Researchers at Rush University Medical Center have identified a key immunological defense reaction to the metals in joint replacement devices, leading to loosening of the components and early failure.
The study, funded by the National Institutes of Health, won the annual William H. Harris, MD Award for scientific merit from the Orthopaedic Research Society. Currently posted online, it is expected to be published in the June issue of the Journal of Orthopaedic Research.
Over 600,000 total joint replacements are performed in the United States each year. The vast majority are successful and last well over 10 years. But in up to 10 percent of patients, the metal components loosen, requiring the patient to undergo a second surgery.
The loosening is often caused by localized inflammation, an immune reaction to tiny particles of debris from the components themselves as they rub against one another. No infection is involved.
"As soon as joint replacement devices are implanted, they begin to corrode and wear away, releasing particles and ions that ultimately signal danger to the body's immune system," said Nadim Hallab, associate professor at Rush University Medical Center and the study author.
There are two different types of inflammatory pathways: one that reacts to foreign bodies like bacteria and viruses, which cause an infection, and another that reacts to "sterile" or non-living danger signals, including ultraviolet light and oxidative stress.
This is the first time that researchers have shown that debris and ions from implants trigger this danger-signaling pathway.
According to Hallab, when specialized cells of the immune system, called macrophages, encounter this metallic debris, they "engulf it in sacs called lysosomes and try to get rid of the debris by digesting it with enzymes." But the particles damage the lysosomes, Hallab said, "and the cells start screaming 'danger.'"
These danger signals are detected by large complexes of proteins, called inflammasomes. The inflammasomes mobilize, precipitating a chain of chemical events that cause inflammation.
The researchers are hopeful that identification of this molecular pathway that triggers inflammation without infection could lead to new and specific therapeutic strategies to avoid the early failure of joint replacements.
Other researchers at Rush involved in the study were Marco Caicedo, Ronak Desai, Kyron McAllister, Dr. Anand Reddy, and Dr. Joshua Jacobs.
Sharon Butler | EurekAlert!
Further reports about: > Immune cell activation > Orthopaedic > bacteria > body's immune system > danger-signaling pathway > immune reaction > immune system > immunological defense reaction > inflammation > joint replacement devices > lysosomes > metal debris > oxidative stress > ultraviolet light > viruses
Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University
The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy