Years ago, blood transfusion necessarily meant infusing whole blood into a person. Nowadays, however, blood is rarely transfused in the form of whole blood because there are already ways to separate the various constituents of blood from each other to produce the different kinds of blood products.

Blood products are needed in a variety of conditions such as accidents, surgery, bleeding disorders, cancer and other serious conditions. Which blood product to transfuse depends on the condition of the patient.

For example, in cases of severe anemia where additional oxygen-carrying cells are needed, red blood cells are transfused; platelets are given in certain cases of bleeding while white blood cells are supplied in occasional cases of serious infection, etc..

Before any blood product is transfused, a variety of tests are conducted to ensure that the donated blood is safe and compatible with the patient’s blood, but these tests are not foolproof.

Likewise, there are blood transfusion transmitted and related diseases for which no routine and cost-effective tests are available. Hence, transfusion of any blood product carries a small risk of an acute or late adverse effect. That is why physicians order the transfusion of a blood product only if they are sure that the benefit of transfusion outweighs the risks of receiving blood.

The more common immediate adverse effects of blood transfusion include: Fever and chills that occurs when the recipient’s antibodies react with the antigens in the donated blood product; allergic reactions that range in severity from simple hives (urticaria) to anaphylactic shocks that can be rapidly fatal; hemolytic reactions — destruction of red blood cells caused by transfusion of incompatible blood type; fluid overload; electrolyte and chemical imbalance; and, bacterial contamination that can result in serious infection.

Delayed and long-term adverse effects of blood transfusion include delayed hemolysis or destruction of red blood cells; accumulation of too much iron in the body; some rare disorders affecting the immune system; and, blood transfusion transmitted infectious diseases.

The list of blood transfusion transmitted infectious diseases is long and still growing. Despite careful donor selection and blood product testing, the risk of transmitting infections by blood transfusion cannot be completely eliminated because infectious agents can be detected only after they have settled long enough to proliferate in blood. In addition, for some infections, there are no routine cost-effective laboratory tests available.

Below are some of the more common and important — but not the only — infections that can be transmitted by blood transfusion:

AIDS/HIV – Blood products are routinely screened for HIV. Still, the risk of acquiring HIV infection following blood transfusion is not zero. It is about one for every 2,135,000 units transfused.

Hepatitis B – Blood transfusion is indeed a major route of transmission of hepatitis B. Chronic hepatitis B is the most common cause of liver cirrhosis. Liver cirrhosis, by itself, can cause liver failure and death. At the same time, it predisposes a person to liver cancer. Liver cirrhosis precedes 80 percent of all liver cancers. Between 10-12 percent of all Filipinos, i.e., more than eight million Filipinos, have chronic hepatitis B. This is the main reason why liver cancer has a very high incidence in the Philippines.

Hepatitis C - Hepatitis C virus (HCV) infection is the most common transfusion transmitted infection in the United States (and presumably in many other countries). The virus is another cause of cirrhosis of the liver. The risk of Hepatitis C infection is about one in 1,935,000 units transfused.

Human T-lymphocytotrophic Virus (HTLV-1) - This is a virus that is associated with adult T-cell leukemia/lymphoma and a neurological disorder similar to multiple sclerosis. The risk of acquiring this virus 1 in 641,000 units transfused.

TTV - Transfusion Transmitted Virus is a newly described virus that is implicated in the development of fulminant hepatitis and chronic liver disease.

Malaria – This disease, experts used to say, is rarely transmitted by blood products. Nevertheless, a significant number of malaria cases are transfusion associated.

Cytomegalovirus (CMV) and Toxoplasmosis (a protozoan infection) – these infectious agents can cause serious disease in people with poor immune systems.

Address inquiries on health matters to Dr. Eduardo G. Gonzales, DLSU College of Medicine, Dasmarinas, Cavite 4114.