Erythrocytapheresis Improves Health-Related Quality of Life in High-Altitude Migrants with Chronic Mountain Sickness: A Single-Arm Before–After Trial at 4,000–4,500 m

Xie, Weiwei, Xianli Wu, Yiding Li, Qing Xiang, Na Wu, Haolun Sun, Bianba Duojie, Hongda Zhao, Jun Liang, and Ye Fan. Erythrocytapheresis Improves Health-Related Quality of Life in High-Altitude Migrans with Chronic Mountain Sickness: A Single-Arm Before–After Trial at 4,000–4,500 m. High Alt Med Biol. 00:00–00, 2026. Chronic mountain sickness (CMS) arises from maladaptive responses to prolonged residence at altitudes exceeding 2,500 m. Despite the known efficacy of erythrocytapheresis on CMS, the impact of this intervention on health-related quality of life for individuals diagnosed with CMS remains poorly understood. We conducted a single-arm before–after trial using erythrocytapheresis on a total of 22 male migrants with CMS who had resided at high altitudes (4,000–4,500 m) for 6.5 (3.8, 9.3) years. Participants underwent between 1 and 4 erythrocytapheresis sessions, with 1–2 days between each one. The participants exhibited significant improvements following the intervention: health-related quality of life score increased from 85.0 (80.0, 85.3) to 90.0 (90.0, 94.3) ( p < 0.001, d = 0.57); CMS score decreased from 7.0 (6.0, 8.0) to 3.0 (2.8, 4.0) ( p < 0.0001, d = 0.62); the distance in the 6-Minute Walk Test improved from 612.5 (598.8, 623.0) meters to 654.0 (636.3, 676.3) meters ( p < 0.0001, d = 0.62); and SpO 2 levels rose from 87.5 (85.8, 90.0) to 90.0 (87.0, 92.5) ( p = 0.012, d = 0.38). Erythrocytapheresis proves to be an effective intervention for enhancing health-related quality of life and reducing the severity of CMS in migrant populations.