Supplementary Material for: Peripheral Blood Lymphocyte Subgroups in Patients Undergoing Hemodialysis with Medium Cut-Off Membranes and High-Flux Membranes: THE SHE Continuation Study

Introduction: Chronic kidney disease (CKD) poses a significant global health burden, with increasing prevalence and high morbidity and mortality rates, particularly in end-stage kidney disease (ESKD). While traditional risk factors contribute, the exact mechanisms remain elusive, with inflammation playing a pivotal role. Medium cut-off (MCO) membranes offer promise in improving dialysis outcomes by efficiently clearing uremic toxins without substantial albumin loss. We aimed to elucidate the impact of MCO and high-flux (HF) membranes on peripheral blood lymphocyte subpopulations in hemodialysis patients.
Methods: Twenty-four ESKD patients underwent 36 sessions each with MCO and HF membranes. Immunophenotyping by flow cytometry was performed to analyze lymphocyte subsets.
Results: NK cell percentages significantly increased with MCO, returning to baseline with HF. Th1 cells decreased post-HF, while Th2 and TFH cells increased with MCO and persisted. Treg cells remained stable with MCO but decreased with HF.
Conclusion: MCO dialysis induced an anti-inflammatory shift, evidenced by increased Th2 and TFH cells and stable Treg cells. NK cells also responded favorably to MCO. These findings underscore MCO membranes' potential to modulate immune responses and improve patient outcomes in ESKD.

引言：慢性肾脏病(Chronic kidney disease, CKD)已成为严重的全球公共卫生负担，其患病率持续上升，且发病率与死亡率居高不下，在终末期肾脏病(End-stage kidney disease, ESKD)患者中尤为显著。尽管传统危险因素已被证实与CKD相关，但其确切发病机制仍未明确，其中炎症反应发挥了关键作用。中截留(Medium cut-off, MCO)膜可通过高效清除尿毒症毒素且不造成大量白蛋白丢失，为改善透析预后带来了新的希望。本研究旨在阐明中截留膜与高通量(High-flux, HF)膜对血液透析患者外周血淋巴细胞亚群的影响。
方法：本研究纳入24名终末期肾脏病患者，每名患者分别接受36次中截留膜透析与高通量膜透析治疗。采用流式细胞术进行免疫表型分析，以检测淋巴细胞亚群。
结果：采用中截留膜透析时，自然杀伤(Natural Killer, NK)细胞占比显著升高，而采用高通量膜透析时该占比可恢复至基线水平。辅助性T细胞1(Helper T cell 1, Th1)在高通量膜透析后占比降低；辅助性T细胞2(Helper T cell 2, Th2)与滤泡辅助性T细胞(Follicular helper T, TFH)在中截留膜透析后占比升高并维持于较高水平。调节性T细胞(Regulatory T, Treg)在中截留膜透析时保持稳定，但在高通量膜透析后占比下降。
结论：中截留膜透析可诱导机体产生抗炎表型，具体表现为辅助性T细胞2与滤泡辅助性T细胞占比升高、调节性T细胞占比保持稳定。自然杀伤细胞对中截留膜透析也呈现出良好的应答反应。本研究结果证实，中截留膜具有调控免疫应答的潜力，有望改善终末期肾脏病患者的临床预后。