� Blood transfusions ar a valuable treatment mechanics in modern medicine, merely can issue forth with the risk of donor disease transmission. Researchers are continually studying the biology of blood products to understand how certain diseases ar transmitted in an feat to tighten this risk during line of descent transfusions. According to a study in sheep prepublished online in Blood, the official daybook of the American Society of Hematology, the risk of exposure of transmission bovine spongiform encephalopathy (BSE, commonly known as "sore cow disease") by blood transfusion is surprisingly high.
BSE is one of a group of rare neurodegenerative disorders called transmissible spongiform encephalopathies (TSEs), and there is no reliable noninvasive test for detecting transmission before the onset of clinical disease. In add-on to BSE, these diseases include scrapie, a close related disease in sheep, and Creutzfeld-Jakob disease (CJD) in world, which causes neurological symptoms such as unsteadiness and involuntary movements that train as the illness progresses, rendering late-stage sufferers completely immobile at the time of death.
A new variant of CJD (termed vCJD) was recognised in the United Kingdom in the mid-1990s, apparently as a result of the transmission system of BSE to world. Because the symptoms of this disease can take many days to appear, it was not known how many people power have been infected, and without a reliable test for identifying these individuals, clinicians were very interested that the infection could be transmissible between the great unwashed by blood transfusion or contaminated surgical and dental instruments. As a resultant role, costly dominance measures were introduced as a precautionary measure to reduce the risk of disease infection, although at the time it was unclear whether there actually was a significant risk or whether the control measures would be effective. This sheep study sought to punter understand how readily TSEs could be transmitted by blood transfusion in order to avail develop more targeted controls.
"It is vitally important that we better understand the mechanisms of disease transmission during line of descent transfusions so we can buoy develop the most effective control measures and minimize human-to-human infections," said Dr. Fiona Houston, now a Faculty of Veterinary Medicine, University of Glasgow, UK, and booster cable author of the study.
The nine-year study conducted at the University of Edinburgh compared rates of disease transmission by examining stock transfusions from sheep infected with BSE or scrapie; the BSE donors were experimentally septic, while the scrapie donors had naturally acquired the disease. While scrapie is not thought to convey to humanity, it was included as an infection acquired under field atmospheric condition, which could possibly give different results than those obtained from experimentally infected animals. Because of the similarity in size of sheep and humans, the team was able to collect and transfuse volumes of blood equivalent to those taken from human blood donors.
The outcome of the experiment showed that both BSE and scrapie could be effectively transmissible between sheep by blood transfusion. Importantly, the team noted that transmission could occur when blood was collected from donors before they developed signs of disease, simply was more likely when they were in the later stages of infection. Of the 22 sheep who received infected blood from the BSE donor group, basketball team showed signs of TSEs and trey others showed evidence of infection without clinical signs, yielding an overall transmittance rate of 36 per centum. Of the 21 septic scrapie recipients, nine developed clinical scrapie, yielding an overall transmission rate of 43 percent.
Investigators noted that the results were consistent with what is known about the four recorded cases of vCJD acquired by descent transfusion in humans. In addition to the stage of infection in the donor, factors such as genetic pas seul in disease susceptibility and the blood component transfused may influence the transmission rate by transfusion in both sheep and humans.
"The study shows that, for sheep infected with BSE or scrapie, transmission rates via rip transfusion can be high, particularly when donors ar in the later stages of infection. This suggests that blood transfusion represents an efficient route of transmission for these diseases," said Dr. Houston. "Since the results are consistent with what we know about human transmission, the work helps justify the control measures put in place to safeguard human blood supplies. It also shows that blood from BSE- and scrapie-infected sheep could be used efficaciously in nonhuman experiments to answer important questions, such as which blood components are most heavily septic, and to develop much-needed diagnostic tests."
The American Society of Hematology (http://www.hematology.org/) is the world's largest professional guild concerned with the causes and handling of lineage disorders. Its mission is to farther the understanding, diagnosis, treatment, and bar of disorders affecting blood, bone bone marrow, and the immunologic, styptic, and vascular systems, by promoting inquiry, clinical care, education, grooming, and advocacy in hematology.
Source: Becka Livesay
American Society of Hematology
More info
