Background: Acute kidney disease (AKD) is a recent definition reflecting ongoing physiopathological processes of an acute renal injury (AKI). Information on AKD in hematopoietic stem cell transplant (HSCT) is scarce and there is no available data on long-term outcomes. We aimed to determine the cumulative incidence of AKD in the first 100 days after HSCT; to identify risk factors for AKD in HSCT; and to determine the impact of AKD in 3-year overall survival and relapse-free survival in HSCT. Methods: A retrospective cohort study was conducted, considering AKD when AKI was present and the patient continued to meet the KDIGO criteria (creatinine and/or urinary output criteria) for 7 days or more. Survival analysis methods considering competing events were used for risk factors and disease-free survival, Cox proportional regression for overall survival, and stepwise regression methods for multivariable models. Results: We enrolled 422 patients. AKD incidence was 22.9% (95% CI: 19.2–27.4%). Higher body mass index (HR: 1.05, 95% CI 1.01–1.10; p = 0.034), HCT-CI score ≥ 2 (HR: 1.83, 95% CI 1.11–3.13; p = 0.027), allogeneic transplantation (HR:2.03, 95% CI 1.26–3.33; p = 0.004), higher C-reactive protein (HR:1.01, 95% CI 1.01–1.02; p < 0.001), and exposure to nephrotoxic drugs (HR: 4.81, 95% CI 1.54–4.95; p = 0.038) were independently associated with AKD. AKD had a significant impact on overall survival (HR: 1.75; 95% CI 1.27–2.39; p = 0.001). Conclusion: An awareness of the risk factors for AKD allows the identification of high-risk patients, enabling the timely implementation of preventive measures to alleviate the progression and impact of the disease.

Multiple myeloma (MM) is frequently associated with cytogenetic abnormalities, with high-risk cytogenetics linked to poorer survival. Acute kidney injury (AKI) is common in MM, but its relationship with high-risk cytogenetics remains underexplored. This study aimed to assess the association between high-risk cytogenetics and AKI in newly diagnosed MM patients and to evaluate their impact on overall survival, relapse-free survival, and progression to chronic kidney disease (CKD) in the first two years after diagnosis. We conducted a single-center retrospective cohort study including patients newly diagnosed with MM between 2018 and 2022. We enrolled 122 patients. AKI was observed in 36.9% of patients, rising to 62.3% among those with high-risk cytogenetics. High-risk cytogenetics (OR: 3.32; 95% CI: 1.17–6.40; p = 0.024), CKD (OR: 9.14; 95% CI: 2.92–18.65; p < 0.001), kappa free light chains, hypercalcemia, difference in free light chain (dFLC), and bone marrow plasmocyte percentage were independently associated with AKI. Both AKI (HR: 2.71; 95% CI: 1.18–6.23; p = 0.019) and high-risk cytogenetics (HR: 3.33; 95% CI: 1.13–9.76; p = 0.029) were independently associated with lower overall survival. Among survivors without prior CKD, progression to CKD was higher in those with AKI (30.7% vs. 9.3%; p = 0.041). High-risk cytogenetics were significantly associated with AKI in MM patients. Both factors independently predict worse survival and increased risk of CKD progression.

Renal involvement is an important complication of multiple myeloma (MM) and is related not only to worse clinical outcomes but also to lower quality of life, particularly when progressing to end-stage renal disease. Traditionally, MM patients were not considered eligible for kidney transplant; however, these paradigms are changing. The new era of MM therapies brought proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, and, most recently, cellular therapies, leading to longer survival and sustained hematological responses. Knowledge of cytogenetic abnormalities has helped risk stratification. These advances result in the identification of patients who achieve durable remission and may benefit from kidney transplant programs as an option for renal replacement therapy. Reported 5-year allograft survival ranges from 50 to 66%, progression-free survival is 44%, and overall survival is 61%, depending on pre-transplant remission depth. This review summarizes updated available evidence regarding kidney transplants in MM, proposes evidence-based eligibility criteria for kidney transplantation in this population, and outlines therapeutic strategies for long-term follow-up. In conclusion, kidney transplantation may be a feasible option for carefully selected MM patients achieving deep and sustained remission, though prospective data are still needed.