24-hour ambulatory blood pressure monitoring 9 years after pediatric cardiac surgery: a pilot and feasibility study.

BACKGROUND: Children undergoing cardiac surgery are at risk of high blood pressure (BP), a risk factor for cardiovascular and kidney disease. Twenty-four-hour ambulatory BP monitoring (ABPM) is a reference standard hypertension (HTN) test. Little data exist on ABPM abnormalities in children several years post cardiac surgery. This study aimed to (a) determine ABPM feasibility; (b) describe and compare ABPM measures and abnormalities (percent load, masked HTN [MH]; non-dipping, mean systolic/diastolic BP > 95th percentile; pre-HTN (ABPM); white-coat HTN [WCH]) to casual BP; and (c) compare BP in patients with and without acute kidney injury (AKI). METHODS: Prospective, follow-up pilot study of children (0-18 years) who underwent cardiac surgery from 2007 to 2009 at Montreal Children's Hospital. We recorded if participants had post-operative AKI and assessed the following outcomes at 9-year follow-up: casual BP classified by three single-visit measures (normal; elevated BP [eBPSingleVisit]; HTNSingleVisit); ABPM. Bivariable analyses were used to compare characteristics between groups. RESULTS: Twenty-three patients (median [interquartile range], 8.6 [8.0, 9.0] years post cardiac surgery) were included; 16 (70%) male. Six participants (26%) had eBPSingleVisit or higher. On ABPM, 11 (48%) had ≥ 1 abnormality: 9 (39%) had non-dipping; 3 (13%) had pre-HTN; 3 (13%) had WCH; none had HTN or MH. There were no differences in ABPM according to AKI status. CONCLUSION: Our pilot study determined that ABPM was feasible in children years after cardiac surgery and frequently identified ABPM abnormalities. Future research in larger populations is needed to define specific risk factors for HTN in children after cardiac surgery.

Urine Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1 to Detect Pediatric Cisplatin-Associated Acute Kidney Injury.

Background: Few studies have described associations between the AKI biomarkers urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) with AKI in cisplatin-treated children. We aimed to describe excretion patterns of urine NGAL and KIM-1 and associations with AKI in children receiving cisplatin. Methods: Participants (n=159) were enrolled between 2013 and 2017 in a prospective cohort study conducted in 12 Canadian pediatric hospitals. Participants were evaluated at early cisplatin infusions (at first or second cisplatin cycle) and late cisplatin infusions (last or second-to-last cycle). Urine NGAL and KIM-1 were measured (1) pre-cisplatin infusion, (2) post-infusion (morning after), and (3) at hospital discharge at early and late cisplatin infusions. Primary outcome: AKI defined by serum creatinine rise within 10 days post-cisplatin, on the basis of Kidney Disease Improving Global Outcomes guidelines criteria (stage 1 or higher). Results: Of 159 children, 156 (median [interquartile range (IQR)] age: 5.8 [2.4-12.0] years; 78 [50%] female) had biomarker data available at early cisplatin infusions and 127 had data at late infusions. Forty six of the 156 (29%) and 22 of the 127 (17%) children developed AKI within 10 days of cisplatin administration after early and late infusions, respectively. Urine NGAL and KIM-1 concentrations were significantly higher in patients with versus without AKI (near hospital discharge of late cisplatin infusion, median [IQR] NGAL levels were 76.1 [10.0-232.7] versus 14.9 [5.4-29.7] ng/mg creatinine; KIM-1 levels were 4415 [2083-9077] versus 1049 [358-3326] pg/mg creatinine; P<0.01). These markers modestly discriminated for AKI (area under receiver operating characteristic curve [AUC-ROC] range: NGAL, 0.56-0.72; KIM-1, 0.48-0.75). Biomarker concentrations were higher and better discriminated for AKI at late cisplatin infusions (AUC-ROC range, 0.54-0.75) versus early infusions (AUC-ROC range, 0.48-0.65). Conclusions: Urine NGAL and KIM-1 were modest at discriminating for cisplatin-associated AKI. Further research is needed to determine clinical utility and applicability of these markers and associations with late kidney outcomes.

Association of Urine Platinum With Acute Kidney Injury in Children Treated With Cisplatin for Cancer.

Cisplatin is a chemotherapeutic agent highly excreted in urine and known to cause acute kidney injury (AKI). As AKI diagnosis by serum creatinine (SCr) is usually delayed, endeavors for finding early AKI biomarkers continue. This study aims to determine if urine platinum (UP) concentration 24 hours after cisplatin infusion is associated with AKI, and to evaluate the association between urine platinum and tubular damage biomarkers: neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1). Children treated with cisplatin in 12 Canadian centers (April 2013 to December 2017) were included. Urine from the morning after the first cisplatin infusion of the first or second cisplatin cycle was measured for urine platinum, NGAL, and KIM-1. SCr and serum electrolytes were used to detect AKI by either SCr elevation or urinary electrolyte wasting (potassium, magnesium, phosphate). The associations of urine platinum with AKI, NGAL, and KIM-1 were assessed. A total of 115 participants (54% boys, median age, 8.5 years; interquartile range, 4.0-13.4) were included, of which 29 (25%) and 105 (91%) developed AKI defined by SCr and electrolyte criteria, respectively. Higher urine platinum was associated with higher cisplatin dose (Spearman rho, 0.21) and with younger age (Spearman rho, -0.33). Urine platinum was not associated with postinfusion AKIor KIM-1, but was weakly associated with NGAL, particularly in participants without SCr AKI (Pearson's r, 0.22). Urine platinum may be a marker of mild tubular injury but is not likely to be a useful biomarker of clinically evident AKI.

Tubular injury and cell-cycle arrest biomarkers to predict acute kidney injury in noncritically ill children receiving aminoglycosides.

Aim: NGAL, IL-18, KIM-1 as well as urinary TIMP2 and IGFBP7 and their mathematical product (TIMP2*IGFBP7) were evaluated for detecting pediatric aminoglycoside acute kidney injury (AG-AKI). Methods: In a prospective study, noncritically ill children received aminoglycosides (AG) ≥3 days. The area under the curve (AUC) for biomarkers to detect AKI was calculated by a) days before AKI onset; b) treatment days. Results: There were 113 AG episodes (68% febrile neutropenia). The AKI group had a higher proportion with febrile neutropenia. The AKI group had significantly lower NGAL 3 days before AKI, as patients with febrile neutropenia had a lower NGAL during AG treatment (p < 0.05). NGAL, IL-18 and TIMP2*IGFBP7 had AUC ≥0.73 at 3, 2 and 2 days before AKI onset. Conclusion: NGAL, IL-18 and TIMP2*IGFBP7 were modest early biomarkers of AG-AKI. Febrile neutropenia was associated with lower NGAL.