[Free light chains reduction on acute kidney injury in multiple myeloma: critical role of high cut-off membranes].

We report our experience with five patients, with dialysis dependent AKI and multiple myeloma (MM). Two of them were already suffering from a mild degree of renal insufficiency, one was on follow-up for smouldering MM and two had a relapse of symptomatic MM. Median concentration of the involved FLC (iFLC) was 15104 mg/L (range 1196-24384). All patients underwent three times per week HCO-HD for 6 hour sessions using Theralite 2100 (median 10, range 6-13 sessions) with one having further twelve sessions of 4 hours using SUPRA device (Bellco). In addition, they followed a bortezomib and dexamethasone regimen according to a bi-weekly schedule (3-5 cycles) plus Thalidomide. iFLC concentrations were measured by immunonephelometry in blood at the beginning of each dialysis session. All patients but one, showed a very good partial hematological response. The only exception demonstrated a partial response. iFLCs decreased between 72,8% and 99,7% in a median period of three weeks. After 6 months three patients underwent autologous stem-cell transplantation (ASCT), one of whom repeated the procedure 6 months later. In conclusion, three patients became dialysis independent at the end of the HCO-HD period, one patient became dialysis independent three months later and one remained dialysis dependent. Recovery of renal function in 4 out of 5 patients with a very good hematological response is a consequence of an early and fast removal of the iFLC joined to an efficient therapeutic regimen.