A patient types as D-negative with high-protein anti-D...

A patient types as D-negative with high-protein anti-D IS and 37C incubation. The test is pos at the AHG phase of testing. Rh control is negative throughout. This patient should receive:

a. D-pos blood only
b. D-neg blood only
c. Either D-pos or D-neg blood
d. No blood until further testing is performed to determine the D type of the patient.

I thought the answer would be (b) but apparently my professor says its (c).
Since the Rh(-) patient is producing anti-D, wouldn't you want to only give Rh(-) donor blood? Wouldn't the patients anti-D's destroy Rh(+) blood, as the anti-D would attach to the donor D antigens? Therefore, only Rh(-) would be given.

Thanks for help. :)

The patient isn't Rh negative. It's termed more appropriately weak D or in the past was called Du positive. Under rare instances depending on the D structure of the patient but because they form a weak D antigen then they won't produce anti-D. Either Rh negative or Rh positive blood can be given.

Weak D testing is no longer recommended for crossmatch procedures. The only time weak D testing is undertaken now is for baby blood typing in order to determine is Rhogam is indicated for the mother.

Hi Lab Guy,
I have another question about Rh testing that may be you could help me with.

Why is a weak test for the D-antigen not performed in the presence of a positive DAT?

Thanks! :)

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