Transfusion medicine handbook

5. Fractionated Products

5.4.8 Rh(D) Immunoglobulin-VF (Anti-D immunoglobulin)

Rh(D) Immunoglobulin-VF is a sterile, preservative-free solution with an anti-D antibody content of either 625 IU or 250 IU per vial. Rh(D) Immunoglobulin-VF is prepared for NZBS by CSL Behring from plasma obtained from USA remunerated donors who have been immunised to the RhD antigen. Rh(D) Immunoglobulin-VF is intended for deep intramuscular injection [11]. Rh(D) Immunoglobulin-VF must not be administered intravenously because of the potential for anaphylactic reactions. 

Anti-D immunoglobulin acts by suppressing the immune response of RhD negative individuals exposed to RhD positive red cells. Such exposure follows the passage of cells from the fetal to the maternal circulation or the transfusion of RhD positive red cells. Clinical studies indicate that the administration of anti-D immunoglobulin to an RhD negative mother within 72 hours of the birth of an RhD positive infant reduces the incidence of RhD isoimmunisation from 12 - 13% to 1 - 2%. Studies have also shown that this number can be reduced to < 1.0% by antenatal prophylaxis with anti-D immunoglobulin administered at 28 weeks gestation and the second following delivery [11].

Indications for Use

Rh(D) Immunoglobulin-VF is indicated for prevention of RhD sensitisation in RhD negative females at or below childbearing age [11].

Rh(D) Immunoglobulin-VF may, in certain circumstances, also be used for protection against the development of anti-D sensitisation when RhD positive donor red cells are transfused to RhD negative females without child-bearing potential and to RhD negative males.

Precautions

There is some evidence to suggest that intramuscular administration of anti-D immunoglobulin may be associated with an increased risk of lack of effect in patients with a body mass index (BMI)≥30. An Expert Panel Consensus Position Statement provides recommendations regarding the use of anti-D immunoglobulin in these patients.

Contraindications

Rh(D) Immunoglobulin-VF should not be given to RhD positive individuals or to RhD negative individuals previously sensitised to the RhD antigen.

Rh(D) Immunoglobulin-VF should not be given to RhD negative women with detectable anti-D except where the antibody is passively acquired due to prior antenatal administration. If unsure whether the anti-D detected in the mother’s blood is passively acquired or preformed, the treating clinician and/or a NZBS Transfusion Medicine Specialist/ Medical Officer should be consulted. If there is continuing doubt, Rh(D) Immunoglobulin-VF should be administered. Although there is no benefit in administering Rh(D) Immunoglobulin-VF to a woman who is already sensitised to RhD antigen, there is no more risk than when it is given to a woman who is not sensitised.

Dosage and Administration : Antenatal and Postpartum Prophylaxis

For dosing see Section 6.14: Hemolytic Disease of the Fetus and Newborn (HDFN), Table 6.9 of this Handbook.

Anti-D dosing is described in NZBS document 111G130 USE OF RH D IMMUNOGLOBULIN (Anti-D Immunoglobulin) DURING PREGNANCY AND THE POST PARTUM PERIOD which in turn derives from sources including the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), published systematic reviews [12] [13], and discussion in NZBS’ Clinical Advisory Group.

NZBS is aware that an alternative approach to RAADP may be to administer a single 1500 IU anti-D dose at 28 weeks, however this is currently not endorsed in NZ. It should be noted that the NZ Ministry of Health does not recommend routine antenatal anti-D prophylaxis (RAADP).

Dosage and Administration: Transfusion of RhD Positive Blood Components

The recommended dose of Rh(D) Immunoglobulin-VF is 100 IU per mL RhD positive red cells. A single 625 IU dose of Rh(D) Immunoglobulin-VF will therefore suppress the immune response induced by up to 6 mL of RhD positive red cells. Consultation with an NZBS Transfusion Medicine Specialist/ Medical Officer is recommended in the event that a recipient has been transfused with a larger volume of RhD positive red cells.

The amount of red cell contamination in platelet components supplied by NZBS is less than 1 mL per unit and therefore adequately covered by a single 250 IU dose of Rh(D) Immunoglobulin-VF. A single 250 IU dose of Rh(D) Immunoglobulin-VF (administered subcutaneously in severely thrombocytopenic patients) is likely to be sufficient to cover up to five adult therapeutic doses of RhD positive platelets given within a 6-week period.