Background
Autologous stem cell transplantation (ASCT) is potentially beneficial for patients with myeloma-related renal impairment but is associated with high rates of complications in dialysis-dependent patients and requires specific precautions.
Methods
Patients diagnosed with myeloma and concomitant dialysis-dependent renal dysfunction were admitted for ASCT after achieving at least partial response with bortezomib-based induction therapy. For both patients, mobilization consisted of granulocyte colony stimulating factor for 5 days and CD34 directed Plerixafor on Day 1. Melphalan was administered at a dose of 140 mg/m2 and a pre-emptive session of haemodialysis was planned 24 hours after melphalan. Peripheral blood stem cell infusion was done after 24 hours. A central venous sample for blood gas analysis was obtained daily and ad hoc dialysis was planned at the earliest sign of metabolic acidosis (pH <7.35, HCO3 <15 or K >6 mEq/L).
Results
Two patients with biopsy proven cast nephropathy and dialysis dependence (twice a week) were taken for ASCT with the above protocol. No variation from usual stem cell yield or engraftment kinetics was noted. Patient 1 (M, 49 years) achieved very good partial response post-transplant and has been dialysis free for 18 months post-ASCT. Patient 2 (M, 48 years) achieved negative immunofixation post-ASCT and was dialysis free for 9 months post-transplant, following which he requires one session of dialysis every 3–4 weeks for onset of uraemic symptoms.
Conclusions
ASCT in dialysis-dependent patients is associated with a higher risk of drug toxicity, infections and transplant-related mortality. Use of reduced dose melphalan, pre-emptive dialysis after 24 hours and monitoring for acidosis and symptoms of uraemia to identify acidosis at an early stage allows safe administration of high dose chemotherapy. A major proportion of patients can potentially achieve reduction or freedom from dialysis support post-transplant.