Renal Prognostic Benefit of High Cut Off Dialysis Membrane Treatment in the Management of Dialysis-Dependent Severe Acute Renal Failure Secondary to Myeloma Cast Nephropathy in a Local Cohort

Introduction: The objective of this observational study on a local cohort was to report the prognostic interest of using a High Cut-Off membrane dialysis protocol in the management of MM (myeloma tubulopathy) in patients with severe dialysis-dependent acute kidney injury (AKI). Methodology: This was a retrospective study conducted over a one-year period from September 1, 2023, to August 31, 2024. All hospitalized patients with dialysis-dependent AKI diagnosed with MM were treated according to the High Cut-Off protocol of usual chemotherapy. A free light chain proteinuria level above 1500 mg/L was required to confirm the diagnosis of MM. Results: In our cohort, we included 14 patients diagnosed with MM, 9 of whom were treated with the High Cut-Off protocol. Among these, 5 recovered renal function (RF), and 4 did not; 5 patients underwent conventional dialysis without RF recovery. The average age was 77 years, ranging from 45 to 92 years, with the highest age group being 65 to 85 years. Women were predominant, with a sex ratio of 1.4. The hematological diagnosis was similar in all groups (HCO , HCO^-, and conventional dialysis). Our results show a higher percentage of patients with subacute MM or pre-existing chronic kidney disease (CKD) in the HCO group, with mean creatinine levels of 133 μmol/L, 117 μmol/L, and 106.5 μmol/L, respectively. No patient with creatinine > 115 μmol/L was found in the HCO group, while there were 3/5 (60%) in the HCO^- group and 5 in the conventional dialysis group. A significant decrease in free light chain levels was observed at the end of the protocol in 4 patients (25%) in the HCO group compared to none (0%) in the conventional dialysis group. In the group treated successfully with the HCO protocol, the time to RF recovery after initiating HCO treatment was 3 months for 3 patients and 6 months for 2 patients. Conclusion: In our study, the results suggest that the HCO protocol is beneficial, with 56% of patients weaned from dialysis, while no recovery was observed in the untreated group. Renal recovery was most notable around the third month after initiating the protocol. Further studies are needed to confirm these findings. This renal recovery, along with dialysis weaning, could have a significant positive impact on the quality of life of patients with MM and beneficial medico-economic repercussions.