OB Antibody Titer

Red blood cell antibody titers are most often requested on patients during pregnancy and are ordered on these patients by requesting the OB Antibody Titers Order. The blood bank will send the patient’s sample to Vitalant or American Red Cross for testing.

TITEROB

6 mL red non-gel and 16 mL EDTA tubes

If known, enter the name of the specific antibody or antibodies to be sent for titration (ex. Anti-D).
See link below for specimen details, methodology, setup schedule and reference ranges.

 

Refrigerated

Gel separator tube used
Hemolysis

Routine 1-2 days
ASAP within 24 hours
STAT within 8 hours

Titrations can provide information about the relative amount of antibody present or about the relative strength of antigen expression on the red cells. Numerous IgG antibodies have been reported to cause hemolytic disease of the fetus and newborn (HDFN) most common of which are anti-D, anti-K, anti-c, anti-C and anti-Fya. The titer for the alloimmunized pregnancy has been the mainstay in decision making and should be established in the first trimester to serve as a baseline. The pregnancy should be followed with sequential titer. A difference of two dilutions or a titer of 32 or higher is considered a significant result.