Effect of high cut-off dialysis for acute kidney injury secondary to cast nephropathy in patients with multiple myeloma: a systematic review and meta-analysis

Blanca Tarragón; Nan Ye; Martin Gallagher; Shaundeep Sen; Jose Maria Portolés; Amanda Y Wang

doi:10.1093/ckj/sfaa220

Effect of high cut-off dialysis for acute kidney injury secondary to cast nephropathy in patients with multiple myeloma: a systematic review and meta-analysis

Clin Kidney J. 2020 Dec 12;14(8):1894-1900. doi: 10.1093/ckj/sfaa220. eCollection 2021 Aug.

Authors

Blanca Tarragón^{1

2}, Nan Ye^{2

3}, Martin Gallagher^{2

4}, Shaundeep Sen^{4

5}, Jose Maria Portolés^{1

6}, Amanda Y Wang^{2

4

5}

Affiliations

¹ Department of Nephrology, Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain.
² Renal and Metabolic Division, George Institute for Global Health, University of New South Wales, Sydney, NSW, Australia.
³ Division of Nephrology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
⁴ Department of Renal Medicine, Concord Repatriation General Hospital, Concord, NSW, Australia.
⁵ Concord Clinical School, The University of Sydney, Sydney, NSW, Australia.
⁶ REDInREN Instituto Salud Carlos III 016/009/009, Public Health Research Network, Madrid, Spain.

Abstract

Background: Acute kidney injury (AKI) caused by cast nephropathy is associated with increased morbidity and mortality among patients with multiple myeloma (MM). High cut-off haemodialysis (HCO-HD) has proven to be effective in the removal of serum light chains but the effect on clinical outcomes, especially renal recovery, remains uncertain.

Methods: A systematic review and meta-analysis were performed examining all randomized controlled trials (RCTs) and observational studies (OBSs) assessing the effect of HCO-HD on clinical outcomes of patients with MM complicated by cast nephropathy-induced severe AKI. The primary outcome was all-cause mortality at the end of the study. The secondary outcomes included all-cause mortality at 12 months, HD independence and serum kappa and lambda light chain reduction. Pooled analysis was performed using random effects models.

Results: We identified five studies, comprising two RCTs and three retrospective cohort studies, including 276 patients with a mean follow-up of 18.7 months. The majority of the studies were of suboptimal quality and underpowered. Compared with patients treated with conventional HD, HCO-HD was not associated with a survival benefit at 12 months {five studies, 276 patients, relative risk [RR] 1.02 [95% confidence interval (CI) 0.76-1.35], I ² = 33.9%} or at the end of the studies at an average of 34 months [five studies, 276 patients, RR 1.32 (95% CI 0.71-2.45), I ² = 62.0%]. There was no difference in HD independence at 90 days [two trials, 78 patients, RR 2.23 (95% CI 1.09-4.55)], 6 months [two studies, 188 patients, RR 1.19 (95% CI 0.68-2.06)] or 12 months [two studies, 188 patients, RR 1.14 (95% CI 0.58-2.26)]. Patients receiving HCO dialysis, however, had a greater reduction in serum kappa [two studies, 188 patients, weighted mean difference (WMD) 46.7 (95% CI 38.6-54.7), I ² = 52.0%] and lambda [two studies, 188 patients, WMD 50.3 (95% CI 21.4-79.3), I ² = 95.1%] light chain levels.

Conclusion: Current evidence from RCTs and OBSs suggests HCO dialysis is able to reduce serum free light chains but makes no significant improvement in all-cause mortality and renal outcomes compared with conventional HD for patients with myeloma cast nephropathy. However, there is a trend towards better renal outcomes with the use of HCO dialysis. The lack of long-term data and the small sample sizes of the included studies limit this analysis. Therefore further large-scale RCTs with longer follow-up are needed to assess the effect of HCO dialysis on clinical outcomes in patients with myeloma cast nephropathy.

Keywords: acute kidney injury; high-cutoff hemodialysis; meta-analysis; myeloma cast nephropathy; systematic review.