Comment from David Askenazi

Thank you for putting together this important initiative. I speak from the perspective of an academic clinical scientist who done translational science primarily on newborns with kidney injury. I have also been part of pediatric studies - include the studies that help validate the use of NGAL for pediatric ICU patients. A few important points from my vantage points are as follows:<br/>1. Throughout this process, please DON&quot;T FORGET THE BABIES! Nephrotoxins are used in over 90% of all infants admitted to the ICU ! And yes, AKI is also bad in babies. <br/>2. We have published multiple articles looking at how the degree of prematurity impacts normal urine biomarkers values. In the vast majority of newborns (34 weeks and older - and those who are severely premature who become 34 weeks gestational age equivalent) the urine biomarker values are almost identical to term and older children. In those who are more premature, the values may differ (some rise and some are lower) but can still be helpful if the baseline values are known.<br/>3. In people who are not able to provide a urine sample (bed bound children and adults; and infants) it is essential that providers DO NOT USE cotton or other absorbents to capture the urine. We and others have shown that protein-based tests and metabolomic based tests are skewed with a lot of variability. Non-invasive urine collection systems are needed to capture fresh urine in this population.<br/>4. Screening for nephrotoxic AKI with urine biomarkers is valuable in high risk patients. We performed 2 studies (one in neonates and one in pediatiric popultaions) that clearly showed that the negative predictive value of NGAL was &gt;94%. Importantly, those who we missed (normal NGAL and high Creatinine) had transient AKI likely due to dehydration. So urine biomarkers are an EXCELLENT way to screen for AKI. but several things are important to note: a) a high pre-test probability is needed - we use the NINJA rules of 3 or more meds or amingolycosde/vancomycin for 3 or more days to start screening. b) a good screening tool will have many negatives and only few positives. How many Hgb levels are measured to find an anemic patient - do not expect or demand that the rate of AKI is high for a biomarker to be helpful. c) Please help make access to urine biomarkers easier across different hospitals and different machines. In our hospital we had to wait and wait and wait because eventhough we can validate the test on the current platform (as many hospitals do and many hospitals have done for decades) our hospital waited and waited for concerns that the urine test could only be used on the instrument it was approved on.