Acute Kidney Injury in Patients with Leukaemia Submitted to Allogeneic Hematopoietic Stem Cell Transplant – KDIGO Classification with Creatinine and Urinary Output Criteria: Cohort Analysis

Background: Allogeneic Hematopoietic Stem Cell Transplant (allo-HSCT) is often complicated by Acute Kidney Injury (AKI) and has been increasingly used in patients with leukaemia. Studies on this subject include patients with several haematological diseases and use only Serum Creatinine (SCr) to define AKI. We aimed to evaluate incidence, risk factors and 5-year prognostic impact of AKI in patients with leukaemia submitted to allo-HSCT by SCr and Urinary Output (UO). Methods: We conducted a single-centre retrospective cohort study. AKI was defined according to KDIGO classification. We used survival analysis methods considering competing events - the Fine and Gray method - to identify AKI risk factors and assess the impact of AKI on disease-free survival. Additive Cox proportional hazards regression models were applied to analyse time until death from all causes. Stepwise selection regression methods were used to create the final multivariable model. Results: We included 164 patients. The cumulative incidence of AKI was 63.4% 100 days post-HSCT. On the first day of AKI, 76.9% presented SCr criteria, 15.4% presented UO criteria and 7.7% presented both criteria. The highest stage of AKI was 1 in 61.8%, 2 in 21.6% and 3 in 16.7%. Variables independently associated with AKI: HCT-CI >2 (HR:1.88,95%CI:1.13- 3.11;p=0.015), radiotherapy in the past (HR:2.07,95%CI:2.07- 1.06;p=0.034), LDH at hospital admission (HR:1.51,95%CI:1.03- 2.21;p=0.035), shock (HR:1.57,95%CI:1.02-2.39;p=0.039), and sepsis (HR:3.36,95%CI:1.22-9.24;p=0.019). Severe AKI was independently associated with lower overall survival along the first 5 years (HR:1.76,95%CI:1.03-3.00;p=0.037). Conclusion: AKI in leukaemia patients submitted to allo-HSCT had a cumulative incidence of 63.4% and more than 15% of these patients presented only with UO reduction on the day of AKI onset. Two thirds of the patients evolved with AKI stage 2 or 3. Sepsis, previous radiotherapy treatments at any time before HSCT, HCT-CI scoring higher than 2 points, shock and higher LDH levels increased the risk of developing AKI. Severe AKI was associated to lower overall survival throughout the first five years after allo-HSCT. To our knowledge, this is the first study considering both SCr and UO for AKI patients with Leukaemia submitted to allogeneic Hematopoietic Stem Cell Transplant.