Antibody Titer, Unexpected Antibodies
Orderable EAP code:
Billable EAP Codes:
CPT Codes:
Lab Section:
Includes:
Non-ABO antibody titers
Turnaround Time:
Routine: 48 hours
Urgent: 24 hours
Test Schedule:
Monday through Friday, 07:00 to 15:30.
Interpretation:
Interpretation depends on clinical setting.
Specimen Requirements:
6.0 mL blood in a LAVENDER top tube.
See link for instructions for identification and labeling of Transfusion Service specimens. Sample Information (Opens in a new window)
Pediatric Specimen Requirements:
Less than 4 months old: 1 to 2 mL blood in a LAVENDER top tube.
4 months to 3 years: 3 mL blood in a LAVENDER top tube.
Comments:
Antibody detection must be done first.
Semiquantitative method for determining serum concentration of clinically significant IgG (non-ABO) antibodies. Serial, two-fold dilutions of serum are tested against red cells carrying the antigen of interest (e.g., D, K) using the indirect antiglobulin method. Result is expressed as the reciprocal of the highest serum dilution that still shows (1+) agglutination. This test is used to monitor serum alloantibody levels in previously sensitized pregnant women for prenatal management of hemolytic disease of the newborn (HDN). In women with Rh alloimmunization, anti-D levels greater or equal to 16 are generally considered an indication for invasive fetal testing. For non-D antibodies, a threefold rise in titer is generally considered an indication for invasive fetal testing. Antibody titers do not always correlate with the clinical condition of the unborn child. False positives and false negatives do occur. Test will be reflexed as appropriate whenever a significant antibody is detected on a prenatal antibody screen.
Synonyms:
Rh Titer
Titer, Blood Group Antibodies