Abstract
BACKGROUND: Autologous 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. METHODS: Retrospective 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. RESULTS: We 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. CONCLUSION: Acute 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.