graft versus host disease
Creative Minds: Taking Aim at Adverse Drug Reactions
Posted on by Dr. Francis Collins
Sherrie Divito
As a practicing dermatologist, Sherrie Divito sees lots of patients each week at Brigham and Women’s Hospital, Boston. She also sees lots of research opportunities. One that grabbed her attention is graft-versus-host disease (GvHD), which can arise after a bone-marrow transplant for leukemia, lymphoma, or various other diseases. What happens is immune cells in the donated marrow recognize a transplant patient’s body as “foreign” and launch an attack. Skin is often attacked first, producing a severe rash that is a harbinger of complications to come in other parts of the body.
But Divito saw something else: it’s virtually impossible to distinguish between an acute GvHD-caused rash and a severe skin reaction to drugs, from amoxicillin to carbamazepine. In her GvHD studies, Divito had been researching a recently identified class of immune cell called tissue-resident memory T (Trm) cells. They remain in skin rather than circulating in the bloodstream. The clinical similarities made Divito wonder whether Trm cells may also help to drive severe skin allergies to drugs.
Divito has received a 2016 NIH Director’s Early Independence Award to find out. If correct, Divito will help not only to improve the lives of thousands of people with GvHD, but potentially benefit the millions of other folks who experience adverse reactions to drug.
Regenerative Medicine: Making Blood Stem Cells in the Lab
Posted on by Dr. Francis Collins
Caption: Arrow in first panel points to an endothelial cell induced to become hematopoietic stem cell (HSC). Second and third panels show the expansion of HSCs over time.
Credit: Raphael Lis, Weill Cornell Medicine, New York, NY
Bone marrow transplants offer a way to cure leukemia, sickle cell disease, and a variety of other life-threatening blood disorders.There are two major problems, however: One is many patients don’t have a well-matched donor to provide the marrow needed to reconstitute their blood with healthy cells. Another is even with a well-matched donor, rejection or graft versus host disease can occur, and lifelong immunosuppression may be needed.
A much more powerful option would be to develop a means for every patient to serve as their own bone marrow donor. To address this challenge, researchers have been trying to develop reliable, lab-based methods for making the vital, blood-producing component of bone marrow: hematopoietic stem cells (HSCs).
Two new studies by NIH-funded research teams bring us closer to achieving this feat. In the first study, researchers developed a biochemical “recipe” to produce HSC-like cells from human induced pluripotent stem cells (iPSCs), which were derived from mature skin cells. In the second, researchers employed another approach to convert mature mouse endothelial cells, which line the inside of blood vessels, directly into self-renewing HSCs. When these HSCs were transplanted into mice, they fully reconstituted the animals’ blood systems with healthy red and white blood cells.
