Risk factors for acute kidney injury in patients undergoing allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic cell transplantation (allo-HSCT) is a potent procedure for the treatment of hematologic diseases, yet it is associated with high risks of treatment-related complications. Except for transplant-related organ toxicities, renal insufficiencies which emerge earlier significantly limit patients' long survival. To analyze risk factors for acute kidney injury (AKI), we conducted a retrospective cohort study of 96 patients undergoing HSCT.

During the first 100 days after allo-HSCT, all patients were evaluated for renal function by measuring serum creatinine clearance and glomerular filtration rate (GFR) with a classification below: Grade 0 (<25%, decline in creatinine clearance), Grade 1 (≥25% decline in creatinine clearance but <2-fold increase in serum creatinine), Grade 2 (≥2-fold rise in serum creatinine but no need for dialysis), and Grade 3 (≥2-fold rise in serum creatinine and need for dialysis). Cox regression model was used to calculate the hazard ratios (HRs) of demographic data, clinical variables, and risk factors for AKI.

Twenty-eight (29.2%) patients occurred Grades 1-3 renal dysfunction (Grade 1, 14 patients; Grade 2, 12 patients; Grade 3, 2 patients), and ratios of early kidney injury increased in high-risk malignancy group (HR = 2.945, 95% confidence interval (CI)=1.293-6.421), patients treated with myeloablative conditioning regimen (HR=2.463, 95% CI=1.757-4.320), and patients with acute GVHD (HR=3.553, 95% CI=1.809-6.978), sepsis (HR=3.215, 95% CI=1.189-6.333 ), or hepatic veno-occlusive disease (VOD) (HR=3.487, 95% CI=1.392-6.524). Whereas, HLA histocompatibility showed no striking increased risk for acute renal injury (HR=1.684, 95% CI=0.648-4.378). The survival rate was lower in patients with severe nephrotoxicity (21.4%) than in patients without nephrotoxicity (70.6%) (P=0.001).

Nephrotoxicity is the primary risk factor for AKI, severely impacting on survival. Sorts of risk factors mentioned will be useful for evaluation for kidney function of patients undergoing allo-HSCT.