Time-Dependent Kinetics and Saturation Dynamics of Interleukin-6 Clearance During Combined HA380 Hemoadsorption and Continuous Renal Replacement Therapy in Sepsis-Associated Acute Kidney Injury.

BACKGROUND: The HA380 hemoadsorption cartridge is increasingly used in septic patients receiving continuous renal replacement therapy (CRRT) for cytokine removal. However, its adsorption kinetics and saturation threshold in clinical settings remain unclear. METHODS: We conducted a prospective observational study in the intensive care unit of the First Affiliated Hospital of Harbin Medical University from July 2023 to July 2024. Thirty patients with sepsis-associated acute kidney injury (SA-AKI) who required CRRT were enrolled. Blood samples were collected from the inflow and outflow ports of the HA380 cartridge at baseline and every two hours during a 24-hour treatment session. Interleukin-6 (IL-6) concentrations were determined by ELISA, and clearance efficiency was calculated. Key laboratory parameters, including procalcitonin (PCT), C-reactive protein (CRP), and acid-base balance, were compared before and after treatment. Changes in adsorption efficiency over time were analyzed using linear mixed-effects models. RESULTS: IL-6 clearance reached its maximum at 2 hours (90.0%) and progressively decreased by 13.32% compared with baseline at 14 h (p=0.004). PCT and white blood cell counts decreased significantly after therapy (p<0.05), while CRP levels showed no significant change. Blood pH and base excess improved significantly, whereas reductions in serum creatinine and urea nitrogen were not statistically significant. CONCLUSIONS: In patients with SA-AKI undergoing CRRT combined with HA380 hemoadsorption, IL-6 removal was most effective within the first 2 hours, the clearance rate shows an increasing trend from 4 to 12 hours and then decreases and declined notably after approximately 12 hours, indicating cartridge saturation. These findings suggest that cartridge replacement within this timeframe may help maintain effective cytokine clearance and support optimal treatment performance.