Acute kidney injury in multiple myeloma patients undergoing autologous hematopoietic stem cell transplant: a cohort study.

backgroundAutologous hematopoietic stem cell transplant plays an important role in multiple myeloma (MM) treatment. Increasing incidence of MM and growing awareness of acute kidney injury (AKI) as a complication of hematopoietic stem cell transplant results in the need to better understand AKI in these patients. We aimed to evaluate incidence, risk factors and 5-year prognostic impact of AKI in MM patients undergoing autologous hematopoietic stem cell transplant.

methodsRetrospective cohort study. AKI was defined by the KDIGO classification using creatinine and urinary output criteria. We used survival analysis methods considering competing events for risk factors and disease-free survival, Cox proportional regression for overall survival and stepwise regression methods for multivariable models.

resultsWe analyzed data regarding 143 patients. The cumulative incidence of AKI and moderate-to-severe AKI was 49.7% and 14.1%, respectively. Factors with independent impact on AKI were obesity (HR: 1.83, 95% CI 1.07-3.11; p = 0.026), Hematopoietic cell transplantation-specific comorbidity index (HCT-CI) ≥ 2 (HR: 1.85, 95% CI 1.08-3.17), chronic kidney disease (CKD) (HR: 2.06, 95% CI 1.05-4.04), amyloidosis (HR: 2.25, 95% CI 1.25-4.06), mucositis grade 3-4 (HR: 2.19, 95% CI 1.25-3.86) and exposure to nephrotoxic drugs (HR: 2.0856, 95% CI 1.04-4.19). Moderate-to-severe AKI had an impact (HR: 1.62, 95% CI 1.15-2.31) on 5-year overall survival.

conclusionAcute kidney injury affects almost half of MM patients undergoing autologous hematopoietic stem cell transplantation, and reduction in urinary output allows early diagnosis in almost a quarter of the patients. Obesity, HCT-CI ≥ 2, CKD, amyloidosis, mucositis grade 3-4 and exposure to nephrotoxic drugs are significant risk factors. Moderate-to-severe AKI is associated with lower 5-year overall survival.