ShareThisUrine tests, that diagnostic standby that already reveals everything from drug use to pregnancy, are being proposed for a growing number of new medical applications.
Researchers are regularly expanding the list of telltale proteins and metabolic markers that can be detected in urine samples to help diagnose illness and even predict how different individuals may respond to treatments.
A Children's Hospital Boston, scientists have found a protein detectible in urine that could serve as a diagnostic marker for appendicitis.
Such a test could fill an important void in detecting a dangerous condition that's often missed in kids, despite advances in imaging with computerized tomography and ultrasound.
Experts say medical imaging and other tests still result in 3 percent to 30 percent of pediatric appendix patients having needless surgery, while 30 percent to 45 percent of children diagnosed with the condition have had their appendix burst before surgery, raising the risk of complications.
So the effort led by Dr. Richard Bachur, acting chief of emergency medicine at the hospital, to identify a dependable biomarker for an inflamed appendix has the potential to not only reduce the severity of illness, but also protect children from needless, expensive surgery.
The team started with a candidate list of 57 potential biomarkers found by screening urine specimens for proteins, gene expression studies and other tests, then narrowed the field with additional tests on 67 children admitted to the hospital with suspected appendicitis over an 18-month period.
The best marker, called LRG, was elevated in almost all of the 25 confirmed appendicitis cases, even when they appeared normal in imaging studies, and the levels increased with the severity of the condition.
Bachur and his colleagues are now trying to simplify tests for the protein and further validate their findings. And they note that while the marker appears to be a solid sign of appendicitis in children, it may not turn out to be a valid test in older patients.
In Britain, Cambridge doctors backed by the Wellcome Trust recently reported results of a trial of a new diagnostic test for sexually transmitted Chlamydia infection in men, which can give results in an hour.
That's important, because male patients involved in the experiment said they were willing to wait that long to find out if they were infected and then take the standard one-dose antibiotic while they were still in the clinic.
The technique, which includes a special urine collection system, was found to be more accurate than any other urine-based tests for the infection, and superior to the standard sampling that requires use of urethral swabs.
Other British researchers, this time from the Imperial College London and Pfizer, say analysis of urine samples could soon be able to predict how an individual will respond to particular drugs.
They found that various levels of metabolites -- byproducts of metabolism -- can indicate how the body will absorb and react to a drug.
The study worked with 99 men, aged 18 to 64, who took one dose of the common painkiller acetaminophen. The researchers took urine samples from the men before they took the drug and for six hours afterward to track metabolites.
The researchers determined that a compound called para-cresol sulphate, produced by bacteria in the intestines, was an indicator of how the men would metabolize the drug.
Jeremy Nicholson, a professor of bimolecular medicine and senior author, said lab studies had suggested that pre-dose metabolic profiles might be useful in drug dosing, "but this is the first time we've been able to show convincingly that it will work in humans."
The researchers say such metabolic profiling should allow drug companies seeking to personalize medicines to consider not only genetics, but also a person's digestive environment when trying to match treatments to individual requirements and avoid adverse side effects.
(Contact Lee Bowman at BowmanL(at)shns.com)
(Distributed by Scripps Howard News Service, http://www.scrippsnews.com)
The Medical Journal
