Comparison of middle molecule removal with expanded hemodialysis versus haemodiafiltration among Chinese hemodialysis patients.

BACKGROUND

This study aimed to compare uremic toxin removal with expanded hemodialysis against post-dilution online haemodiafiltration therapy in Chinese patients with chronic kidney failure in a single treatment.

METHODS

This randomized, controlled, open-label, parallel, multicenter trial enrolled prevalent patients on hemodialysis. The study endpoints were to establish the non-inferiority of expanded hemodialysis versus haemodiafiltration in removing beta-2-microglobulin (β2M) and lambda-free light chains (λFLC) and to evaluate the reduction ratios of urea, alpha-1-microglobulin (α1M), myoglobin, complement factor D, kappa-free light chains (κFLC) and Chitinase-3-like protein 1 (YKL-40) during a mid-week dialysis session. The 95% confidence intervals of the difference in λFLC and β2M reduction ratios with expanded hemodialysis were compared against pre-defined non-inferiority margins (-3.783 and -7.848, respectively). Non-inferior reduction ratios were tested for superiority using hierarchical testing.

RESULTS

Overall, 274 adult patients were randomized to expanded hemodialysis ( = 138) or haemodiafiltration ( = 136). No differences in demographics, baseline characteristics, and treatment parameters were observed between the arms. The reduction ratio of λFLC with expanded hemodialysis was superior to haemodiafiltration; reduction ratio difference of 17.0% [95% confidence interval: 14.8%, 19.2%]. The reduction ratio of β2M with expanded hemodialysis was non-inferior to haemodiafiltration; reduction ratio difference of -1.2% [95% confidence interval: -2.5%, 0.2%]. Expanded hemodialysis showed significantly higher removal of α1M, YKL-40, complement factor D, myoglobin, and κFLC than haemodiafiltration therapy. There were no significant differences in Kt/V, urea reduction ratio, and the rate of complications between the arms.

CONCLUSION

Our study demonstrates the effectiveness of expanded hemodialysis therapy in removing multiple middle molecules compared to haemodiafiltration therapy, with no observed differences in the overall safety of Chinese patients.