodialysis, and the pre-dialysis IgE level was independently associated with CKD-aP.

Key words: Pruritus, Chronic kidney disease-associated pruritus, IgE, Maintenance hemodialysis