Blood grouping viva answers .pdf

exam viva

1. BLOOD GROUPING VIVA ANSWERS
1. What is Landsteiner’s law
Landsteiner's law states that if a red blood cell (RBC) lacks an ABO antigen, the
corresponding antibody will always be present in the serum. This law describes the
relationship between antigens on RBCs and antibodies in the serum for the ABO blood system.
2. Indications for blood grouping
1. Blood transfusion.
2. Paternity disputes.
3. Medicolegal use in criminal cases.
4. As a part of routine checkup.
3. Father of blood grouping
Karl Landsteiner is known as the father of blood grouping. He discovered the
ABO blood group system in 1901.
4. Names of blood group system you know
1. ABO: Classifies blood based on the presence of A and B antigens on red blood
cells. People can have type A, type B, type O, or type AB blood.
2. Rhesus: Discovered in 1940, the name comes from the use of rhesus monkey blood
in the original test for the Rh antigen.
3. Kidd
4. Duffy
5. Kell
5. What is ABO system
- It is the first and the most important blood group system, discovered by Landsteiner.
- It is based on the presence or absence of A or B antigen over the red blood cells.
- There are 4 main blood groups such as A, B, AB & O.
- The alleles (A, B, O) are located at the ABO locus on chromosome 9.
- For a blood transfusion, the ABO blood group system is used to match the blood type of
the donor and the person receiving the transfusion.
6. What is Rh system
The Rh system, also known as the Rhesus system, is a blood type system that
determines if a person has a protein called the Rh factor on their red blood cells.
Rh type → A person's Rh type is either Rh-positive or Rh-negative, depending on whether they
have the Rh factor protein.

2. 7. What is Bombay blood group
Bombay individual lack all the 3 antigens (A, B or H)
Bombay individual have all 3 antibodies anti -A, anti-B, anti -H in the sera.
8. Indication for blood transfusion
1. Severe anemia (Hb < 6-7 g/dL)
2. Acute blood loss (> 20% blood volume)
3. Chronic blood loss (e.g., cancer, ulcers)
4. Sickle cell disease (acute chest syndrome, stroke)
5. Thrombocytopenia (< 10,000-20,000/μL)
6. Coagulopathy (e.g., liver disease, warfarin reversal)
7. Massive transfusion (> 10 units of blood)
8. Fibrinogen deficiency
9. Hemophilia
10. Von Willebrand disease
9. What are the three anti sera used and each one’s colour
1. Anti-A is coloured blue.
2. Anti-B be coloured yellow.
3. Anti-D is colourless.
10. Ideal storage of anti-sera solutions
-Store at 4 to 6°C.
-Preservatives like sodium azide (0.1%) is added to prevent microbial contamination
-Protect from light to prevent degradation
-Use clean and sterile container
11. What is auto control and its use in blood grouping in slide method
Autocontrol in blood grouping is a quality control measure where a drop of the
patient's blood is mixed with saline. It helps identify issues with the sample, such as
contamination, improper storage, or the presence of autoantibodies, ensuring accurate blood
typing results
Auto control is necessary to rule out auto agglutination of patient’s red cells, which occurs
when autoantibodies are present in patient’s serum. In auto control tube, patient’s red cells are
mixed with patient’s own serum and the tube is centrifuged; if agglutination occurs, it is
autoantibody-induced. Auto control test is particularly essential when ABO grouping is being
done only by forward method and blood group is typed as AB.

3. 12. What are transfusion reactions
Transfusion reaction is defined as any adverse event (undesirable response or
effect of complications related to transfusion) that occurs in patient during or after transfusion
of whole blood, blood components or human derived plasma products. It may range from mild
to severe & at times can be fatal.
13. Classify transfusion reactions














14. What are the samples to be collected post transfusion reaction event

4. 15. What is TRALI
✓ Transfusion-related acute lung injury (TRALI) is a serious complication arising from
blood transfusions, characterized by sudden acute respiratory distress occurring during
or within six hours post-transfusion.
✓ TRALI is thought to be caused primarily by donor-derived antibodies activating
recipient neutrophils, leading to pulmonary inflammation and edema.
✓ Symptoms include severe hypoxemia, low blood pressure, and sometimes fever.
✓ Management is supportive, and awareness has increased due to its potential severity
and underreporting.
16. What is TACO
✓ TACO- Transfusion Associated Circulatory Overload.
✓ It is a non-immune transfusion reaction.
✓ TACO- results in pulmonary congestion and acute heart failure.
✓ These are the most important and most common complications leading to death.
✓ The risk of circulatory overload is particularly high in patients with chronic anemia and
in infants and elderly.
✓ The onset may be immediate or may be delayed up to 24 hrs.
17. TRALI vs TACO
TRALI, a severe frequently fatal immunological complication in which factors in a transfused
blood product trigger the activation of neutrophils in the lung microvasculature, resulting in
pulmonary oedema and symptoms of respiratory failure
Transfusion associated circulatory overload (TACO), is a non-immune mediated fatal
complication, resulting in pulmonary congestion and acute heart failure due to excess fluid in
the blood vessels. TACO is severe in patients with chronic anemia, infants and the elderly.
18. What is anemia
Anemia is defined as reduced Hemoglobin / RBC volume / oxygen carrying capacity of RBCs.
A hemoglobin value of less than 13.5 gm/dl in a man and less than 12.0 gm/dl in a woman.
19. What is polycythemia
Polycythemia is a condition where there is an abnormal increase in the number of red blood
cells, Hb and PCV leading to thickened blood and increased risk of clotting.
20. What is phlebotomy – indications
Phlebotomy is the process of drawing blood out, which can be done for diagnostic purpose,
blood donation, or for therapeutic purpose like hemochromatosis (excess iron) or polycythemia
vera (high red blood cell count).
21. Universal donor
People with blood type O can donate blood to anyone and are called universal
donors.

5. 22. Universal recipient
People with blood type AB can accept blood from all donors and are called
universal recipients.
23. Concept behind universal donor and recipient
Universal Donor: An individual with O negative blood type can donate to any blood group
because their RBCs lack A, B, and D antigens.
Universal Recipient: An individual with AB positive blood type can receive blood from any
group because their plasma lacks anti-A, anti-B, and anti-D antibodies.
24. Types of blood grouping tests
There are two methods for ABO grouping - cell grouping (forward grouping) and serum
grouping (backward or reverse grouping).
• ABO and Rh tests
The most common blood type tests, which determine the presence or absence of antigens on
red blood cells. The ABO test determines the blood type as A, B, AB, or O, while the Rh test
determines if the Rh antigen is present (positive) or absent (negative).
• Slide testing
A quick and simple method that uses small amounts of reagents and is often used in
emergencies.
• Tube testing
A faster and more sensitive alternative to the slide method that uses less reagents.
• Microplate agglutination method
Uses automated platforms to detect antigens and antibodies.
25. Which is the best test for blood grouping
“Test tube method of blood grouping is more reliable than slide method.”
In two positive control tubes, anti-A serum is mixed with group A red cells and anti-B
is mixed with group B red cells respectively. In two negative control tubes, anti-A serum is
mixed with group B red cells and anti-B serum is mixed with group A red cells respectively.
These controls are necessary to confirm that reagents are working properly. Test tube method
of blood grouping is more reliable than slide method. This is because centrifugation brings
antigen and antibodies closer together and allows detection of weaker antigen antibody
reactions.
26. Advantage and disadvantage of slide method
Advantages
1. Requires minimal equipment and technical expertise, making it easy to perform.

6. 2. Results can be obtained in a few minutes.
3. Requires only basic reagents and glass slides, making it economical.
4. Can be performed in field settings or resource-limited areas since it doesn't require
sophisticated laboratory facilities.
5. The agglutination reaction is directly visible to the naked eye or under a microscope.
Disadvantages
1. Results depend on the observer's interpretation, increasing the chance of errors.
2. Poor mixing of reagents and blood can lead to inaccurate results.
3. External factors like temperature, humidity, and light can affect agglutination.
4. It may not reliably detect weak antigen-antibody reactions, leading to false negatives.
5. The method does not include strict controls, which can compromise accuracy.
6. Improper technique can cause cross-contamination or false positives.
27. Advantage and disadvantage of tube method
Advantages:
1. Centrifugation enhances the reaction by bringing antigen and antibodies closer together
and allows detection of weaker antigen antibody reactions.
2. Drying is avoided and smaller amounts of reagent are required.
Disadvantages:
1. Time consuming
2. Needs trained technician to perform and report
28. Interpretation of tube method of blood grouping
Agglutination indicates the presence of the corresponding antigen. No agglutination indicates
the absence of the corresponding antigen.

7. 29. What are the side effects of blood transfusion
1. Hemolytic reactions
2. Febrile reactions
3. Allergic reactions
4. Anaphylactic reactions
5. Infection
6. Circulatory overload
7. Metabolic toxicity
8. Graft-versus-host disease
9. Iron overload
30. Most common blood group in India
Most common blood group in India - O positive blood group
31. Risk of gastric cancer and peptic ulcer and which blood group is associated with the
conditions mentioned
Blood group O has been associated with a higher risk of developing peptic ulcers, particularly
those linked to H. pylori infection. This may be due to how blood group O antigens interact
with the bacterium.
Blood group A has increased risk associated with gastric cancer.
32. What is forward grouping
Forward grouping also known as red cell grouping is in which antigens on RBCs are detected,
there are two methods for ABO grouping - cell grouping (forward grouping) and serum
grouping (backward or reverse grouping).
33. What is reverse grouping
Reverse grouping is a blood test that determines a person's blood type by adding their serum
sample to red blood cells with known A and B antigens. The test is also known as serum
grouping or back typing.
34. What is cell grouping
Cell grouping / forward grouping is when red blood cells (RBCs) stick together in a certain
pattern. This can be seen in different medical conditions and can help doctors diagnose what's
going on.
Types of Cell Grouping:
1. Rouleaux formation: RBCs stack on top of each other like coins. This can happen in
conditions like multiple myeloma.
2. Agglutination: RBCs clump together because of antibodies or other stuff. This can happen
in conditions like autoimmune hemolytic anemia.
3. Sludge: A mix of RBCs, white blood cells, and platelets that accumulate in small blood
vessels. This can happen in conditions like sepsis.

8. Why is Cell Grouping Important?
Cell grouping can be a big clue for doctors when diagnosing medical conditions. For example,
Rouleaux formation can mean someone has a paraproteinemia or a severe inflammatory
response. Agglutination can mean someone has an autoimmune disorder or a transfusion
reaction.
35. What is serum grouping
Serum grouping is a blood test that determines a person’s ABO blood type by checking the
antibodies in the serum or plasma
36. What is cross matching
Cross matching is a process of testing whether donor blood group is compatible with recipient
blood group prior to blood transfusion
37. What is the purpose of cross matching
The purpose of a crossmatch is to ensure that a recipient's blood is compatible with a donor's
blood before a transfusion or transplant:
38. Complication of mismatched blood transfusion
A mismatched blood transfusion occurs when blood with an incompatible blood type is
transfused into a patient. This can lead to a severe and potentially life-threatening reaction.
Immediate Complications
1. Acute Hemolysis: The immune system attacks and destroys the transfused red blood cells,
leading to a rapid drop in blood pressure, kidney failure, and even death.
2. Anaphylaxis: A severe allergic reaction that can cause respiratory failure, cardiac arrest, and
even death.
3. Shock: A severe drop in blood pressure can lead to inadequate blood flow to vital organs,
resulting in shock.
Delayed Complications
1. Delayed Hemolysis: A slower destruction of transfused red blood cells, which can lead to
jaundice, anemia, and kidney damage.
2. Graft-Versus-Host Disease (GVHD): A rare but potentially life-threatening complication
where the immune cells in the transfused blood attack the patient's tissues.
3. Transfusion-Related Acute Lung Injury (TRALI): A rare but potentially life-threatening
complication where the transfused blood causes inflammation and damage to the lungs.
Long-Term Complications
1. Chronic Kidney Disease: Repeated episodes of hemolysis can lead to chronic kidney damage
and disease.
2. Iron Overload: Repeated blood transfusions can lead to an accumulation of iron in the body,
causing damage to organs such as the heart, liver, and pancreas.

9. 3. Immune System Suppression: Repeated exposure to foreign blood can weaken the immune
system, making the patient more susceptible to infections.
It's essential to note that these complications can be prevented or minimized by ensuring proper
blood typing and cross-matching before transfusion.
39. What is Rh incompatibility
Rh incompatibility occurs when a pregnant woman with Rh-negative blood
type carries a fetus with Rh-positive blood type, inherited from the father. This can lead to a
maternal immune response against the fetal red blood cells (RBCs).
Pathophysiology:
1. Initial sensitization: During the first pregnancy, exposure to Rh-positive fetal RBCs (e.g.,
during delivery, miscarriage, or invasive procedures) may sensitize the Rh-negative mother.
Her immune system produces anti-Rh antibodies (IgG type).
2. Subsequent pregnancies:
If the fetus in a subsequent pregnancy is Rh-positive, maternal IgG antibodies cross the
placenta and target the fetal RBCs.
This leads to hemolysis (destruction of RBCs) in the fetus.
Complications:
1.Hemolytic Disease of the Newborn (HDN):
2.Fetal anemia.
3.Jaundice (from bilirubin, a breakdown product of hemoglobin).
4.Hydrops fetalis (severe edema and heart failure in the fetus).
5.Kernicterus (bilirubin-induced brain damage).
40. What is ABO incompatibility
ABO incompatibility refers to the presence of antibodies in the recipient's Plasma
against the antigens on the donor’s RBCs. This results in Agglutination reaction.
41. What is erythroblastosis fetalis
Erythroblastosis fetalis (Hemolytic disease of the newborn):
It is an alloimmune hemolytic anemia developing in the fetus and newborn baby.
◆ Hemolysis is extravascular.
❖ HDN develops when the IgG antibodies against blood group of fetus passes from mother to
fetus through the placenta.
Occurs in two forms:

10. ■ Rh incompatibility in which mother is Rh negative and fetus is Rh positive. The anti-D
antibodies are responsible for the hemolytic anemia.
■ ABO incompatibility in which mother's blood group is O and fetus is either of A or B blood
group. Either anti-A or anti-B antibodies cause hemolysis.
42. What is the use of Anti D
Anti-D is used in blood grouping to detect the presence of the D antigen on red blood cells,
which determines if a person is Rh-positive (D antigen present) or Rh-negative (D antigen
absent).
This is part of the ABO and Rh blood typing system, which is crucial for safe blood
transfusions, organ transplantation, and pregnancy management.
43. What are the products available in blood bank used for transfusion
1. Whole Blood: Contains all components of blood, including red blood cells (RBCs),
plasma, platelets, and white blood cells. It is used in severe trauma or major blood loss.
2. Red Blood Cells (RBCs): used to treat anemia or blood loss, to restore the oxygen-
carrying capacity of the blood.
3. Platelets: Used to treat or prevent bleeding in patients with low platelet counts
(thrombocytopenia) due to conditions like leukemia, chemotherapy, or bone marrow
disorders.
4. Plasma: The liquid portion of the blood, containing water, electrolytes, proteins,
hormones, and waste products. used to treat patients with clotting disorders, burns, or
shock.
5. Fresh Frozen Plasma (FFP): Contains clotting factors and is used to treat bleeding
disorders
6. Cryoprecipitate: rich in clotting factors like fibrinogen, used for patients with
hemophilia or to manage bleeding related to low fibrinogen levels.
7. Granulocytes (White Blood Cells): used in severe neutropenia or in patients who are in
risk of infection.
44. What is transfusion
Transfusion is the process of transferring blood or blood components from one
person (the donor) to another person (the recipient).
This is commonly done to treat conditions like anemia, severe blood loss from surgery or injury,
or certain medical conditions that affect the production of blood cells.
Transfusions can involve whole blood, or more commonly, specific blood components such as
red blood cells, plasma, platelets, or clotting factors.
Blood transfusions are carefully matched to the recipient's blood type to prevent adverse
reactions
45. What is transplant Transplant is a surgical procedure in which an organ, tissue or group
of cells are removed from one person (the donor) and transplanted into another person (the
recipient), or moved from one site to another in the same person.

11. 46. Types of blood bags used in blood bank
1. Single blood bag - whole blood collection and anticoagulant used is citrate,
phosphate, dextrose, adenine
2. Double blood bag - whole blood collection. Separation of two components - red cells
and plasma obtained via centrifugation and extraction
3. Triple bag - whole blood collection. Separation of three components - red cells
plasma and platelets. Anticoagulant used is citrate, phosphate, dextrose - saline,
adenine, glucose, mannitol.
47. What are the anticoagulants used in blood bank
Anticoagulants used in blood banks:
1. ACD (Acid Citrate Dextrose)
2.CPD (Citrate Phosphate Dextrose)
3. CPDA-1 (citrate phosphate dextrose adenine)
4. SAGM - Saline, Adenine, glucose, Mannitol
48. What is CPDA / SAGM
CPDA- Citrate phosphate dextrose adenine – 35 days
SAGM - Saline, Adenine, glucose, Mannitol – 42 days
49. Uses of each component of anticoagulant use in blood bank
CPDA –
➢ Citrate: Anticoagulation by binding of calcium in plasma.
➢ Phosphate: Acts as a buffer to minimize the effects of decreasing pH in blood.
➢ Dextrose: Maintenance of red cell membrane and metabolism.
➢ Adenine: Generation of ATP (energy source).
SAGM -
➢ Saline – nutrition source
➢ Adenine – Generation of ATP (energy source).
➢ Glucose – gives energy to RBC
➢ Mannitol – supports intergrity of RBC membrane
50. Validity of each product in blood bank
1. Whole Blood: 35 / 42 days
2. Red Blood Cells (RBCs): 35 / 42 days
3. Platelets: 7 days
4. Fresh Frozen Plasma (FFP): 1 year from date of collection
5. Cryoprecipitate: 1 year from date of collection

12. 6. Granulocytes: 24 hours
7. Plasma: 1 year from date of collection (when frozen) or 5 days (when refrigerated)
51. Storage of each product in blood bank
1. Red blood cells and whole blood: Stored in refrigerators at 2–6°C for up to 42 days.
2. Platelets: Stored at room temperature in agitators for up to 7 days.
3. Plasma and Cryoprecipitate: Frozen and stored in freezers at –30°C for up to one
year.
4. Fresh frozen plasma (FFP): Can be stored at –18°C for one year.
52. What is coomb’s test
RBCs coated with incomplete antibody or C3 complement, doesn't cause
agglutination of RBCs. These are agglutinized by Coombs reagent, which contains antibodies
against human IgG/IgM/complement.
53. Types of coomb’s test
Direct Coombs test:
Detects incomplete antibodies/complement coated on surface of patient's RBC.
Sample used: RBC component of blood + Coomb’s reagent
Uses:
1. Hemolytic disease of newborn
2. Autoimmune Hemolytic Anaemia
3. Drug induced red cell sensitization
4. Hemolytic transfusion reaction-investigstion
Indirect Coomb’s test:
Detects presence of incomplete antibodies/complement in patient's serum.
Sample used: Patient's serum + O Rh positive RBC suspension + Coombs reagent
Uses:
1. Hemolytic disease of Newborn
2. Cross matching for blood transfusion.
54. Indication for ICT and DCT
The direct Coombs test, or direct antiglobulin test (DAT), is indicated primarily for:
Autoimmune Hemolytic Anemia: To confirm the presence of antibodies attached to red blood
cells, indicating that the immune system is attacking them.
Hemolytic Disease of the Newborn: To detect maternal antibodies that may affect the fetus.
Transfusion Reactions: To identify if a patient's immune response is targeting transfused red
blood cells due to incompatibility.

13. The indirect Coombs test is primarily indicated for:
Prenatal Testing: To screen pregnant women for antibodies that may cause hemolytic disease
in newborns.
Blood Transfusion Compatibility: To detect antibodies in a recipient's serum that may react
against donor red blood cells, preventing transfusion reactions.
Antibody Identification: To identify specific antibodies, present in patients, aiding in the
diagnosis of conditions like autoimmune hemolytic anemia or drug-induced hemolysis.
55. Types of blood donors
1. Replacement donors
2. Voluntary donors
3. Paid / Professional donors
56. Ideal candidate for blood donation
Ideal candidates for blood donation are individual who
1. Are healthy and free of any chronic medical conditions
2. Age between 18 and 60
3. Weigh at least 50 kg
4. Has a hemoglobin level of at least 12.5 g/dL
5. Have a blood pressure between 100/60 and 140/90 mmHg
6. Have a pulse rate between 60 and 100 beats per minute
7. Have not donated blood in the past 3 months
8. Have not traveled to areas with high risk of malaria, dengue, or other infectious
diseases
9. Are not pregnant or breastfeeding
10. Are willing to provide consent and answer medical history questions
11. Pass the physical examination and medical screening
12. Are free of tattoos and piercings in the past 12 months
13. ⁠No recent fever, infection or surgery
14. ⁠Should not be less than 2 weeks after vaccination
15. ⁠No history of unprotected sex or multiple partners
57. What is autologous blood transfusion
Autologous blood transfusion is the collection of blood from a single patient and
re-transfusion back to the same patient when required. The primary driving forces for the use
of autologous blood transfusion are to reduce the risk of transmission of infection and to protect
an increasingly scarce resource.

14. 58. What is the transfusion transmissible infections (TTI) you know
VIRAL-
1.Human immunodeficiency virus (HIV)
2.Hepatitis B virus (HBV)
3.Hepatitis C virus (HCV)
BACTERIAL-
1.Treponema pallidum (Syphilis)
PARASITIC-
1.Plasmodium species
59. How to prevent transfusion transmissible diseases
• Donor selection
This includes excluding donors with high-risk behaviors or backgrounds, such as those with a
history of certain diseases or travel to endemic areas.
• Screening
This includes laboratory screening for bloodborne pathogens like HIV, HBV, HCV, and
Treponema pallidum. Nucleic acid testing (NAT) can detect acute window period and occult
infections.
• Pathogen reduction
This includes specific processing like leukodepletion, pathogen reduction, and
inactivation. Bacterial culturing can detect contaminated platelets.
Other measures include:
• Skin disinfection and diversion bags to limit bacterial contamination
• Quarantine of plasma to prevent window infections
• Post-donation and post-transfusion notification to identify infected recipients
60. Ideal time duration between two blood donations by a donor what is the reason behind
it? The ideal time between blood donations is at least 12 weeks / 3 months
to ensure that hemoglobin levels don't drop too low over time. This is because it takes about
four to six weeks for red blood cells to be completely replaced after a donation.
61. What is blood substitute any examples?
Blood substitutes are used to replace lost blood volume or oxygen in the body.
Volume expanders
These non-oxygen-carrying solutions, such as saline, Ringer's lactate (RL), albumin, dextran,
and starches, are used to replace lost plasma volume.

15. 62. What are the organisms that could be spread via blood transfusion