4.3 Rh Blood Group System

Question 1

A complete Rh typing for antigens C, c, D, E, and e revealed negative results for C, D, and E. How is the individual designated?

Answer 1

Rh negative

Question 2

How is an individual with genotype Dce/dce classified?

Answer 2

Rh positive

Question 3

If a patient has a positive DAT, should you perform a weak D test on the cells?

Answer 3

No, the cells are already coated with antibody

Question 4

Which donor unit is selected for a recipient with anti-c?

A. r´r
B. R0R1
C. R2r´
D. r´ry

Answer 4

r´ry

Question 5

Which genotype usually shows the strongest reaction with anti-D?

Answer 5

D–/D–

Question 6

Why is testing for Rh antigens and antibodies different from ABO testing?

Answer 6

ABO reactions are primarily caused by IgM antibodies and usually occur at room temperature; Rh antibodies are IgG and agglutination usually requires a 37°C incubation and enhancement media

Question 7

Testing reveals a weak D that reacts 1+ after indirect antiglobulin testing (IAT). How is this result classified?

Answer 7

Rh-positive

Question 8

What is one possible genotype for a patient who develops anti-C antibody?

A. R1r
B. R1R1
C. r’r
D. rr

Answer 8

rr

Question 9

A patient developed a combination of Rh antibodies: anti-C, anti-E, and anti-D. Can compatible blood be found for this patient?

Answer 9

rr blood could be used without causing a problem

Question 10

A patient tests positive for weak D but also appears to have anti-D in his serum. What may be the problem?

Answer 10

A D mosaic may make antibodies to missing antigen parts

Question 11

Which offspring is not possible from a mother who is R1R2 and a father who is R1r?

A. DcE/DcE
B. Dce/DCe
C. DcE/DCe
D. Dce/dce

Answer 11

DcE/DcE

Question 12

Which weak D phenotypes necessitate Rh immune globulin (RhIg) prophylaxis:
1, 2, 3, none of the above

Answer 12

None of the above

Question 13

What antibodies could an R1R1 make if exposed to R2R2 blood?

Answer 13

Anti-E and anti-c

Question 14

What does the genotype —/— represent in the Rh system?

Answer 14

Rhnull

Question 15

What techniques are necessary for weak D testing?

Answer 15

37°C incubation + IAT

Question 16

A patient types as AB and appears to be Rh positive on slide typing. What additional tests should be performed for tube typing?

Answer 16

Rh negative control

Question 17

According to the Wiener nomenclature and/or genetic theory of Rh inheritance:

Answer 17

There are multiple alleles at a single complex locus that determine each Rh antigen

Question 18

The Wiener nomenclature for the E antigen is:

Answer 18

rh”

Question 19

A physician orders 2 units of leukocyte-reduced RBCs. The patient is a 55-year-old male with anemia. He types as an AB negative, and his antibody screen is negative. There is only 1 unit of AB negative in inventory. What is the next blood type that should be given?

Answer 19

A negative

Question 20

Which technology may report an Rh-weak D positive as Rh negative?
A. Gel system
B. Solid phase
C. Tube testing
D. None of these options

Answer 20

Gel System