Rationale for the evaluation of renal functional reserve in allogeneic stem cell transplantation candidates: a pilot study

Abstract

Purpose The main purpose of our study was to evaluate the ability of renal functional reserve (RFR) to stratify the risk of acute kidney injury (AKI) occurrence within 100 days of hematopoietic stem cell transplantation (HSCT) and to predict any functional recovery or the onset of chronic kidney disease (CKD). A secondary aim was to identify the clinical/laboratory risk factors for the occurrence of AKI. Patients and methods The study design is prospective observational. We enrolled 48 patients with normal basal glomerular filtration rate (bGFR) who underwent allogenic HSCT. A multiparameter assessment and the renal functional reserve test (RFR-T) using an oral protein load stress test were performed 15 days before the HSCT. Results Different RFRs corresponded to the same bGFR values. Of 48 patients, 29 (60%) developed AKI. Comparing the AKI group to the group that did not develop AKI, no statistically significant difference emerged in any characteristic related to demographic, clinical, or multiparameter assessment variables except for the eGFR. eGFR ≤100 ml/min/1.73 m2 was significantly related to the risk of developing AKI (Fisher exact test, p = 0.001). Moreover, RFR-T was lower in AKI+ patients vs. AKI- patients; but did not allow statistical significance (28% vs. 40%). In AKI patients, RFR > 20% was associated with complete functional recovery (one-sided Fisher extact test, p = 0.041). The risk of failure to recover increases significantly when RFR ≤ 20% (OR = 5.50, IC95% = 1.06-28.4). Conclusion RFR identifies subclinical functional deterioration conditions essential for post-AKI recovery. In our cohort of patients with no kidney disease (NKD), the degree of pre-HSCT eGFR is associated with AKI risk, and a reduction in pre-HSCT RFR above a threshold of 20% is related to complete renal functional recovery post-AKI. Identifying eGFR first and RFR second could help select patients who might benefit from changes in transplant management or early nephrological assessment.

Assessment of Risk Factors for Acute Kidney Injury with Machine Learning Tools in Children Undergoing Hematopoietic Stem Cell Transplantation

“…Consequently, prospective adjustment of the currently available methodology for pediatric specificity is needed, though it appears challenging. However, the first promising results correlate an RFR > 20% before HSCT with a subsequent recovery from AKI after transplantation [39]. Therefore, larger studies, aimed at defining RFR thresholds in children planned for HSCT, or at finding surrogate markers for such assessment, are awaited.…”

Potential utility of renal functional reserve testing in clinical nephrology

“…Monitoring of hyperfiltration and RFR could help in the assessment and treatment of patients with diabetic nephropathy [ 51 ], obesity [ 52 ], autosomal dominant polycystic kidney disease [ 53 ], presurgery and in follow up of patients requiring tumor nephrectomy [ 47 , 54 ], in intensive care [ 7 ], as well as cardio, hepato, onco-renal, or metabolic syndromes [ 55 – 57 ], and as a prognostic indicator after acute kidney injury (AKI) [ 21 , 39 , 57 ]. Furthermore, measurement of RFR may create opportunities for more evidence-based individualization of therapies in diverse settings [ 6 ▪▪ ].…”