Rh “Rhesus” Blood Types - Are you positive or negative?! - Hematology

Summary

This video delves into the complexities of Rh blood types, explaining the Rh antigen system and its significance in determining Rh positivity or negativity. The discussion covers the types of hemolytic anemia, including autoimmune and drug-induced forms, and the crucial difference between the ABO and Rh blood group systems. Key concepts like Rh incompatibility during pregnancy and the risk of hemolytic disease of the newborn are explained, emphasizing the importance of prenatal care for Rh-negative mothers. The video also clarifies how the immune system responds to Rh-positive blood exposure, highlighting the potential risks during blood transfusions and pregnancy.

Takeaways

• 😀 The Rh blood type system refers to the rhesus antigen, an antigen on the surface of red blood cells that determines whether someone is Rh positive or negative.
• 😀 The Rh system is separate from the ABO blood group system, and there are multiple Rh antigens such as C, D, and E.
• 😀 A person can be Rh positive or Rh negative depending on whether they have the D antigen; Rh positive means having the D antigen, while Rh negative means lacking it.
• 😀 Rh incompatibility can lead to hemolytic disease of the newborn, particularly if the mother is Rh negative and the baby is Rh positive.
• 😀 Hemolytic anemia has three main subtypes: autoimmune, drug-induced, and alloimmune hemolytic anemia, with alloimmune hemolytic anemia being the focus here.
• 😀 The Rh factor is inherited based on the parents' Rh status. If both parents are Rh negative, the child will be Rh negative, but if one is Rh positive and the other Rh negative, the child's Rh status can vary.
• 😀 Hemolytic disease of the newborn typically affects the second pregnancy, where Rh negative mothers carrying an Rh positive baby may face complications.
• 😀 The Rh system differs from the ABO system because it does not produce spontaneous antibodies. In the Rh system, antibodies form only after exposure to Rh positive blood.
• 😀 If an Rh negative person is exposed to Rh positive blood, their immune system will gradually form antibodies, and a second exposure can trigger a stronger, more severe immune response.
• 😀 In the event of Rh incompatibility, Rh negative mothers may be given Rh immunoglobulin during prenatal visits to prevent complications in future pregnancies.
• 😀 Immediate reactions to Rh positive blood transfusions in Rh negative individuals are possible on subsequent exposures, causing hemolysis and symptoms like jaundice and high bilirubin.

Q & A

What is the Rh blood type system?

The Rh blood type system is based on the presence or absence of the Rh factor, a specific antigen on the surface of red blood cells. If the Rh factor is present, a person is Rh-positive (Rh+); if absent, the person is Rh-negative (Rh-).

How does the Rh factor relate to the ABO blood type system?

The Rh factor is a separate blood type system from the ABO system. While the ABO system categorizes blood into types A, B, AB, and O, the Rh system classifies blood as either Rh-positive or Rh-negative, depending on the presence or absence of the Rh antigen.

What is hemolytic anemia, and how does it relate to the Rh system?

Hemolytic anemia refers to the destruction of red blood cells at a rate faster than they can be produced. In the context of the Rh system, hemolytic anemia can occur when an Rh-negative person is exposed to Rh-positive blood, leading to the immune system attacking the foreign red blood cells.

What is Rh sensitization, and how does it happen?

Rh sensitization occurs when an Rh-negative person is exposed to Rh-positive blood, causing their immune system to produce antibodies against the Rh factor. This can happen through blood transfusions or during pregnancy if the mother is Rh-negative and the baby is Rh-positive.

Why does hemolytic disease of the newborn (HDN) occur?

HDN occurs when an Rh-negative mother is carrying an Rh-positive baby. If the mother's immune system has become sensitized to Rh-positive blood from a previous pregnancy or transfusion, her antibodies can attack the baby's red blood cells, leading to hemolysis and jaundice in the newborn.

How does Rh incompatibility affect the first pregnancy versus subsequent pregnancies?

In the first pregnancy, Rh incompatibility usually does not cause problems because the mother’s immune system is not yet sensitized to Rh-positive blood. However, in subsequent pregnancies, if the mother is sensitized, her immune system will react more strongly and quickly to Rh-positive blood, leading to more severe hemolysis.

What is the role of Rh immunoglobulin (RhIg) in preventing Rh sensitization?

Rh immunoglobulin (RhIg), commonly known as RhoGAM, is given to Rh-negative mothers during pregnancy or after childbirth to prevent the development of antibodies against Rh-positive blood cells. This helps prevent Rh sensitization and reduces the risk of hemolytic disease of the newborn in future pregnancies.

What are the common symptoms of hemolysis due to Rh incompatibility?

Common symptoms of hemolysis due to Rh incompatibility include jaundice (yellowing of the skin and eyes), increased unconjugated bilirubin, high lactate dehydrogenase (LDH) levels, and low haptoglobin levels, which indicate the breakdown of red blood cells.

Can Rh incompatibility occur from sources other than pregnancy?

Yes, Rh incompatibility can also occur from blood transfusions. If an Rh-negative person receives Rh-positive blood, their immune system may develop antibodies against the Rh factor, leading to hemolysis upon subsequent exposures to Rh-positive blood.

What is extravascular hemolysis, and how is it related to Rh incompatibility?

Extravascular hemolysis is the destruction of red blood cells outside the bloodstream, primarily in the spleen. In Rh incompatibility, once an Rh-negative person is sensitized to Rh-positive blood, antibodies attack the red blood cells, leading to this type of hemolysis, which can cause symptoms like jaundice and anemia.