Kidney damage biomarkers in predicting renal complications of allogeneic hematopoietic cell transplantation: a pilot prospective observational study.

Kidney dysfunction is a significant complication of allogeneic hematopoietic cell transplantation (alloHCT). Standard serum creatinine (sCr) testing is imperfect due to latency from the event causing damage to sCr increase. The purpose of this study was to evaluate the role of kidney damage biomarkers in the field of alloHCT. Seventy adult alloHCT candidates from 2 centers were recruited. 34 patients constituted pilot cohort and 36 - validation cohort. In pilot cohort serum and urine samples obtained at baseline and 7 timepoints were tested using ELISA assays for LFABP-1, KIM-1, NAG, uromodulin, TIMP-2 and IGFBP-7. Urine concentrations were corrected to urine creatinine concentration (uCr). Results were analyzed as predictors of acute kidney injury (AKI) within 100 days from alloHCT using receiver operating curve (ROC). LFABP-1, KIM-1, uromodulin, NAG and TIMP-2 performed significant predictive value for AKI. The best results were obtained for LFABP-1 and NAG and these biomarkers were tested in validation cohort where the results were borderline significant. Given the heterogeneity of the studied population, calculations for the whole group were performed: ROC for day +7/baseline ratio of urinary LFABP-1 and NAG in predicting AKI within 100 days from alloHCT was 0.673 and 0.678 respectively (p < 0.05). ROC for baseline urinary LFABP-1 in predicting early AKI was 0.721 (p < 0.05). Findings from our study confirm that patients undergoing alloHCT frequently experience subclinical kidney damage. However, due to the multifactorial nature of renal insults and preexisting kidney impairment, the predictive value of studied biomarkers in this population is limited.