A technical specialist from a transfusion service in Northern California writes that physicians sometimes ask for a titer to be done when anti-D is detected and the patient has received Rh Immune Globulin, and wonders "When is this practice indicated?"

The following comments have been received.

ADDENDA May 4, 2007

1. The Editors think that colleagues might find the strong statement against using titers to distinguish native versus passive anti-D in the "Practice guidelines for prenatal and perinatal immunohematology, revisited" by W. John Judd, for the Scientific Section Coordinating Committee of the AABB to be germane to this discussion. In addition, the information at the prior discussions:

• Management of a pregnant woman who may have native anti-D, but has also received an antepartum dose of RhIG
• A case report of the mysterious development of anti-D in pregnancy

may also be of interest.

ADDENDA May 8, 2007

2. The Medical Director from a Transfusion Service in the Northeast reports that they do not do an anti-D titer if there is a history of prophylactic Rh Immune Globulin. They document it as passively acquired anti-D due to RHIG. However, in the absence of the history, they will do the titer. Obstetricians may ask for a titer if they feel there was history of trauma or bleeding etc., as they may feel the 28 week prophylaxis may not have sufficiently covered the patient. In her opinion, "it is best to ask the why a titer is being requested."

ADDENDA May 13, 2007

3. A prominent member of the Australian and New Zealand Society of Blood Transfusion (ANZSBT) reports, "Antenatal prophylaxis with RhD-Immunoglobulin has raised a number of issues in Australia. We have seen a small number of 'near misses' where native anti-D was thought to be passive and as a result less stringent follow up of the patients ensued."

Their suggested approach is documented in "Blood Grouping & Antibody Screening in the Antenatal & Perinatal Setting" available on the ANZSBT website.

Please submit comments to the e-Network Forum.

Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator

W. Tait Stevens, MD
CBBS e-Network Forum Assistant Editor & Moderator