Blood transfusion: risks and dangers

We begin this section with an article dated 7/01/2009 of the newspaper El Mundo, entitled "Increased security for donated blood"

The summary of the news would be that "The FDA (the agency that regulates medicines in the U.S.) has given its approval to a new test to detect AIDS virus, hepatitis C and B in donated blood. This is a unique analysis of RNA viruses that are performed in a single platform and in real time. "

According to this test "his only objective is to improve the safety of donated blood through earlier identification of infections with traditional serological tests."

Why this new test is necessary? Because, as the news, "according to data from the World Health Organization (WHO), 5% of new AIDS cases reported each year are caused by blood transfusions, figures that the new analysis will seek to reduced. Also, the contaminated blood is responsible for between eight and 16 million hepatitis B infections annually and about 4.7 million cases of hepatitis C. "

Sure many people with a clinical diagnosis which sees the need for blood transfusion, most patients do not object to such treatment, or because they rely on medical equipment, or for lack of information the true risks of blood transfusions.

We have compiled some information on the risks associated with blood transfusions and have achieved the following:

According Ginecol Obstet Méx 1998; Volume 66 (7): 277-283

The risk of transmitting infectious diseases via transfusion
Dr.. Ricardo Figueroa Damián, A. Senior Investigator National Institute of Perinatology, Mex., D.F. Department of Infectious Diseases and Immunology, reminds us first of improper practices more common in the transfusion.

Frequently improper practices in blood transfusion
* The use of globular package as a volume expander.
* The use of fresh frozen plasma to improve hypoalbuminemia.
* Transfuse globular package to improve the general conditions of the patient.
* The indication of platelet concentrates as prophylaxis in patients with immune thrombocytopenic purpura without evidence of active bleeding.

Risks of blood transfusion
According to the same report the risks of blood transfusions may be immediate or delayed:

Immediate reactions:
* Hemolysis
* Fever
* Allergy
* Hypervolemia
* Non-cardiogenic pulmonary edema
* Hypothermia
* Bacterial sepsis

These occur with a frequency ranging from 0.04 per cent hemolysis up to 0.5 percent for fever.

Delayed reactions:
Late reactions are more frequent, include conditions that may occur after several days, to reactions that occur years after the transfusion of blood between them is:

* Delayed hemolytic reactions, three to seven days posttransfusion.
* Isoimmunization erythrocytes, leukocytes or platelets.
* Graft versus host disease which usually occurs in patients with bone marrow transplantation or treatment with radiotherapy and chemotherapy.
* Post-transfusion purpura and infectious disease transmission.

Report also set out below transfusion-transmitted infections.
Infections transmitted by blood transfusion

Through transfusion can be transmitted a significant number of infections in some cases the route of transmission has been clearly labeled, while in others there is a risk potentially transmitted by this route. Table III shows the microorganisms (MO), which has clearly recognized its transmission through transfusion. Among infections that can potentially be transmitted by blood or blood products are: yellow fever, dengue, bebesiosis, Lyme disease, filariasis, Crutzfeldt-Jakob disease and infection by Ebola and Marburg viruses 3.

Summary of infectious risks in blood transfusion

HIV. Human immunodeficiency virus
"Stimulation of the current risk of HIV transmission via transfusion requires many meanings and use of complex mathematical models, whichever also take into account that the variables used in the calculation of risk change over time. Cumming et al 8 have calculated a risk of 1-infected individual 153 000 units transfused, also showing that the current precautionary measures have a 99.9% certainty. "

Hepatitis B
"In the U.S. despite the use of highly sensitive tests for detection of HBV in the blood to be donated, hepatitis B is still 5 to 10% of cases of posttransfusion hepatitis 11."

Hepatitis C
"In the U.S. the seroprevalence studies of antibodies against HCV (anti-HCV) have shown that 0.2 to 0.6% of volunteer donors are infected 14. In Mexico, the seroprevalence rate of anti-HCV in the general population is 0.61% in pregnant women 15 and of 0.53% 16. "

Hepatitis G
"The VHG is the etiologic agent of viral hepatitis more recently identified, so their clinical course and prognosis is unknown. Some researchers ascribe a pathogenic role, while others, associated with HCV, which could cause persistent infections and cause chronic liver disease and 18. Based on serological studies, it has been estimated that HGV is a common infectious agent in the U.S., has calculated that in that country two to five million individuals are infected with HGV, however, the number of sick individuals is under 18. The transmission of HGV has been related mainly to transfusion and organ transplantation. At the present time do not have any diagnostic test for this virus and therefore can not be detected in the blood will be transfused. "

Cytomegalovirus (CMV)
Belongs to the family of herpesviruses, as such causes latent infection. It primarily affects lymphoid cells and neurons. It is a ubiquitous virus in the human population, its transmission routes are: through bodily secretions such as urine, milk or nasopharyngeal secretions, perinatal, sexual and iatrogenic including transfusion and organ transplantation. CMV infection is common and affects most of the population but the development of disease is a rare event. "

"They are immunosuppressed individuals most susceptible to the disease, including patients at higher risk include: immature infants, AIDS patients and organ transplant recipients 19. "

"The risk of acquiring infection is proportional to the number of units transfused, with an estimated risk of 5 to 12% by unit 20."

To understand why these infections are called "window period", ie the time it takes the immune system to produce enough antibodies to be detectable in an analysis. Recall that the average time of production of these antibodies is twenty-five days. However, in exceptional cases it may take up to six months. As if a donated blood is tested for HIV or other viruses or pathogens, not guaranteed to be safe because during the HIV window period, for example, can not be detected, but pass it on.

Another danger is added to the deletion in the immune system's ability to fulfill its task. Medical reports recognize that in colon cancer patients the blood used as a surgical therapy produces an adverse effect on long-term survival compared with those not transfused blood.

Why is it impossible to have blood transfusions safe?
According to Armando Cortes (MD and Professor, Department of Pathology, Faculty of Health, Universidad del Valle. Head of Laboratory, Hospital Universitario del Valle. Director Blood Bank, Colombian Red Cross Sectional Valle, Cali, Colombia) in the article: " Pharmacological alternatives to blood transfusions and components "says:

"The best way to reduce the problem of diseases transmitted by transfusion is to decrease their frequency, with very strict orders that eliminate unnecessary transfusions.

It has succeeded in removing the risk of disease transmission with transfusion because:
* No laboratory test is 100% sensitive.
* There is no justification for costs, prevent many other diseases of low incidence.
* There are no tests for all infectious agents, eg, Creutzfeldt-Jakob disease.
* The presence of an early window period of hepatitis B and C, and the HIV-1 infection before antibodies are produced.
* The relative inefficiency of the history of the donor and 2,3,5 selection. "

After the above we reached the following conclusion: It is very important to promote alternative therapies exist to blood transfusions to be abandoning a practice, it can save lives, but also destroy them as statistics confirm. If today a blood transfusion had to pass all health records and controls as having to do any food or medicine, it certainly would not admit or drug therapy or as the risks and side effects that are implicit to transfusions blood. But as they are used for a long time!

As one doctor on one occasion: "The safest transfusion is not performed.

*Automatic Translation