XMRV Data Reviewed at AABB Annual Meeting

By K. Kimberly McCleary, President & CEO

The AABB is holding its annual meeting in San Diego this weekend where 6,000 blood banking professionals, scientists and physicians are gathered to hear the latest information of importance to blood safety. The organization, formerly known as the American Association of Blood Banks, now uses just the acronym because of its expanded mission to advance safe transfusion and cellular therapies.

With two years of study of XMRV as a potential threat to the blood supply, blood banking professionals in many countries including the United States have responded with new guidelines and research studies designed to evaluate the possible risk to blood donors and recipients of blood and other cellular therapies derived from blood. The AABB formed two task forces, the (blood) Interorganizational XMRV Task Force and an XMRV Task Force on Cellular Therapies. The American Red Cross, America’s Blood Centers, two blood collection organizations in Canada, as well as the National Institutes of Health, Centers for Disease Control & Prevention, Food and Drug Administration and several scientists from academic centers are active on these committees. I serve as a member of both groups and have helped to inform discussions focused on XMRV with a broader understanding of the biology of CFS, including other viral links, and the literature as a whole.

There will be three XMRV-related topics discussed at this year’s AABB annual meeting.

Michael Busch, MD, PhD, of Blood Systems Research Institute

Session:
Update on Bugs of Current Focus
Speakers: Michael Busch, MD, PhD; David Leiby, PhD; Bryan Spencer, MPH
Objectives:
   • Review current approaches to mitigating risk for transfusion-transmitted malaria.
   • Discuss the current efforts at mitigating risk of transfusion-transmitted babesiosis.
   • Determine the current status of XMRV as a human pathogen and emerging transfusion-transmitted diseases.
This session will update attendees on current and possible future risks of known and emerging infections in the blood supply. Current and potential future risk mitigation strategies for three infectious agents will be discussed.

Session:
Transfusion-Transmitted Infectious Diseases: Miscellaneous Viruses
Moderators: Michael Busch, MD, PhD; Margaret Fearon, MD
Objectives:
   • Learn about the projected impact of a potential travel deferral of blood donors to mitigate dengue transmission risk in the U.S. and respective yields of an investigational antigen test vis-à-vis dengue NAT screening in blood donors.
   • Relate new findings on lack of evidence of XMRV transmission via blood transfusion to published prior reports and the controversy surrounding this retrovirus.
   • Describe the relationship between duration and level of viremia to symptomatic disease in persons infected with West Nile virus and relate these findings to sample type assayed (whole blood vs. plasma).

Roger Dodd, PhD of the American Red Cross

Presentation of Research Results:
No Serologic Evidence of Transmission of XMRV By Transfusion Using A Linked Donor-Recipient Repository
Authors: Roger Y. Dodd, Susan L. Stramer, Kerri Dorsey, E Moritz, Shimian Zou, Yanyun Wu, Xiaoxing Qiu, Pricilla A. Swanson, Gerald Schochetman and John R. Hackett, Jr.

A manuscript describing the results of the above study, conducted as a collaboration between the American Red Cross, Abbott Diagnostics, Gen-Probe Inc. and Yale University School of Medicine, has been accepted for publication publication in the journal Transfusion. We have received permission from the authors to provide a brief summary of the results of that study, as presented at the AABB meeting earlier this evening.

The study’s objective was to determine the prevalence of XMRV infection in U.S. blood donors and to examine the risk of transfusion transmission. Two populations of routine blood donor samples were used. One included 1,435 samples and the other included 13,399 samples. Samples from a repository that linked donors’ samples to recipients of those blood donations were also tested. The presence of antibodies to XMRV-recombinant antigens were tested for XMRV RNA using validated, high-throughput systems developed by Abbott Diagnostics and Gen-Probe. Both companies’ tests were used in the Blood XMRV Scientific Research Working Group (SRWG) study and were highly sensitive.
Using criteria established for the antibody tests, they did not find any evidence of confirmed XMRV/MLV antibodies among 17,140 blood donors. There was no detectable XMRV RNA in 1,435 routine blood donation samples, in any sample with isolated antibody reactivity, in donation samples that are positive for HTLV antibodies, or from 830 samples collected from 109 highly transfused recipients. The investigators did find a low frequency of antibodies to individual XMRV/MLV recombination antigens in some donors and recipients; however, antibody positivity could not be confirmed by the presence of all three antibody markers and no recipient tested RNA positive. Further testing led to the conclusion that “whatever the origin of the isolated and uncomfirmed antibody reactivity observed, these were not attributable to transfusion-transmitted XMRV/MLV.” They concluded with a statement that, “the findings of our study, coupled with the prior studies that did not confirm any association of XMRV/MLV with human disease, indicate that these viruses do not currently pose a threat to blood recipients or to public health.”

UPDATE: This study was published ahead of print on Nov. 21, 2011 in Transfusion:
Xenotropic murine leukemia virus–related virus does not pose a risk to blood recipient safety
Roger Y. Dodd, John Hackett Jr, Jeffrey M. Linnen, Kerri Dorsey, Yanyun Wu, Shimian Zou, Xiaoxing Qiu, Priscilla Swanson, Gerald Schochetman, Kui Gao, James M. Carrick, David E. Krysztof, Susan L. Stramer

The SRWG study originally included four phases, the fourth of which would have tested existing blood donor repositories for evidence of XMRV and MLV. The third phase results, as published in Science on Sept. 22, led to agreement that the fourth phase would not be necessary; it was also known that the American Red Cross had initiated this study independent from the SRWG, involving many of the same teams as were participating in the SRWG. So, in effect, this Red Cross-initiated study completes the SRWG mission.

Additional details about the study design, methods and findings will be available upon publication of the paper in Transfusion. We thank our colleagues at the American Red Cross and their collaborators for the proactive effort to conduct this study.

The American Red Cross and America’s Blood Centers continue to adhere to the AABB guidance to defer blood donors who have a history of or current diagnosis of CFS. The CFIDS Association of America has long discouraged individuals with CFS (past or present) from donating blood, tissues or organs, out of concern for both the donor and the recipient in light of the large number of infectious agents that have been associated with CFS over the years, and the common problems associated with orthostatic intolerance that can be aggravated by the loss of blood and fluid volume. The AABB guidelines will be reviewed again upon results of the other multicenter study of XMRV and related viruses being led by Dr. Ian Lipkin of Columbia University. This study has not yet begun and results are not expected to be available until later next year.

K. Kimberly McCleary has served as the Association’s chief staff executive since 1991.

Media coverage of the Red Cross-Abbott-GenProbe study:

“Controversial new virus tied to fatigue not transmitted by blood,” by Michelle Fay Cortez, Bloomberg News (Oct. 22, 2011)
“Scientists say XMRV poses no risk to the blood supply,” by Amy Dockser Marcus, Wall Street Journal (Oct. 24, 2011)

Updated Nov. 21, 2011 at 9:25 a.m. to include publication of Red Cross study in Transfusion.

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