Blood stem cell transplant patients fight off infection by a common but dangerous virus better if their donors appear immune to that virus, according to City of Hope researchers. The results bolster the case for boosting donor immunity prior to transplantation.
 Don Diamond (Photo ©2007 Philip Channing) |
Researchers led by Don J. Diamond, Ph.D., professor and director of the Division of Translational Vaccine Research, found that hematopoietic cell transplant recipients needed less therapy to battle cytomegalovirus, or CMV, infection following their procedures when the donors’ cells were primed to fight the virus.
CMV, a type of herpes virus, infects more than half of all U.S. adults, but most show few symptoms. But people with suppressed immune systems, including those who take immunosuppressant drugs to control rejection after bone marrow or organ transplant, cannot keep the virus in check and can develop a fatal form of pneumonia.
The research team followed 178 transplant patients treated in the Department of Hematology & Hematopoietic Cell Transplantation who showed signs of CMV infection. Of those, 50 received stem cells from donors that had little or no immunity to the virus, and 128 received cells from donors with elevated immune response.
The researchers saw that, on average, the recipients of immune-ready cells required antiviral therapy for a shorter time and were less likely to need to repeat it.
 Electron microscopy shows cytomegalovirus infection in the lungs. (Image courtesy CDC/Dr. Edwin P. Ewing Jr.) |
“The results held true even when we adjusted for other factors,” such as post-transplant complications and treatments that can increase CMV risk, said Diamond.
In addition, the researchers looked at the fortunate 128 transplant recipients’ infection-fighting T cells for molecular evidence that their immune systems were, in fact, stronger. They found that evidence, marking the first time researchers have done so.
The findings suggest that priming a donor’s immune system to fight CMV before a transplant can help the recipient fight off the virus. Diamond, who leads a clinical study testing a pretransplant donor vaccine against CMV, believes the study supports the need for improving donor immunity to CMV.
“Our hypothesis has been that we can reduce CMV-related complications and mortality by vaccinating donors,” he said. “This is another strong indicator that we’re on the right track.”
The Bea and Edwin Wolfe Charitable Trust supported the purchase of equipment used in the research. Study findings appeared in the June 18 issue of the journal Blood. Other researchers on the study include Wendi Zhou, M.D., Ph.D., Jeff Longmate, Ph.D., Simon F. Lacey, Ph.D., Joycelynne M. Palmer, Ph.D., Ghislaine Gallez-Hawkins, Lia Thao, Ricardo Spielberger, M.D., Ryotaro Nakamura, M.D., Stephen J. Forman, M.D., and John A. Zaia, M.D.