Professor Adeli: Defining the new normal for paediatric laboratory testing

Monday, June 24, 2013
Prof. Khosrow Adeli and the CALIPER team.
Prof. Khosrow Adeli and the CALIPER team.

If you’re a 35-year-old man and your cholesterol is below 5.2 mmol/L, you know your test results are normal because the parameters of “normal” cholesterol in adults have been well established. But what if you’re a five-year-old boy? Surprisingly, in the past, there were very few standards against which pediatric tests results could be measured, and those that did exist were inadequate. To address this issue, Professor Khosrow Adeli from the Department of Laboratory Medicine and Pathobiology (LMP) and Head of Clinical Biochemistry at The Hospital for Sick Children (SickKids) has been working to develop a current and accurate database of normal values that represent Canada’s children and youth.

This national initiative is called the Canadian Laboratory Initiative on Paediatric Reference Intervals (CALIPER), a collaborative effort between the clinical laboratory at SickKids and hospitals across Canada. Adeli’s paper, “Closing the Gaps in Pediatric Laboratory Reference Intervals: A CALIPER Database of 40 Biochemical Markers in a Healthy and Multiethnic Population of Children”, published in Clinical Chemistry, was recently recognized as one of the top three clinical papers to be published at SickKids in 2012.

“There hasn’t been a lot of uniformity around laboratory testing for children. For example, there is no information available as to what represents a healthy level of cholesterol if you’re a five-year-old Caucasian child. The reference is not well-established, which is surprising but true. We’re addressing this problem. This is not just a Toronto or Canadian problem, this is a world-wide problem,” says Prof. Adeli.

Creating a comprehensive database isn’t easy. Prof. Adeli’s team of 60 volunteers sets up clinics and also travels to local schools to take blood samples from healthy children ranging in age from birth to 18 years. They recently collected 172 samples in one day at an elementary school, bringing the total number of participants in CALIPER to almost 6,000 children. Once samples are collected, they are tested for levels of particular chemistry, endrocrine, fertility, and, in an upcoming study, cancer markers. The team’s biostatistician then performs analysis to define reference intervals for children from birth to 18 years.

The team now has data for over 100 different tests that cover a broad range of diseases and medical conditions in children. These tests are used for analysis of a variety of issues including cancer risk, kidney function, cardiovascular health and liver disease. Prof. Adeli explains, “These tests are having a major impact on the treatment and monitoring of children. They cover a large number of diseases that are routinely done, so this is applicable to the day-to-day care of kids in hospitals, clinics and the community.”

Since his landmark publication in 2012, Prof. Adeli continues to develop this initiative and has recently published another paper in Clinical Biochemistry and two more in Clinical Chemistry. With these publications he has expanded the reference interval database, but the work continues. “Our goal is quite ambitious. Our goal is to have reference values for children for almost all tests that are being used to monitor children. We’re not there yet but we’re getting close to covering all of the tests.”

What’s on the horizon? Prof. Adeli is working on a CALIPER mobile application, which will allow physicians across the country convenient access to the database. “We’re really excited about this initiative and we want our results to be as accessible as possible. We’re hoping that our research and the application can be used anywhere in the world.”