Screening Test for Liver Disease in Children May Be Unreliable
Upper threshold of the test used for screening in children's hospitals may be too high to be useful
MONDAY, April 5 (HealthDay News) -- The upper limit of the test most commonly used to screen children for chronic liver disease varies widely from one children's hospital to another, and is set so high that it may not reliably detect the disease, according to research published in the April issue of Gastroenterology.
Using data from the National Health and Nutrition Examination Survey, Jeffrey B. Schwimmer, M.D., of the University of California, San Diego School of Medicine, and colleagues established gender-specific, biology-based pediatric thresholds for alanine aminotransferase (ALT) for the diagnosis of nonalcoholic fatty liver disease, hepatitis C or hepatitis B. They compared the sensitivity and specificity of ALT thresholds currently used in children's hospitals to the thresholds they developed.
The researchers found the median upper limit of ALT at children's hospitals to be 53 U/L; the 95th percentile ALT levels in healthy children were 25.8 U/L in boys and 22.1 U/L in girls. Using the current ALT thresholds used by children's hospitals, median sensitivity for detection of nonalcoholic fatty liver disease, hepatitis B and hepatitis C ranged from 32 to 48 percent, and median specificity was 92 percent in boys and 96 percent in girls. Using the thresholds the researchers developed, median sensitivity was 72 percent in boys and 82 percent in girls, and median specificity was 79 percent in boys and 85 percent in girls.
"In conclusion, upper-limit-of-normal values widely used for ALT in children are too high to reliably detect chronic liver disease," the authors write. "We propose that there be a re-examination of laboratory thresholds used for children. Studies in varied populations will be needed to prospectively test these values for the ability to determine the presence and absence of liver disease."