Investigators established pediatric reference intervals for two common tests for cardiovascular disease during a first-of-its-kind study published in the April issue of The Journal of Applied Laboratory Medicine.
The findings are crucial to advancing the diagnosis and treatment of heart conditions in children, according to the American Association for Clinical Chemistry (AACC), the study publisher.
“Lack of evidence-based pediatric reference standards for cardiac biomarker interpretation complicates test interpretation,” the study researchers wrote. “The current study establishes comprehensive pediatric reference limits for high-sensitivity cardiac troponin I and NT-proBNP in the CALIPER cohort and demonstrates the importance of considering age in interpretation. These data valuably contribute to the limited literature on expected health-associated values for cardiac biomarkers in children and will be helpful to clinical laboratories in interpreting these [increasingly] utilized assays in neonates, children, and adolescents.”
Many pediatric hospitals have started to use high-sensitivity cardiac troponin (hs-cTn) and N-terminal pro B-type natriuretic peptide (NT-proBNP) to detect levels of the proteins cTn I or T and NT-proBNP, respectively. Recent studies have shown that their use could improve care for children with congenital heart disease, heart failure, and multisystem organ failure caused by sepsis, among other conditions. However, precise pediatric reference intervals for hs-cTn and NT-proBNP had not been determined, a major limitation of these tests for children, AACC noted.
Pediatric reference intervals are the range of normal test values appropriate for the age, stage of development, ethnicity, and gender of a child. They are essential for interpreting test results accurately; without them, children are at risk for misdiagnosis and inappropriate or even harmful medical care.
Khosrow Adeli, PhD, and Mary Kathryn Bohn, a PhD candidate, both of The Hospital for Sick Children in Toronto, wanted to determine pediatric reference intervals for both hs-cTnI and NT-proBNP. They analyzed approximately 200 blood samples from healthy pediatric patients, ranging in age from newborn to 18 years old, using an hs-cTnI test and an NT-proBNP test made by the same diagnostic manufacturer.
Based on the results of their analysis, the researchers followed the Clinical and Laboratory Standards Institute EP-28A3c guidelines to determine reference limits at the 2.5th, 97.5th, and 99th percentiles.
Significantly, according to AACC, Adeli and Bohn found that blood concentrations of both hs-cTnI and NT-proBNP are substantially elevated in newborns, with 99th percentiles of 55.8 ng/L and 1,785 ng/L, respectively.
Therefore, test results for hs-cTnI and NT-proBNP that don’t surpass these levels are normal in newborns, while such high results in adults indicate cardiovascular disease.
The finding could prevent the misdiagnosis of heart issues in newborns, and underscores why pediatric reference intervals are so critical for these tests, AACC added.