A new marker for osteoarthritis
Osteoarthritis (OA) is a common, crippling age-related disease characterized by the gradual destruction of cartilage cushioning the joints. To assess cartilage erosion, doctors routinely rely on measurement of the joint space width using radiographs. To be visible on an X-ray film, however, significant cartilage degradation must have already occurred. By the time radiographs reveal destruction, the damage to the joint is usually irreversible. Due to this method’s relatively insensitive nature, it also takes at least a year or two to detect progression of damage that has been captured on radiographs.
To improve the early diagnosis and effective treatment of OA, medical researchers have turned to the promise of biochemical markers – molecules released into bodily fluids during the process of tissue turnover. Recently, researchers in the Netherlands identified a novel marker linked to both the prevalence and the progression of OA, particularly at the knee and the hip. They share their breakthrough findings in the August 2004 issue of Arthritis & Rheumatism.
Building on the analysis of cartilage metabolism, the researchers concentrated on peptide fragments of type II collagen. Since type II collagen is located almost exclusively in cartilage, a fragment – abbreviated as CTX-II – was seen as a potential marker for cartilage destruction. To determine the relationship between CTX-II and OA, researchers drew on a large, established sample: 1,235 men and women ages 55 and older enrolled in the Rotterdam Study, a long-term research effort to investigate the incidence of, and risk factors for, chronic disabling diseases. Researchers followed up with participants, whose average was 66, over a time span of six-and-a-half years.
At the study’s onset, 19 percent of the subjects had clear radiographic evidence of OA in at least one knee; 10 percent had OA in at least one hip. At baseline, urine samples from all subjects were assessed for the concentration of CTX-II. The participants were then divided into four groups for further evaluation and continued monitoring, according to their levels of CTX-II.
According to the researchers’ calculations, subjects with a CTX-II level in the highest quartile had a 4-fold increased risk of developing OA in either the knee or hip compared with subjects in the lowest quartile. During the follow-up period, confirmed by repeated radiographs, subjects with the highest concentration of CTX-II were significantly more likely to experience rapid, destructive progression of OA – 6 times more likely at the knee and 8 times more likely at the hip. The subjects with the highest CTX-II levels also had the highest complaints of joint pain. In addition, the researchers found a slight rise in CTX-II concentration with increasing age among women. However, the strong correlation between CTX-II and both the incidence and severity of OA was shown to be independent of age, sex, and body mass index.
"This is the first large follow-up study in which the use of CTX-II as a biomarker for cartilage degradation and disease progression has been investigated," emphasizes the team’s leading researcher and spokesperson, M. Reijman, MSc. "Based on the results, we conclude that the CTX-II concentration is markedly associated with the prevalence and progression of OA of the knee and hip, and that these associations are independent of known risk factors for radiographic OA. The presence of joint pain seems to augment this relationship," he notes, "which might reflect the effects of an ongoing OA process. The increase of CTX-II in women after menopause may reflect a protective effect of estrogen against cartilage loss. Further research is necessary to establish the clinical utility of this novel biomarker for OA."
David Greenberg | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Rice University researchers test 3-D carbon nanostructures' thermal transport abilities
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...