We want to thank everyone who sent their questions to our experts. Unfortunately, they could respond only to a limited number of submissions, and we are not accepting additional inquiries.
1. What is the status of the development of artificial blood?
Answer: The science of developing usable substitutes for blood goes back almost 100 years. However, none are yet licensed by the FDA for general usage.
2. There have been reports of blood substitutes being prepared by a number of sources. These substitutes can be given without the need for blood type or disease checks and have a much greater shelf life than regular donated human blood. What companies are preparing such substitutes, and when can we expect to see them on the market?
Answer: The production of such substances is a highly competitive and expensive commercial operation. Many important activities have been launched and many have failed. Some persist, but the research being conducted is well cloaked between the companies and the FDA.
3. Do animals have specific blood types and Rh factors?
Answer: Yes, animals do have blood types. Canine blood groups were first described in 1910 following Landsteiner's discovery of the human ABO system in 1900. Cats and other animals have blood-group antigens also. The protein structures of these antigens are different from those found in humans, so you could not use the blood of a dog or cat to transfuse humans. However, veterinarians need to be aware of blood compatibility when transfusing animals just as physicians are aware when transfusing blood into humans. Rh is specifically a human blood group that is not found in other animals.
4. Are there differences in how the various blood types respond to various illnesses or diseases or differences in immune systems?
Answer: Not really. Although some immune diseases are more common in patients with particular blood types, this is not a common finding.
5. Every so often my wife becomes anemic because of past chemo treatments of Taxol -- she is currently on Femara. When that happens the doctor gives her Procrid®. Is there something else that she can take or do to build up her blood?
Answer: Procrit® is a brand of erythropoietin, a naturally occurring hormone made in the kidney that causes red cell production. There are some newer preparations of erythropoietin that last longer and can be given less frequently than Procrit®. Generally, erythropoietin works better if supplemental iron is also given.
6. Could the regular donation of one's blood be an effective way to lower one's blood cholesterol level and/or help to maintain a healthy cholesterol level? Are there any studies being done on this possible method of blood cholesterol maintenance?
Answer: Donating blood does not lower serum cholesterol because cholesterol is continuously made in the liver and the actual amount of fluid blood (plasma) donated during blood transfusion is small.
7. What effect, if any, does a blood transfusion have on the recipient's blood for DNA testing -- say, for the purpose of forensic identification?
Answer: DNA is found in every nucleated cell in the body. Mature red cells do not have nuclei. Therefore, red cells alone would not interfere with DNA analysis. However, some white blood cells that contain nuclei can be found in transfused red cells so that it is possible that a recent blood transfusion could confuse DNA forensic analysis. However, the number of white cells transfused in this situation would be small, so the effect of transfusion on forensic analysis would be minimal.
8. How do groupings of blood types correlate with certain parts of the world?
Answer: Extensive mapping was done in the first part of the 20th century on aboriginal populations. Blood group O was highest in the Americas, and B in Africa. The presence of blood groups in specific areas may have been influenced by prehistoric epidemics and certainly by population migration. Now, there are only small aboriginal populations left and a large enough sampling cannot be obtained.
9. In your opinion, is it possible to think that blood, specifically human blood, can and will eventually be broken down into many additional subsets rather than just A, B, AB, O? Are you aware of scientific studies done where, let's say, a person that has been able to better fight off a particular disease or cancer, has had their blood transfused into a person that is, for lack of a better word, dying from a particular disease? In other words, is it possible that the antibodies (or some other blood disease fighter) that a particular person has "trained" in their own body to be passed on to help "teach" another person's blood?
Answer: There are many blood group systems other than ABO. The idea of giving blood from someone who has recovered from a disease goes back 150 years and was done therapeutically in the 1850s in New Orleans. Gamma globulins, which are blood fractions used therapeutically, are essentially concentrated antibodies. The concept of passing on substances that can create new immunity in the recipient is generally thought to be dangerous because they could create an immunity against the recipient. That is the basis for "graft vs. host" disease.
10. What is Landsteiner's Rule?
Answer: Karl Landsteiner did not put forth a rule, but his discovery of the major blood groups set the stage for the testing of blood for compatibility prior to transfusion.
(For more information on this subject, read an article on blood groups in Blood Basics and a bio of Karl Landsteiner in Innovators & Pioneers.)
11. What poses a larger threat: a specimen for compatibility testing that is mislabeled or the possibility of acquiring a deadly disease from a transfusion?
Answer: In the United States at the present time there are more deaths reported to the FDA from blood incompatibility than there are from disease transmission.
12. Is there any relationship between the four different blood types and the likelihood of patients developing blood disorders? For example, I have ITP and type O+ blood. Is this a common relationship?
Answer: No such relationship has been proven.
13. In a small close area in the evening, say at a backyard barbeque, if a mosquito bites a human with HIV and then moves on to bite a second or maybe even a third person, can HIV be transferred to the other individuals as a result of the mosquito bite?
Answer: In the early days of the AIDS epidemic that was thought to be a problem and considered at length in rural Florida, in the area of Belle Glade. The fact that the incidence of AIDS in that population was not uniform in all ages, but matched the patterns seen in major metropolitan areas, was convincing evidence that it was not the mosquito bite but lifestyle that was the mitigating factor in disease transmission.
There has never been a documented case of mosquito transmission of HIV.
14. I am 63 yrs old and my white blood cells are getting lower. Should I be concerned?
Answer: There are several reasons for a white cell count to fall, including medications, coexistent illnesses, and bone marrow diseases. I would recommend a follow up with your doctor.
15. What can we do to make sure our blood stays healthy, in other words, since it is produced in the bone, do we need to take nutrients to at least keep the bone healthy? Does drinking milk help with bone health? What about blood health, once it leaves its source?
Answer: Some vitamins and minerals are very important for maintaining healthy red blood cell production. These include iron, folic acid, B12, and B6. Bone health does not specifically improve blood health, but a healthy diet is recommended for good health in general.