Renal function is frequently impaired in plasma cell dyscrasias. In patients suffering from multiple myieloma (MM), the acute kidney injury (AKI) is a serious prognostic factor. The nephrologists are interested in the fast reduction of free light chains (FLC) blood levels through extracorporeal treatments in order to facilitate the recovery of renal function, to offer more effective chemotherapy and to improve renal and patient outcomes. Extended haemodialysis with high-molecular weight cut-off (HCO) membranes are effective in the removal of FLC but they have high cost and produce a substantial loss of albumin.1 Recent studies reported the effectiveness of haemodiafiltration with ultrafiltrate regeneration in the reduction of FLC in MM with renal failure.2–4 The haemodiafiltration with ultrafiltrate regeneration by adsorption in resin and endogenous reinfusion (HFR) is an extracorporeal clearance technique that combines convection, adsorption and diffusion without albumin removal. We report our experience. We studied the effects of HFR on the removal of FLC in 3 haemodialysis-dependent patients with MM and AKI admitted to our department from June to October. Two patients had lambda-IgG MM and one had lambda-IgA MM. Through a temporary vascular catheter, we treated with Supra-HFR® (™BELLCO, Italy) with three sessions per week of 210min. Blood flow was between 200 and 250ml/min, dialysate flow was 500ml/min and the ultrafiltration rate depending on the patients’ interdialysis weight gain. In 3 of these sessions, we analysed the pre- and post-HFR blood levels of kappa- and lambda-FLC (Table 1). Serum FLC concentrations were measured with N Latex FLC kit (Siemens) using the BN II SIEMENS nephelometer. The normal ranges with this assay are 6.70–22.40mg/L for kappa-FLC and 8.30–27.00mg/L for lambda-FLC. The reduction rates were between 32.2% and 49.5%. Blood albumin concentration did not change and we didn’t need of albumin replace therapy. The results of the reduction rates of FLC were similar that in previous reports. Supra-HFR had a cost of approximately 120 euros per session. In Italy the Gambro HCO 1100 dialyser (Theralite 2100®) has a cost of approximately 1000 euros per session. Also in our experience, the HFR therapy is effective in removing FLC with lower cost (compared with HCO membranes) and no significant loss of albumin.
The authors have nothing to declare.