A new study puts to rest any worries that diseases of dementia might be passed along through blood transfusions. The findings are published in The Annals of Internal Medicine.
Recent research has shown that a number of neurological conditions, including Alzheimer’s disease and Parkinson’s disease, can be induced in healthy laboratory animals through the injection of diseased brain tissue from human patients. This has raised concerns of the possibility of dementia diseases being transmitted between individuals, particularly through the common practice of blood transfusions.
To find out if this is a possibility, researchers at Karolinska Institutet conducted a study based on a unique Swedish-Danish transfusion database. Their results show that these diseases cannot be transmitted in this way.
“The results are unusually clear for such a complicated subject as this,” says principal investigator Gustaf Edgren, docent at the Department of Medical Epidemiology and Biostatistics. “We’ve been working with this question for a long time now and have found no indication that these diseases can be transmitted via transfusions.”
The study was a team effort between researchers at Karolinska Institutet and Statens Serum Institut in Copenhagen. By analyzing data of 1.7 million blood donors and 2.1 million patients given blood transfusions in Sweden and Denmark, the researchers were able to identify over 40,000 patients who had been given blood from donors diagnosed with one of the studied dementia diseases within 20 years of having given blood.
The patients were then tracked up to 44 years through the linking of a number of registries, including the Swedish and Danish patient registries. A total of 1.4 million patients who had not received blood from donors with a subsequent diagnosis were used as controls.
The two groups were compared through statistical analysis taking account of sex, age, place of residence, blood group, number of transfusions and time since first transfusion. The findings show that the patients in the two groups had exactly the same risk of contracting these dementia diseases.
“Blood transfusions are extremely safe in the Western world today, but even so we are working continuously and proactively on identifying any overlooked risks,” says Edgren. “The Swedish-Danish database that we have built up and used in many similar studies clearly demonstrates the value of our vast health registries. This kind of study would have simply been extremely difficult anywhere else in the world.”
Source: Karolinska Institutet