A protein detectable in urine might serve as a “biomarker” for appendicitis, revealed by researchers at the Proteomics Center at Children’s Hospital Boston.
Their report was published online June 23 by the Annals of Emergency Medicine.
Appendicitis is the most common childhood surgical emergency, but the diagnosis can be challenging, especially in children, often leading to either unnecessary surgery in children without appendicitis, or a ruptured appendix and serious complications when the condition is missed. Recent figures indicate that 3 to 30 percent of children have unnecessary appendectomies, while 30 to 45 percent of those diagnosed with appendicitis already have a ruptured appendix.
Researchers led by Richard Bachur, MD, acting chief of emergency medicine at Children’s Hospital Boston, Hanno Steen, PhD, director of the Proteomics Center, and clinical fellow Alex Kentsis, MD, PhD, decided to take a systematic approach, performing a proteomics study using state-of-the are mass spectrometry (a technique that detects and quantifies proteins in a sample). Their two-part study has identified the most accurate biomarker for acute appendicitis known to date.
Researchers examined bio markers in 67 children seen at the hospital for suspected appendicitis over an 18-month period, 25 of whom ultimately had proven appendicitis. Seven promising urine biomarkers were identified. The best of them was leucine-rich alpha-2-glycoprotein (LRG), which appears to be a specific marker of local inflammation.
LRG was strongly elevated in diseased appendices, even when those appendices appeared normal on imaging, and the amount of LRG correlated with the severity of the appendicitis as judged by histologic review of the appendix specimens. Although mass spectrometry isn’t widely available clinically, urine LRG elevations were detected by immunoblotting, suggesting that a rapid clinical test, such as a urine dipstick, could be developed through further research.
The researchers note that since their study was limited to children, and that patterns of biomarkers likely vary in older patients, LRG testing would need to be studied in other clinical settings.
Source: Children’s Hospital Boston, USA