Joseph R. Anticaglia, MD
Medical Advisory Board
Blood transfusions — before blood types were discovered — were particularly dangerous, and unpredictable. If a patient received the wrong type of blood from a donor, the mixing of two incompatible blood types had a high risk of the blood clotting, severe immune reactions, and death. Such blood incompatibility caused destruction of red blood cells with symptoms such as fever, chills, muscle aches, nausea/vomiting, dark urine, shortness of breath, and rapid heart rate.
Austrian physician and immunologist Karl Landsteiner, at the University of Vienna in 1900-1901, discovered the major human blood groups A, B, and C, which was later renamed O, as well as the ABO blood group. He observed that red blood cells have characteristic antigens on the outside of their cells. Yearslater, he and colleague Alexander Weiner, describe the Rh Rhesus) factor — see below. Other scientists discovered the AB blood group in 1902.
Antibodies and Antigens
Antibodies are proteins found in plasma. They make up part of your natural “Department of Defense.” They help identify foreign intruders, such as viruses, and alert the immune system, which sets in motion a seriesof reactions to seek, destroy, and dispose of them.
Antigens are primarily composed of proteins, and polysaccharides(sugars).Thesesubstances can trigger the body’s immune system to produce antibodies. Antigens are typically located on the surface of cells, meaning they’re found on the cell membrane. Eachantigen has a characteristic shape that the immune system recognizes, either as a friendly part of your body or a harmful intruder.
Blood Types
Landsteiner classified blood types by the presence of unique antigens on the surface of red blood cells. Blood type “O” is called O becauseit’s short for the German word ohne, which means “without” or “zero”. Your blood type depends on two systems: ABO blood type and Rh Factor.
ABO Blood Type
There are four main blood types: A, B, AB, and O. They’re categorized into different blood types depending on which antigen is located on the surface of the red blood cell (RBC).
TypeA Blood — The A antigen is located on the surface of the RBC.
TypeB Blood — The B antigen is located on the surface of the RBC.
TypeAB Blood — Antigens A and B are located on the surface of the RBC.
TypeO Blood — Neither A, nor B antigen is found on the surface of the RBC.
O positive (O+ ) is the most common blood type in the U. S.,roughly thirty eight percent (38%). AB negative (AB-) is the least common blood type in the U. S.,lessthan one percent.
Universal Donors
People with O- blood type blood do not have A, B, or Rh protein molecules on their RBC’s. They are considered universal RBC donors , meaning their red blood cells can be safely transfused to individuals regardless of their blood type. Universal plasma donors are people that have type AB blood , meaning their plasma can be safely given to individuals with any blood type.
Rh Factor
The Rh factor is a protein found on the surface, the outside of red blood cells, that determines whether the blood of a donor, and that of the recipient is compatible. It’s also known as the Rhesusfactor and the RhD Antigen.
In a 1940 paper, Landsteiner and colleagues described the Rh factor as being positive, or negative thus doubling the four main blood types (see glossary).
Rh positive people have the Rh factor protein on the surface of their red blood cells. About eighty five percent of the population is Rh positive.
Rh negative people do not have the RH factor protein on the surface (outside) of their red blood cells. About fifteen (15%) have the Rh protein on their RBC’s.
Genetics
The ABO blood group and Rh factor are inherited from biological parents. The Rh positive gene is dominant. It was in the early part of the last century that researchersfigured out the classification of blood types. Today, we take such scientific breakthroughs for granted.
Pregnancy
Doctors routinely order a blood test for pregnant women to identify their blood type. The results of the test are important , since it can affect the health of the mother, and the baby. For instance, if the mother is Rh negative, and the baby is Rh positive, the mother can produce antibodies that stream acrossthe placenta breaking down the baby’s red blood cells causing severeanemia endangering the life of the baby.
But the mother can be treated with Rh immunoglobulin (which is an antibody that prevents a mother from developing antibodies that attack the baby’s red blood cells). Such treatment has been available for more than fifty (50) years, and has become routine to avoid the breakdown of the baby’s RBCs, and catastrophic anemia.
‘Silent’ Heroes
Blood donors are called “silent heroes” — becausemost often they donate blood anonymously, expecting nothing in return, and do it without payment. Their donations have saved lives, helped people recover from surgeries, accidents and illnessessuch as blood disorders, and is essential for cancer treatment.
Many things we take for granted as being routine. Everybody has a blood type be it A, B, AB, or O, and a Rh factor, either positive or negative. Blood transfusions, blood donors, and immunoglobulins save lives. Just routine stuff, right?
Every so often it may be useful to pause a moment or two to reflect on the years of work, dedication, and ingenuity by men and women whose innovations have become just “routine stuff.”
Rh factor and blood transfusions
People with RH positive blood can receive both RH positive and RH negative transfusions; people with RH negative blood can only receive RH negative transfusions.
RH factor in genetics
the RH factor is inherited from biological parents. The RH positive gene is dominant. so even if a person has one RH positive gene and one RH negative gene their RH factor will be positive.
Glossary
Karl Landsteiner maintained that blood groups are inherited. He published a paper in 1901 about the ABO blood group, and in 1930 received the Nobel Prize in medicine.
Blood type “O” is called O because it’s short for the German word ohne, which means “without” or “zero”.
Blood types
The four main blood types, A, B, AB, and O can be further classified into Rh factor positive, and negative systems; thus, doubling the four main blood types due to the research of Landsteinerm and colleagues.
A positive (A+), A negative (A-), B positive (B+), B negative (B-), AB positive (AB+), AB negative (AB-), O positive (O+), O negative (O-).
References
- Johns Hopkins; Blood Transfusionsin Adults; Health, Johns Hopkins
- Dariush D Farhud; Karl Landsteiner; Iranian Journal of Public Health, June 2018
- SanDiego Blood Bank; What is the Universal Donor Blood Type
- ACOG; The Rh Factor: How It Can Affect Your Pregnancy
This article is intended solely as a learning experience. Pleaseconsult your physician for diagnostic and treatment options.