Uses and sources of data on long-term survival after blood transfusion

A policy case study of blood in Australia

In 2008 the Australian government decided to remove white blood cells from all blood products. This policy of universal leucodepletion was a change to the existing policy of supplying leucodepleted products to high risk patients only. The decision was made without strong information about the cost-effectiveness of universal leucodepletion. The aims for this policy analysis are to generate cost-effectiveness data about universal leucodepletion, and to add to our understanding of the role of evidence and the political reality of healthcare decision-making in Australia. The cost-effectiveness analysis revealed universal leucodepletion costs $398,943 to save one year of life. This exceeds the normal maximum threshold for Australia. We discuss this result within the context of how policy decisions are made about blood, and how it relates to the theory and process of policy making. We conclude that the absence of a strong voice for cost-effectiveness was an important omission in this decision.

Transfusion-related mortality: the ongoing risks of allogeneic blood transfusion and the available strategies for their prevention

As the risks of allogeneic blood transfusion (ABT)-transmitted viruses were reduced to exceedingly low levels in the US, transfusion-related acute lung injury (TRALI), hemolytic transfusion reactions (HTRs), and transfusion-associated sepsis (TAS) emerged as the leading causes of ABT-related deaths. Since 2004, preventive measures for TRALI and TAS have been implemented, but their implementation remains incomplete. Infectious causes of ABT-related deaths currently account for less than 15% of all transfusion-related mortality, but the possibility remains that a new transfusion-transmitted agent causing a fatal infectious disease may emerge in the future. Aside from these established complications of ABT, randomized controlled trials comparing recipients of non-white blood cell (WBC)-reduced versus WBC-reduced blood components in cardiac surgery have documented increased mortality in association with the use of non-WBC-reduced ABT. ABT-related mortality can thus be further reduced by universally applying the policies of avoiding prospective donors alloimmunized to WBC antigens from donating plasma products, adopting strategies to prevent HTRs, WBC-reducing components transfused to patients undergoing cardiac surgery, reducing exposure to allogeneic donors through conservative transfusion guidelines and avoidance of product pooling, and implementing pathogen-reduction technologies to address the residual risk of TAS as well as the potential risk of the next transfusion-transmitted agent to emerge in the foreseeable future.

Lack of evidence of transfusion transmission of Creutzfeldt-Jakob disease in a US surveillance study

BACKGROUND

Since 2004, several reported transfusion transmissions of variant Creutzfeldt-Jakob disease (vCJD) in the United Kingdom have reawakened concerns about the possible risk of similar transmissions of nonvariant or classic forms of CJD.

STUDY DESIGN AND METHODS

Patients with a CJD diagnosis and a history of donating blood were reported to the study coordinator. Through review of blood distribution and hospital records, the recipients of blood components from these donors were identified. We then determined each recipient's vital status and, if deceased, the cause(s) of death identified by matching the recipient's personal identifiers with the Centers for Disease Control and Prevention's National Death Index database. We conducted such searches after recipients were enrolled in this study and annually thereafter for those who remained alive.

RESULTS

The study included a total of 36 blood donors who subsequently developed CJD and 436 recipients. Through 2006, 91 of these recipients were still alive, 329 were deceased, and 16 were lost to follow-up. After transfusion, these three groups had survived a total of 2096.0 person-years. A total of 144 recipients survived 5 years or longer after transfusion and 68 of them had received blood donated 60 or fewer months before the onset of CJD in the donor. We identified no recipient with CJD.

CONCLUSIONS

The current results of this large, ongoing lookback study show no evidence of transfusion transmission of CJD. They reinforce the conclusion that the risk, if any, of transfusion transmission of prion disease by CJD donors is significantly lower than the comparable risk of such transmission by vCJD donors.

Hepatitis B virus DNA-positive, hepatitis B surface antigen-negative blood donations intercepted by anti-hepatitis B core antigen testing: the Canadian Blood Services experience

BACKGROUND

The benefit of introducing anti-hepatitis B core antigen (HBc) screening for intercepting potentially infectious donations missed by hepatitis B surface antigen (HBsAg) screening in Canada was studied.

STUDY DESIGN AND METHODS

Anti-HBc testing of all donations was implemented in April 2005, along with antibody to hepatitis B surface antigen (anti-HBs) and hepatitis B virus (HBV) DNA supplemental testing of anti-HBc repeat-reactive, HBsAg-negative donations. The proportion of potentially infectious donations intercepted by anti-HBc over the initial 18 months of testing was calculated based on three assumptions relating infectivity of HBV DNA-positive units to anti-HBs levels. Lookback was conducted for all DNA-positive donations.

RESULTS

Of 493,344 donors, 5,585 (1.13%) were repeat-reactive for the presence of anti-HBc, with 29 (0.52%) being HBV DNA-positive and HBsAg-negative. The proportion of potentially infectious donations intercepted by anti-HBc screening was 1 in 17,800 if all HBV DNA-positive donations were infectious, 1 in 26,900 if infectivity was limited to donations with an anti-HBs level of not more than 100 mIU per mL, and 1 in 69,300 if only donations with undetectable anti-HBs were infectious. For 279 components in the lookback study, no traced recipients were HBsAg-positive and 7 recipients were anti-HBc-reactive in association with 4 donors, 3 of whom had an anti-HBs level of more than 100 mIU per mL and 1 of whom had a level of 61 mIU per mL.

CONCLUSION

Implementation of anti-HBc screening reduced the risk of transfusing potentially infectious units by at least as much as had been expected based on the literature. The lookback did not provide proof of transfusion transmission of HBV from HBV DNA-positive, anti-HBc-reactive, HBsAg-negative donors but it did not establish lack of transmission either.

[Evaluation of pre- and post-transfusion serological screening in France in 2001]

Screening of labile blood products recipients for HIV and HCV has been performed in France since a government recommendation was issued in 1996. It has been designed to get transfusion related contamination of recipients through pre- and post-transfusion serological tests. Since then, residual risk has decreased dramatically and it was suspected that recommendations might sometimes be ignored. A nationwide survey has been done to measure the real screening rate and its cost efficacy ratio. In addition accuracy of tracability and recipients mortality has also been evaluated. A random sample of 1115 labile blood products among all the 1203 378 distributed during first semester of 2001 in France has been drawn. They have been matched with test results obtained in hospital files. Tracability has been considered accurate if name, surname and birth date of recipients were exactly the same both in hospital file and in the file of the Etablissement Français du Sang. A total of 1092 hospital files has been retrieved. Pre transfusion HIV and HCV tests have been performed in 58.5 % of cases, 95 % CI [55.6-61.5], and post-transfusion tests in 30.5 % [28.5-35.5] of cases. Only 19.5% [16.6-22.6] of recipients, not known to be dead 6 months after transfusion, have had both pre and post-transfusion tests. No HIV or HCV contamination has been notified by the Haemovigilance network during the same period. Accuracy rate of tracability was 96.25% [94.9-97.3]. Furthermore 35.8% [33-38.7] of recipients were found dead within 6 months after transfusion. A logistic regression analysis showed that the hospital area, the hospital size (more than 300 beds) and the annual amount of blood bags transfused in it (less than 5000) were factors independently associated with having a full pre and post-transfusion screening. Currently, the screening program may detect 0.14 cases of HIV and 0.05 HCV transfusion related contamination of recipient every year. The total cost of this program is about 20 million euro and the cost per case exceeds 110 million euro. The program will be of no use in case of an emerging transmitable disease. This program does not comply to any evaluation criteria of screening programs and its cost efficacy ratio is very poor.

Long-term survival after blood transfusion: a population based study in the North of England

BACKGROUND

Blood transfusion may transmit infectious diseases with long incubation periods. Estimation of the risks of transmission of such disease requires know-ledge of long-term survival of transfused patients. No such information is available in the UK, where there is particular concern about possible transmission by trans-fusion of variant CJD.

STUDY DESIGN AND METHODS

Information on survival after transfusion and demographics was collected for all patients transfused during June 1994 in a population of 2.9 million served by a single blood center.

RESULTS

A total of 2899 patients were transfused with 10,760 units of RBCs (99% of RBCs issued during the study period). Follow-up to death or 5 years was completed for 98.2 percent, and 46.9 percent of all transfusion recipients were alive at 5 years; 41 percent of transfused RBC units and 36 percent of transfused FFP were given to patients who were alive at 5 years. Median age at transfusion was 67 years (mean, 60.9 years). Shorter patient survival was associated with increasing patient age, increasing numbers of RBC units transfused, trans-fusion of plasma or PLTs, and nonsurgical indications for transfusion.

CONCLUSIONS

Posttransfusion survival is lower than estimated in previous decades in other countries. This is probably due to a relative increase in use of transfusion for older patients and for medical indications. Our figures may be used to predict and stratify the risk of infections, such as variant CJD, amongst different groups of transfusion recipients.