Albuminuria in hematopoietic cell transplantation patients: prevalence, clinical associations, and impact on survival

Abstract

Chronic kidney disease (CKD) is common after hematopoietic cell transplantation (HCT). We prospectively measured the urinary albumin:creatinine ratio (ACR) in 142 patients. Total (intact) monomeric albumin was determined by liquid chromatography of untreated urine samples collected weekly to day 100 after HCT. Albuminuria was defined as ACR (mg/g creatinine) > 30; proteinuria, as ACR >300. Cox and logistic regression analyses evaluated ACR as a risk factor for clinical events. The prevalence of albuminuria was 37% at baseline, 64% at day 100, and 50% at 1 year. Proteinuria occurred in 4% of patients at baseline, in 15% at day 100, and in 4% at 1 year. Characteristics associated with albuminuria include age, sex, donor type, hypertension, and sinusoidal obstruction syndrome (SOS). Albuminuria was associated with an increased risk of acute graft-versus-host disease (aGVHD) and bacteremia, but not acute kidney injury (AKI). Albuminuria at day 100 was associated with CKD at 1 year (odds ratio = 4.0; 95% confidence interval [CI] = 1.1 to 14.6). Nonrelapse mortality (NRM) risk was elevated (hazard ratio = 6.8; 95% CI = 1.1 to 41.5) in patients with overt proteinuria at day 100. Albuminuria occurs frequently after HCT and is correlated with aGVHD, bacteremia, hypertension, and progression of renal disease. Proteinuria at day 100 is associated with an 6-fold increased risk of NRM by 1 year after HCT.

Figure 1

Cumulative incidence curves of non-relapse mortality from day 100 to 1 year post-HCT displayed by degree of albuminuria. N=43 for ACR <30; N=54 for ACR 30–300; N=17 for ACR ≥300.

Figure 2

Kaplan-Meier curves of overall survival from day 100 to 1 year post-HCT by degree of albuminuria. N=44 for ACR<30; N=58 for ACR 30–300; N=18 for ACR ≥ 300.