Chronic kidney disease in long-term survivors of myeloablative allogeneic haematopoietic cell transplantation: prevalence and risk factors.

BACKGROUND: Chronic kidney disease (CKD) seems to be common in long-term survivors of haematopoietic cell transplantation (HCT). However, the range of its frequency is very wide, likely due to variability in the definitions of CKD and the periods of follow-up.
METHODS: We conducted a cross-sectional and retrospective study in 158 adults who received myeloablative allogeneic HCT for lymphohaematologic malignancies at least 3 years ago and are alive today. The mean survival time was 6.15 +/- 4.88 years (range: 3-16 years). CKD was defined as a sustained decrease in glomerular filtration rate (GFR) or persistent proteinuria for a period more than 3 months. GFR was calculated based on serum creatinine (Cr) using the Modification of Diet in Renal Disease formula. Serum Cr and proteinuria were measured at least on three occasions separated by one or more months before the investigation. CKD was classified according to the National Kidney Foundation CKD staging. Proteinuria was defined as positive dipstick test > or =1+. The factors associated with the presence of CKD with a decrease of GFR (CKD > or = stage 3) were examined using multivariate logistic regression analysis, adjusted for demographic and clinical characteristics.
RESULTS: The prevalence of proteinuria was found in 36 out of 158 patients (22.8%). The prevalence of each CKD stage was as follows: Stage 0 (no CKD), 98 patients (62.0%); Stage 1, 18 patients (11.4%); Stage 2, 15 patients (9.5%); Stage 3, 8 patients (5.1%); Stage 4, 10 patients (6.3%) and Stage 5, 9 patients (5.7%). Initiation of chronic dialysis treatment or transplant was performed in seven CKD stage-5 patients (4.4%) at a mean of 10.9 +/- 3.72 years after HCT. Multivariate analysis identified acute kidney injury with HCT [odds ratio (OR), 9.920; 95% confidence interval (CI), 2.084-39.68; P = 0.0051], hypertension after HCT (OR, 4.031; 95% CI, 1.044-13.06; P = 0.0346) and survival time after HCT (OR, 4.275; 95% CI, 2.823-23.04; P = 0.0481) as significant factors associated with the presence of CKD > or = stage 3.
CONCLUSIONS: A remarkably high percentage of long-term survivors had evidence of proteinuria and all stages of CKD. CKD in transplant recipients may result from incomplete recovery from acute renal insults, hypertension and increasing longevity. The CKD cohort should be at a great risk for end-stage renal disease and cardiovascular morbidity and mortality. The burden of CKD should be recognized as a significant public health problem.