Every three minutes someone in the United States is diagnosed with leukemia, lymphoma, or myeloma (cancer of the blood, bone marrow, and lymph nodes).
Treating blood cancers often requires stem cell transplants, but these cells can mount a deadly immune attack on a patient's organs, a condition known as graft-versus-host disease (GVHD). With a $2.75 million grant from the National Institutes of Health, Phung Nguyen, a research scientist at the University of California, San Francisco School of Medicine, is studying how diet, particularly fat, affects GVHD in transplant patients.
The disease comes in two forms: acute GVHD usually develops soon after transplant and can cause liver and digestive problems, painful rashes, and even organ failure. Chronic GVHD can develop months or years after transplant. Symptoms vary from patient to patient and can range from mild, such as dry eyes and fatigue, to irreversible organ damage. In some chronic patients, symptoms progress quickly from mild to severe.
“Stem cell transplants from donors have increased the life expectancy of these cancer patients, but they are not without risks,” Nguyen says. “If the donor cells recognize the recipient's organ as foreign, chronic graft-versus-host disease can develop.”
Previous studies have shown that diets high in long-chain fatty acids, such as fats, olive oil, and soybean oil, increase infections, length of hospital stay, respiratory distress syndrome, and systemic inflammation in patients with GVHD, so Nguyen is looking more closely at the role of fatty acids in inflammation and transplant rejection.
His team will study how medium-chain fatty acid foods such as coconut oil and avocado affect the metabolism of donor cells in patients with chronic GVHD. He believes that dietary treatment could reduce or prevent the inflammatory response, reducing patients' need for corticosteroids, which have limited effectiveness in preventing permanent organ damage.
“The goal of our current research project is to understand how medium-chain fatty acid metabolism influences GVHD severity and mortality,” he said.
Blood cancers account for approximately 10% of cancers diagnosed in the country each year.
Nguyen was awarded a competitive R01 grant and will be funded over five years by the NIH's National Heart, Lung, and Blood Institute. He is collaborating with Stephanie Li of the Fred Hutchinson Cancer Center in Seattle and Nosha Farhadfar of the University of Florida.
