In Rh typing using a high protein anti-D reagent, which interpretation is correct when AHG reaction is positive with patient cells but check cells are not performed?

In Rh typing using a high protein anti-D reagent, which interpretation is correct when AHG reaction is positive with patient cells but check cells are not performed?

• A. Rh negative, weak D positive
• B. Rh positive, weak D positive
• C. Rh negative, weak D negative
• D. Invalid Rh typing

Answer: (D)

The test outcome hinges on confirming that an AHG-positive signal is specifically due to anti-D binding to the D antigen, not a non-specific reaction from the reagent. High-protein anti-D reagents can cause non-specific agglutination, so without check cells you can’t distinguish a true D-positive result from a false positive. When check cells are not performed, the Rh typing result is considered invalid because you have no independent verification that the AHG reaction reflects real D antigen presence. To get a valid result, you must include check cells to confirm the specificity of the reaction; if the check cells behave as expected, the result can be trusted; if they do not, the test should be repeated with appropriate controls or a different reagent.

The test outcome hinges on confirming that an AHG-positive signal is specifically due to anti-D binding to the D antigen, not a non-specific reaction from the reagent. High-protein anti-D reagents can cause non-specific agglutination, so without check cells you can’t distinguish a true D-positive result from a false positive. When check cells are not performed, the Rh typing result is considered invalid because you have no independent verification that the AHG reaction reflects real D antigen presence. To get a valid result, you must include check cells to confirm the specificity of the reaction; if the check cells behave as expected, the result can be trusted; if they do not, the test should be repeated with appropriate controls or a different reagent.