Interpretation of Rh Typing Immunohematology Review 451
ANTI-D CONTROL Rh TYPE
+ 0 Pos
0 0 Neg*
+ + Invalid
*Test for weak D if donor or infant of mother being evaluated for RhIG.
FALSE POSITIVE FALSE NEGATIVE
Warm or cold autoagglutinins
Rouleaux
Polyagglutinable RBCs
Nonspecific agglutination due to ingredient in reagent,
e.g., dye, preservative
Contaminated or incorrect reagent
Failure to add reagent
RBC suspension too heavy
Resuspending cell button too vigorously
Contaminated or incorrect reagent
Blocking of ag sites by abs, e.g., severe HDFN due to anti-D