Blood Bank Final Exam

What are the three ways you can do a crossmatch?

- Instant spin

- AHG

- Electronic

What is the weak D phenotype?

a quantitative reduction in the amount of D antigen on a RBC

---- no antibody made/normal D epitope -----

What is the partial D phenotype?

a qualitative change in the expression of the D epitope or missing parts of the D epitope

What happens in the "regulator pathway" that forms a Rh Null phenotype?

There is a mutation in the RHAG gene and/or RhAG protein, so even though the RHD and RHCE genes are normal their proteins do no get expressed

What happens in the "amorph pathway" that forms a Rh Null phenotype?

The RHAG gene and Protein are normal and functioning correctly but a mutation in the RHD/RHCE genes results in their proteins not being expressed

weak expression of Kell BGS antigens due to point mutations in the KEL gene

Kmod

weak expression of Kell BGS dues to the lack of XK protein

McLeod phenotype

What null phenotype can be found in Polynesians and Pacific Islanders?

JK (a-b-)

What null phenotype is found in the African American population? What evolutionary advantage comes with it?

Fy (a-b-)

Resistant to Plasmodium vivax

What is the F antigen?

- present when c and e antigen are present (r and R0)

- anti-f is often seen with anti-e and anti-c

What is the G antigen?

Present when either D or C are present

What is the clinical significance of G antibodies?

•Patients with anti-G should receive units negative for D and C antigens

•Pregnant women with anti-D and -C should be investigated for anti-G. If it is only anti-G, they are still candidates for RhIg.

What pre-analytical factors are required for pre-transfusion testing?

- Full name, MRN, and DOB should be on tube and easy to read

- Must be able to obtain the time of draw, date of draw, and the initials of the person who drew it

- SAMPLE MUST BE LABELED BEDSIDE

What does AHG bind?

The Fc portion of IgG

List characteristic components of a DAT

- In-vivo

- Testing patient RBC's

- No enhancement used

- AHG

- Validate negative results with check cells

List characteristic components of a IAT

- In-vitro

- Testing patient plasma/serum

- Liss commonly used for enhancement

- IS → 37 → AHG

- Validate negative results with check cells

What is used to neutralized α-ABO ?

Saliva

What is used to neutralize α-Le ?

Saliva

What is used to neutralize α-P ?

Pigeon Egg Whites

What is used to neutralize α-Sda ?

Urine (Tamm-Horsfall)

What is used to neutralize α-Ch/Rg ?

Fresh Plasma

What transferase does the AA/AO gene code for? What is the sugar?

N-Acetylgalactosaminyl transferase

N-Acetyl-D-galactosamine

What transferase does the BB/BO gene code for? What is the sugar?

Galactosyl transferase

D-Galactose

What transferase does the AB gene code for? What is the sugar?

Both N-Acetylgalactosaminyl transferase and Galactosyl transferase

N-Acetyl-D-galactosamine and D-Galactose

Which antigens have IgM antibodies?

ABO, H, Lewis, Lu

Which antigens have IgG antibodies?

Fy, Kell, Kidd, MN, Rh

Which antigens are carbohydrates?

H, I/i, Lewis

Which antigens are proteins?

ABO, Fy, Kell, Kidd, Lu, Rh

Which Duffy is most common in white people?

Fy (a+b+)

Lack of H or h + lack of Se =

Bombay

Lack of H or h + functional Se =

Para-Bombay

What does the H gene code for? What is it's function?

L-fucosyltransferase which transfers L-fucose on the terminal end of PS2

In regards to the I/i antigens, virtually all adults are ____ and babies are ___

Adults = I

Babies = i

What are the most common haplotypes of the Kell BGS?

k, Kpb, Jsb

These antigens are rich in disulfide bonds

Kell antigens

What are the three antigens of the Kidd BGS?

Jka, Jkb, JK3

If a person is JK null, they can form _________ which will react with any cell that possesses a JK antigen

α-JK3

How can you differentiate JK null RBC's from normal RBC's?

By using 2M Urea, JK null RBC's will not lyse like normal RBC's

Why do "Kidd's Kill"?

The α-JK3 are known for falling below detectable level and then responding with a very strong anmnestic response

What does the Lewis gene code for?

L-fucosyltransferase that adds a fucose on PS1

Nonsecretor (se) + functional Lewis =

Le(a+b-) in secretions

Secretor (Se) + functional Lewis =

Le(a-b+) in secretions

Pregnant women can transiently type as

Le(a-b-)

What is the most common Lewis antigen formed?

Le(a-b+)

Which Lutheran antigen is high frequency?

Lu(a-b+)

Which antigens can absorb reversibly onto RBC's?

Lewis

Where are M and N located?

Glycophorin A

_______ haplotype is 2x as likely as the ________ haplotype

MS / NS

Where are Ss antigens located?

Glycophorin B

______ will be present if Glycophorin B is, _____ will be present depending on what is inherited

U / S or s

If an individual lacks U, that individual would also lack .....

S and s

U-S-s-

R1 =

DCe

R2 =

DcE

R0 =

Dce

Rz =

DCE

r =

dce

r' =

dCe

r" =

dcE

ry =

dCE

_____________ is essential for RhD and RhCE expression

RhAG protein

_____ is the receptor of the Human Parvovirus B19

P

Early abortions are associated with _____ or _____

α-PP1PK or α-P

Which antibodies are clinically significant?

ABO, Rh, Kell, Duffy, Kidd, SsU, Lu, H

- Thermal range >30C

- Titer >1000

- Reactivity strongly enhanced with albumin

- Anti-I

- Capable of binding complement

- Clinically significant

- Associated with disease

Pathological Autoantibodies

- Mild to life threatening intravascular hemolysis

- Broad thermal range (confirm identity w/ thermal amplitude test)

- Occurs in the elderly

Cold Hemagglutinin Disease (CHD)

- Biphasic

- Intravascular hemolysis

- IgG w/ P antigen specificity

- Most common in children

- Confirm w/ Donath-Landsteiner test

Paroxysmal Cold Hemoglobinuria (PCH)

- Penicillin

+ DAT IgG

Drug binds RBC membrane → Induces Ab formation → Abs bind drug on RBC membrane → Extravascular hemolysis

Drug adsorption

- IgG

- Reacts best at AHG

- May activate complement

- React w/ high incidence antigens → mimics Rh allo-antibodies (like α-e)

Warm Autoantibody

- Quinidine and Phenacetin

+ DAT C3

Drug-Immune complex forms → Binds nonspecifically to RBC and activates complement → Intra/Extravascular hemolysis

Immune complex

- Cephalosporin

- Non-immunogenic

+ DAT IgG and C3

Modifies RBC membrane → other proteins adsorb to the cell

Protein adsorption

- Methyldopa

- Neoantigen

- Down regulates normal immune system

+ DAT IgG and C3

Induction of Autoimmunity

Associated w/ ABO incompatible blood

- Febrile

- Abdominal, flank, or back pain

- Pain at transfusion site

- Feeling of impending doom

- Hemoglobinemia, hemoglobinuria

- Hypotension

- Renal failure

- Shock

- DIC

- Positive DAT

Acute Hemolytic Transfusion Reaction (AHTR)

An acute non-immune transfusion reaction caused by transfusion of bacteria-contaminated blood component (mostly platelets)

- temperature spike of ≥2C

- rigors

- hypotension

Transfusion associated sepsis (TAS)

- at least 1C spike in temperature

- Chills, nausea or vomiting

- Tachycardia

- Increase in BP

- Tachypnea

Febrile Non-Hemolytic Transfusion Reaction (FNHTR)

- IgE

- Urticaria

Acute Allergic Reaction

Usually seen in IgA deficient individuals

- Bronchoconstriction (wheezing)

- Angioedema (tongue swelling)

- Diarrhea

- Hypotension, cardiac arrythmia, loss of consciousness, shock, cardiac arrest

Severe Allergic Reacion

Acute non-immune complication due to too much input and not enough output

- Respiratory distress

- Chest tightness

- Hypertension

- Jugular vein distension

- Elevated central venous pressure

- Pulmonary edema, cardiomegaly, distended pulmonary artery

- BNP

Transfusion associated Circulatory Overload (TACO)

Leading cause of transfusion associated fatalities. Caused by α-HLA/HNA (1 hit) or neutrophils damaging pulmonary endothelium in capillaries (2-hit)

- Respiratory distress

- Severe hypoxemia

- Fever

- Hypotension

Transfusion Associated Acute Lung Injury (TRALI)

Replacement of one total blood volume in 24 hours or replacement of 50% of total blood volume in 3 hours

- May see metabolic and coagulation abnormalities

- Hypothermia

- Chelating affects→ tingling, shivering, light headedness, tetany, hyperventilation

- Hyperkalemia

Massive Transfusion (MT)

Due to:

- Newly formed antibody due to exposure

- Anamnestic response

- Positive DAT

Delayed Serologic/Hemolytic Transfusion reaction (DHTR)

A delayed immune response due to an attack by viable donor lymphocytes

- Maculopapular rash

- Fever

- Watery diarrhea, bloody stools, abdominal pain

- Elevated liver function

- Pancytopenia 3-30 days post transfusion

Transfusion Associated Graft vs Host Disease (TA-GVHD)

A delayed immune complication resulting in thrombocytopenia

- Mostly seen in females of child bearing age

- 1-24 days post transfusion

- Sometimes febrile reactions

- Patient must be previously sensitized to human platelet antigens

Post Transfusion Purpure (PTP)

Non-immune complication of transfusion dependency/chronic transfusion

Iron Overload

What is the deferral period for ASA/ASA-drugs/Feldene (aspirin)?

2 full days (>48 hours)

What is the deferral period for Plavix or Ticlid?

14 days

What is the deferral period for Finasteride or Isotretinoin?

1 month

What is the deferral period for Avodart?

6 months

What is the deferral period for Soriatane?

3 years

What is the deferral period for Tegison?

Permanent

What is the deferral period for Human GH or bovine insulin?

indefinite

What is the deferral period for measles, mumps, typhoid, and yellow fever vaccines?

2 weeks

What is the deferral period for German measles (rubella) and chicken pox (varicella zoster)?

4 weeks

What is the deferral period for HBIG and unlicensed vaccines?

12 months

What is the deferral period for Hep B and Flu vaccines?

no deferral

What is the deferral period for someone who had lived in a malaria-endemic area?

3 years

What is the deferral period for someone who has traveled to a malaria-endemic area?

1 year

What is the deferral period for someone who had lived > 3 months in the Uk or who was associated with a military base in certain European countries between 1980 and 1996?

Indefinite

What are the physical requirements to donate blood products?

- Age >16yo

- Not intoxicated or ill

- No rash or evidence of drug use

- >110 lbs

- <99.5 F (37.5C)

- Women: 12.5 Hgb/ >38% Hct

- Men: 13.0 Hgb/ > 39% Hct

Which diseases are screened with questions only?

Malaria, Prions, CJD/vCJD

Which diseases require a look back?

- HBsAg

- HBV DNA NAT

- total anti-HBc