Similar Risks for Late-Onset Chronic Kidney Disease in Myeloablative and Reduced-Intensity Allogeneic Hematopoietic Cell Transplant Survivors.

Chronic kidney disease (CKD) has been reported in nearly 20% of recipients of myeloablative (MA) allogeneic hematopoietic cell transplantation (HCT). HCT using reduced-intensity (RIC) conditioning is associated with lower morbidity and mortality, but the risk of CKD after RIC HCT is not well known. We conducted a retrospective cohort study to compare the incidence of CKD after MA and RIC HCT. Adult allogeneic HCT recipients were eligible if (1) they received an allogeneic HCT between 2000 and 2005, (2) survived for ≥ 1 year post-HCT, and (3) had no history of CKD pre-transplant. The dose of total body irradiation in MA and RIC regimens was 1320 cGy (165 cGy twice daily × 4 days) and 200 cGy (single fraction), respectively, and was given without kidney shielding. CKD was defined as glomerular filtration rate (GFR) < 60 ml/min/1.73m² for ≥ 3 months (National Kidney Foundation definition) anytime after 180 days post-HCT. GFR was estimated using the Modification of Diet in Renal Disease equation [GFR = 186 × (S_Cr)^−1.154 × (Age)^−0.203 × (0.742 if female) × (1.210 if African American)]. Study eligibility criteria were met by 221 patients (MA=104, RIC=117); median follow-up was 28 (range, 12–75) months for MA and 25 (range, 12–67) months for RIC group. At the time of transplant, MA recipients were younger (median age 38 vs. 54 years, P<0.01), less likely to have HTN (7% vs. 22%, P<0.01) and more likely to have a body mass index of <30 (87% vs. 72%, P=0.01). The two groups were comparable with respect to prevalence of diabetes mellitus, smoking, HCT co-morbidity index scores, incidence of acute renal failure (ARF) within the first 180 days, and duration of cyclosporine (CSA) use. A total of 60 (MA=30, RIC=30) patients developed CKD, resulting in a 3-year cumulative incidence rate of 29% (95% confidence intervals, 20–37%) in MA and 27% (18–35%) in the RIC group (p=0.44). In multivariate analysis, conditioning regimen intensity had no impact on risk of developing CKD (relative risk [RR] for MA 1.60 [0.86–2.97] vs. RIC regimen). Factors independently associated with an increased risk of CKD were age at HCT (RR 1.05 [1.02–1.08] for each year increase), acute graft-versus-host disease (RR 2.16 [1.19–3.93]) and CSA use for >6 months (RR 3.48 [2.33–2.56]). ARF within the first 180 days also predicted the risk for CKD. Compared to severe ARF [lowest GFR ≤ 30], RR of CKD was 0.40 [0.23–0.69] for moderate ARF [lowest GFR 31–59] and 0 for no ARF [lowest GFR ≥ 60]. In conclusion, CKD is frequent in long term adult allogeneic HCT survivors. RIC is associated with similar risks of CKD as MA conditioning. Older age, ARF, acute graft-versus-host disease and prolonged CSA exposure increases the risk of CKD. Continuous monitoring of renal function is necessary in allogeneic HCT survivors and studies exploring prevention strategies are needed.