"I drink too much. The last time I gave a urine sample it had an olive in it," said the late Rodney Dangerfield. And while the comic bemoaned, "I get no respect," not so of the urine that sprinkled his joke.
Urine, in diagnostic circles, is elevated to rarified status. Sue Selgren, marketing manager at Siemens, summed it up, "Urine testing remains a simple, painless and cost effective way to gain significant information about a patient." She also noted that changes through the years have made for a more effective process. "Previously, 24-hour urine collections were needed to provide a precise measurement of urine albumin and protein. But collection of a timed urine sample is inconvenient and associated with errors, largely due to improper timing and missed samples," said Selgren. "Now our urinalysis strips include a urine creatinine test that corrects for varying urine concentration to assist in early detection of kidney disease."
This year has yielded more than a few headlines for the continued importance of urine testing. Here are some of the highlights from 2012.
Urine Test With PSA
A new urine test developed at the University of Michigan, when used with PSA, can eliminate unnecessary prostate biopsies and reduce overtreatment. The prostate cancer-specific test uses genetic biomarkers - TMPRSS2:ERG gene fusion and PCA3 DNA - common in most prostate cancers and detectible in a simple urine test.
According to test developers Scott Tomlins, MD, PhD, and Arul Chinnaiyan, MD, PhD, patients with low levels of these genetic fingerprints have only a 20% chance of being diagnosed with prostate cancer and their chance of having a high-risk cancer is less than 10%. Conversely, patients with high levels of the two biomarkers in their urine have an 80% chance of having cancer with a 50% risk of having a high-grade cancer, according to information supplied by the university. The test is available at the University of Michigan Comprehensive Cancer Center with expectation of wider availability coming.
Similarly, the Fred Hutchinson Cancer Research Center, Seattle, has offered initial results of a multicenter study indicating that two investigational urine-based biomarkers associated with prostate cancers can help signal aggressive, life-threatening cancers. The study is one prong of the Canary Prostate Active Surveillance Study, focused on identifying and validating biomarkers of high-risk prostate cancer.
Scientists from the University of Washington and Battelle Centers for Public Health Research and Evaluation have identified metabolites in urine that potentially could predict young children at risk of developing autistic spectrum disorder (ASD). The findings, published in Autism Research, revealed that certain kinds of porphyrins are much higher in the urine of some children with autism, compared with non-autistic children of the same age. When children with autism were randomly compared with typically developing children or children with other developmental disorders, the porphyrin biomarkers correctly identified more than 30% of autistic children without incorrectly identifying a single non-autistic child.
Urine tests could become a rapid, low-cost way to screen for this type of autism risk, resulting in earlier diagnosis and customized treatments.
Predicting Bone Fracture Risk
A urine test can indicate a premenopausal woman's risk of bone fracture, according to researchers from the University of Pittsburgh. Their findings, in the November edition of Menopause, suggest that above-normal levels of N-Telopeptide (NTX), a byproduct of bones breaking down, in women in their 40s and early 50s indicate a greater risk of bone fracture.
Women with a baseline NTX above the median were 59% more likely to have a fracture than those below the meridian. In addition, when women with high NTX levels also had a low spinal bone density measurement, their risk of fracture was three times higher.
Screening for Precancerous Polyps
The University of Alberta, Edmonton, Ontario, has developed a simple urine test to detect pre-cancerous adenomatous polyps in the colon. The non-invasive test is conducted using metabolomics, which detects and profiles the small molecule end products of cellular metabolism. The first version of this new metabolomics medical technology was tested on 1,200 patients and had an accuracy rate of 82%. A second version tested with 97% accuracy.
Test developer Richard Fedorak, MD, presented his findings in San Diego in May, before medical gastro-intestinal specialists. Though the test now requires nuclear magnetic resonance to detect the metabolites in frozen samples, Fedorak expects the final urine test, being commercialized by Metabolomic Technologies, will be read and analyzed by mass spectrometry machines.
Predictor of Renal Failure
Researchers at Henry Ford Hospital, Detroit, have used a urine test to search for excess protein - an effective marker of acute renal failure in patients with severe sepsis. Among patients with sepsis who had no prior history of protein in the urine, a urine dipstick test predicted the presence of renal failure in 55% of the patients. Results of the study were presented in May at the annual meeting of the National Kidney Foundation, Washington, DC. Investigators believe the test may allow early diagnosis of renal failure before substantial damage is done.
While research paves the way of the future, current trends in practice are also exciting. Erika Johnson, vice president of marketing, Iris Diagnostics, pointed toward increased use of automation and imaging in urine testing as positive game changers.
"We have combined urine strip chemistry and urine microscopy in an automated system that reduces hands-on time for the technologist and standardizes the test so that results are better," said Johnson. This is accomplished by the use of two integrated instruments, with results returned in a single report giving an overall picture of patient condition.
"If you run your strip chemistries separately from your microscopic exam, there can be cases where the two may not correlate," said Johnson. "When you combine the two results into one system, those occurrences are flagged. A technologist can see if something is wrong or should be repeated rather than sending off two discrepant answers to a clinician."
Automation technology also allows for captured images of all of the microscopic particles. "When you look at samples under a microscope and manually count the particles, you have no document later that you could show to a clinician if you were to question your results," said Johnson. "When you use a digital approach, those images can be stored digitally, sent to the clinician if he wants to take a look. That's the way medicine is going - digital, electronic records are the future. Imaging technology fits right in."
Selgren said Siemens' point-of-care urinalysis instruments now offer automated quality checks and connectivity in order to simplify data entry and integrate with practice management software. Johnson agreed that software improvements have added to the heft of automation. For example, Iris' iWARE allows the laboratory to customize software rules to their own quality parameters and incorporate patient demographics rather than applying more general overall thresholds or clinical decision points.
Valerie Neff Newitt is on staff at ADVANCE. Contact: email@example.com.