Tubular Injury Biomarkers to Predict CKD and Hypertension at 3 Months Post-Cisplatin in Children.

Abstract

Urine kidney injury biomarkers measured during cisplatin therapy may identify patients at risk for adverse subsequent kidney outcomes. We examined relationships between tubular injury biomarkers collected early (early visit [EV]: first or second cisplatin cycle) and late (late visit [LV]: last or second-last cisplatin cycle) during cisplatin therapy, with 3-month post-cisplatin chronic kidney disease (CKD) and hypertension. We analyzed data from the Applying Biomarkers to Minimize Long-Term Effects of Childhood/Adolescent Cancer Treatment Nephrotoxicity Study: twelve-center prospective cohort study of 159 children receiving cisplatin. We measured urine neutrophil gelatinase-associated lipocalin (NGAL)/creatinine, kidney injury molecule-1 (KIM-1)/creatinine, tissue inhibitor of metalloproteinase-2 (TIMP-2), and insulin-like growth factor-binding protein 7 (IGFBP-7) (TIMP-2 and IGFBP-7 expressed as their product, ng/ml^2/1000) at an EV and LV during cisplatin therapy with pre-infusion, post-infusion, and hospital discharge sampling. Area under the curve (AUC) was calculated for biomarkers to detect 3-month post-cisplatin CKD (KDIGO guidelines: low estimated glomerular filtration rate (eGFR) or elevated uACR for age) and hypertension (three blood pressures; per American Academy of Pediatrics guidelines). At median follow-up of 90 days, 52/118 (44%) and 17/125 (14%) developed CKD and hypertension, respectively. Biomarker prediction for 3-month CKD was low to modest; NGAL combined with KIM-1 at EV discharge yielded the highest AUC (0.67, 95% CI 0.57-0.77). Biomarker prediction of 3-month hypertension was stronger, but modest; the highest AUC was from combining EV pre-infusion NGAL and TIMP-2*IGFBP-7 (0.71, 95% CI 0.62-0.80). When EV pre-infusion NGAL and TIMP-2*IGFBP-7 were added to the 3-month hypertension clinical predictive model, AUCs increased from 0.81 (0.72-0.91) to 0.89 (0.83-0.95) (p<0.05). Tubular injury biomarkers we studied were individually not strong predictors of 3-month post-cisplatin kidney outcomes. Adding biomarkers to existing clinical prediction models may help predict post-therapy hypertension and identify higher kidney-risk patients.