WASHINGTON – A study appearing online today in Clinical Chemistry, the premier journal in the field and a publication of AACC, has for the first time established precise newborn reference intervals for several steroid hormones and amino acids that play key roles in child development. This research could lead to earlier diagnosis and more effective treatment of numerous developmental disorders, from pediatric cancer and diabetes to congenital adrenal hyperplasia, and could aid detection of neonatal exposure to harmful endocrine-disrupting chemicals.
To correctly interpret clinical test results for pediatric patients, physicians must evaluate results within the context of reference intervals—the range of normal test values appropriate for the age, stage of development, ethnicity, gender, and geographical location of a child. However, limited access to samples from geographically diverse populations of healthy children has significantly hindered the establishment of precise pediatric reference intervals. The magnitude of this problem is greatest for newborns because, due to their low body weights, it is difficult to obtain the volumes of blood that are needed to perform reference interval studies. AACC’s Pediatric Reference Range Committee set out to change this by filling some of the critical gaps in newborn reference intervals. The Committee was led by 2016 AACC President Dr. Patricia Jones, clinical director of the chemistry and metabolic disease labs at Children’s Medical Center, Dallas, and Dr. Dennis Dietzen, director of the core laboratory and metabolic genetics laboratory at St. Louis Children’s Hospital, St. Louis.
This group aimed to establish carefully crafted reference intervals for four steroid hormones and 25 amino acids, which play important roles in physical, sexual, metabolic, and neurologic development. To accomplish this, the researchers obtained 310 dried blood spot samples from the National Institutes of Health’s National Children’s Study biobank. These samples came from a geographically diverse population of newborns aged 0–4 days. The researchers analyzed the samples using a technology known as liquid chromatography tandem-mass spectrometry, which can test for multiple compounds at once using minimal amounts of blood. From this analysis, they determined that 10 of the 25 amino acid distributions were dependent on sex, but did not correlate with age, birthweight, or geographic location over the first 4 days of life. The group also found that newborn steroid distributions correlated negatively with age and birthweight over the first 4 days of life, but were not related to geographic location.
“To the best of our knowledge, these data are the first of their kind generated from the National Children’s Study biobank,” Jones said. “The strengths of these data include the large sample of the youngest children and a level of geographic heterogeneity not previously achieved. The reference interval data for four steroid hormones and 25 amino acids … presented herein is the first step to providing the best biochemical parameters of healthy growth and development and enabling better recognition and detection of abnormal adrenal, reproductive, and metabolic pathology.”
Significantly, this study also demonstrates that newborn reference intervals can be derived from archived dried blood spot samples such as those obtained from the National Children’s Study biobank. Other studies could use this method to develop newborn reference intervals for vital biological compounds with minimal amounts of blood. Unfortunately, the National Children’s Study was discontinued in 2014, and though plans are underway to replace it, a lack of pediatric samples could still impede current initiatives to improve the accuracy and quality of pediatric reference intervals. To ensure that researchers have a reliable source of pediatric samples for these studies, AACC released a position statement earlier this year urging Congress to mandate and fund a national repository of specimens from healthy children.
Dedicated to achieving better health through laboratory medicine, AACC brings together more than 50,000 clinical laboratory professionals, physicians, research scientists, and business leaders from around the world focused on clinical chemistry, molecular diagnostics, mass spectrometry, translational medicine, lab management, and other areas of progressing laboratory science. Since 1948, AACC has worked to advance the common interests of the field, providing programs that advance scientific collaboration, knowledge, expertise, and innovation. For more information, visit www.myadlm.org.
Clinical Chemistry is the leading international journal of clinical laboratory science, providing 2,000 pages per year of peer-reviewed papers that advance the science of the field. With an impact factor of 7.457, Clinical Chemistry covers everything from molecular diagnostics to laboratory management.