Although bone marrow transplants have long been standard for acute leukemia, current treatments still rely on exact matches between donor and patient.
Now, scientists at the University of Perugia, Italy, and the Weizmann Institute of Science have improved on a method of transplanting bone marrow-based stem cells from a mismatched donor, making it safer for use when no exact match exists. They were invited to present their findings at the recent annual American Society of Hematology conference in New Orleans.
More than a decade ago, Prof. Yair Reisner of the Weizmann Institute's Immunology Department pioneered a method for transplanting stem cells from family members who are a partial match. Based on these studies (in mice), he joined forces with Prof. Massimo F. Martelli, Head of the Hematology and Clinical Immunology Section at the University of Perugia, to demonstrate in more than 300 patients that the cure rate of these so-called "mega dose" transplants is similar to that of transplants from matched, unrelated donors picked from international bone marrow donor registries. To combat the body's tendency to reject the foreign cells, these stem cells are stripped of immune cells called T cells and given in high doses that overwhelm the host's own immune system.
Although removing donor T cells from the bone marrow reduces the risk of graft-versus-host disease - caused when the T cells attack the recipient's tissues - the immune system is slow to recover after the transplant, leaving the patient at risk of serious infection. Doctors are faced with a difficult choice: Either remove the T cells from the bone marrow, increasing the risk of infection, or leave the T cells in the graft, putting the patient at risk for lethal graft-versus-host disease.
Martelli, working with Reisner, has now found a way to facilitate the recovery of the immune responses in recipients of T cell-depleted bone marrow transplants. In a clinical trial, 25 of 26 leukemia and lymphoma patients who received mismatched mega dose T cell-depleted stem cell transplants from relatives showed prompt immune recovery, and their immune systems were functioning well several months later.
The scientists knew that certain regulatory T cells (T regs), rather than causing graft-versus-host disease, could actually help to prevent it in mice. T regs have also been shown to keep other immune responses in check, including preventing autoimmune attacks on the body's own cells. In the present study, after purifying T regs from the donor's blood, the cells were infused intravenously into the cancer patients, who had previously undergone standard radiation and chemotherapy treatments. Three days later, the patients received the donor stem cells, along with another kind of T cell - those that fight disease.
The patients who underwent this procedure showed quick, lasting improvements in immune activity; most experienced no symptoms even though they received large doses of the T cells that are generally associated with lethal graft-versus-host disease.
Further follow up on these patients and additional clinical trials will be needed before the procedure can be widely adopted. But these results strongly suggest that T regs used in mega-dose stem cells will further enhance the cure rate for bone marrow transplant patients without a matched donor in the family.Prof. Yair Reisner's research is supported by the M.D. Moross Institute for Cancer Research; the Kirk Center for Childhood Cancer and Immunological Disorders; the Mario Negri Institute for Pharmacological Research Weizmann Institute of Science Exchange Program; the Gabrielle Rich Center for Transplantation Biology Research; the Russell Berrie Foundation; and Mr. and Mrs. Seymour Spira, Palm Beach Gardens, FL.
Prof. Reisner is the incumbent of the Henry H. Drake Professorial Chair in Immunology.
The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials and developing new strategies for protecting the environment.
Weizmann Institute news releases are posted on the World Wide Web at http://wis-wander.weizmann.ac.il, and are also available at http://www.eurekalert.org.
Yivsam Azgad | idw
First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife
Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering