Abstract
Abstract 5002
Kidney failure is a major cause of morbidity in patients with Multiple Myeloma (MM). While up to half of MM patients can be shown to have renal impairment, 10% will become dialysis dependent. The main mechanism of kidney failure is cast nephropathy, which is linked to high amounts of circulating free light chains. A proposed strategy to prevent this outcome is the use of extended high cutoff (HCO) dialysis. An ongoing randomized controlled trial is testing the Gambro HCO1100 filter. Here we report the use of another dialyzer (Bellco Phylther), which has a smaller pore size than the Gambro filter, but which may prove to be as effective and is less costly.
We present three patients with symptomatic MM, elevated κ or λ serum free light chains (>500mg/L), biopsy confirmed cast nephropathy, and kidney failure (estimated GFR <15ml/min/1.73 m2) requiring dialysis. In all patients, dialysis consisted of 10 hemodiafiltration dialysis sessions in the first two weeks and three times a week thereafter using a high flux Bellco Phylther HF22SD dialyzer (Bellco, Modena, Italy). All patients received concurrent chemotherapy: bortezomib 1.3mg/m2 IV and dexamethasone 40mg po on days 1, 4, 8 and 11 of a 21 day cycle and liposomal doxorubicin at 30mg/m2 on day 4 of every cycle. Serum free light chains were determined pre- and immediately post-dialysis using a nephelometric immunoassay (FREELITE, The Binding Site, Birmingham UK).
Patient Characteristics and Responses
| . | Age . | Disease . | MM type . | Renal Biopsy . | sFLC at start2 (mg/L) . | eGFR at start . | sFLC at 2 weeks3 (mg/L) . | sFLC at 3months . | eGFR at 3months . | Renal Recovery4 . |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 64F | Relapse | IgAκ | CN | 45,000 | 4 | 6560 | 19 | 48 | Yes |
| 2 | 73F | New | λ | CN | 13,420 | 9 | 41 | 14 | 35 | Yes |
| 3 | 76F | New | κ | CN1 | 3560 | 9 | 69 | 3.2 | 8 | No |
| . | Age . | Disease . | MM type . | Renal Biopsy . | sFLC at start2 (mg/L) . | eGFR at start . | sFLC at 2 weeks3 (mg/L) . | sFLC at 3months . | eGFR at 3months . | Renal Recovery4 . |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 64F | Relapse | IgAκ | CN | 45,000 | 4 | 6560 | 19 | 48 | Yes |
| 2 | 73F | New | λ | CN | 13,420 | 9 | 41 | 14 | 35 | Yes |
| 3 | 76F | New | κ | CN1 | 3560 | 9 | 69 | 3.2 | 8 | No |
CN- Biopsy-proven cast nephropathy
CN and tubulointerstitial nephritis.
Affected sFLC at baseline before the start of HCO HDF.
Affected sFLC 2 weeks after the start of HCO HDF.
Indepedence from dialysis.
eGFR – estimated GFR (ml/min/1.73 m2) using the MDRD Study equation
We observed significant (>50%) and rapid reductions in sFLCs. These reductions were sustained at 3 months in all cases, likely because of effective anti-myeloma treatment. Two of the three patients had recovery of kidney function and remain dialysis-independent at least 6 months after cessation of dialysis. Interestingly, the only patient that did not recover kidney function was also found to have tubulointerstitial disease on renal biopsy in addition to cast nephropathy.
The HCO Bellco Phylther dialyzer appears effective in the rapid reduction of sFLCs in light chain MM patients with cast nephropathy requiring dialysis and concurrent anti-myeloma drug therapy. While the numbers are small, our review suggests that patients with uncomplicated MM cast nephropathy may benefit from aggressive hemodiafiltration with this HCO membrane. This dialysis membrane and protocol are worth considering for further study in patients with MM cast nephropathy.
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.
