Moderate Renal Function Impairment Does Not Affect Outcomes of Reduced-Intensity Conditioning with Fludarabine and Melphalan for Allogeneic Hematopoietic Stem Cell Transplantation

Nonrelapse mortality (NRM) after reduced-intensity allogeneic transplants is likely to be influenced by abnormalities in renal function. We studied 141 patients diagnosed with acute myelogenous leukemia (AML) (n = 131) or high-risk myelodysplastic syndrome (MDS) (n = 10) who underwent allogeneic transplantation with fludarabine (Flu)/melphalan (Mel)-based regimens and hypothesized that moderate to mild renal function impairment increases NRM in this setting. Flu dose consisted of 25-30 mg/m² for 4 days and Mel dose was 100-180 mg/m². Donors were HLA-compatible siblings (n = 69) and matched unrelated donors (n = 72). Disease status at transplantation was complete remission (n = 56, 40%) or active disease (n = 85, 60%). The influence of the estimated glomerular filtration rate (GFR) measured before transplantation on outcomes was analyzed. GFR was estimated by both the Cockcroft-Gault (CG) and the modified diet in renal disease (MDRD) equations, using the creatinine value obtained prior to starting chemotherapy. Evaluated outcomes were overall survival (OS), NRM, and treatment-related mortality (TRM) at day 100 and 1-year posttransplantation. Median age was 55 years (range: 21-74 years); 59% of the patients were male. Estimated GFR by CG was ≥90 for 45 (32%), 60-89 for 78 (55%), and <60 for 18 (13%) patients. When estimated by MDRD, GFR was ≥90 for 65 (46%), 60-89 from 66 (47%), and <60 for 10 (7%) patients. The majority of patients by both estimations had a GFR between 60 and 89 (n = 78 by CG and n = 66 by MDRD) with no difference in the evaluated outcomes between this group and the subgroup of patients with a GFR <60 (P > .05). There were no differences in OS and NRM at day 100 and 1-year posttransplantation in the 3 groups by any GFR estimation method. In conclusion, a mild to moderate decrease in GFR was not associated with an increase in NRM.

Key Words: Transplantation, Toxicity, Reduced intensity, Renal function, Creatinine