Donor-Derived Disease Transmission Events in the United States: Data Reviewed by the OPTN/UNOS Disease Transmission Advisory Committee
Ison MG, Hager J, Blumberg E, et al
Am J Transplant. 2009;9:1929-1935. Epub 2009 Jun 16
Transplantation of Kidneys From Donors at Increased Risk for Blood-Borne Viral Infection: Recipient Outcomes and Patterns of Organ Use
Reese PP, Feldman HI, Asch DA, et al
Am J Transplant. 2009; 9: 2338-2345. Epub 2009 Aug 21
Summary
The first study, a summary of the newly created United Network for Organ Sharing (UNOS) Disease Transmission Advisory Committee (DTAC), retrospectively reviewed all potential donor-derived transmission events that were reported from January 1, 2005 through December 31, 2007. According to the summary, such events increased from 7 in 2005 to 60 in 2006 and to 97 in 2007. In 2007, there were 9 reported recipient deaths attributable to proven donor transmission events from 8 donors. There were 4 proven and 1 possible malignancies and 4 proven, 2 probable, and 6 possible infectious diseases due to donor-derived transmissions. Although transmission was reported in only 0.96% of deceased donors overall, improved recognition, mandatory reporting, and enhanced communication may provide a better estimate of the true incidence of donor-derived transmission events.
The second study is a retrospective UNOS registry analysis of kidney transplantation from deceased donors classified as high risk for transmission of viral infection by the Centers for Disease Control and Prevention (CDC) according to 1994 guidelines. From August 1, 2004 to August 1, 2006, 48,054 adults were added to the kidney transplant waiting list and 7016 (14.6%) received standard criteria donor (SCD) kidney transplants, 671 (1.4%) received kidneys from CDC high-risk donors, 1936 (4.0%) received expanded criteria donor (ECD) kidneys, and 794 (1.7%) received kidneys from cardiac death donors (DCD). After censoring for living donors, hepatitis B- or C-positive donors, ECD/DCD donors, ECD/CDC, and DCD/CDC donors, a multivariable Cox regression analysis determined that recipients of SCD/CDC kidneys did not experience any differences in mortality or graft loss compared to SCD kidney recipients from non-CDC high risk donors. Among transplant centers performing > 10 transplants during the study period, the median proportion of CDC/total transplants was 7.2% (range, 1.1%-35.6%), with higher volume centers more likely to transplant higher proportions of kidneys from CDC high-risk donors. An analysis of recovered kidneys revealed that 6.8% of SCD vs 7.8% (P = .13) of CDC high-risk kidneys were discarded. Based on this analysis, the authors concluded that center use of kidneys from CDC high-risk donors varies widely, although SCD kidney recipients experienced good short-term outcomes.
Viewpoint
The UNOS DTAC core tasks include estimation of the risk of donor-derived disease transmission, accumulation of evidence necessary for this estimation through review of cases reported to UNOS, provision of initial notification to public health agencies when there are suspected transmission of reportable diseases, reporting of aggregate findings to the transplant community, and provision of recommendations to the Organ Procurement and Transplantation Network (OPTN) on policy with the goal of reducing donor-derived transmission events. Recent high-profile transmissions include human immunodeficiency virus (HIV), hepatitis C virus, lymphocytic choriomeningitis virus, West Nile virus, rabies, Chagas disease, tuberculosis, leukemia, and lymphoma. The DTAC has devised a classification scheme for determining the likelihood of the transmission event being donor-derived and includes proven, probable, possible, and excluded categories. Any case that is classified as proven, probable, or possible is further categorized as confirmed.
The first study discussed is the first formal DTAC report of potential disease transmission cases reported to the OPTN. The second study is an attempt to characterize the scope and magnitude of kidney utilization from donors at high risk for viral transmission. Unfortunately, the CDC guidelines, published in 1994, included a list of behavioral and clinical characteristics (such as intravenous drug use) that identifies donors thought to be at increased risk for recent bloodborne viral infections. However, this definition of a "high-risk CDC" donor is now outdated and applies only to HIV transmission. New CDC high-risk structured guidelines are being formulated with a focus on bloodborne pathogens, such as hepatitis B and C as well as HIV. The diagnosis of donor-transmitted infections requires suspicion on the part of the caregivers, utilization of newer diagnostic tools, and coordination of epidemiologic investigations with communication between medical centers, organ procurement organizations, regulatory, and public health agencies. To this end, the CDC has recently announced plans to develop and operate a Transplantation Sentinel Network that is charged to detect and prevent the transmission of diseases to transplant recipients by means of donor organs and tissues.